Potential antioxidant, α-glucosidase, butyrylcholinesterase and acetylcholinesterase inhibitory activities of major constituents isolated from Alpinia officinarum hance rhizomes: computational studies and in vitro validation

Alpinia officinarum is a commonly used spice with proven folk uses in various traditional medicines. In the current study, six compounds were isolated from its rhizomes, compounds 1-3 were identified as diarylheptanoids, while 4-6 were identified as flavonoids and phenolic acids. The isolated compounds were subjected to virtual screening against α-glucosidase, butyrylcholinesterase (BChE), and acetylcholinesterase (AChE) enzymes to evaluate their potential antidiabetic and anti-Alzheimer's activities. Molecular docking and dynamics studies revealed that 3 exhibited a strong binding affinity to human a α- glucosidase crystal structure compared to acarbose. Furthermore, 2 and 5 demonstrated high potency against AChE. The virtual screening results were further supported by in vitro assays, which assessed the compounds' effects on α-glucosidase, cholinesterases, and their antioxidant activities. 5-Hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1-phenylheptan-3-one (2) showed potent antioxidant effect in both ABTs and ORAC assays, while p-hydroxy cinnamic acid (6) was the most potent in the ORAC assay. In contrary, kaempferide (4) and galangin (5) showed the most potent effect in metal chelation assay. 5-Hydroxy-1,7-diphenylhepta-4,6-dien-3-one (3) and 6 revealed the most potent effect as α-glucosidase inhibitors where compound 3 showed more potent effect compared to acarbose. Galangin (5) revealed a higher selectivity to BChE, while 2 showed the most potent activity to (AChE).

Evidence on the inhibitory effect of Brassica plants against Acinetobacter baumannii lipases: phytochemical analysis, in vitro, and molecular docking studies

BACKGROUND

Infections caused by Acinetobacter baumannii are becoming a rising public health problem due to its high degree of acquired and intrinsic resistance mechanisms. Bacterial lipases penetrate and damage host tissues, resulting in multiple infections. Because there are very few effective inhibitors of bacterial lipases, new alternatives for treating A. baumannii infections are urgently needed. In recent years, Brassica vegetables have received a lot of attention since their phytochemical compounds have been directly linked to diverse antimicrobial actions by inhibiting the growth of various Gram-positive and Gram-negative bacteria, yeast, and fungi. Despite their longstanding antibacterial history, there is currently a lack of scientific evidence to support their role in the management of infections caused by the nosocomial bacterium, A. baumannii. This study aimed to address this gap in knowledge by examining the antibacterial and lipase inhibitory effects of six commonly consumed Brassica greens, Chinese cabbage (CC), curly and Tuscan kale (CK and TK), red and green Pak choi (RP and GP), and Brussels sprouts (BR), against A. baumannii in relation to their chemical profiles.

METHODS

The secondary metabolites of the six extracts were identified using LC-QTOF-MS/MS analysis, and they were subsequently correlated with the lipase inhibitory activity using multivariate data analysis and molecular docking.

RESULTS

In total, 99 metabolites from various chemical classes were identified in the extracts. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) revealed the chemical similarities and variabilities among the specimens, with glucosinolates and phenolic compounds being the major metabolites. RP and GP showed the highest antibacterial activity against A. baumannii, followed by CK. Additionally, four species showed a significant effect on the bacterial growth curves and demonstrated relevant inhibition of A. baumannii lipolytic activity. CK showed the greatest inhibition (26%), followed by RP (21%), GP (21%), and TK (15%). Orthogonal partial least squares-discriminant analysis (OPLS-DA) pinpointed 9 metabolites positively correlated with the observed bioactivities. Further, the biomarkers displayed good binding affinities towards lipase active sites ranging from -70.61 to -30.91 kcal/mol, compared to orlistat.

CONCLUSION

This study emphasizes the significance of Brassica vegetables as a novel natural source of potential inhibitors of lipase from A. baumannii.

Euphorbia grantii Oliv. standardized extract and its fraction ameliorate doxorubicin-induced cardiomyopathy in Ehrlich carcinoma bearing mice

ETHNOPHARMACOLOGICAL RELEVANCE

Euphorbia plants have long been used as traditional medicine in China, Europe, America, Turkey, India, Africa, Iran, and Pakistan because of its high medicinal value and health advantages especially as a remedy for several types of cancer.

AIM OF THE STUDY

Doxorubicin (DOX) is one of the most frequently prescribed drugs in cancer chemotherapy, with dose-limiting cardiotoxicity. The development of medicinal approaches to attenuate drug's toxicity represents an area of great concern in cancer research. Because research on this topic is still disputed and limited, we aim to investigate the potential of supplementation with Euphorbia grantii Oliv. on DOX-induced cardiomyopathy in Ehrlich carcinoma bearing mice.

MATERIALS AND METHODS

The high-performance thin layer chromatography (HPTLC) analysis of total methanolic extract (TE), and its bioactive dichloromethane fraction (DCMF) was applied for the determination of friedelin. Male BALB/c mice were used to keep the Ehrlich ascites tumor cells. The experiment was performed for a 2-weeks period.

RESULTS

A good linearity relationship was found to be with correlation coefficient (r2) value of 0.9924 for the isolated friedelin. Limit of detection (LOD) and limit of quantitation (LOQ) was found to be 0.00179, and 0.000537 ng/band respectively for friedelin. The amount of friedelin in the TE and DCMF were determined by using calibration curve of standard as 106.32 ± 5.69 μg, and 159.2 ± 4.24 μg friedelin/mg extract, respectively. DOX-induced cardiomyopathy by decreasing the ejection fraction (EF) compared to the Ehrlich and negative control groups. It resulted in a decrease in the EF by 30 and 39% compared to the other groups. High and low doses of the TE and DCMF did not result in significantly different ejection fractions compared to the Ehrlich group. Co-administration of DCMF with DOX ameliorated the alteration in the serum CKMB and LDH levels. As revealed from histopathological study, DOX impairs viability of cardiac myocytes and DCMF could effectively and extensively counteract this action of DOX and potentially protect the heart from severe toxicity of DOX.

CONCLUSIONS

Finally, our results indicated that Euphorbia grantii Oliv. would be the best option to reduce DOX adverse effects.

LC-QToF chemical profiling of Euphorbia grantii Oliv. and its potential to inhibit LPS-induced lung inflammation in rats via the NF-κB, CY450P2E1, and P38 MAPK14 pathways

Acute lung injury (ALI) is a life-threatening syndrome that causes high morbidity and mortality worldwide. The aerial parts of Euphorbia grantii Oliv. were extracted with methanol to give a total methanolic extract (TME), which was further fractionated into dichloromethane (DCMF) and the remaining mother liquor (MLF) fractions. Biological guided anti-inflammatory assays in vitro revealed that the DCMF showed the highest activity (IC50 6.9 ± 0.2 μg/mL and 0.29 ± 0.01 μg/mL) compared to. celecoxib (IC50 of 88.0 ± 1 μg/mL and 0.30 ± 0.01 μg/mL) on COX-1 and COX-2, respectively. Additionally, anti-LOX activity was IC50 = 24.0 ± 2.5 μg/mL vs. zileuton with IC50 of 40.0 ± 0.5 μg/mL. LC-DAD-QToF analysis of TME and the active DCMF resulted in the tentative identification and characterization of 56 phytochemical compounds, where the diterpenes were the dominated metabolites. An LPS-induced inflammatory model of ALI (10 mg/kg i.p) was used to assess the anti-inflammatory potential of DCMF in vivo at dose of 200 mg/kg and 300 mg/kg compared to dexamethasone (5 mg/kg i.p). Our treatments significantly reduced the pro-inflammatory cytokines (TNF-α, IL-1, IL-6, and MPO), increased the activity of antioxidant enzymes (SOD, CAT, and GSH), decreased the activity of oxidative stress enzyme (MDA), and reduced the expression of inflammatory genes (p38.MAPK14 and CY450P2E1). The western blotting of NF-κB p65 in lung tissues was inhibited after orally administration of the DCMF. Histopathological study of the lung tissues, scoring, and immunohistochemistry of transforming growth factor-beta 1 (TGF-β1) were also assessed. In both dose regimens, DCMF of E. grantii prevented further lung damage and reduced the side effects of LPS on acute lung tissue injury.

GC-MS analysis and the effect of topical application of essential oils of Pinus canariensis C.Sm., Cupressus lusitanica Mill. and Cupressus arizonica Greene aerial parts in Imiquimod-Induced Psoriasis in Mice

ETHNOPHARMACOLOGICAL RELEVANCE

Traditionally, Coniferous plants, in particular Pinus and Cupressus species, have been used in the treatment of burns, skin infections, and immune-mediated inflammatory diseases such as psoriasis.

AIM OF THE STUDY

A comparative study between essential oils (EOs) extracted from aerial parts of three coniferous plants: Pinus canariensis C.Sm. (PC), Cupressus lusitanica Mill. (CL) and Cupressus arizonica Greene (CA), cultivated in Egypt, was designed to investigate their composition and their anti-psoriasis mechanism.

MATERIALS AND METHODS

The phytochemical profiles were confirmed using Gas Chromatography-Mass Spectrometry (GC-MS) method. In-vivo Imiquimod (IMQ)-induced psoriasis model was performed and EOs were applied topically and compared to mometasone cream as a standard subsequently histopathological analysis and inflammatory biomarkers were measured.

RESULTS

In GC-MS analysis, Monoterpene hydrocarbons, sesquiterpene hydrocarbons and oxygenated monoterpenes were the major detected classes in the three plants, except in Pinus canariensis essential oil, oxygenated monoterpenes were absent. A significant attenuation of imiquimod-induced psoriasis symptoms after topical application of P. canariensis C.Sm., and C. lusitanica Mill. essential oils were observed by reducing the psoriasis area severity index (PASI) score, alleviating histopathological alteration, restoring the spleen index, and decreasing serum levels of interleukins 23 and 17A. Indeed, the results of Pinus canariensis essential oil is comparable to mometasone and showed no significant difference from standard treatment. On the other hand, the topical application of C. arizonica essential oil failed to alleviate imiquimod-induced psoriasis symptoms as observed in the PSAI score, the histopathological investigation, and the spleen index.

CONCLUSION

The essential oils of P. canariensis C.Sm., and C. lusitanica Mill aerial parts could be promising candidates for psoriasis treatment and for further studies on inflammation-related skin diseases.

Effect of Phenolics from Aeonium arboreum on Alpha Glucosidase, Pancreatic Lipase, and Oxidative Stress; a Bio-Guided Approach

Metabolic syndrome (MetS) is a global issue affecting over a billion people, raising the risk of diabetes, cardiovascular disorders, and other ailments. It is often characterized by hypertension, dyslipidemia and/or obesity, and hyperglycemia. Chemical investigation of Aeonium arboreum (L.) Webb & Berthel led to the isolation of six compounds, viz. β-sitosterol, β-sitosterol glucoside, myricetin galactoside, quercetin rhamnoside, kaempferol rhamnoside, and myricetin glucoside. Interestingly, A. arboreum's dichloromethane (DCM), 100 and 50% MeOH Diaion fractions and the isolated compound (quercetin-3-rhamnoside) revealed potent α-glucosidase inhibitory activity, especially 50% Diaion fraction. In addition, they also showed very potent antioxidant potential, especially the polar fractions, using DPPH, ABTS, FRAP, ORAC, and metal chelation assays. Notably, the 50% Diaion fraction had the highest antioxidant potential using DPPH and ORAC assays, while the 100% Diaion fraction and quercetin-3-rhamnoside showed the highest activity using ABTS, FRAP, and metal chelation assays. Also, quercetin-3-rhamnoside showed a good docking score of -5.82 kcal/mol in comparison to acarbose. In addition, molecular dynamic stimulation studies illustrated high stability of compound binding to pocket of protein. Such potent activities present A. arboreum as a complementary safe approach for the management of diabetes mellitus as well as MetS.

Hypophyllanthin and Phyllanthin from Phyllanthus niruri Synergize Doxorubicin Anticancer Properties against Resistant Breast Cancer Cells

Doxorubicin (DOX) is a cornerstone chemotherapeutic agent for the treatment of several malignancies such as breast cancer; however, its activity is ameliorated by the development of a resistant phenotype. Phyllanthus species have been studied previously for their potential anticancer properties. The current work is aimed to study the potential cytotoxicity and chemomodulatory effects of hypophyllanthin (PN4) and phyllanthin (PN5) isolated from Phyllanthus niruri to DOX against the adriamycin multidrug-resistant breast cancer cells (MCF-7ADR) and elucidate their mechanism of action. The major compounds of the active methylene chloride fraction were isolated and assessed for their potential cytotoxicity and chemomodulatory effects on DOX against naïve (MCF-7) and resistant breast (MCF-7ADR) cancer cells. The mechanism of action of both compounds in terms of their impacts on programmed/non-programmed cell death (apoptosis and autophagy/necrosis), cell cycle progression/arrest, and tumor cell migration/invasion was investigated. Both compounds PN4 and PN5 showed a moderate but similar potency against MCF-7 as well as MCF-7ADR and significantly synergized DOX-induced anticancer properties against MCF-7ADR. The chemomodulatory effect of both compounds to DOX was found to be via potentiating DOX-induced cell cycle interference and apoptosis induction. It was found that PN4 and PN5 blocked the apoptosis-escape autophagy pathway in MCF-7ADR. On the molecular level, both compounds interfered with SIRT1 expression and consequently suppressed Akt phosphorylation, and PN5 blocked apoptosis escape. Furthermore, PN4 and PN5 showed promising antimigratory and anti-invasive effects against MCF-7ADR, as confirmed by suppression of N-cadherin/β-catenin expression. In conclusion, for the first time, hypophyllanthin and phyllanthin isolated from P. niruri showed promising chemomodulatory effects to the DOX-induced chemotherapeutic activity against MCF-7ADR. Both compounds significantly synergized DOX-induced anticancer properties against MCF-7ADR. This enhanced activity was explained by further promoting DOX-induced apoptosis and suppressing the apoptosis-escape autophagy feature of the resistant breast cancer cells. Both compounds (hypophyllanthin and phyllanthin) interfered with the SIRT1/Akt pathway and suppressed the N-cadherin/β-catenin axis, confirming the observed antiproliferative, cytotoxic, and anti-invasive effects of hypophyllanthin and phyllanthin.

SIRT1/Nrf2/NF-κB Signaling Mediates Anti-Inflammatory and Anti-Apoptotic Activities of Oleanolic Acid in a Mouse Model of Acute Hepatorenal Damage

Background and objectives: Oleanolic acid (OA) is a penta-cyclic triterpene with diverse bioactivities such as anticarcinogenic, antiviral, antimicrobial, hepatoprotective, anti-atherosclerotic, hypolipidemic, and gastroprotective. However, its effects on hepatorenal damage remain unclear. The protective activity of OA, separated from Viscum schimperi (Loranthaceae), against TAA (thioacetamide)-produced acute hepatic and renal damage was explored. Materials and Methods: Mice were treated with OA for 7 days before TAA (200 mg/kg, i.p.). Serum indices of hepatorenal injury, pathological lesions, molecular biological indexes, and inflammatory/apoptotic genes were estimated. Results: The tissues of both organs were greatly affected by the TAA injection. That was evident through increased serum markers of hepato-renal injury as well as remarkable histopathological lesions. TAA-induced injury was associated with oxidative and inflammatory responses in both organs as there was an elevation of oxidative stress parameters (4-HNE (4-hydroxy-nonenal), MDA (malondialdehyde), NOx (nitric oxide)), decline of antioxidants (reduced glutathione (GSH), superoxide dismutase (SOD), and total antioxidant capacity (TAC)), and an increase in the gene expression/level of inflammatory mediators (interleukins (1β&6)). The inflammatory response was linked to a significant activation of NF-κB (nuclear-factor kappa-B)/TNF-α (tumor-necrosis factor-alpha) signaling. The inflammatory response in both organs was accompanied by apoptotic changes, including a rise in the gene expression and level of apoptotic parameters (caspase-3 and Bax) along with a decline in Bcl-2 (anti-apoptotic parameter) gene expression and level. These pathogenic events were found to be closely related to the suppression of the antioxidant signaling pathway, Nrf2 (nuclear-factor erythroid 2-related factor-2)/SIRT1 (sirtuin-1)/HO-1 (heme-oxygenase 1). On the other hand, OA significantly ameliorated TAA-induced injury in both organs. On the other hand, OA counterpoised the inflammatory response as it ameliorated NF-κB/TNF-α signaling and cytokine release. OA enhanced Nrf2/SIRT1/HO-1 signaling and counteracted apoptotic damage. Conclusions: OA showed anti-inflammation and antiapoptotic capacities that effectively suppressed TAA-induced acute hepatorenal damage.

In Vitro Cytotoxic Study of Euphorbia grantii Oliv. Aerial Parts against MCF-7 and MCF-7ADR Breast Cancer Cell Lines: A Bioactivity-Guided Isolation

The development of highly efficient and low-toxicity anticancer drugs is one of the most critical problems in the medical field. Euphorbia grantii is commonly reported as an antiviral plant; a dilute solution of its latex is used for intestinal worms and to promote blood clotting and tissue healing. Our study evaluated the antiproliferative activity of the total extract, its respective fractions, and the isolated compounds from E. grantii aerial parts. A phytochemical study was done by several chromatographic methods, and the cytotoxic activity was assessed using the sulforhodamine B assay. The dichloromethane fraction (DCMF) exhibited promising cytotoxic activity against breast cancer cell lines (MCF-7 and MCF-7^ADR), with an IC₅₀ of 10.31 and 10.41 μg/mL, respectively. Chromatographic purification of the active fraction revealed the isolation of eight compounds. Among the isolated compounds, euphylbenzoate (EB) exhibited a promising effect with an IC₅₀ of 6.07 and 6.54 μM against MCF-7 and MCF-7^ADR, respectively, while other compounds showed no activity. Euphol, cycloartenyl acetate, cycloartenol, and epifriedelinyl acetate showed moderate activity (33.27-40.44 μM). Euphylbenzoate has smartly tackled both apoptosis and autophagy programmed cell death mechanisms. These results demonstrated that E. grantii aerial parts yield active compounds with significant antiproliferative potential.

Robust Antiviral Activity of Santonica Flower Extract (Artemisia cina) against Avian and Human Influenza A Viruses: In Vitro and Chemoinformatic Studies

The evolution of drug-resistant viral strains following natural acquisition of resistance mutations is a major obstacle to antiviral therapy. Besides the improper prescription of the currently licensed anti-influenza medications, M2-blockers and neuraminidase inhibitors, to control poultry outbreaks/infections potentiates the emergence of drug-resistant influenza variants. Therefore, there is always a necessity to find out new alternatives with potent activity and high safety. Plant extracts and plant-based chemicals represent a historical antiviral resource with remarkable safety in vitro and in vivo to control the emerging and remerging health threats caused by viral infections. Herein, a panel of purified plant extracts and subsequent plant-derived chemicals were evaluated for their anti-avian influenza activity against zoonotic highly pathogenic influenza A/H5N1 virus. Interestingly, santonica flower extract (Artemisia cina) showed the most promising anti-H5N1 activity with a highly safe half-maximal cytotoxic concentration 50 (CC₅₀ > 10 mg/mL) and inhibitory concentration 50 (IC₅₀ of 3.42 μg/mL). To confirm the anti-influenza activity, we assessed the anti-influenza activity of the selected plant extracts against seasonal human influenza A/H1N1 virus and we found that santonica flower extract showed a robust anti-influenza activity that was comparable to the activity against influenza A/H5N1. Furthermore, the mode of action for santonica flower extract with strong inhibitory activity on the abovementioned influenza strains was elucidated, showing a virucidal effect. To go deeper about the activity of the chemometric component of the extract, the major constituent, santonin, was further selected for in vitro screening against influenza A/H5N1 (IC₅₀ = 1.701 μg/mL) and influenza A/H1N1 (IC₅₀ = 2.91 μg/mL). The oxygen of carbonyl functionality in the cyclohexene ring succeeded to form a hydrogen bond with the neuraminidase active site. Despite the fact that santonin revealed similarity to both reference neuraminidase inhibitors in forming hydrogen bonds with essential amino acids, it illustrated shape alignment to oseltamivir more than zanamivir according to Tanimoto algorithms. This study highlights the applicability of santonica flower extract as a promising natural antiviral against low and highly pathogenic influenza A viruses.

6-Paradol Alleviates Testosterone-Induced Benign Prostatic Hyperplasia in Rats by Inhibiting AKT/mTOR Axis

INTRODUCTION

Benign prostatic hyperplasia (BPH) is a common disease among elderly men. Its pharmacological treatment is still unsatisfactory. 6-Paradol (6-PD) is an active metabolite found in many members of the Zingiberaceae family. It was reported to possess anti-proliferative, antioxidant, and anti-inflammatory activities. The present study aimed at exploring the potential of 6-PD to inhibit testosterone-induced BPH in rats as well as the probable underlying mechanism.

METHODS

Male Wistar rats were divided into 6 groups and treated as follows: Group 1 (control group) received vehicles only, Group 2 testosterone only, Groups 3 and 4 received 6-PD (2.5 and 5.0 mg/kg; respectively) and testosterone, and Group 6 received finasteride and testosterone.

RESULTS

Daily treatment of animals with 6-PD at the two dose levels of 2.5 and 5 mg/kg significantly ameliorated a testosterone-induced rise in prostate index and weight. This was confirmed by histological examinations of prostatic tissues that indicated a reduction in the pathological changes as well as inhibition of the rise in glandular epithelial height in 6-PD treated rats. Immunohistochemical investigations showed that 6-PD prevented the up-regulation of cyclin D1 induced by testosterone injections. Further, 6-PD significantly modulated mRNA expression of both Bcl2 and Bax in prostate tissues of testosterone-treated rats in favor of anti-proliferation. It also showed antioxidant activities as evidenced by inhibition of accumulation of malondialdehyde (MDA) and exhaustion of catalase (CAT) activity. In addition, 6-PD displayed significant anti-inflammatory activities as it prevented up-regulation of interleukin-6 (IL-6) and nuclear factor kappa B (NF-κB). Immunoblotting analysis revealed that 6-PD significantly inhibited testosterone-induced activation of AKT and mTOR in prostate tissues.

CONCLUSIONS

6-PD protects against testosterone-induced BPH in rats. This can be attributed, at least partly, to its antiproliferative, antioxidant, and anti-inflammatory properties as well as its ability to inhibit activation of the AKT/mTOR axis.

Effect of Light Quality and Media Components on Shoot Growth, Rutin, and Quercetin Production from Common Buckwheat

Common buckwheat (Fagopyrum esculentum Moench) seeds are important nutritious grains that are widely spread in several human food products and livestock feed. Their health benefits are mainly due to their bioactive phenolic compounds, especially rutin and quercetin, which have a positive impact on heart health, weight loss, and diabetes management. In this study, we evaluated different media and light treatments for the in vitro cultures of common buckwheat (CB) in order to find the most optimum one producing the highest yield with the highest purity of these compounds. The subcultured treated samples included in this study were shoots, leaves, stems, hairy roots, and calli. From the several treated samples and under different light stress conditions, the best production was achieved by growing the shoots of common buckwheat in hormone-free media containing activated charcoal and exposing to blue light, attaining 4.3 mg and 7.0 mg/g of extracts of rutin and quercetin, respectively, compared to 3.7 mg of rutin/g of extract and traces of quercetin in the seeds of CB. Continuous multiplication of CB shoots in the media containing charcoal and different concentrations of kinetin produced an extract with 161 mg/g of rutin and 26 mg/g of quercetin with an almost 20-fold increase in rutin content. The rutin content under these conditions reached up to 16% w/w of the extract. The hairy root cultures of the leaves exposed to red light showed a significantly high yield of quercetin attaining 10 mg/g of extract. Large-scale production of CB shootlets under the best conditions were carried out, which enabled the isolation of pure quercetin and rutin using a simple chromatographic procedure. The identity and purity of the isolated compounds were confirmed through NMR and HPLC analyses.

Phenolics from Chrozophora oblongifolia Aerial Parts as Inhibitors of α-Glucosidases and Advanced Glycation End Products: In-Vitro Assessment, Molecular Docking and Dynamics Studies

Simple Summary

The chemical investigation of Chrozophora oblongifolia aerial parts resulted in the isolation of five phenolic compounds. The isolated metabolites were tested for their antioxidant and advanced glycation end-products (AGEs) formation, α-glucosidase, and lipase inhibitory activities. 1,3,6-Trigalloyl glucose exhibited the highest activity as an antioxidant and AGEs inhibitor as well as an α-glucosidase inhibitor. It showed promising binding affinity and stability towards the human intestinal maltase-glucoamylase α-glucosidases, as revealed through coupled molecular docking and dynamics studies that could encourage the utilization of this compound in the management of diabetes and its complications.

Abstract

Modern life is associated with low physical activity that leads to the accumulation of fats, gaining more weight, and obesity. Accumulation of fat in the abdomen region contributes to diabetes via insulin resistance and hyperglycemia. Polyphenols are major plant constituents that exert antidiabetic activity through different mechanisms, including radicle scavenging activity, regulation of glucose uptake, and inhibition of fat and polysaccharide hydrolysis in addition to their inhibitory role regarding the formation of advanced glycation end products (AGEs). Chemical investigation of C. oblongifolia aerial parts resulted in the isolation of five major compounds: apeginin-7-O-β-D-glucoside (1), quercetin-3-O-β-D-glucuronic acid (2), quercetin-3-O-β-D-galacturonic acid (3), rutin (4), and 1,3,6-trigalloyl glucose (5). The isolated compounds were tested for their antioxidant and AGEs formation, α-glucosidase, and lipase inhibitory activities. Compound 5 revealed the highest antioxidant and AGEs inhibitory activity in bovine serum albumin (BSA)-methylglyoxal, BSA-fructose, and arginine-methylglyoxal models. Moreover, it exhibited a potent inhibitory profile on Saccharomyces cerevisiae α-glucosidases compared to the positive control, acarbose. Compound (5) further depicted promising binding affinity and stability towards the human intestinal maltase-glucoamylase α-glucosidases, which is a diabetes-related therapeutic target, through coupled molecular docking and dynamics studies. The obtained results encourage the usage of 1,3,6-trigalloyl glucose in the management of diabetes and its complications. However, detailed in-vivo studies for this compound should be performed.

Identification of Chemopreventive Components from Halophytes Belonging to Aizoaceae and Cactaceae Through LC/MS-Bioassay Guided Approach

Six halophytes, namely, Aptenia cordifolia var. variegata, Glottiphyllum linguiforme, Carpobrotus edulis, Ferocactus glaucescens, F. pottsii and F. herrerae were investigated for chemopreventive effect. Prioritization of most promising plant for further investigation was carried out through an integrated liquid chromatography-high resolution electrospray ionization mass spectrometry profiling-bioassay guided approach. NAD(P)H: quinone oxidoreductase-1 (NQO-1) induction in cultured murine hepatoma cells (Hepa-1c1c7) and inhibition of nitric oxide (NO) production in lipopolysaccharide-activated macrophages (RAW 264.7) were carried out to investigate chemopreventive effect. Bioassay data revealed that F. herrerae, A. cordifolia, C. edulis and F. glaucescens were the most active with 2-, 1.7-, 1.6- and 1.5-folds induction of NQO-1 activity. Only F. glaucescens exhibited >50% inhibition of NO release. LCMS profiling of the F. glaucescens revealed its high content of flavonoids, a known micheal acceptor with possible NQO-1 induction, as proved by quantitative high-performance liquid chromatography analysis. Thus, the extract of F. glaucescens was subjected to chromatographic fractionation leading to the isolation of four compounds including (i) 2S-naringenin, (ii) trans-dihydrokaempferol (aromadendrin), (iii) 2S-naringenin-7-O-β-d-glucopyranoside and (iv) kaempferol-7-O-β-d-glucopyranoside (populnin). The current study through an LCMS dereplication along with bio guided approach reported the activity of populnin as NO inhibitor and NQO-1 inducer with promising chemopreventive potential.

Nitric-Oxide-Mediated Vasodilation of Bioactive Compounds Isolated from Hypericum revolutum in Rat Aorta

Simple Summary

Hypericum revolutum (HR) is reported to produce vasodilating activity in phenylephrine-precontracted aortae, where the chloroform fraction is the most potent. Chemical investigation of this fraction yielded two new compounds, revolutin (1) and hyperevolutin C (2), along with three known metabolites, β-sitosterol (3), euxanthone (4), and 2,3,4-tirmethoxy xanthone (5). Isolated compounds 1, 2, 3, and 5 produce vasodilation activities that are dependent on endothelial nitric oxide release.

Abstract

Vasodilators are an important class in the management of hypertension and related cardiovascular disorders. In this regard, the chloroform fraction of Hypericum revolutum (HR) has been reported to produce vasodilating activity in phenylephrine-precontracted aortae. The current work aims to identify the active metabolites in the chloroform fraction of HR and illustrate the possible mechanism of action. The vasodilation activities were investigated using the isolated artery technique. NO vascular release was assessed by utilizing the NO-sensitive fluorescent probe DAF-FM. Free radical scavenging capacity was assessed utilizing DPPH. Chemical investigation of this fraction yielded two new compounds, revolutin (1) and hyperevolutin C (2), along with three known metabolites, β-sitosterol (3), euxanthone (4), and 2,3,4-tirmethoxy xanthone (5). Compounds 1, 2, 3, and 5 showed significant vasodilation activities that were blocked by either endothelial denudation or L-NAME (nitric oxide synthase inhibitor), pointing towards a role of endothelial nitric oxide in their activities. In confirmation of this role, compounds 1–3 showed a significant release of NO from isolated vessels, as indicated by DAF-FM. On the other hand, only compound 5 showed free radical scavenging activities, as indicated by DPPH. In conclusion, isolated compounds 1, 2, 3, and 5 produce vasodilation activities that are dependent on endothelial nitric oxide release.

Phytochemical profile, enzyme inhibition activity and molecular docking analysis of Feijoa sellowiana O. Berg

Feijoa sellowiana leaves and fruits have been investigated as a source of diverse bioactive metabolites. Extract and eight metabolites isolated from F. sellowiana leaves were evaluated for their enzymatic inhibitory activity against α-glucosidase, amylase, tyrosinase, acetylcholinestrerase and butyrylcholinesterase both in vitro and in silico. Feijoa leaves’ extract showed strong antioxidant activity and variable levels of inhibitions against target enzymes with a strong anti-tyrosinase activity (115.85 mg Kojic acid equivalent/g). Additionally, α-tocopherol emerged as a potent inhibitor of AChE and BChE (5.40 & 10.38 mmol galantamine equivalent/g, respectively). Which was further investigated through molecular docking and found to develop key enzymatic interactions in AChE and BChE active sites. Also, primetin showed good anti BChE (11.70 mmol galantamine equivalent/g) and anti-tyrosinase inhibition (90.06 mmol Kojic acid equivalent/g) which was also investigated by molecular docking studies.

Highlights

Isolation of eight bioactive constituents from Feijoa sellowiana leaves.

In vitro assays using different enzymatic drug targets were investigated.

In silico study was performed to define compound interactions with target proteins.

Feijoa leaf is an excellent source of anti-AChE and antityrosinase bioactives.

Self-Nanoemulsifying Drug Delivery System Loaded with Psiadia punctulata Major Metabolites for Hypertensive Emergencies: Effect on Hemodynamics and Cardiac Conductance

Vasodilators are an important class of antihypertensive agents. However, they have limited clinical use due to the reflex tachycardia associated with their use which masks most of its antihypertensive effect and raises cardiac risk. Chemical investigation of Psiadia punctulata afforded five major methoxylated flavonoids (1–5) three of which (1, 4, and 5) showed vasodilator activity. Linoleic acid-based self-nanoemulsifying drug delivery system (SNEDDS) was utilized to develop intravenous (IV) formulations that contain compounds 1, 4, or 5. The antihypertensive effect of the prepared SNEDDS formulations, loaded with each of the vasodilator compounds, was tested in the angiotensin-induced rat model of hypertension. Rats were subjected to real-time recording of blood hemodynamics and surface Electrocardiogram (ECG) while the pharmaceutical formulations were individually slowly injected in cumulative doses. Among the tested formulations, only that contains umuhengerin (1) and 5,3′-dihydroxy-6,7,4′,5′-tetramethoxyflavone (5) showed potent antihypertensive effects. Low IV doses, from the prepared SNEDDS, containing either compound 1 or 5 showed a marked reduction in the elevated systolic blood pressure by 10 mmHg at 12 μg/kg and by more than 20 mmHg at 36 μg/kg. The developed SNEDDS formulation containing either compound 1 or 5 significantly reduced the elevated diastolic, pulse pressure, dicrotic notch pressure, and the systolic–dicrotic notch pressure difference. Moreover, both formulations decreased the ejection duration and increased the non-ejection duration while they did not affect the time to peak. Both formulations did not affect the AV conduction as appear from the lack of effect on p duration and PR intervals. Similarly, they did not affect the ventricular repolarization as no effect on QTc or JT interval. Both formulations decreased the R wave amplitude but increased the T wave amplitude. In conclusion, the careful selection of linoleic acid for the development of SNEDDS formulation rescues the vasodilating effect of P. punctulata compounds from being masked by the reflex tachycardia that is commonly associated with the decrease in peripheral resistance by most vasodilators. The prepared SNEDDS formulation could be suggested as an effective medication in the treatment of hypertensive emergencies, after clinical evaluation.

Repurposing of Some Natural Product Isolates as SARS-COV-2 Main Protease Inhibitors via In Vitro Cell Free and Cell-Based Antiviral Assessments and Molecular Modeling Approaches

The emergence of the SARS-CoV-2 pandemic has prompted scientists to search for an efficient antiviral medicine to overcome the rapid spread and the marked increase in the number of patients worldwide. In this regard natural products could be a potential source of substances active against coronavirus infections. A systematic computer-aided virtual screening approach was carried out using commercially available natural products found on the Zinc Database in addition to an in-house compound library to identify potential natural product inhibitors of SARS-CoV-2 main protease (MPRO). The top eighteen hits from the screening were selected for in vitro evaluation on the viral protease (SARS-CoV-2 MPRO). Five compounds (naringenin, 2,3',4,5',6-pentahydroxybenzophenone, apigenin-7-O-glucoside, sennoside B, and acetoside) displayed high activity against the viral protein. Acteoside showed similar activity to the positive control GC376. The most potent compounds were tested in vitro on SARS-CoV-2 Egyptian strain where only naringenin showed moderate anti-SARS-CoV-2 activity at non-cytotoxic micromolar concentrations in vitro with a significant selectivity index (CC50/IC50 = 178.748/28.347 = 6.3). Moreover; a common feature pharmacophore model was generated to explain the requirements for enzyme inhibition by this diverse group of active ligands. These results pave a path for future repurposing and development of natural products to aid in the battle against COVID-19.

Comparative Study on the Essential Oils from Five Wild Egyptian Centaurea Species: Effective Extraction Techniques, Antimicrobial Activity and In-Silico Analyses

The genus Centaurea is recognized in folk medicine for anti-inflammatory, anti-itch, antitussive, purgative, astringent, and tonic activities. To study the chemical determinant for antimicrobial activity essential oils (EOs), five Centaurea species were analyzed including: C. scoparia, C. calcitrapa, C. glomerata, C. lipii and C. alexandrina. Conventional hydro-distillation (HD) and microwave-assisted extraction (MAE), as new green technologies, were compared for the extraction of essential oils. GC/MS analysis identified 120 EOs including mostly terpenoid except from C. lipii and C. alexandrina in which nonterpenoids were the major constituents. Major terpenoids included spathulenol, caryophyllene oxide and alloaromadendrene oxide-2. To probe antibacterial activity, potential EO inhibitors of a bacterial type II DNA topoisomerase, DNA gyrase B were screened via an in silico molecular docking approach. Spathulenol and alloaromadendrene oxide-2 possessed the best binding affinity in the ATP- binding pocket of Gyrase B enzyme. Principal component analysis and agglomerative hierarchical clustering were used for sample classification and revealed that sesquiterpenes contributed the most for accessions classification. In vitro antimicrobial activity against Staphylococcus aureus, Escherichia coli and Aspergillus niger for all EOs were also evaluated. EOs from C. lipii, C. glomerata and C. calcitrapa exhibited significant MIC against S. aureus with an MIC value of 31.25 µg/mL.

Correction to: Protective effect of 6-paradol in acetic acid-induced ulcerative colitis in rats

An amendment to this paper has been published and can be accessed via the original article.

Protective effect of 6-paradol in acetic acid-induced ulcerative colitis in rats

Background

Ulcerative colitis is a gut inflammatory disorder due to altered immune response to gut microbiome, with interplay of environmental and genetic factors. TNF-α activates inflammatory response through a cascade of immune responses, augmenting pro-inflammatory mediators and proteases, activating chemotaxis, and infiltration of inflammatory cells, leading to ulceration and haemorrhage through cytotoxic reactive oxygen species. 6-Paradol, a dietary component in several plants belonging to the Zingiberaceae family, has shown anti-inflammatory and antioxidant activities. Current study evaluates the effect of 6-paradol in amelioration of ulcerative colitis in rats for the first time.

Methods

6-Paradol (95% purity) was obtained from seeds of Aframomum melegueta. Rats were divided randomly into six groups (n = 8). Group one was administered normal saline; group two was treated with the vehicle only; group three, sulfasalazine 500 mg/kg; and groups four, five, and six, were given 6-paradol (50, 100, 200, respectively) mg/kg orally through gastric gavage for 7 days. Colitis was induced on 4th day by intrarectal administration of 2 ml acetic acid (3%), approximately 3 cm from anal verge. On 8th day, rats were sacrificed, and distal one-third of the colon extending proximally up to 4 cm from anal orifice was taken for biochemical and gross examination. Two centimetres of injured mucosal portion was taken for histopathological investigations. SPSS (ver.26) was used for statistical analysis.

Results

Colonic and serum glutathione (GSH) levels decreased, while colonic and serum malondialdehyde (MDA), colonic myeloperoxidase (MPO) activity, serum interleukin-6 (IL-6), serum tumour necrosis factor-α (TNF-α) levels, and colon weight to length ratio were increased significantly in the colitis untreated group compared to normal control. Treatment with 6-paradol considerably improved all these parameters, especially at a dose of 200 mg/kg (p < 0.001), revealing non-significant differences with sulfasalazine 500 mg/kg and normal control (p = 0.998). Sulfasalazine and 6-paradol in a dose dependent manner also markedly reversed mucosal oedema, atrophy and inflammation, cryptic damage, haemorrhage, and ulceration. There were non-significant differences between low and medium doses and between medium and high doses of 6-paradol for IL-6 and serum MDA levels.

Conclusion

6-Paradol demonstrated protection against acetic acid-induced ulcerative colitis, probably by anti-inflammatory and antioxidant actions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03203-7.

Genetic diversity, LC-ESI-MS chemical profile and in vivo antitumor activity of three Egyptian soybean cultivars

Soybean (Glycine max L.) is one of the most important and widely consumed food plants worldwide. The objective of this study was to investigate the metabolite profiling of three Egyptian soybean cultivars (Giza 22, Giza 35 and Giza 111) and their in vivo antitumor effect. Random amplified polymorphic DNA (RAPD) analysis developed polymorphism level of 75% in 72 distinct markers. Applying LC-ESI-MS analysis, twenty-nine metabolites were recognized from the 80% methanol extract of all cultivars. In vivo antitumor activity of the 80% methanolic extract against solid Ehrlich ascites carcinoma (EAC) inoculated in mice model, showed a significant diminishing in tumor volume and reduced Glutathione (rGSH) and a significant increase in malondialdehyde (MDA) which was supported by histopathological examination. Among the studied cultivars, Giza 22 cultivar contained the highest total phenolic content (TPC) that may contribute to its impressive antioxidant capacity and antitumor activity.

Natural Peroxisome Proliferator-Activated Receptor γ (PPARγ) Activators for Diabetes

CONTEXT

Metabolic syndrome (MetS) represents a worldwide problem. Drugs used in MetS target different symptoms, like excessive body weight, insulin resistance, hyperglycemia, dyslipidemia, or hypertension. Peroxisome proliferator-activated receptors (PPAR) regulate the gene expression involved in lipid metabolism, inflammation, and adipogenesis. Activation of PPARγ has become a target of interest to counter hyperglycemia linked with MetS and type 2 diabetes (T2DM).

OBJECTIVE

The current review intended to summarize reported research on medicinal plants, or their bioactive constituents, with PPARγ-activating potential.

DESIGN

The research team searched the literature up to 2016 using electronic databases- ScienceDirect, PubMed, Google-Scholar, SpringerLink, Scopus, and Wiley-for publications on medicinal plants with promising PPARγ modulators using keywords diabetes mellitus, natural products, peroxisome proliferator-activated receptors, metabolic syndrome, adipogenesis.

SETTING

This study was conducted in the Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia, Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt, and Department of Pharmacognosy and Pharmaceutical Chemistry, College of Pharmacy, Taibah University, Al Madinah, Al Munawwarah, Saudi Arabia.

RESULTS

Several natural products were considered to be good ligands for PPARγ. The PPARγ agonistic activity of over 100 plants covered in this review was supported by experimental evidence. Some of the plants and their constituents had been studied for their possible mechanisms of action.

CONCLUSIONS

Findings discussed in this review highlighted PPARγ's role as an organizer of lipid metabolism and glucose homeostasis, thus supporting its function as a target for antidiabetic agents. The discovery that some natural compounds and plants could activate PPARγ opens up the prospect for future development of strategies to take advantage of its therapeutic potential in diabetes. Therefore, the current review could provide significant information for biotechnological or pharmaceutical applications in targeted drug delivery and design.

6-Shogaol suppresses the growth of breast cancer cells by inducing apoptosis and suppressing autophagy via targeting notch signaling pathway

OBJECTIVES

Breast cancer is one of the most commonly diagnosed cancer among women globally. Shogaol, the active constituent of many spices belonging to the Zingiberaceae family, has received wide attention among other shogaols in terms of its anticancer activity against different neoplasms. To date, its efficacy at the detailed molecular level against breast cancer has not been established.

METHODS

In the current study, we investigated the cytotoxic potential and the underlying molecular details of 6-shogaol against breast adenocarcinomacells (MCF-7), and breast ductal carcinoma cells (T47D). Cytotoxicity assay, cell cycle analysis. Real-time PCR (qPCR), apoptosis and autophagy techniques were used for the determination and molecular investigation of its anticancer properties.

RESULTS

The current study shows that, Notch signaling downregulation (Hes1 and CyclinD1 genes), caused by 6-shogaol, lead to antiproliferative activity in breast cancer cells. The study further shows that treatment with 6-shogaol induced significant and time dependent cell cycle accumulation in G₂/M-phase. 6-Shogaol also induced significant apoptosis in breast cancer cells. Interestingly, 6-shogaol inhibited autophagy in breast cancer cell lines, which might force these cells to undergo apoptosis.

CONCLUSION

6-Shogaol is a promising candidate to be considered as a treatment of breast cancer.

Major flavonoids from Psiadia punctulata produce vasodilation via activation of endothelial dependent NO signaling

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Methanol extract of Psiadia punctulata (MAPP) produced a significant vasodilation.

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Chloroform fraction and its methylated flavonoids were responsible for this effect.

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Vasodilation is referred to endothelial nitric oxide and, Ca²⁺ dependent eNOS.

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Interference with calcium entrance is another possible mechanism of vasodilation.

Vasodilators are important pharmacologic agents for managing and/or treating hypertension. Medicinal plants are considered as valuable source of bioactive compounds. We used a bioguided approach to isolate, identify, and investigate the possible vasodilation activities and mechanism(s) of the prepared methanol extract from aerial parts of Psiadia punctulata (MAPP), its bioactive fraction and active compounds. Vascular effects of MAPP were studied using isolated artery technique in the presence or absence of specific candidate pathways inhibitors, and found to produce a significant vasodilation of phenylephrine preconstricted rat aortae. The bioactive chloroform fraction yielded five methoxylated flavonoids: umuhengerin (1), gardenin A (2), gardenin B (3), luteolin-3′,4′ -dimethyl ether (4), and 5,3′-dihydroxy-6,7,4′,5′-tetramethoxyflavone (5). Metabolites 1, 4, and 5 produced a significant vasodilation. Removal of the endothelium significantly inhibited MAPP vasodilation. Nitric oxide synthase inhibition and not prostacycline inhibition or K⁺ channel blocking, was found to cause the observed vasodilation inhibition. Both guanylate cyclase and adenylate cyclase inhibitions markedly inhibited MAPP vasodilation. In conclusion MAPP possesses vasodilation activities that is mediated through endothelial nitric oxide pathway, calcium dependent endothelial nitric oxide synthase activation, and interference with the depolarization process through calcium channel blocking activity.

Psiadia punctulata major flavonoids alleviate exaggerated vasoconstriction produced by advanced glycation end products

Exaggerated vasoconstriction plays important roles in vascular complication in aging and many diseases like diabetes. Here, we investigated the protective effect of Psiadia punctulata (PP) on advanced glycation end products (AGEs)-induced aggravated vasoconstriction. The effect of total methanol extract of PP leaves (PPT) on AGE-induced vascular injury was studied through bioassay-guided fractionation procedures in order to find the bioactive fraction and isolate the bioactive compounds. Vascular reactivity was studied using the isolated artery technique by adding cumulative concentrations of phenylephrine (PE) or acetyl choline (ACh). In addition, the antiglycating effect, as well as the effect on AGEs intermediates dityrosine and N`-formylkynurenine and their radical scavenging activity were measured. The results showed that PPT alleviated the AGEs-induced aggravated vasoconstriction in a concentration-dependent manner. The bioassay guided fractionation procedures suggested the chloroform fraction (Fr I) to be responsible for the activity. Chemical investigation of this fraction resulted in isolation of four major bioactive compounds that were identified as: umuhengerin (1), gardenin (2), luteolin-3`,4`-dimethyl ether (3), and 5,3`-dihydroxy-6,7,4`,5`-tetramethoxyflavone (4). The four compounds alleviated the exaggerated vasoconstriction in a dose dependent manner. In search for their mechanism of action, we observed that PPT, Fr. I and the isolated compounds did not improve the impaired vasodilation associated with AGEs exposure. PPT, Fr. I and the isolated compounds 1–4 inhibited AGEs formation and their protein oxidation intermediates. Furthermore, PPT, Fr. I and the isolated compounds 1–4 showed weak radical scavenging activity with compound 4 as the most potent. In conclusion, PPT appears to protect against AGEs-induced exaggerated vasoconstriction through antiglycation and radical scavenging activities.

Abstract 308: In-vitro combination analysis for colossolactone-G with gemcitabine and 5-fluoruracil against colorectal cancer cells

Naturally occurring terpenoids isolated from Ganoderma colossum showed potential chemotherapeutic properties. In the current work, we assessed the potential chemomodulatory effects of colossolactone-G to gemcitabine (GCB) and 5-fluorouracil (5FU) against colorectal cancer cells. Colossolactone-G induced moderate cell killing effects against both HT29 and HCT116 cells with IC50’s of 90.5±1.7 µM and 22.3±3.9 µM, respectively. By equitoxic combination, colossolactone-G synergized the cytotoxic effects of GCB and 5FU against both HT29 and HCT116 cells resulting in combination index ranging from 0.22 to 0.67. By assessing cell cycle distribution, both GCB and 5FU induced moderate cell cycle arrest at G0/G1-phase and S-phase. Despite colossolactone-G lacks any influence on cell cycle distribution, it significantly potentiated GCB and 5FU induced cell cycle arrest in S-phase and G2/M-phase. Longer exposure (48 h) of cells to colossolactone-G alone induced antiproliferative effect and accumulation of cells at G0/G1-phase. In addition, cell cycle arrest attributed to GCB, 5FU, colossolactone-G and their combinations was accompanied by significant accumulation of cells at Pre-G phase which is indicative of cell death. Further assessment for cells undergoing apoptosis was measured using annexin-V/FITC and PI staining coupled with flowcytometric analysis. Similarly, colossolactone-G treatment alone did not induce any significant apoptosis in both cell lines. However, 5FU and GCB induced significant apoptosis which was further potentiated by colossolactone-G combination. Besides, autophagic death within HCT116 and HT29 cells was assessed using acridine orange lysosomal stain coupled with flow-cytometric analysis in response to single and combination treatments of 5FU, GCB, colossolactone-G. In HCT116, colossolactone-G significantly suppressed the process of autophagy and decreased acridine orange lysosomal fluorescence signal to 52.7% of control cells. On the other hand, colossolactone-G significantly increased autophagic response in HT29 cells. GCB treatment alone decreased autophagic signal within HT29 cells. However, colossolactone-G combination with 5FU or GCB resulted in significant increase in autophagy by 8.7% and 82.7% of control cells, respectively. In conclusion, colossolactone-G represents promising chemomodulatory adjuvent to GCB and 5FU via potentiating their apoptotic, autophagic and cell cycle interference properties.

Citation Format: Rinad A. Aljohani, Riham S. Eldine, Gehan A. Hegazy, Aliaa A. Alamoudi, Ghada A. Agabnoor, Ali M. El-Halawany, Ahmed M. Al-Abd. In-vitro combination analysis for colossolactone-G with gemcitabine and 5-fluoruracil against colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 308.

Abstract 305: Combination analysis for the potential chemomodulatory effects of mansorin-A and its naphthoquinone derivative (mansonone-G) to 5-fluorouracil against liver cancer cells

Mansorin-A and its naphthoquinone derivative, mansonone-G are naturally occurring compounds isolated from the trunk of Mansonia gagei, family Sterculariaceae. In a previous work, they showed potential anticancer effects besides their antioxidant properties. Herein, we investigated their potential chemomodulatory effects to 5-fluorouracil (5FU) against two liver cancer cell lines (Huh7 and HepG2). Despite the significant cell killing effect of 5FU to Huh7 and HepG2 cells (IC50’s of 2.6±0.2 µM and 0.82 ± 0.2 µM, respectively), the resistance fractions of both cell lines were considerably high (53.2±1.7% and 39.4±2.7%, respectively). Mansorin-A and mansonone-G induced moderate cytotoxicity against both liver cancer cell lines with IC50’s ranging from 25.8±3.2 µM to 36.3±2.7 µM. In Huh7, mansorin-A and mansonone-G synergized cell killing effect of 5FU and decreased its IC50’s to 0.9±0.1 and 1.0±2.1 µM, respectively. On the other hand, mansorin-A and mansonone-G showed apparent antagonism by combination with 5FU (CI values of 6.2 and 9.4, respectively) against HepG2 cells. However, both compounds significantly abolished the resistant fraction of HepG2 to 5FU (3.3±0.3% and 8.4 ± 2.6%, respectively). Further investigation showed that mansonone-G alone showed antiproliferative effect and arrested cells in G0/G1-phase. Both mansorin-A and mansonone-G enhanced 5FU induced cell cycle arrest at G0/G1-phase with reciprocal decrease in cells entering S-phase and G2/M-phase. In addition, apoptosis due to 5FU treatment alone and in combination with mansorin-A and mansonone-G was assessed using annexin-V/FITC staining coupled with flowcytometry. Yet, both mansorin-A and mansonone-G enhanced 5FU induced apoptotic effect against liver cancer cells. Mansonone-G alone induced significant apoptosis in both HepG2 and Huh7 cells. Besides apoptosis, autophagy induction properties of mansorin-A and mansonone-G were assessed using flowcytometry after acridine orange staining. Mansonone-G aborted autophagy in both HepG2 and Huh7 cell lines and indirectly forced liver cancer cells to undergo apoptotic cell death. On the other hand, both mansorin-A and mansonone-G significantly induced the production of reactive oxygen species within both HepG2 and Huh-7 cells which might directly induce apoptosis in both cell lines. In conclusion, mansonone-G and to a lesser extent mansorin-A, potentiated the anticancer properties of 5FU against liver cancer cells via potentiating its cell cycle arrest and potentiating its apoptotic influence due to ROS production.

Citation Format: Hanadi G. Aljohani, Gehan A. Hegazy, Ali M. El-Halawany, Aliaa A. Alamoudi, Ghada M.A. Agabnoor, Ahmed M. Al-Abd. Combination analysis for the potential chemomodulatory effects of mansorin-A and its naphthoquinone derivative (mansonone-G) to 5-fluorouracil against liver cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 305.

Abstract 5819: Colossolactone-G enhances the anticancer properties of 5-fluorouracil and gemcitabine against colorectal cancer cells

The use of anti-cancer adjuvant therapy is rationalized by potentiating the efficacy, and/or protecting from major side effects of chemotherapeutics. Gemcitabine and 5-fluorouracil are important chemotherapeutic agents which are frequently used to treat cancers such as colorectal cancer. Colossolactone-G is a naturally occurring triterpenoid metabolite isolated from the fruiting body of Ganoderma colossum. Herein, we assessed the potential chemomodulatory effects of Colossolactone-G to 5-fluorouracil and gemcitabine against human colorectal cancer cells. After 72 h of exposure, colossolactone-G per se possesses cytotoxic effects against HCT116 and HT29 cells with IC50's of 15.9±3.6 µM and 90.5±1.7 µM, respectively. In addition, colossolactone-G improved the cytotoxic profile of gemcitabine against HCT116 cells reducing its IC50 from 0.28±0.1 µM to 19.41±3.1 nM with combination index indicative of synergism (CI-value = 0.154). Similarly, colossolactone-G enhanced the cytotoxicity of gemcitabine against HT29 cells reducing its IC50 from 6.2±1.1 µM to 0.6±0.3 µM with combination index indicative of synergism (CI-value = 0.219). Besides, colossolactone-G synergized the cytotoxic profile of 5-fluorouracil against HCT116 and HT29 cells decreasing its IC50's from 10.8±4.6 to 3.1±0.5 µM (CI-value = 0.302), and from 12.9±3.7 to 3.2±0.6 µM (CI-value = 0.426), respectively. By assessing cell cycle distribution after 24 h using DNA content flowcytometry, both gemcitabine and 5-fluorouracil induced moderate cell cycle arrest at S-phase which was increased by combination with colossolactone-G and was further extended to induce accumulation of cells at G0/G1-phase. Longer exposure (48 h) of cells to colossolactone-G alone induced antiproliferative effect and accumulation of cells at G0/G1-phase. Besides, the S-phase arrest induced by gemcitabine and 5-fluorouracil was further increased by combination with colossolactone-G for 48 h and was accompanied by reciprocal decrease in cells in G2/M-phase. Cell cycle arrest attributed to gemcitabine and 5-fluorouracil treatment resulted in increasing cells undergoing apoptosis as shown by annexin-V/FITC staining. Similarly, combination with colossolactone increased the percentage of cells undergoing apoptosis in both cell lines. In conclusion, colossolactone-G represents promising chemomodulatory compound of natural origin which improves the anti-colorectal cancer activity of gemcitabine and 5-fluorouracil in a cell cycle dependent manner. Detailed molecular assessment for the underlying mechanisms of colossolactone-G chemomodulatory activity is currently under investigation.

Citation Format: Rinad A. Aljohani, Gehan A. Hegazy, Aliaa A. Alamoudi, Ali M. El-Halawany, Riham S. Eldine, Ghada Agabnoor, Ahmed M. Al-Abd. Colossolactone-G enhances the anticancer properties of 5-fluorouracil and gemcitabine against colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5819.

Abstract LB-073: Mansonone-G is more potent antiproliferative against liver cancer cells than its coumarin derivative (mansorin-A) despite their antagonistic interaction with 5-fluorouracil

O-Napthoquinones and their structurally related coumarins are naturally occurring compounds with potential anticancer properties. In the current work mansonone-G and its coumarin derivative, mansorin-A were isolated from the trunk of Mansonia Gagei family Sterculariaceae and evaluated for potential solo anticancer effects and/or chemomodulatory properties to 5-fluorouracil (5-FU) against liver cancer cells (HepG2 and Huh-7). Mansonone-G exerted moderate cytotoxic properties against both HepG2 and Huh-7 cells with IC50's of 36.3±2.6 µM and 25.9±2.7 µM; and resistance fraction (R-value) of 4.7±0.1% and 3.4±0.4%, respectively. However, mansorin-A exerted weaker cytotoxic profile against the same cell lines (HepG2 and Huh-7) with IC50's of 24.6±1.7 µM and 29.5±5.8 µM, respectively; and R-values were higher than 50% in both cell lines. Surprisingly, mansonone-G attenuated the potency of 5-FU against both cell lines under investigations (HepG2 and Huh-7) and increased its IC50's from 0.8±0.2 to 36.5±7.2 µM and from 2.6±0.2 to 10.1±2.1 µM, respectively. Interestingly, equitoxic combination of mansonone-G abolished the R-fractions of both cell lines (HepG2 and Huh-7) to 5-FU from 39.4±2.7% and 53.2±1.7%, respectively to less than 5% in both cell lines. Similarly but to lesser extent, mansorin-A increased the IC50's of 5-FU against HepG2 and Huh-7 cells from 0.8±0.2 to 56.0±12.7 µM and from 2.6±0.2 to 7.4±3.9 µM, respectively. Similarly, equitoxic combination of mansorin-A abolished the R-fractions of both cell lines to 5-FU to less than 5%. To confirm these apparent antagonism interactions between mansonone-G or mansorin-A with 5-FU, apoptosis/necrosis analysis for single and combination treatments was undertaken using annexin-V/FITC staining coupled with flowcytometry. Mansorin-A significantly decreased apoptotic cell death attributed to treatment with 5-FU in both HepG2 and Huh-7 cell lines. However, mansonone-G significantly increased apoptosis induced by 5-FU in both cell lines. In addition to apoptosis, autophagic cell death was assessed using acridine orange staining coupled with flowcytometry. Mansorin-A did not influence autophagic cell death; 5-FU increased cells undergoing autophagy; and mansonone-G decreased cells undergoing autophagy. Mansorin-A combination decreased 5-FU induced autophagic cell death. On the other hand, combination of mansonone-G with 5-FU resulted in decreased autophagic cell death. By studying the influence of treatments under investigation to cell cycle distribution using DNA content flowcytometry, both mansonone-G and mansorin-A induced significant cell cycle accumulation in G0/G1-phase. This antiproliferative effect of mansonone-G and mansorin-A prohibit cell progression to S-phase and accordingly might result in desensitizing cells to the S-phase selective cytotoxicity of 5-FU. In conclusion, despite the potential antiproliferative effects of mansonone-G and mansorin-A against liver cancer cells, they antagonize the cytotoxic effects of the S-phase specific agents such as 5-FU. In addition, this antagonism might be partly attributed to conflicting autophagic effects of mansonone-G/mansorin-A and 5-FU.

Citation Format: Hanadi G. Aljohani, Gehan A. Hegazy, Aliaa A. Alamoudi, Ghada M. Agabnoor, Ali M. El-Halawany, Ahmed M. Al-Abd. Mansonone-G is more potent antiproliferative against liver cancer cells than its coumarin derivative (mansorin-A) despite their antagonistic interaction with 5-fluorouracil [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-073.

Phenolics from Barleria cristata var. Alba as carcinogenesis blockers against menadione cytotoxicity through induction and protection of quinone reductase

Background

There are increasing interests in natural compounds for cancer chemoprevention. Blocking agents represent an important class of chemopreventive compounds. They prevent carcinogens from undergoing metabolic activation and thereby suppressing their interaction with cellular macromolecular targets.

Methods

The effect of phenolic compounds isolated from Barleria cristata var. alba as chemopreventive agent was evaluated. The ethyl acetate fraction of B. cristata was subjected to different chromatographic techniques for isolation of its major phenolic compounds. The isolated compounds were evaluated for their potential to induce the cancer chemopreventive enzyme marker NAD(P)H quinonereductase 1 (NQO1) in murine Hepa-1c1c7 cell model.

Results

The ethyl acetate fraction of B. cristata var. alba yielded five known compounds identified as verbascoside (1), isoverbascoside (2), dimethoxyverbascoside (3), p-hydroxy benzoic acid (4), and apigenin-7-O-glucoside (5). Among the tested compounds, isoverbascoside (2) was shown to potently induce the activity of the enzyme in a dose –dependent manner. As a functional assay for detoxification, compound 2 was the strongest to protect Hepa-1c1c7 against the toxicity of menadione, a quinone substrate for NQO1.

Conclusion

This effect seemed to be attributed to the compound’s potential to induce both the catalytic activity and protein expression of NQO1 as revealed by enzyme assay and Western blotting, respectively.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2214-9) contains supplementary material, which is available to authorized users.

Saudi plants as a source of potential β-lactamase inhibitors

This study was performed to assess the potential β-lactamase inhibitory properties of nineteen crude Saudi plant extracts belonging to eight families against extended spectrum β-lactamase (ESβL) strains of Klebsiella pneumoniae and other medically important pathogens. A total of 276 microbial isolates of pathogenic bacteria were used in this study; only 15 of them showed decreased sensitivity to one or several of ceftazidime, aztreonam, cefotaxime or ceftriaxone, which are deemed to be possible producers of ESβL. Antibacterial activities of plant extracts were carried out against ESβL positive isolates by the disc diffusion method. The potential ESβL suppressing activities of plant extracts and prepared fractions, (chloroform and methanol), with or without antibiotic were studied by disc diffusion method. Results revealed that selected plant extracts showed no antibacterial activity against tested strains; meanwhile, only Echinops viscosus, Pulicaria arabica, Tephrosia nubica, Chrozophora oblongifolia, and Clutia myricoides showed pronounced ESβL inhibitory activities. The extracts were quantified for phenolic compounds and their antioxidant properties. Bio-guided fractionation of the active extracts revealed that the chloroform fraction of C. myricoides possess a promising ESβL inhibitory activity. The separation and the structural elucidation of the active compounds from C. myricoides will offer beneficial leads for developing β-lactamase inhibitors.

Abstract 131: Chemotherapeutic effects of naturally occurring colossolactones against solid tumor cells in-vitro

Colossolactones were isolated previously from the Vietnamese mushroom ganoderma colossum, such triterpenoids. The different colossolactone compounds (schisanalactonoe a, colossolactone I, ergosterol, colossolactone III, colossolactone II, colossolactone IV, colossolactone E) characterized by the presence of a six-membered lactone ring (ring D) with or without a seven-membered lactone rings (ring A) were isolated. In the current study, using DPPH free radical scavenging assay, all colossolactone compounds showed weak antioxidant activity with EC50’s of 99.46, 220.32, 219.65, 100.81, 238.54, 116.57 and 131.94 µM, respectively. Isolated compounds were examined for their potential anticancer activity against breast (MCF-7), cervix (HeLa), colorectal (HCT-116) and liver (HepG2) cancer cells. Cytotoxicity of the isolated compounds was assessed in the aforementioned cell lines using SRB assay after 72 h of exposure and fitted using Emax model. Amongst colossolactones, schisanalactonoe-A and colossolactone-IV showed the best cytotoxic profile in all cell lines under investigation with IC50’s ranged from 4.9 to 64.2 µM; and R-fraction less than 47.5%. Further mechanistic studies for the detailed mechanism of cytotoxicity of schisanalactonoe-A and colossolactone-IV are currently carried out.

Citation Format: Mohammed A. Baghdadi, Fahad A. Al-Abbasi, Ali M. El-Halawany, Ahmed M. Al-Abd. Chemotherapeutic effects of naturally occurring colossolactones against solid tumor cells in-vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 131. doi:10.1158/1538-7445.AM2017-131

New xanthones and cytotoxic constituents from Garcinia mangostana fruit hulls against human hepatocellular, breast, and colorectal cancer cell lines

ETHNOPHARMACOLOGICAL RELEVANCE

Cancer has proceeded to surpass one of the most chronic illnesses to be the major cause of mortality in both the developing and developed world. Garcinia mangostana L. (mangosteen, family Guttiferae) known as the queen of fruits, is one of the most popular tropical fruits. It is cultivated in Southeast Asian countries: Malaysia, Indonesia, Sri Lanka, Burma, Thailand, and Philippines. Traditionally, numerous parts of G. mangostana have been utilized to treat various ailments such as abdominal pain, haemorrhoids, food allergies, arthritis, leucorrhoea, gonorrhea, diarrhea, dysentery, wound infection, suppuration, and chronic ulcer.

AIM OF STUDY

Although anticancer activity has been reported for the plant, the goal of the study was designed to isolate and characterize the active metabolites from G. mangostana and measure their cytotoxic properties. In this research, the mechanism of antiproliferative/cytotoxic effects of the tested compounds was investigated.

MATERIALS AND METHODS

The CHCl₃ fraction of the air-dried fruit hulls was repeatedly chromatographed on SiO₂, RP₁₈, Diaion HP-20, and polyamide columns to furnish fourteen compounds. The structures of these metabolites were proven by UV, IR, 1D, and 2D NMR measurements and HRESIMS. Additionally, the cytotoxic potential of all compounds was assessed against MCF-7, HCT-116, and HepG2 cell lines using SRB-U assay. Antiproliferative and cell cycle interference effects of potentially potent compounds were tested using DNA content flow cytometry. The mechanism of cell death induction was also studied using annexin-V/PI differential staining coupled with flow cytometry.

RESULTS

The CHCl₃ soluble fraction afforded two new xanthones: mangostanaxanthones V (1) and VI (2), along with twelve known compounds: mangostanaxanthone IV (3), β-mangostin (4), garcinone E (5), α-mangostin (6), nor-mangostin (7), garcimangosone D (8), aromadendrin-8-C-β-D-glucopyranoside (9), 1,2,4,5-tetrahydroxybenzene (10), 2,4,3`-trihydroxybenzophenone-6-O-β-glucopyranoside (11), maclurin-6-O-β-D-glucopyranoside (rhodanthenone) (12), epicatechin (13), and 2,4,6,3`,5`-pentahydroxybenzophenone (14). Only compound 5 showed considerable antiproliferative/cytotoxic effects with IC₅₀'s ranging from 15.8 to 16.7µM. Compounds 3, 4, and 6 showed moderate to weak cytotoxic effects (IC₅₀'s ranged from 45.7 to 116.4µM). Using DNA content flow cytometry, it was found that only 5 induced significant cell cycle arrest at G₀/G₁-phase which is indicative of its antiproliferative properties. Additionally, by using annexin V-FITC/PI differential staining, 5 induced cells killing effect via the induction of apoptosis and necrosis in both HepG₂ and HCT116 cells. Compound 3 produce necrosis and apoptosis only in HCT116 cells. On contrary, 6 induced apoptosis and necrosis in HepG₂ cells and moderate necrosis in HCT116 cells.

CONCLUSION

Fourteen compounds were isolated from chloroform fraction of G. mangostana fruit hulls. Cytotoxic properties exhibited by the isolated xanthones from G. mangostana reinforce the avail of it as a natural cytotoxic agent against various cancers. These evidences could provide relevant bases for the scientific rationale of using G. mangostana in anti-cancer treatment.

Abstract 2151: Gingerol, paradol and shogaol overcome colorectal cancer cell resistance to sorafenib via enhancing its cellular uptake, entrapment and intracellular metabolism

Sorafenib is tyrosine kinase inhibitor used for the treatment of hepatocellular and renal carcinomas but suffers from resistance in some tumors such as colorectal cancer. Colorectal cancer multi-drug resistance might be attributed to over-expression/over-activation of P-glycoprotein (P-gp) efflux pump and/or intracellular metabolism. Gingerol, paradol and shogaol are naturally occurring major compounds within the family Zingiberaceae. Gingerol and its related hydroxyphenylalkanones are known for their potential interference with P-gp function as well as intracellular drug metabolism. In the present study, we investigated the influence of gingerol, paradol and shogaol on the cytotoxic profile of sorafenib in colorectal cancer cell lines (HT-29, HCT-116, LS-174T and CaCo-2) via their influence on sorafenib cellular accumulation and intracellular metabolism. Sorafenib alone showed considerable cytotoxic activity against all testes colorectal cell lines with IC50 ranging from 2.0±0.3 to 11.10±0.8 μM. Gingerol, paradol and shogaol significantly enhanced the cytotoxicity of sorafenib against HT-29 cells and decreased its IC50 from 9.2±0.4 μM to 6.6±0.7, 3.8±0.4 and 4.7± 0.4 μM, respectively. Similarly in HCT-116, gingerol, paradol and shogaol significantly decreased sorafenib IC50 from 11.3±0.8 μM to 5.7±0.7, 5.9±0.4 and 7.7± 0.5 μM, respectively. Using DNA cytometric analysis, combination of gingerol, paradol or shogaol with sorafenib significantly decreased the proliferating cell fractions from 16.9±1.1% to 11.6±1.1%, 14.7±1.1% and 9.16±1.8%, respectively. In parallel, combination of gingerol, paradol or shogaol with sorafenib significantly increased the c-PARP concentration from 60.0±20.0 pg/cell to 256.5±25.8, 244±61.4, and 202.9±37.2 pg/cell, respectively. Gingerol and paradol, but not shogaol increased the intracellular accumulation of the P-gp probe, rhodamine at concentration range (3-100 μM). However, using recombinant ATPase attached p-gp molecules, shogaol and paradol significantly inhibited the ATPase activity. Gingerol, paradol and shogaol increased sorafenib uptake and decreased its extracellular concentration from 1491.7±132.0 ng/ml to 511.0±16.0, 216.0±39.0 and 256.4±15.6 ng/ml, respectively. Only gingerol and paradol increased sorafenib intracellular accumulation and increased its level from 239.0±16.0 pg/cell to 297.0±32.6 and 327.0±12.0 pg/cell, respectively. Both paradol and shogaol enhanced the intracellular metabolism of sorafenib to its N-oxide active metabolite and entrapped it within cellular compartment. In conclusion, gingerol, paradol and shogaol significantly enhanced the anti-cancer profile of sorafenib via influencing its cellular pharmacokinetics.

Citation Format: Mohamed G. Mehanna, Fahad A. Al-Abbasi, Tarek Elawady, Ali M. El-Halawany, Ahmed M. Al-Abd. Gingerol, paradol and shogaol overcome colorectal cancer cell resistance to sorafenib via enhancing its cellular uptake, entrapment and intracellular metabolism. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2151.

Abstract 2181: Chemotherapeutic, chemomodulatory and vascular protective effects of naturally occurring hydroxyphenylalkanes and diarylheptanoids

Hydroxyphenylalkanes and diarylheptanoids possess potential therapeutic values in different patho-physiological conditions such as inflammation, oxidative stress, cardiovascular disorders and malignancy. Doxorubicin is widely used chemotherapeutic agent against several types of neoplastic disorders. In the current study, naturally isolated hydroxyphenylalkane and diarylheptanoid compounds were investigated for their potential chemo-modulatory effects on the top of their potential vascular protective role with doxorubicin. Shogaol and 4-methoxygingerol showed considerable cytotoxic effects against HCT116, HeLa, HepG2 and MCF7 cells with IC50 ranging from 3.1 to 18.7 μM and from 9.1 to 19.4 μM, respectively. Using DPPH free radical scavenging assay, diarylheptanoids were stronger antioxidant than hydroxyphenylalkanes with EC50 ranging from 0.5 to 5.9 μM and from 4.6 to 9.5 μM, respectively. In addition, all tested diarylheptanoids significantly ameliorated CCl4 induced disturbed intracellular GSH/GSSG balance. Gingerol moderately enhanced the cytotoxic profile of doxorubicin against HepG2 and Huh7 cells decreasing their IC50's from 0.52 to 0.37 μM and from 50 to 30 nM, respectively. Combination index of gingerol with doxorubicin (combination at equitoxic ratio of 1/100) was indicative of additive interaction (CI-value were 1.1 and 1.0, respectively). To further investigate the interactive characteristics between doxorubicin and gingerol, cell cycle distribution of HepG2 and Huh7 cells was studied using DNA cytometry after exposure to their single and equitoxic combination. Doxorubicin induced cell accumulation at S-phase and G2/M-phase while, gingerol combination with doxorubicin significantly induced cell cycle arrest at G2/M-phase. To study the potential vascular protective effect of gingerol against doxorubicin induced vascular toxicity, doxorubicin (10 μM for 1h) was incubated with or without different concentrations of 6-gingerol (3, 10 and 30 μM for 1h) on isolated aortic rings and their response to phenylephrine (PE) and acetylcholine (ACh) was examined. Co-incubation of 6-gingerol (30 μM) completely blocked the exaggerated vasoconstriction and impaired vascular relaxation induced by doxorubicin

Citation Format: Mohammed A. Baghdadi, Eman A. Al-Ghamdi, Abdulmohsin J. Alamoudi, Fahad A. Al-Abbasi, Hany M. El-Bassossy, Ali M. El-Halawany, Ahmed M. Al-Abd. Chemotherapeutic, chemomodulatory and vascular protective effects of naturally occurring hydroxyphenylalkanes and diarylheptanoids. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2181.

Abstract 2188: Isolation and anticancer properties of some naturally occurring sesquiterpene lactones from Pulicaria undulate

Sesquiterpene lactones are natural compounds abundant in several plant families with a variety of biological activities such as antitumor effects. Camptothecin is famous topoisomerase interactive agent with anticancer properties against several types of malignancies. The purpose of this study is to investigate the potential chemotherapeutic effects of some naturally occurring sesquiterpene lactones isolated from Pulicaria undulate. Compounds with promising anticancer profile has been further investigated for potential chemomodulatory effects to camptothecin in different tumor cell types. Cytotoxicity of the isolated terpenoids were assessed against human breast adenocarcinoma (MCF7), human colorectal cancer (HCT116 and LS174T) and human hepatocellular carcinoma (HepG2) cells using sulpharhodamine-B assay after cell exposure for 72 h. Cytotoxic parameters (IC50 and R-fraction) were calculated from cell viability after fitting using Emax model. Two sesquiterpene lactones, 2α-hydroxy alantolactone and tomentosin, showed considerable cytotoxic profile against cell lines under investigation with IC50's ranging from 5 to 22 μM and from 14 to 39 μM, respectively. Treatment with camptothecin alone showed significant cytotoxicity with IC50's range from 0.13 to 1.5 μM in the same panel of cell lines. Equitoxic combination of tomentosin with camptothecin (combination ratio was 1:100) resulted in 60% reduction for the IC50 of camptothecin alone in HCT116 cells. On the other hand, equitoxic combination for hydroxy alantolactone with camptothecin did not significantly enhance the cytotoxicity of camptothecin against HCT116 cells. To explain the interactive characteristics of hydroxy alantolactone and tomentosin with camptothecin, annexin-V/PI staining coupled with flow cytometry analysis for apoptosis and necrosis was assessed after treatment with camptothecin alone or in combination with hydroxy alantolactone or tomentosin. Again, tomentosin combination with camptothecin significantly increased apoptotic as well as necrotic cell populations compared to camptothecin treatment alone by 2-3 folds. On the other hand, combination of camptothecin with hydroxy alantolactone significantly increased apoptotic cell population with reciprocal decrease in necrotic cell population. In conclusion, hydroxy alantolactone and tomentosin might be promising anticancer agents. However, further molecular investigation is required to understand the nature of interaction between the isolated sesquiterpene lactones and cornerstone chemotherapeutics such as camptothecin.

Citation Format: Mohammed M. Arab, Fahad A. Al-Abbasi, Mohamed-Elamir F. Hegazy, Ali M. El-Halawany, Ahmed M. Al-Abd. Isolation and anticancer properties of some naturally occurring sesquiterpene lactones from Pulicaria undulate. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2188.

Abstract 4846: Chemotherapeutic and chemomodulatory effects of naturally occurring tetrahydrofuran type terpenoid

Naturally occurring terpenoid compounds are diverse active constituent in several plants and known of their potential anticancer activities. Camptothecin (CPT) is a topoisomerase inhibitor agent with well documented anti-neoplastic activity against several types of tumors. The purpose of this study is to investigate the potential chemotherapeutic effects of some terpenoid compounds isolated from Salvia africana lutea, Stachys aegyptiaca, Tanacetum sinaicum. Terpenoid compounds with promising anticancer profile has been further investigated for potential chemomodulatory effects to CPT against different tumor cell types. Cytotoxicity of the isolated terpenoids were assessed against human breast adenocarcinoma (MCF7), human colorectal cancer (HCT116 and LS174T) and human hepatocellular carcinoma (HepG2) cells using sulpharhodamine-B assay after cell exposure for 72 h. Cytotoxic parameters (IC50 and R-fraction) were calculated from cell viability after fitting to Emax mathematical model. The tetrahydrofuran type terpenoid, (R,E)-6-hydroxy-6-methyl-2-((2S,5R)-methyl-5-vinyltetrahydrofuran-2-yl)hept-4-en-3-one (TSS-7), isolated from Tanacetum sinaicum showed considerable cytotoxicity with IC50 ranging from 49 to 70 μM in all tested cell lines. On the other hand, IC50 of CPT ranged from 0.13 to 1.5 μM in the same cell lines under investigation. Combination index analysis (CI-value) for TSS-7 with CPT showed synergistic relationship in MCF7, HCT116 and HepG2 (CI-values were 0.17, 0.17 and 0.39 respectively). However, the same combination of TSS-7 and CPT against LS174T cells showed antagonistic relationship (CI-value of 1.2). Further investigation for apoptosis/necrosis assessment using annexin-V/PI staining was undertaken for single and combination treatment of CPT and TSS-7. In HCT116 cells, TSS-7 combination with CPT significantly increased apoptotic and necrotic cells compared to CPT treatment alone. However, in LS174T cells, TSS-7 combination with CPT significantly decreased apoptotic and necrotic cells compared to CPT treatment alone. Cell cycle analysis using DNA cytometry showed strong G2/M arrest induced by CPT treatment. Yet, TSS-7 increased cell population in S-phase and to a lesser extend in G2/M-phase which might be the reason for temporal synergism/antagonism of TSS-7 and CPT in different cell lines. In conclusion, TSS-7 could be considered promising anticancer chemomodulatory terpenoid compound which requires further molecular investigations to elucidate its sub-cellular molecular target.

Citation Format: Eman M. Atiya, Fahad A. Al-Abbasi, Mohamed-Elamir F. Hegazy, Ali M. El-Halawany, Ahmed M. Al-Abd. Chemotherapeutic and chemomodulatory effects of naturally occurring tetrahydrofuran type terpenoid. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4846.

Gingerol Synergizes the Cytotoxic Effects of Doxorubicin against Liver Cancer Cells and Protects from Its Vascular Toxicity

Hydroxyphenylalkanes and diarylheptanoids possess potential therapeutic value in different pathophysiological conditions, such as malignancy. In the current study, naturally isolated hydroxyphenylalkane and diarylheptanoid compounds were investigated for potential chemo-modulatory effects in addition to potential vascular protective roles with doxorubicin. Diarylheptanoids showed stronger antioxidant effects, in comparison to hydroxyphenylalkanes, as demonstrated by DPPH assay and amelioration of CCl₄-induced disturbed intracellular GSH/GSSG balance. Shogaol and 4′-methoxygingerol showed considerable cytotoxic effects against HCT116, HeLa, HepG2 and MCF7 cells, with IC₅₀ values ranging from 3.1 to 19.4 µM. Gingerol significantly enhanced the cytotoxic profile of doxorubicin against HepG₂ and Huh7, cells decreasing its IC₅₀s by 10- and 4-fold, respectively. Cell cycle distribution was studied using DNA cytometry. Doxorubicin alone induced cell accumulation at S-phase and G₂/M-phase, while in combination with gingerol it significantly induced cell cycle arrest at the G₂/M-phase. Additionally, the vascular protective effect of gingerol against doxorubicin (10 µM) was examined on isolated aortic rings. Co-incubation with 6-gingerol (30 µM) completely blocked the exaggerated vasoconstriction and impaired vascular relaxation induced by doxorubicin. In conclusion, despite its relatively weak antioxidant properties, gingerol protected from DOX-induced vascular damage, apparently not through a ROS scavenging mechanism. Besides, gingerol synergized the cytotoxic effects of DOX against liver cancer cells without influencing the cellular pharmacokinetics.

Phenolics from Garcinia mangostana Inhibit Advanced Glycation Endproducts Formation: Effect on Amadori Products, Cross-Linked Structures and Protein Thiols

Accumulation of Advanced Glycation Endproducts (AGEs) in body tissues plays a major role in the development of diabetic complications. Here, the inhibitory effect of bioactive metabolites isolated from fruit hulls of Garcinia mangostana on AGE formation was investigated through bio-guided approach using aminoguanidine (AG) as a positive control. Including G. mangostana total methanol extract (GMT) in the reaction mixture of bovine serum albumin (BSA) and glucose or ribose inhibited the fluorescent and non-fluorescent AGEs formation in a dose dependent manner. The bioassay guided fractionation of GMT revealed isolation of four bioactive constituents from the bioactive fraction; which were identified as: garcimangosone D (1), aromadendrin-8-C-glucopyranoside (2), epicatechin (3), and 2,3',4,5',6-pentahydroxybenzophenone (4). All the tested compounds significantly inhibited fluorescent and non-fluorescent AGEs formation in a dose dependent manner whereas compound 3 (epicatechin) was found to be the most potent. In search for the level of action, addition of GMT, and compounds 2-4 inhibited fructosamine (Amadori product) and protein aggregation formation in both glucose and ribose. To explore the mechanism of action, it was found that addition of GMT and only compound (3) to reaction mixture increased protein thiol in both glucose and ribose while compounds 1, 2 and 4 only increased thiol in case of ribose. In conclusion, phenolic compounds 1-4 inhibited AGEs formation at the levels of Amadori product and protein aggregation formation through saving protein thiol.

Abstract 5557: Chemotherapeutic and chemomodulatory effects of naturally occurring O-naphthoquinone and related coumarins against solid tumor cells in-vitro

Napthoquinones are naturally occurring compounds with potential anticancer activity. In the current study a group of O-naphthoquinone compounds (mansonone-G, mansonone-N, mansonone-O and mansonone-S) and their structurally related coumarins (mansorin-A, mansorin-B, mansorin-C and mansorin-D) were isolated from the trunk of Mansonia Gagei family Sterculariaceae. Isolated compounds were examined for their potential anticancer activity in breast (MCF-7), cervix (HeLa), colorectal (CaCo-2) and liver (HepG2) cancer cells. Cytotoxicity of the isolated compounds was assessed in the aforementioned cell lines using SRB assay after 72 h of exposure and fitted using Emax model. Amongst naphthoquinones, mansonone-O showed the best cytotoxic profile in all cell lines under investigation with IC50 range from 0.74 to 36 μM; and R-fraction less than 5.7%. On the other hand, all coumarin compounds showed potentially low IC50 (from 1.0 to 38.7 μM) in all tested cell lines. However, the R-fraction reached as high as 90.5% in some cell lines (MCF-7). The effect of O-naphthoquinones and their related coumarins against P-gp efflux pump was tested and compared to verapamil using doxorubicin as P-gp probe. Mansonone-O, mansorin-C and mansorin-D inhibited the efflux activity of P-gp pump by 158.1%, 250.5% and 115.4%, respectively compared to 255.1% by verapamil. Accordingly, equitoxic combination of mansonone-O with paclitaxel against colorectal cancer cells was further investigated using Chou & Talaly equation. The IC50 of paclitaxel was significantly reduced after combination with mansonone-O compared to its single paclitaxel treatment (5.14 nM and 24.9 nM, respectively). The combination of paclitaxel with mansonone-O was synergistic in nature with calculated combination index of 0.33. Furthermore, cell cycle analysis was studied after combination of mansonone-O with paclitaxel. Combination of mansonone-O with paclitaxel significantly increased the cell population in G2/M phase (from 4.2±0.5% to 11.2±1.2%) with reciprocal decrease in the non-proliferating cell fraction (G0/G1) from 73.5±1.7% to 66.8±1.6%. In conclusion, mansonone-O (naturally occurring naphthoquinone) synergizes the anticancer effect of paclitaxel. This synergism might be partly attributed to interfering with the efflux activity of P-gp pump and/or interfering with cell cycle progression. Further mechanistic studies for the proposed intracellular targets of mansonone-O and related compounds is strongly recommended.

Citation Format: Mohammed A. Baghdadi, Fahad A. Al-Abbasi, Ali M. El-Halawany, Ahmed M. Al-Abd. Chemotherapeutic and chemomodulatory effects of naturally occurring O-naphthoquinone and related coumarins against solid tumor cells in-vitro. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5557. doi:10.1158/1538-7445.AM2015-5557

Anti-tuberculous activity of treponemycin produced by a streptomyces strain MS-6-6 isolated from Saudi Arabia

A Streptomyces strain MS-6-6 with promising anti-tuberculous activity was isolated from soil samples in Saudi Arabia. The nucleotide sequence of its 16S rRNA gene (1426 bp) evidenced a 100% similarity to Streptomyces mutabilis. Through an anti-tuberculous activity-guided approach, a polyketide macrolide was isolated and identified as treponemycin (TP). The structure of the isolated compound was determined by comprehensive analyses of its 1D and 2D NMR as well as HRESI-MS. In addition to the promising anti-tuberculous activity (MIC = 13.3 µg/mL), TP showed broad spectrum of activity against the Gram positive, Gram negative strains, and Candida albicans. Improvement of TP productivity (150%) was achieved through modification in liquid starch nitrate medium by replacing KNO3 with corn steep liquor and yeast extract or tryptone, and removing CaCO3 and K2HPO4. The follow up of TP percentage as well as its metabolites profile for each media was assessed by LC/DAD/MS.