Cannabinoids and standardized cannabis extracts inhibit migration, invasion, and induce apoptosis in MCF-7 cells through FAK/MAPK/Akt/NF-κB signaling

BACKGROUND

Breast cancer is the highest incidence of all types of cancer in women, and the cancer metastasis process accounts for a majority of cancer deaths. Two major cannabinoids, Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), from Cannabis sativa are expected to have anti-cancer activity. This study aimed to investigate the effects of THC, CBD, and standardized cannabis extracts (F1, F2, and F3) on migration, invasion, and apoptosis of human breast cancer (MCF-7) cells.

METHODS

Cell viability, survival, and apoptosis were determined using the MTT, clonogenic, and nuclear staining assays, respectively, while cancer cell migration and invasion were evaluated by the wound healing, trans-well, and filopodia assays. Western blot analysis was used to find out the mechanisms of the cannabinoids against MCF-7 cells.

RESULTS

CBD, THC, and F1 inhibited filopodia formation, migration, and invasion of MCF-7 cells through suppressing the expression of the FAK, Akt, ERK1/2, p38MAPKs, and NF-κB upstream pathways, as well as inhibiting the Rac1/Cdc42 downstream pathways. In addition, CBD significantly inhibited the mTOR pathway. Furthermore, CBD and F1 induced apoptosis in MCF-7 cells via the Bcl-2/caspase-3 pathways.

CONCLUSION

These results indicate that THC, CBD, and F1 have great abilities for preventing breast cancer cell metastasis in in vitro experiments.

Effects of standardized [6]-gingerol extracts and [6]-gingerol on isolated ileum and lower esophageal sphincter contractions in mice

Standardized [6]-gingerol extracts were prepared by microwave-assisted extraction using 20% v/v glycerin in ethanol and 20% v/v eutectic mixture of sucrose and citric acid in ethanol as alternative green solvents. The extracts obtained from 20% v/v glycerin in ethanol (GEE) and 20% v/v eutectic mixture of sucrose and citric acid in ethanol (EMSCEE) were standardized by HPLC to contain 17.0 mg/g of [6]-gingerol. The effects of the extracts on mouse ileal contractions via M3 and 5-HT3 receptors as well as lower esophageal sphincter (LES) contraction were determined in vitro relative to the marker compound, [6]-gingerol. [6]-Gingerol, GEE and EMSCEE demonstrated significant and concentration-dependent inhibitory effects on ileal contraction in mice via M3 and 5-HT3 receptors in a noncompetitive manner. In addition, [6]-gingerol and EMSCEE tend to increase the LES tone. These results indicated the potential of GEE and EMSCEE to attenuate nausea and vomiting and might be used as nutraceuticals.

Differential neuroprotective effect of curcuminoid formulations in aluminum chloride-induced Alzheimer's disease

Alzheimer's disease (AD) is a slowly progressive brain degenerative disorder which gradually impairs memory, thinking, and ability to perform easy routine tasks. This degenerative disorder mainly targets the elderly people and has imposed an endemic burden on society. Hence, there is a crucial need to investigate the efficacious herbal pharmacotherapies that can effectively mitigate and prevent the pathological hallmarks of AD. The current study aims to explore the potential efficacy of curcuminoid-rich extract (CRE) and its ternary complex (TC). Experimental rodents were administered with AlCl₃ (300 mg/kg) to induce AD and treated with rivastigmine, curcuminoid crude extract, CRE, and TC orally for three consecutive weeks. Neurobehavioral, biochemical, and histopathological studies were performed from the last week of the study period. The mRNA expression of different pathological biomarkers was estimated by RT-qPCR analysis. The results of the study suggested that CRE and TC significantly improved the behavioral, biochemical parameters and acetylcholinesterase inhibitory activity in treatment groups. Histological analysis was also carried out indicating that the neurodegenerative changes and neuronal loss were stabilized by CRE and TC supplementation. CRE and TC supplementation remarkably downregulated the interleukin-1α, tumor necrosis factor-α, interleukin-1β, acetylcholinesterase, and β-secretase pathological gene expression. Hence, it was concluded that CRE and TC may act as promising candidates in the prevention of AD via numerous underlying signaling pathways.

Synergistic interactions between artocarpin-rich extract, lawsone methyl ether and ampicillin on anti-MRSA and their antibiofilm formation

Artocarpin-rich extract (ARE) was prepared using a green technology and standardized to contain 49.6% w/w artocarpin, while lawsone methyl ether was prepared using a green semi-synthesis. ARE, LME and ampicillin exhibited weak anti-MRSA activity with the MICs of 31.2-62.5 µg/mL. Based on the checkerboard assay, the synergistic interaction between ARE (0.03 µg/mL) and LME (0.49 µg/mL) against four MRSA isolates were observed with the fractional inhibitory concentration index (FICI) value of 0.008, while those of ARE (1.95-7.81 µg/mL) and ampicillin (0.49 µg/mL) as well as LME (0.49-1.95 µg/mL) and ampicillin (0.49 µg/mL) were 0.016-0.257. The time kill confirmed the synergistic interactions against MRSA with different degrees. The combination of ARE and LME as well as its combinations with ampicillin altered the membrane permeability of MRSA, which led to release of the intracellular materials. In addition, each compound inhibited the biofilm formation of standard MRSA (DMST 20654) and the clinical isolate (MRSA 1096). These findings suggested that cocktails containing ARE and LME might be used to overcome problems associated with MRSA. Additionally, the results implied that combination of either ARE or LME with available conventional antibiotic agents might be effective in countering these perilous pathogens.

Enhancing the water-solubility of curcuminoids-rich extract using a ternary inclusion complex system: Preparation, characterization, and anti-cancer activity

Curcuminoids are known to exert diverse pharmacological effects and used in some pharmaceutical formulations. This study describes the preparation, characterization, and enhancement in the solubility and anticancer activity of a curcuminoids-rich extract (CRE) using a ternary inclusion complex system. CRE containing 88.9% w/w curcuminoids was prepared using a 'green' microwave extraction coupled with fractionation on a column of hydrophobic adsorbent resin. The ternary complex consisting of CRE, hydroxylpropyl-β-cyclodextrin and polyvinylpyrrolidone K30 was prepared using the solvent evaporation method and thoroughly characterized using Fourier-transform infrared spectroscopy, powder X-ray diffractograms, differential scanning calorimetry and scanning electron microscopy. The ternary complex of CRE improved the water-solubility of curcuminoids (up to 70.3 µg/mL) as well as the dissolution rate when compared to those of CRE (0 µg/mL). In addition, the ternary complex exhibited significantly stronger anticancer activity against human lung adenocarcinoma (A-549), human cervical adenocarcinoma (HeLa) and human colon adenocarcinoma (HT-29) cell lines than CRE.

Mulberry leaf polysaccharides ameliorate obesity through activation of brown adipose tissue and modulation of the gut microbiota in high-fat diet fed mice

Improving energy homeostasis and the gut microbiota is a promising strategy to improve obesity and related metabolic disorders. Mulberry leaf is one of the traditional Chinese medicines and functional diets. In this work, a mouse model induced by high-fat diet (HFD) was used to reveal the role of mulberry leaf polysaccharides (MLP). It was found that MLP had a significant effect in limiting body weight gain (reduced by 19.95%, 35.47% and 52.46%, respectively), ameliorating hepatic steatosis and regulating lipid metabolism in HFD induced obese mice (P < 0.05). RT-PCR and western blot analysis suggested that these metabolic improvements were mediated by inducing the development of brown-like adipocytes in inguinal white adipose tissue and enhancing brown adipose tissue activity. Besides, 16S rRNA sequencing results led to the inference that MLP could mitigate the composition and function of the gut microbiota. Together, these findings indicated that MLP possess great potential as a diet supplement or medication for obesity.

Chrysophyllum cainito. L alleviates diabetic and complications by playing antioxidant, antiglycation, hypoglycemic roles and the chemical profile analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Chrysophyllum cainito L. (C. cainito) is a traditional folk medicine in tropical area which can be an alternative agent for diabetes mellitus. Although the antioxidant and antidiabetic activity of the extracts are reported, little is known on the antiglycation activity and effects on diabetic complications.

AIM OF THE STUDY

This work was aimed to investigate the chemical profile, antidiabetic, antioxidant activities of C. cainito. Especially, the antiglycation potential as well as the relationships between components and activities were evaluated.

MATERIALS AND METHODS

The content of the primary components (polyphenols, flavonoids, steroids, and triterpenes), antioxidant, and hypoglycemic effects of ethanolic extracts from C. cainito leaves (CCE-1, 2, 3, 4) and stems (CSE-1, 2, 3, 4) were analyzed and detected. The chemical profiles of CCE-2 were characterized by HPLC-Q-TOF-MS/MS. The antiglycation and protection against oxidative stress effects were determined by in vitro assays. Relationship between bioactivities and components was analyzed by principal component analysis (PCA), heatmap analysis, and Pearson correlation analysis.

RESULTS

The composition was diverse between leaves and stem extracts with different activities. CCE-2 possessed the highest DPPH scavenging activity. CSE-2 displayed the highest ABTS scavenging activity and ferric reducing power. While CCE-3 showed the most effective inhibition on α-amylase and α-glucosidase activity (IC₅₀ 4.103 ± 0.332 μg/mL and 0.180 ± 0.006 mg/mL, respectively). PCA analysis showed that the most important variables in PC1 (60.7%) were total polyphenol and antioxidant activities. The hypoglycemic activity and contents of steroids showed important correlation. Advanced glycation end products formation was effectively inhibited by CCE-2 with myricetin 3-O-rhamnoside as the main constituent. CCE-3 displayed the highest protection effect against L02 cell line oxidation damage.

CONCLUSIONS

C. cainito leaves might be a promising candidate for antioxidant, hypoglycemic and antiglycation dietary supplement or potential agent against diabetes associated chronic diseases.

Computational study and in vitro alpha-glucosidase inhibitory effects of medicinal plants from a Thai folk remedy

The number of patients with type 2 diabetes mellitus (T2DM) has increased worldwide. Although an instant cure was achieved with the standard treatment acabose, unsatisfactory symptoms associated with cardiovascular disease after acabose administration have been reported. Therefore, it is important to explore new treatments. A Thai folk recipe has long been used for T2DM treatment, and it effectively decreases blood glucose. However, the mechanism of this recipe has never been proven. Therefore, the potential anti-T2DM effect of this recipe, which is used in Thai hospitals, was determined to involve alpha-glucosidase (AG) inhibition with a half maximal inhibitory concentration (IC50). In vitro experiments showed that crude Cinnamomum verum extract (IC50 = 0.35 ± 0.12 mg/mL) offered excellent inhibitory activity, followed by extracts from Tinospora crispa (IC50 = 0.69 ± 0.39 mg/mL), Stephania suberosa (IC50 = 1.50 ± 0.17 mg/mL), Andrographis paniculate (IC50 = 1.78 ± 0.35 mg/mL), and Thunbergia laurifolia (IC50 = 4.66 ± 0.27 mg/mL). However, the potencies of these extracts were lower than that of acabose (IC50 = 0.55 ± 0.11 mg/mL). Therefore, this study investigated and developed a formulation of this recipe using computational docking. Among 61 compounds, 7 effectively inhibited AG, including chlorogenic acid (IC50 = 819.07 pM) through 5 hydrogen bonds (HBs) and 2 hydrophobic interactions (HIs); β-sitosterol (IC50 = 4.46 nM, 6 HIs); ergosterol peroxide (IC50 = 4.18 nM, 6 HIs); borapetoside D (IC50 = 508.63 pM, 7 HBs and 2 HIs); borapetoside A (IC50 = 1.09 nM, 2 HBs and 2 His), stephasubimine (IC50 = 285.37 pM, 6 HIs); and stephasubine (IC50 = 1.09 nM, 3 HBs and 4 HIs). These compounds bind with high affinity to different binding pockets, leading to additive effects. Moreover, the pharmacokinetics of six of these seven compounds (except ergosterol peroxide) showed poor absorption in the gastrointestinal tract, which would allow for competitive binding to AG in the small intestine. These results indicate that the development of these 6 compounds into oral antidiabetic agents is promising.

Plant Natural Flavonoids Against Multidrug Resistant Pathogens

The increasing emergence and dissemination of multidrug resistant (MDR) bacterial pathogens accelerate the desires for new antibiotics. Natural products dominate the preferred chemical scaffolds for the discovery of antibacterial agents. Here, the potential of natural flavonoids from plants against MDR bacteria, is demonstrated. Structure-activity relationship analysis shows the prenylation modulates the activity of flavonoids and obtains two compounds, α-mangostin (AMG) and isobavachalcone (IBC). AMG and IBC not only display rapid bactericidal activity against Gram-positive bacteria, but also restore the susceptibility of colistin against Gram-negative pathogens. Mechanistic studies generally show such compounds bind to the phospholipids of bacterial membrane, and result in the dissipation of proton motive force and metabolic perturbations, through distinctive modes of action. The efficacy of AMG and IBC in four models associated with infection or contamination, is demonstrated. These results suggest that natural products of plants may be a promising and underappreciated reservoir to circumvent the existing antibiotic resistance.

Downregulation of miR-21 gene expression by CRE-Ter to modulate osteoclastogenesis: De Novo mechanism

miR-21 expression stimulates osteoclast cells in the context of osteoclastogenesis. A previous report showed that NFκB-miR-21 pathway could serve as an innovative alternative to devise therapeutics for healing diabetic ulcers. Furthermore, our study demonstrated that a highly water-soluble curcuminoids-rich extract (CRE-Ter) inhibits osteoclastogenesis through NFκB pathway. The interplay between miR-21 and CRE-Ter in osteoclastogenesis has not yet been investigated. In this study, we examined the relation of CRE-Ter and miR-21 gene expression in receptor of the nuclear factor κB (NFκB) ligand (RANKL) - induced murine monocyte/macrophage RAW 264.7 cells, osteoclast cells, in osteoclastogenesis. Effect of CRE-Ter on generation of intracellular reactive oxygen species (ROS) was estimated by dichlorofluorescein diacetate (DCFH-DA). The results reveal that CRE-Ter reduced expression levels of miR-21 gene in osteoclasts. The inhibitory effects of CRE-Ter on in vitro osteoclastogenesis were evaluated by reduction in tartrate-resistant acid phosphatase (TRAP) content, and by reduction in expression levels of an osteoclast-specific gene, cathepsin K. Treatment of the osteoclast cells with CRE-Ter suppressed RANKL-induced NFκB activation including phospho-NFκB-p65, and phospho IκBα proteins. Western blot analysis revealed that NFκB inhibitor up-regulated CRE-Ter-promoted expression of phospho-NFκB-p65. In addition, CRE-Ter dose-dependently inhibited phospho-Akt expression. CRE-Ter also dose-dependently reduced DNA binding activity of NFκB and Akt as revealed by EMSA. ChIP assay revealed binding of NFκB-p65 to miR-21 promoters. In conclusion, our results demonstrate that CRE-Ter downregulates miR-21 gene expression in osteoclasts via a de novo mechanism, NFκB- Akt-miR-21 pathway.

Appraisal of anti-Parkinson activity of rhinacanthin-C in haloperidol-induced parkinsonism in mice: A mechanistic approach

This study aimed to appraise the anti-Parkinson's potential of rhinacanthin-C (RC). RC (5, 10, and 20 mg/kg) was orally administered for 25 days in albino mice to treat haloperidol-induced parkinsonism (1 mg/kg). RC significantly (p < .05) improved the motor symptoms in block, bar, rotarod, and balance beam walking tests in treated mice. RC reduced the cataleptic effect dose-dependently. The RC therapy notably (p < .001) enhanced reduced glutathione, catalase, and superoxide dismutase levels while decreased malondialdehyde and nitrite levels in the tissue homogenates of the treated mice. The RC therapy significantly (p < .01-.001) restored the dopamine, norepinephrine, and serotonin levels in the brain tissue of treated mice as co-evidenced from brain histology. RC did not adversely affect complete blood count, and liver and kidney function tests. Taken together, these results have shown that RC is effective in treating motor and non-motor symptoms of Parkinson's disease. PRACTICAL APPLICATIONS: Rhinacanthus nasutus is a medicinally rich plant that has folklore use in several ailments. The plant possessed multiple pharmacological activities due to the presence of naphthoquinones. The major compound of this plant rhinacanthin-C was used in the present study to evaluate it's anti-Parkinson's activity. The results provide scientific evidence of the anti-Parkinson's potential of rhinacanthin-C that support the use of R. nasutus leaves in the prevention and treatment of Parkinson's disorder.

A multifunctional CeO2@SiO2-PEG nanoparticle carrier for delivery of food derived proanthocyanidin and curcumin as effective antioxidant, neuroprotective and anticancer agent

The nanoparticle systems could effectively overcome the drug delivery challenges of food bioactive compounds. In this study, a novel and effective multifunctional PEG modified CeO₂@SiO₂ nanoparticle (CSP-NPs) system was successfully fabricated. Food derived proanthocyanidin (PAC) and curcumin (Cur) were loaded onto CSP-NPs and formed as PAC-NPs and Cur-NPs. Fourier transform Infrared spectra, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and dynamic light scattering were used to characterize the prepared NPs. CSP-NPs, PAC-NPs and Cur-NPs displayed spherical shape with about 35-45 nm size. The bioactivity analysis revealed that CSP-NPs system could effectively deliver PAC and Cur to exhibit strong antioxidant activity, potent neuroprotective effect against Aβ_1-42-mediated toxicity in PC-12 cells (recovered cell viability from 57.5% to 81.0% at the dose of 25 μg/mL) and effective antiproliferative effects on HepG2 and Hela cells. Besides, all prepared nanoparticles (0-100 µg/ml) used in this study showed no significant toxicity on cell models of antioxidative and neuroprotective activities, excepting for cancer cells, suggesting that these nanoparticles had the potential of being utilized in drug delivery. Therefore, CSP-NPs might be a promising delivery system for hydrophilic molecule proanthocyanidin and hydrophobic molecule curcumin against the oxidative damage, neurodegenerative diseases and cancer, which could facilitate the application of food derived nutrients in functional foods industry.

Characterization, antioxidant activities, and inhibition on α-glucosidase activity of corn silk polysaccharides obtained by different extraction methods

The polysaccharides (CSPw, CSPc, CSPa, and CSPu) were prepared by hot water extraction, acid-assisted extraction, alkaline-assisted extraction, and ultrasound-assisted extraction from corn silk, respectively. High performance gel permeation chromatography (HPGPC), fourier-transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) results indicated that the extraction methods had an obvious impact on the molecular weight, structure, and morphology of the CSPs. Among the four polysaccharides, CSPu showed the highest inhibitory α-glucosidase activity, which might be related to its smaller molecular weight. Furthermore, kinetics analyses revealed that CSPu had significant inhibition of α-glucosidase in a non-reversible and competitive manner. Fluorescence quenching analysis illustrated that the interaction mechanism of CSPu and α-glucosidase was claimed as a static quenching mechanism. Isothermal titration calorimetry (ITC) analysis showed that the main driving forces for the interaction of CSPu with α-glucosidase was hydrogen bonding and the binding interactions of them occurred spontaneously.

Synergistic effect on anti-methicillin-resistant Staphylococcus aureus among combinations of α-mangostin-rich extract, lawsone methyl ether and ampicillin

α-Mangostin-rich extract (AME) exhibited satisfactory inhibitory activities against all tested MRSA strains, with minimum inhibitory concentrations (MICs) of 7·8-31·25 µg ml^-1 , whereas lawsone methyl ether (LME) and ampicillin revealed weak antibacterial activity with MICs of 62·5-125 µg ml^-1 . However, the combination of AME and LME showed synergistic effects against all tested MRSA strains with fractional inhibitory concentration index (FICI) values of 0·008-0·009, while the combination of AME and ampicillin, as well as LME and ampicillin produced synergistic effects with FICIs of 0·016-0·257. A time-kill assay against MRSA (DMST 20654 strain) revealed a 6-log reduction in CFU per ml, which completely inhibited bacterial growth for the combinations of AME and LME, AME and ampicillin, and LME and ampicillin at a 8-h incubation, while those against MRSA (2468 strain) were at 10-h incubation. The combination of α-mangostin and LME as well as the combinations of each compound with ampicillin synergized the alteration of membrane permeability. In addition, α-mangostin, LME and ampicillin inhibited the biofilm formation of MRSA. These findings indicated that the combinations of AME and LME or each of them in combination with ampicillin had enhanced antibacterial activity against MRSA. Therefore, these compounds might be used as the antibacterial cocktails for treatment of MRSA.

Taraxacum officinale Wigg. Attenuates Inflammatory Responses in Murine Microglia through the Nrf2/HO-1 and NF-κB Signaling Pathways

As a long-established medicinal and edible homologous plant, Taraxacum officinale Wigg. is widely distributed in Asia, Europe, and other parts of the world. T. officinale is reported to exert a variety of biological and pharmacological activities, including anticancer, hepatoprotective, and anti-obesity effects. In this study, we evaluated the anti-inflammatory effects of ethanol extracts of T. officinale (A-TOW) by examining the suppression of proinflammatory mediators in LPS-stimulated BV2 and mouse hippocampus. Furthermore, A-TOW also inhibited the nuclear translocation of nuclear factor κB p65 caused by stimulation with LPS. In addition, A-TOW regulates heme oxygenase (HO)-1 expression through the nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) in BV2 cells. The effects of A-TOW on the over-expression of proinflammatory mediators were partially reversed by transfection of the cells with HO-1 siRNA. These findings suggest that the potent anti-inflammatory activity of T. officinale, possibly through the regulation of Nrf2/HO-1 and NF-κB signaling pathway.

Chamuangone from Garcinia cowa leaves inhibits cell proliferation and migration and induces cell apoptosis in human cervical cancer in vitro

OBJECTIVES

To examine the effects of chamuangone on human cancer cell proliferation, migration and apoptosis.

METHODS

An MTT assay was used to study the effect of chamuangone on human cervical carcinoma cell growth. An in-vitro scratch migration assay was used to investigate the activity of cell motility after chamuangone treatment. Chamuangone-induced cell apoptosis in HeLa cells was determined using the apoptotic assay kit. The inhibitory activities of chamuangone were examined by ADP-Glo™ kinase assay. The GOLD docking algorithm was used to demonstrate the mechanism against tyrosine kinase of EGFR.

KEY FINDINGS

Chamuangone showed a strong inhibitory cell proliferation of HeLa cells with IC₅₀ values of 3.59 µm and effectively inhibited HeLa cell migration. In addition, chamuangone exhibited the apoptotic cell death induction in a time and dose-dependent manner. Finally, chamuangone also was tested for EGFR-TK inhibition activity. The IC₅₀ value of chamuangone was 2.85 nm, whereas the IC₅₀ value of gefitinib was 15.10 nm.

CONCLUSIONS

The above results confirm the inhibitory effects of chamuangone on HeLa cell proliferation and cell migration. In addition, chamuangone also induces cell apoptosis in HeLa cells. These findings indicate that chamuangone is a compound that is a potential chemotherapeutic agent.

Rhinacanthins-rich extract and rhinacanthin C ameliorate oxidative stress and inflammation in streptozotocin-nicotinamide-induced diabetic nephropathy

In this present study, rhinacanthins-rich extract (RRE) and rhinacanthin C (RC) the main bioactive constituent of Rhinacanthus nasutus was investigated for their protective effect against diabetic nephropathy (DN). Diabetes was induced by administering nicotinamide (100 mg/kg, i.p.)/streptozotocin (60 mg/kg, i.p.) and diabetic rats were orally administered with RRE and RC for 4 weeks. RRE and RC significantly reduced the kidney index, renal oxidative stress markers, and pro-inflammatory cytokines. Furthermore, RRE and RC increased renal levels of glutathione, superoxide dismutase, catalase, and attenuated diabetic induced renal damages. In conclusion, RRE and RC confer protective effect against DN through the inhibition of oxidative stress and inflammation and could be a potential medicinal or nutritional supplement for the prevention of DN. PRACTICAL APPLICATIONS: Rhinacanthus nasutus is a medicinal plant that is extensively used in Thai traditional medicine as an antibacterial, antifungal, antidiabetic, and anti-inflammatory agent. The plant is rich in naphthoquinones, which confer it with several excellent bioactivities. The rich extract of the leaves was prepared with three major bioactive components and the extract was evaluated for its renoprotective effect in diabetic rats. The results from this study provides valuable pharmacological information that supports the use of the plant, especially the rich extract in the prevention and treatment of diabetes and diabetic complications.

Ellagic acid inhibits HIV-1 infection in vitro: Potential role as a novel microbicide

OBJECTIVE

To investigate the in vitro effects of ellagic acid on HIV-1 replication.

METHODS

Anti-HIV-1 activity of ellagic acid was determined in vitro using X4-tropic HIV-1_NPO3 and R5-tropic pBaL Env-recombinant virus. Anti-HIV-1_NPO3 activity of ellagic acid was investigated at a multiplicity of infection (MOI) of 0.01. Anti-HIV-1 integrase and protease activities of ellagic acid were tested using in vitro integration and proteolytic cleavage assays.

RESULTS

Ellagic acid, added either before or after HIV-1_NPO3 exposure, suppressed replication of the virus in C8166 cells up to 34%. Ellagic acid showed an anti-integrase IC₅₀ of 8.7 μM. No cytotoxicity of ellagic acid at concentrations ranging from 12.5 to 100 μM was observed.

CONCLUSION

We conclude that ellagic acid can inhibit HIV-1 infection without cytotoxicity. Thus, it may be a new effective agent that has potential to be developed as a novel microbicide against HIV-1.

Flavonoids of Artocarpus heterophyllus Lam. heartwood inhibit the innate immune responses of human phagocytes

Objectives

To investigate the effects of flavonoids isolated from Artocarpus heterophyllus. heartwood on chemotaxis, phagocytosis, reactive oxygen species (ROS) production and myeloperoxidase (MPO) activity of human phagocytes.

Methods

Chemotaxis was evaluated using a modified Boyden chamber and phagocytosis was determined by flowcytometer. Respiratory burst was investigated by luminol-based chemiluminescence assay while MPO activity was determined by colorimetric assay.

Key findings

Artocarpanone and artocarpin strongly inhibited all steps of phagocytosis. Artocarpanone and artocarpin showed strong chemotactic activity with IC50 values of 6.96 and 6.10 μm, respectively, which were lower than that of ibuprofen (7.37 μm). Artocarpanone was the most potent compound in inhibiting ROS production of polymorphonuclear leucocytes and monocytes with IC50 values comparable to those of aspirin. Artocarpin at 100 μg/ml inhibited phagocytosis of opsonized bacteria (28.3%). It also strongly inhibited MPO release with an IC50 value (23.3 μm) lower than that of indomethacin (69 μm). Structure–activity analysis indicated that the number of hydroxyl group, the presence of prenyl group and variation of C-2 and C-3 bonds might contribute towards their phagocytosis.

Conclusions

Artocarpanone and artocarpin were able to suppress strongly the phagocytosis of human phagocytes at different steps and have potential to be developed into potent anti-inflammatory agents.

Rhinacanthins-rich Extract Enhances Glucose Uptake and Inhibits Adipogenesis in 3T3-L1 Adipocytes and L6 Myotubes

Background:

Obesity is one of the imperative dynamics in the incidence and intensification of type 2 diabetes mellitus (T2DM). Rhinacanthus nasutus leaf extracts are previously reported for their antidiabetic and antiobesity potential.

Objective:

The present study was performed to evaluate glucose uptake stimulatory and antiadipogenic activities of a standardized rhinacanthins-rich extract (RRE) and its marker compounds namely rhinacanthin-C (RC), rhinacanthin-D (RD), and rhinacanthin-N (RN) in 3T3-L1 and L6 cells.

Materials and Methods:

RRE was prepared by a green extraction process, and the marker compounds (RC, RD, and RN) were isolated from the RRE using a silica gel column chromatography. Glucose uptake stimulation in both 3T3-L1 and L6 cells was performed by quantification of residual glucose in the media using glucose oxidase kit. Antiadipogenic activity in 3T3-L1 adipocytes was performed by intracellular lipids quantification using oil red O dye.

Results:

At the highest effective dose, RRE (20 μg/mL) exhibited satisfactory glucose uptake stimulatory effect in 3T3-L1 adipocytes that equivalent to RN (20 μg/mL) and the positive control insulin (0.58 μg/mL) but higher than RC (20 μg/mL) and RD (20 μg/mL). In addition, treatments of L6 myotubes showed that RRE (2.5 μg/mL) exhibited potent and equivalent glucose uptake stimulation (>80%) to RC (2.5 μg/mL) and the standard drugs, insulin (2.90 μg/mL) and metformin (219.5 μg/mL), but higher than RD (2.5 μg/mL) and RN (2.5 μg/mL). Furthermore, RRE (20 μg/mL) exhibited potent antiadipogenic effect in 3T3-L1 adipocytes, which equivalent to RC (20 μg/mL) but higher than RD (20 μg/mL) and RN (20 μg/mL).

Conclusions:

The undertaken study suggests that RRE could be used as an effective remedy in the treatment of obesity-associated T2DM.

SUMMARY

Rhinacanthins-rich extract and its marker compounds showed potent glucose uptake stimulatory activity in 3T3-L1 adipocytes and L6 myotubes

Rhinacanthins-rich extract and rhinacanthin-C showed comparable antiadipogenic effect in 3T3-L1 adipocytes

RRE could be used as an effective remedy in the treatment of obesity-associated T2DM.

Abbreviations used: T2DM: Type-2 diabetes mellitus; RRE: Rhinacanthins-rich extract; RC: Rhinacanthin-C; RD: Rhinacanthin-D; RN: Rhinacanthin-N; α-MEM: α-Minimum essential medium; DMEM: Dulbecco's modified Eagle's medium; HS: Horse serum; FBS: Fetal bovine serum; BSA: Bovine serum albumin; IBMX: 3-isobutyl-1-methylxanthine; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; GO: Glucose oxidase; NMR: Nuclear magnetic resonance; HPLC: High-performance liquid chromatography.

Superoxide Scavenging and Antiglycation Activity of Rhinacanthins-rich Extract Obtained from the Leaves of Rhinacanthus nasutus

Background:

Oxidative stress and nonenzymatic protein glycation lead to serious diabetic complications that increase the risk of mortality. Rhinacanthus nasutus leaf crude extracts are previously reported for their antidiabetic, antiglycation, and antioxidant potential.

Objective:

The present study was performed to prepare a standardized rhinacanthins-rich extract (RRE) and evaluate its superoxide scavenging and antiglycation effects as compared to its marker compounds, namely, rhinacanthin-C (RC), rhinacanthin-D (RD), and rhinacanthin-N (RN).

Materials and Methods:

RRE was obtained by microwave-assisted green extraction along with a simple step of fractionation using Amberlite^® column. RC, RD, and RN were isolated from the RRE using silica gel column chromatography. Superoxide scavenging activity was performed by cyclic voltammetry, and fructose-mediated human serum albumin glycation model was used for antiglycation activity. In silico studies were conducted to identify the structure-activity relationships of rhinacanthins.

Results:

On the basis of kinetic measurements, RRE exhibited the most potent antioxidant activity via E_rC_i mechanism, with a 50% inhibitory concentration (IC₅₀) value of 8.0 μg/mL, antioxidant capacity of 39439 M⁻¹, and binding constant of 45709 M⁻¹. Antiglycation assay showed that RRE exhibited almost equivalent glycation inhibitory effect to that of RC, with IC₅₀ values of 39.7 and 37.3 μg/mL, respectively, but higher than that of RD (IC₅₀ of 50.4 μg/mL), RN (IC₅₀ of 89.5 μg/mL), as well as the positive control, rutin (IC₅₀ of 41.5 μg/mL).

Conclusions:

The potent superoxide scavenging and albumin glycation inhibitory effect of RRE rationalized its therapeutic application in various chronic diseases, especially in the complications of diabetes.

SUMMARY

Rhinacanthins-rich extract (RRE) exhibited potent superoxide scavenging activity

RRE and rhinacanthin-C showed remarkable and comparable antiglycation effect

Rhinacanthins exhibited antiglycation activity by masking specific residues of albumin.

Abbreviations used: RRE: Rhinacanthins-rich extract; RC: Rhinacanthin-C; RD: Rhinacanthin-D; RN: Rhinacanthin-N; IC₅₀: 50% inhibitory concentration; Kao: Antioxidant activity coefficient; Kb: Binding constant; E_rC_i: Reversible electron transfer followed by an irreversible chemical reaction; DM: Diabetes mellitus; AGEPs: Advanced glycation end products; NMR: Nuclear magnetic resonance; HPLC: High-performance liquid chromatography; CV: Cyclic voltammetry; DMSO: Dimethyl sulfoxide; Ipa: Anodic peak current; Ipc: Cathodic peak current; HSA: Human serum albumin; MOE: Molecular operating environment; PASSonline: Online prediction of activity spectra for substances.

A synergistic effect of artocarpanone from Artocarpus heterophyllus L. (Moraceae) on the antibacterial activity of selected antibiotics and cell membrane permeability

Aim/Backgrounds:

Artocarpanone isolated from Artocarpus heterophyllus L. (Moraceae) exhibits antibacterial activity. The present study investigated synergistic activity between artocarpanone and tetracycline, ampicillin, and norfloxacin, respectively, against methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Escherichia coli.

Materials and Methods:

A broth microdilution method was used for evaluating antibacterial susceptibility. Synergistic effects were identified using a checkerboard method, and a bacterial cell membrane disruption was investigated by assay of released 260 nm absorbing materials following bacteriolysis.

Results and Discussion:

Artocarpanone exhibited weak antibacterial activity against MRSA and P. aeruginosa with minimum inhibitory concentrations values of 125 and 500 μg/mL, respectively. However, the compound showed strong antibacterial activity against E. coli (7.8 μg/mL). The interaction between artocarpanone and all tested antibiotics revealed indifference and additive effects against P. aeruginosa and E. coli (fractional inhibitory concentration index [FICI] values of 0.75-1.25). The combination of artocarpanone (31.2 μg/mL) and norfloxacin (3.9 μg/mL) resulted in synergistic antibacterial activity against MRSA, with an FICI of 0.28, while the interaction between artocarpanone and tetracycline, and ampicillin showed an additive effect, with an FICI value of 0.5. A time-kill assay also indicated that artocarpanone had a synergistic effect on the antibacterial activity of norfloxacin. In addition, the combination of artocarpanone and norfloxacin altered the membrane permeability of MRSA.

Conclusion:

These findings suggest that artocarpanone may be used to enhance the antibacterial activity of norfloxacin against MRSA.

A New Antibacterial Tetrahydronaphthalene Lignanamide, Foveolatamide, from the Stems of Ficusfoveolata

An antibacterial assay-guided isolation of the crude ethyl acetate extract from Ficus foveolata stems afforded four compounds, including a tetrahydronaphthalene lignanamide, foveolatamide (1), together with two known lignanamides, flavifloramide B (2) and N-trans-grossamide (3), and a known phenolic amide, N-trans-feruloyltyramine (4). The structures of these compounds were established on the basis of NMR spectroscopic and MS techniques. Among the isolated compounds, only 1 showed satisfactory antibacterial activities against Streptococcus pyogenes, with an MIC and MBC value of 45 µM. This is the first report of these four compounds from the stems of F. foveolata.

Bioassay-guided isolation and evaluation of antimicrobial compounds from Ixora megalophylla against some oral pathogens

Context Ixora megalophylla Chamch. (Rubiaceae) is a new plant species recently found in southern Thailand. Ethyl acetate extracts of its leaves and stems showed antimicrobial activities. Objectives To isolate and identify the antimicrobial compounds from I. megalophylla leaves and stems. Materials and methods The dried leaves (1.7 kg) and stems (3.5 kg) were consecutively extracted with petroleum ether (5 L × 4), ethyl acetate (5 L × 3) and ethanol (5 L × 4) under reflux conditions. The ethyl acetate extract was subjected to an antimicrobial assay guided isolation with Candida albicans and Streptococcus mutans. Compounds 1-10 were identified by (1)H NMR, (13)C NMR and EI-MS. Minimal lethal concentration (MLC) against C. albicans and Streptococcus spp. was determined using a broth microdilution method for 48 and 24 h, respectively. Results and discussion On the basis of the antimicrobial assay guided isolation, 10 known compounds, including vanillic acid (1), syringic acid (2), 4-hydroxy benzaldehyde (3), scopoletin (4), loliolide (5), syringaldehyde (6), sinapaldehyde (7), coniferaldehyde (8), syringaresinol (9) and 2,2'-dithiodipyridine (10), were identified. Compounds 1-5 were purified from the ethyl acetate extract of the leaves, while 6-9 and 10 were from the ethyl acetate and ethanol extracts of the stems, respectively. Among these isolates, 10 showed the strongest antibacterial activities against S. mutans and Streptococcus mitis, with minimum inhibitory concentrations (MICs) of 2-4 μg/mL, and MLC of 4 μg/mL, as well as having a weak antifungal activity against C. albicans (MIC of 125 μg/mL). This is the first report of the antimicrobial activities of 10.