Biochemical basis of the antidiabetic activity of oleanolic acid and related pentacyclic triterpenes

A quick paster type of soluble nanoparticle microneedle patch for the treatment of obesity

Obesity is a major public burden on the working population and induces chronic diseases. Its treatment often requires long-term medication, which makes patient compliance difficult. In this study, we reported the value of HORN-MN, which comprised a fast-soluble hyaluronic acid microneedle matrix and a weak acid-degradable oleanolic acid dimer of rosiglitazone nanoparticles. The results showed that the microneedles easily punctured the stratum corneum and dissolved in the dermis of the abdominal wall within 5 min, followed by the release of rosiglitazone nanoparticles. Thereafter, the nanoparticles were endocytosed by macrophages and white adipocytes, then degraded to oleanolic acid in the lysosomes, thereby, releasing rosiglitazone. Oleanolic acid significantly improved the inflammatory status of obese adipose tissue and promoted white adipocyte browning, and rosiglitazone significantly potentiated WAC browning. Accordingly, the patch demonstrated a remarkable obesity-reducing efficacy in mice. In conclusion, this study developed a quick paster type of soluble rosiglitazone nanoparticle microneedle for the treatment of obesity. This patch can be suitable for working people, with an evident obesity-reducing efficacy but no effect on skin integrity despite multiple administrations.

Synthesis, Anti-Oomycete and Anti-Fungal Activities of Anhydride Derivatives of Oleanolic Acid

Oleanolic acid is a pentacyclic triterpenoid extracted and isolated from the fruit of plants in the Ligustrum lucidum Ait. in the family Oleaceae. To discover biorational natural product-based pesticides, a series of oleanolic acid derivatives containing anhydride active skeletons were prepared by ingeniously introducing an active acyloxy group at its C-28 carboxyl position, and their structures were well characterized by 1H-NMR, 13C NMR, HRMS, and m.p. The stereochemical configuration of compound 8 e was confirmed using single-crystal X-ray diffraction. Furthermore, bioactivities of these compounds as anti-oomycete and anti-fungal agents against two serious agricultural pests, Phytophthora capsici (P. capsici) and Fusarium graminearum (F. graminearum) we assessed. Amongst evaluated compounds, 1) Compounds 8 h and 8 j displayed significant anti-oomycete against P. capsici, with EC50 values of 54.73 and 65.15 mg/L, respectively. 2) The target compounds have obvious selectivity, and their anti-oomycete activity is significantly better than their anti-fungal activity. 3) Interestingly, there are significant differences in the structure-activity relationship of different substituents or the same substituent at different positions anti-oomycete and anti-fungal against P. capsici and F. graminearum, respectively. The study provides an idea for further exploring the bioactivities of 28-acyloxyoleanolic acid derivatives, and develops the application of 28-acyloxyoleanolic acid derivatives containing anhydride in agriculture.

3D-Printed Bifunctional Scaffold for Treatment of Critical Bone Defects Based on Osteoimmune Microenvironment Regulation and Osteogenetic Effects

The critical-sized bone defect resulting from trauma, tumor resection, and congenital deformity fails to undergo spontaneous healing due to its substantial size, while the ensuing inflammatory process and hypoxic environment further impede the regenerative process. Therefore, it has consistently presented a significant clinical challenge. In the present study, we incorporate a glycyrrhizic acid (GA)-functionalized hydrogel onto the surface of a Hydroxyapatite (Hap)-modified Polycaprolactone (PCL) scaffold to fabricate a composite scaffold. The composed scaffold showed favorable anti-inflammatory and antioxidative capabilities by modulating macrophage polarization and scavenging reactive oxygen species (ROS); the modification of Hap enhanced its osteogenic ability. An in vivo rat skull defect model confirmed that the composed scaffold efficiently promotes bone regeneration. In general, the composed scaffold with the ability of osteoimmune microenvironment regulation can effectively repair critical-sized bone defects. This strategy provides a promising method for the reconstruction of large segmental bone defects.

Phytochemical Composition and Functional Properties of Brassicaceae Microgreens: Impact of In Vitro Digestion

The aim of this study was to compare the concentration of phenolic compounds, glucosinolates, proteins, sugars and vitamin C between kohlrabi (Brassica oleracea var. acephala gongylodes), Savoy cabbage (B. oleracea sabauda), Brussels sprouts (B. oleracea gemmifera), cauliflower (B. oleracea botrytis), radish (Raphanus sativus) and garden cress (Lepidium sativum) microgreens for their antioxidant and hypoglycemic potential. In addition, we applied an in vitro-simulated system of human digestion in order to track the bioaccessibility of the selected phenolic representatives, and the stability of the microgreens' antioxidant and hypoglycemic potential in terms of α-amylase and α-glucosidase inhibition after each digestion phase. Using spectrophotometric and RP-HPLC methods with statistical analyses, we found that garden cress had the lowest soluble sugar content, while Savoy cabbage and Brussels sprouts had the highest glucosinolate levels (76.21 ± 4.17 mg SinE/g dm and 77.73 ± 3.33 mg SinE/g dm, respectively). Brussels sprouts were the most effective at inhibiting protein glycation (37.98 ± 2.30% inhibition). A very high positive correlation (r = 0.830) between antiglycation potential and conjugated sinapic acid was recorded. For the first time, the antidiabetic potential of microgreens after in vitro digestion was studied. Kohlrabi microgreens best inhibited α-amylase in both initial and intestinal digestion (60.51 ± 3.65% inhibition and 62.96 ± 3.39% inhibition, respectively), and also showed the strongest inhibition of α-glucosidase post-digestion (19.22 ± 0.08% inhibition). Brussels sprouts, cauliflower, and radish had less stable α-glucosidase than α-amylase inhibitors during digestion. Kohlrabi, Savoy cabbage, and garden cress retained inhibition of both enzymes after digestion. Kohlrabi antioxidant capacity remained unchanged after digestion. The greatest variability was seen in the original samples, while the intestinal phase resulted in the most convergence, indicating that digestion reduced differences between the samples. In conclusion, this study highlights the potential of various microgreens as sources of bioactive compounds with antidiabetic and antiglycation properties. Notably, kohlrabi microgreens demonstrated significant enzyme inhibition after digestion, suggesting their promise in managing carbohydrate metabolism and supporting metabolic health.

Polyvinyl alcohol-chitosan based oleanolic acid nanofibers against bacterial infection: In vitro studies and in vivo evaluation by optical and laser Doppler imaging modalities

The present work focuses on the fabrication of polyvinyl alcohol-chitosan-loaded oleanolic acid-nanofibers (PVA-CS-OLA-NFs) for bacterial infection. The prepared PVA-CS-OLA-NFs were characterized for contact angle, SEM, AFM, XRD, FTIR, and TGA. The solid-state characterization and in vitro performance evaluation of nanofibers reveal consistent interconnection and diameters ranging from 102 ± 9.5 to 386 ± 11.6 nm. The nanofibers have a flat surface topography and exhibit efficient drug entrapment. Moreover, the in vitro release profile of PVA-CS-OLA-NFs was found to be 51.82 ± 1.49 % at 24 h. Furthermore, the hemocompatibility study showed that the developed PVA-CS-OLA-NFs are non-hemolytic to human blood. The PVA-CS-OLA-NFs demonstrate remarkable antibacterial capabilities, as evidenced by their MBC and MIC values, which range from 128 and 32 μg/mL, against the strains of S. aureus. The in-vivo fluorescence optical imaging showed the sustained PVA-CS-OLA-NFs release at the wound site infected with S. aureus for a longer duration of time. Moreover, the PVA-CS-OLA-NFs showed superior wound healing performance against S. aureus infected wounds compared to the marketed formulation. Further, the laser Doppler imaging system improved oxygen saturation, blood supply, and wound healing by providing real-time blood flow and oxygen saturation information.

Cardioprotective potential of oleuropein, hydroxytyrosol, oleocanthal and their combination: Unravelling complementary effects on acute myocardial infarction and metabolic syndrome

Clinical studies have previously established the role of olive products in cardiovascular disease (CVD) prevention, whilst the identification of the responsible constituents for the beneficial effects is still pending. We sought to assess and compare the cardioprotective potential of oleuropein (OL), hydroxytyrosol (HT), oleocanthal (OC) and oleanolic Acid (OA), regarding Ischemia/Reperfusion Injury (IRI) and CVD risk factors alleviation. The scope of the study was to design a potent and safe combinatorial therapy for high-cardiovascular-risk patients on a bench-to-bedside approach. We evaluated the IRI-limiting potential of 6-weeks treatment with OL, HT, OC or OA at nutritional doses, in healthy and metabolic syndrome (MS)-burdened mice. Three combinatorial regimens were designed and the mixture with preponderant benefits (OL-HT-OC, Combo 2), including infarct sparing and antiglycemic potency, compared to the isolated compounds, was further investigated for its anti-atherosclerotic effects. In vivo experiments revealed that the combination regimen of Combo 2 presented the most favorable effects in limiting infarct size and hyperglycemia, which was selected to be further investigated in the clinical setting in Chronic Coronary Artery Syndrome (CCAS) patients. Cardiac function, inflammation markers and oxidative stress were assessed at baseline and after 4 weeks of treatment with the OL-HT-OC supplement in the clinical study. We found that OL, OC and OA significantly reduced infarct size in vivo compared to Controls. OL exhibited antihyperglycemic properties and OA attenuated hypercholesterolemia. OL-HT-OA, OL-HT-OC and OL-HT-OC-OA combination regimens were cardioprotective, whereas only OL-HT-OC mitigated hyperglycemia. Combo 2 cardioprotection was attributed to apoptosis suppression, enhanced antioxidant effects and upregulation of antioxidant enzymes. Additionally, it reduced atherosclerotic plaque extent in vivo. OL-HT-OC supplement ameliorated cardiac, vascular and endothelial function in the small-scale clinical study. Conclusively, OL-HT-OC combination therapy exerts potent cardioprotective, antihyperglycemic and anti-atherosclerotic properties in vivo, with remarkable and clinically translatable cardiovascular benefits in high-risk patients.

In Vitro and In Silico Analysis of PTP1B Inhibitors from Cleistocalyx operculatus Leaves and Their Effect on Glucose Uptake

As part of our ongoing research on new anti-diabetic compounds from ethnopharmacologically consumed plants, two previously undescribed lupane-type triterpenoids (1 and 2) with dicarboxylic groups, an undescribed nor-taraxastane-type triterpenoid (3), and 14 known compounds (4-17) were isolated from the leaves of Cleistocalyx operculatus. Extensive spectroscopic analysis (IR, HRESIMS, 1D, and 2D NMR) was used for structure elucidation, while the known compounds were compared to reference data reported in the scientific literature. All the isolates (1-17) were evaluated for their inhibitory effects on the protein tyrosine phosphatase 1B (PTP1B) enzyme. Compounds 6, 9, and 17 showed strong PTP1B inhibitory activities. The mechanism of PTP1B inhibition was studied through enzyme kinetic experiments. A non-competitive mechanism of inhibition was determined using Lineweaver-Burk plots for compounds 6, 9, and 17. Additionally, Dixon plots were employed to determine the inhibition constant. Further insights were gained through a structure-activity relationship study and molecular docking analysis of isolated compounds with the PTP1B crystal structure. Moreover, all isolates (1-17) were tested for their stimulatory effects on the uptake of 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl) amino]-D-glucose (2-NBDG) in differentiated 3T3-L1 adipocyte cells. Compounds 6, 13, and 17 exhibited strong glucose absorption stimulation activity in a dose-dependent manner.

Betulinic acid improves TNF-α-induced insulin resistance by inhibiting negative regulator of insulin signalling and inflammation-activated protein kinase in 3T3-L1 adipocytes

CONTEXT

Obesity is related to insulin resistance, and adipose tissue-secreted TNF-α may play a role in inducing obesity. TNF-α activates inflammatory protein kinase and impairs insulin signalling.

OBJECTIVES

We investigated the effect of betulinic acid on insulin resistance caused by TNF-α treatment in 3T3-L1 adipocytes.

MATERIAL AND METHODS

3T3-L1 was exposed to TNF-α in the presence and absence of betulinic acid. Various parameters such as glucose uptake assay, cell viability, expression of proteins involved in insulin resistance were studied.

RESULTS

Betulinic acid increased glucose uptake in TNF-α pre-treated cells and inhibited the activation of PTP1B and JNK and reduced IκBα degradation. Tyrosine phosphorylation was increased, and serine phosphorylation was decreased in IRS-1.

DISCUSSION

Betulinic acid restored TNF-α impaired insulin signalling and increased PI3K activation and phosphorylation of Akt and increased plasma membrane expression of GLUT 4, which stimulated glucose uptake concentration-dependently.

CONCLUSION

These results suggest that betulinic acid is effective at improving TNF-α-induced insulin resistance in adipocytes via inhibiting the activation of negative regulator of insulin signalling and inflammation-activated protein kinase and may potentially improve insulin resistance.

Hoslundia opposita vahl; a potential source of bioactive compounds with antioxidant and antibiofilm activity for wound healing

BACKGROUND

Biofilms and oxidative stress retard wound healing. The resistance of biofilms to antibiotics has led to a search for alternative approaches in biofilm elimination. Antioxidants work synergistically with antibacterial agents against biofilms. Hence recent research has suggested plants as candidates in the development of new alternatives in biofilm treatments and as antioxidants due to the presence of phytocompounds which are responsible for their bioactivities. Hoslundia opposita Vahl is one of the plants used by traditional healers to treat wounds and other infections, this makes it a potential candidate for drug discovery hence, in this study, we investigate the antibiofilm and antioxidant activity of methanolic extract of hoslundia opposita Vahl from Uganda. We also identify phytochemicals responsible for its bioactivity.

METHOD

the plant was extracted by maceration using methanol, and the extract was investigated for antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. The antibiofilm activity using microtiter plate assay (MTP) assay where the Minimum biofilm inhibitory concentration required to inhibit 50% or 90% of the biofilm (MBIC50 and MBIC90) and Minimum biofilm eradication concentration required to remove 50% or 90% of the biofilm (MBEC50 and MBEC90) were measured. It was further analysed for its phytochemical composition using quantitative screening, as well as Gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography mass-spectrometry (LC-MS).

RESULTS

H. Opposita Vahl extract showed good antioxidant activity with of 249.6 mg/mL. It inhibited the growth of P. aeruginosa and S. aureus biofilms with MBIC50 of 28.37 mg/mL and 10 mg/mL, respectively. It showed the ability to eradicate P. aeruginosa and S. aureus biofilms with MBEC50 of 23.85 and 39.01 mg/mL respectively. Phytochemical analysis revealed the presence of alkaloids, tannins, flavonoids, and phenols. GC-MS analysis revealed 122 compounds in the extract of which, 23 have evidence of antioxidant or antibiofilm activity in literature. The most abundant compounds were; 1,4- Citric acid, Tetracontane-1,40-diol (43.43.3%, 1, Olean-12-en-28-oic acid, 3-hydroxy-, methyl ester, (3.beta) (15.36%) 9-Octadecenamide (12.50%), Squalene (11.85%) Palmitic Acid 4TMS (11.28%), and alpha Amyrin (11.27%). The LC-MS identified 115 and 57 compounds in multiple reaction mode (MRM) and scan modes respectively.

CONCLUSION

H. opposita Vahl showed antibiofilm and antioxidant activity due to bioactive compounds identified, hence the study justifies its use for wound healing. It can be utilised in further development of new drugs as antibiofilm and antioxidants.

Cardioprotective role of oleanolic acid in patients with type 2 diabetes mellitus

Background

Patients with type 2 diabetes mellitus (T2DM) experience a decline in cardiac function, resulting in poor prognosis. Therefore, restoration of cardiac function and improvement of myocardial fibrosis is an important treatment goal for patients with T2DM.

Material and methods

The chemical structure of oleanolic acid(OA) was downloaded from PubChem and uploaded to PharmMapper. GeneCards and OMIM databases were searched for genes related to OA and disease and plotted into a Venn diagram. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed using R software. Then, a mouse model of diabetes mellitus was established, and ELISA, echocardiographic analysis of cardiac function, TUNEL assay, and reactive oxygen species assay were performed.

Results

Network pharmacology analysis identified the related targets and potential molecular mechanisms underlying the effects of OA in T2DM. ELISA, echocardiographic analysis of cardiac function, and TUNEL assay results showed that OA inhibits apoptosis and improves apoptotic indexes in mice with T2DM-induced myocardial injury.

Conclusion

The results demonstrate the myocardial protective effect of OA in this mouse model.

Multiple nanotechnological approaches using natural compounds for diabetes management

Objectives

Diabetes mellitus (DM) is a long-standing and non-transmissible endocrine disease that generates significant clinical issues and currently affects approximately 400 million people worldwide. The aim of the present review was to analyze the most relevant and recent studies that focused on the potential application of plant extracts and phytocompounds in nanotechnology for the treatment of T2DM.

Methods

Various databases were examined, including Springer Link, Google Scholar, PubMed, Wiley Online Library, and Science Direct. The search focused on discovering the potential application of nanoparticulate technologies in enhancing drug delivery of phytocompounds for the mentioned condition.

Results

Several drug delivery systems have been considered, that aimed to reduce adverse effects, while enhancing the efficiency of oral antidiabetic medications. Plant-based nanoformulations have been highlighted as an innovative approach for DM treatment due to their eco-friendly and cost-effective synthesis methods. Their benefits include targeted action, enhanced availability, stability, and reduced dosage frequency.

Conclusions

Nanomedicine has opened new opportunities for the diagnosis, treatment, and prevention of DM. The use of nanomaterials has demonstrated improved outcomes for both T1DM and T2DM. Notably, flavonoids, including substances such as quercetin, naringenin and myricitrin, have been recognized for their enhanced efficacy when delivered through novel nanotechnologies in preventing T2DM onset and associated complications. The perspectives on the addressed subject point to the development of more nanostructured phytocompounds with improved bioavailability and therapeutic efficacy.

Efficacy of Pistacia lentiscus Plant (Rumi Mastagi) in Comparison to Levosulpiride in Patients with Diabetic Gastroparesis: A Double-Blind Non-Inferior Randomised Control Trial Study

Introduction

Gastrointestinal neuropathies are frequently found in diabetic patients. The pathogenesis of diabetic gastroparesis (DG) is multifactorial. The usual treatment for DG includes dietary modifications, prokinetic and antiemetic agents. There is increasing demand for more effective medicines to treat DG. The current study was conducted on the Pistacia lentiscus stem extract to add to the armamentarium of DG treatment and to find the efficacy of P. lentiscus plant extract (mastic gum) in comparison to levosulpiride in DG for improvement in gastroparesis symptoms and gastric emptying scintigraphy (GES) in a single centric double-blind non-inferiority randomised control trial.

Methods

Thirty-eight individuals were recruited and equally randomised into two study groups based on Gastroparesis Cardinal Symptom Index (GCSI) score and TC99 Radionuclide GES, mastic gum group and levosulpiride group. Both pre and post-intervention (8 weeks) GCSI scores were calculated, GES was performed to quantify the improvement in gastric emptying. Power analysis was performed using G*POWER software version 3.1.9.7 and data analysis using SPSS 23.0, variables measured in mean ± standard deviation (SD). Various statistical tests were used such as independent t-test, Chi-square test or Fisher's exact test, Wilcox Mann-Whitney test, analysis of variance (ANOVA) test, and posthoc pairwise tests.

Results

The mastic gum is found effective in the improvement of 4 h gastric emptying percentage from the mean (SD) 76.60 (± 9.96) to mean (SD) 97.20 (2.17)% (P < 0.001). Mastic gum has the property of HbA1c reduction, which is more significant than that of levosulpiride (P = 0.044). Mastic gum also had significant Low density lipoprotein (LDL) (mg/dL) levels reduction, (P < 0.001), compared to levosupiride. An absolute increase was observed in haemoglobin (HB) level in mastic gum at a 2-month mean (SD) of 1.03 (0.77) (g/dL) (P-value <0.001).

Conclusions

To our knowledge, this is the first study to compare the effect of levosulpiride with mastic gum concerning improvement in diabetic gastroparesis (DG) using GES. In the study, mastic gum was found to have great properties to improve DG with many important pleiotropic effects.

Real-world safety and effectiveness of Pistacia lentiscus (mastic gum) in patients with diabetic gastroparesis: 24-week interim analysis postintervention

INTRODUCTION

Gastrointestinal neuropathies are frequently found in diabetic patients.

AIM

The aim of this study was to find out the safety, adverse reactions, and long-term effectiveness of Pistacia lentiscus plant extract (mastic gum) in diabetic gastroparesis (DG) with respect to sustainable improvement in gastroparesis symptoms (Gastrointestinal Cardinal Symptom Index [GCSI] score) by observational follow-up study of a single-centric double-blind noninferiority randomized control trial.

MATERIALS AND METHODS

Thirty-eight individuals were recruited and equally randomized in two study groups based on GCSI score and TC99 radionuclide gastric emptying scintigraphy (GES), i.e. the mastic gum group and the levosulpiride group. After 24 weeks, the GCSI score was recalculated in both the groups, and patients were evaluated for the safety, adverse reactions, and long-term effectiveness of mastic gum and the standard drug levosulpiride.

RESULTS

In the extended study, mean GCSI score changes at 24 weeks were statistically significant (P < 0.001) (t-test) between the two groups. In the mastic gum arm, the change in mean GCSI score at 24 weeks was statistically nonsignificant mean ± (standard deviation [SD]) 16.7± (3.81) compared to the GCSI score at 2-month postintervention mean (SD) 16.35± (2.27) (intragroup P = 0.89) (repeated measures ANOVA). It strongly indicates that mastic gum provided a sustainable improvement in DG symptoms in comparison to levosulpiride, with excellent subjective well-being postintervention, without any obvious significant adverse effects.

CONCLUSION

Six-month (24-week) interim analysis of patients suggests that mastic gum gives a sustainable improvement in DG symptoms without any obvious adverse effects as compared to levosulpiride.

Identification of Phytochemicals and Assessment of Hypoglycemic and Haematological Potentials of Terminalia catappa Linn leaf Extract in Alloxan-induced Diabetic Wistar Rats

INTRODUCTION

Hypoglycemia and anemia are associated with diabetes mellitus. Medicinal plants and orthodox drugs have been used for the management of this disease. This study aimed to validate the ethnomedical claims of Terminalia catappa Linn. leaf extract in reducing hyperglycemia and hematological potentials in alloxan-induced diabetic rats and to identify likely antidiabetic compounds.

MATERIALS AND METHODS

Ultra-high-performance liquid chromatography was used to identify the various phytochemical constituents. Male Wistar rats were randomly divided into five groups containing 6 rats per group. Group 1 (control) received 0.2 ml/kg of distilled water, group 2 received 130 mg/kg of T. catappa aqueous extract, groups 3-5 were diabetic and received 0.2 ml/g distilled water, 130 mg/kg T. catappa extract and 0.75 IU/kg insulin respectively for 14 days. Hematological parameters were measured and an oral glucose tolerance test was carried out using 2 g/kg body weight glucose. A histological analysis of the pancreas was done.

RESULTS

Twenty-five compounds identified as flavonoids, phenolic acids, tannins, and triterpenoids were detected. The blood glucose levels were significantly (p <0.05) elevated in DM groups but were significantly (p <0.05) reduced following Terminalia catappa leaves extract to DM groups. There was s significant (p <0.05) increase in insulin levels improved hematological parameters (RBC, WBC, and platelets), and increased islet population.

CONCLUSION

These results suggest that T. catappa extract has hypoglycemic, insulinogenic, and hematopoietic potentials in diabetic condition and offer protection to the pancreas which could be attributed to the phytochemical constituents thereby justifying its use in traditional therapy.

EGFR targeted albumin nanoparticles of oleanolic acid: In silico screening of nanocarrier, cytotoxicity and pharmacokinetics for lung cancer therapy

This study aimed to develop cetuximab (CTX) functionalized albumin nanoparticles (ALB-NPs) of oleanolic acid for EGFR targeted lung cancer therapy. The molecular docking methodology has been applied for a selection of suitable nanocarrier. Various physicochemical parameters like particle size, polydispersity, zeta potential, morphology, entrapment efficiency, and in-vitro drug release of all the ALB-NPs were analyzed. Furthermore, the in-vitro qualitative and quantitative cellular uptake study revealed that higher uptake of CTX conjugated ALB-NPs than nontargeted ALB-NPs in A549 cells. The in-vitro MTT assay revealed that the IC50 value of CTX-OLA-ALB-NPs (4.34 ± 1.90 μg/mL) was significantly reduced (p < 0.001) than OLA-ALB-NPs (13.87 ± 1.28 μg/mL) in A-549 cells. CTX-OLA-ALB-NPs caused apoptosis in A-549 cells at concentrations equivalent to its IC50 value and blocked the cell cycle in the G0/G1 phases. The hemocompatibility, histopathology and lung safety study confirmed the biocompatibility of the developed NPs. In vivo ultrasound and photoacoustic imaging confirmed the targeted delivery of the NPs to lung cancer. The findings demonstrated that CTX-OLA-ALB-NPs have potential for site-specific delivery of OLA for effective and targeted therapy of lung carcinoma.

Pentacyclic Triterpenes from Olive Leaves Formulated in Microemulsion: Characterization and Role in De Novo Lipogenesis in HepG2 Cells

Olea europaea L. leaves contain a wide variety of pentacyclic triterpenes (TTPs). TTPs exhibit many pharmacological activities, including antihyperlipidemic effects. Metabolic alterations, such as dyslipidemia, are an established risk factor for hepatocellular carcinoma (HCC). Therefore, the use of TTPs in the adjunctive treatment of HCC has been proposed as a possible method for the management of HCC. However, TTPs are characterized by poor water solubility, permeability, and bioavailability. In this work, a microemulsion (ME) loading a TTP-enriched extract (EXT) was developed, to overcome these limits and obtain a formulation for oral administration. The extract-loaded microemulsion (ME-EXT) was fully characterized, assessing its chemical and physical parameters and release characteristics, and the stability was evaluated for two months of storage at 4 °C and 25 °C. PAMPA (parallel artificial membrane permeability assay) was used to evaluate the influence of the formulation on the intestinal passive permeability of the TTPs across an artificial membrane. Furthermore, human hepatocarcinoma (HepG2) cells were used as a cellular model to evaluate the effect of EXT and ME-EXT on de novo lipogenesis induced by elevated glucose levels. The effect was evaluated by detecting fatty acid synthase expression levels and intracellular lipid accumulation. ME-EXT resulted as homogeneous dispersed-phase droplets, with significantly increased EXT aqueous solubility. Physical and chemical analyses showed the high stability of the formulation over 2 months. The formulation realized a prolonged release of TTPs, and permeation studies demonstrated that the formulation improved their passive permeability. Furthermore, the EXT reduced the lipid accumulation in HepG2 cells by inhibiting de novo lipogenesis, and the ME-EXT formulation enhanced the inhibitory activity of EXT on intracellular lipid accumulation.

Natural Compounds and Glutathione: Beyond Mere Antioxidants

The tripeptide glutathione plays important roles in many cell processes, including differentiation, proliferation, and apoptosis; in fact, disorders in glutathione homeostasis are involved both in the etiology and in the progression of several human diseases, including cancer. Natural compounds have been found to modulate glutathione levels and function beyond their role as mere antioxidants. For example, certain compounds can upregulate the expression of glutathione-related enzymes, increase the availability of cysteine, the limiting amino acid for glutathione synthesis, or directly interact with glutathione and modulate its function. These compounds may have therapeutic potential in a variety of disease states where glutathione dysregulation is a contributing factor. On the other hand, flavonoids' potential to deplete glutathione levels could be significant for cancer treatment. Overall, while natural compounds may have potential therapeutic and/or preventive properties and may be able to increase glutathione levels, more research is needed to fully understand their mechanisms of action and their potential benefits for the prevention and treatment of several diseases. In this review, particular emphasis will be placed on phytochemical compounds belonging to the class of polyphenols, terpenoids, and glucosinolates that have an impact on glutathione-related processes, both in physiological and pathological conditions. These classes of secondary metabolites represent the most food-derived bioactive compounds that have been intensively explored and studied in the last few decades.

Antihyperglycemic Potential of Spondias mangifera Fruits via Inhibition of 11β-HSD Type 1 Enzyme: In Silico and In Vivo Approach

The 11 β- hydroxysteroid dehydrogenase 1 (11 β-HSD1) is hypothesized to play a role in the pathogenesis of type 2 diabetes and its related complications. Because high glucocorticoid levels are a risk factor for metabolic disorders, 11β-HSD1 might be a viable therapeutic target. In this investigation, docking experiments were performed on the main constituents of Spondias mangifera (SM) oleanolic acid, β-amyrin, and β-sitosterol to ascertain their affinity and binding interaction in the human 11β-hydroxysteroid dehydrogenase-1 enzyme’s active region. The results of in vitro 11β HSD1 inhibitory assay demonstrated that the extract of S. mangifera had a significant (p < 0.05) decrease in the 11-HSD1% inhibition (63.97%) in comparison to STZ (31.79%). Additionally, a non-insulin-dependent diabetic mice model was used to examine the sub-acute anti-hyperlipidemic and anti-diabetic effects of SM fruits. Results revealed that, in comparison to the diabetic control group, SM fruit extract (SMFE) extract at doses of 200 and 400 mg/kg body weight considerably (p < 0.05 and p < 0.01) lowered blood glucose levels at 21 and 28 days, as well as significantly decreased total cholesterol (TC) and triglycerides (TG) and enhanced the levels of high-density lipoprotein (HDL). After 120 and 180 s of receiving 200 and 400 mg/kg SMFE, respectively, disease control mice showed significantly poorer blood glucose tolerance (p < 0.05 and p < 0.01). SMFE extract 200 (p < 0.05), SMFE extract 400 (p < 0.01), and Glibenclamide at a dosage of 5 mg/kg body weight all resulted in statistically significant weight increase (p < 0.01) when compared to the diabetic control group after 28 days of treatment. According to in silico, in vitro, and in vivo validation, SMFE is a prospective medication with anti-diabetic and hypoglycemic effects.

Role of potential bioactive metabolites from traditional Chinese medicine for type 2 diabetes mellitus: An overview

Type 2 diabetes mellitus (T2DM) is a metabolic disease with persistent hyperglycemia primarily caused by insulin resistance (IR). The number of diabetic patients globally has been rising over the past decades. Although significant progress has been made in treating diabetes mellitus (DM), existing clinical drugs for diabetes can no longer fully meet patients when they face complex and huge clinical treatment needs. As a traditional and effective medical system, traditional Chinese medicine (TCM) has a unique understanding of diabetes treatment and has developed many classic and practical prescriptions targeting DM. With modern medicine and pharmacy advancements, researchers have discovered that various bioactive metabolites isolated from TCM show therapeutic on DM. Compared with existing clinical drugs, these bioactive metabolites demonstrate promising prospects for treating DM due to their excellent biocompatibility and fewer adverse reactions. Accordingly, these valuable metabolites have attracted the interest of researchers worldwide. Despite the abundance of research works and specialized-topic reviews published over the past years, there is a lack of updated and systematic reviews concerning this fast-growing field. Therefore, in this review, we summarized the bioactive metabolites derived from TCM with the potential treatment of T2DM by searching several authoritative databases such as PubMed, Web of Science, Wiley Online Library, and Springer Link. For the convenience of readers, the content is divided into four parts according to the structural characteristics of these valuable compounds (flavonoids, terpenoids, alkaloids, and others). Meanwhile, the detailed mechanism and future directions of these promising compounds curing DM are also summarized in the related sections. We hope this review inspires increasingly valuable and significant research focusing on potential bioactive metabolites from TCM to treat DM in the future.

Pharmacological activities and gas chromatography–mass spectrometry analysis for the identification of bioactive compounds from Justicia adhatoda L

The current study aimed to assess the pharmacological potential of Justicia adhatoda by evaluating the presence of biologically active compounds using the gas chromatography–mass spectrometry approach and to undertake biological activities for the effectiveness of the present compounds using standard tests. A total of 21 compounds were identified in the gas chromatography–mass spectrometry analysis of the ethyl acetate fraction in which 14 of the identified compounds are recognized for their pharmacological potential in the literature. In total, four fractions (ethyl acetate, chloroform, n-hexane, and aqueous) were evaluated for pharmacological activities. In carrageenan-induced inflammation, the chloroform fraction exhibited high anti-inflammatory activity (46.51%). Similarly, the analgesic potential of ethyl acetate fraction was the most effective (300 mg/kg) in the acetic acid-induced test. Similarly, in the formalin test, ethyl acetate fraction exhibited maximum inhibition in both early (74.35%) and late phases (88.38). Maximum inhibition of pyrexia (77.98%) was recorded for the ethyl acetate fraction (300 mg/kg). In DPPH assay, the ethyl acetate fraction revealed the highest scavenging potential among other fractions (50 μg/ml resulted in 50.40% and 100 μg/ml resulted in 66.74% scavenging).

Recent Advances Regarding the Molecular Mechanisms of Triterpenic Acids: A Review (Part I)

Triterpenic acids are phytocompounds with a widespread range of biological activities that have been the subject of numerous in vitro and in vivo studies. However, their underlying mechanisms of action in various pathologies are not completely elucidated. The current review aims to summarize the most recent literature, published in the last five years, regarding the mechanism of action of three triterpenic acids (asiatic acid, oleanolic acid, and ursolic acid), corelated with different biological activities such as anticancer, anti-inflammatory, antidiabetic, cardioprotective, neuroprotective, hepatoprotective, and antimicrobial. All three discussed compounds share several mechanisms of action, such as the targeted modulation of the PI3K/AKT, Nrf2, NF-kB, EMT, and JAK/STAT3 signaling pathways, while other mechanisms that proved to only be specific for a part of the triterpenic acids discussed, such as the modulation of Notch, Hippo, and MALAT1/miR-206/PTGS1 signaling pathway, were highlighted as well. This paper stands as the first part in our literature study on the topic, which will be followed by a second part focusing on other triterpenic acids of therapeutic value.

Lipophilic Bioactive Compounds Transported in Triglyceride-Rich Lipoproteins Modulate Microglial Inflammatory Response

Microglial cells can contribute to Alzheimer’s disease by triggering an inflammatory response that leads to neuronal death. In addition, the presence of amyloid-β in the brain is consistent with alterations in the blood–brain barrier integrity and triglyceride-rich lipoproteins (TRL) permeation. In the present work, we used lab-made TRL as carriers of lipophilic bioactive compounds that are commonly present in dietary oils, namely oleanolic acid (OA), α-tocopherol (AT) and β-sitosterol (BS), to assess their ability to modulate the inflammatory response of microglial BV-2 cells. We show that treatment with lab-made TRL increases the release and gene-expression of IL-1β, IL-6, and TNF-α, as well as NO and iNOS in microglia. On the other hand, TRL revealed bioactive compounds α-tocopherol and β-sitosterol as suitable carriers for oleanolic acid. The inclusion of these biomolecules in TRL reduced the release of proinflammatory cytokines. The inclusion of these biomolecules in TRL reduced the release of proinflammatory cytokines. AT reduced IL-6 release by 72%, OA reduced TNF-α release by approximately 50%, and all three biomolecules together (M) reduced IL-1β release by 35% and TNF-α release by more than 70%. In addition, NO generation was reduced, with the inclusion of OA by 45%, BS by 80% and the presence of M by 88%. Finally, a recovery of the basal glutathione content was observed with the inclusion of OA and M in the TRL. Our results open the way to exploiting the neuro-pharmacological potential of these lipophilic bioactive compounds through their delivery to the brain as part of TRL.

Synthesis of Benzylidene Analogs of Oleanolic Acid as Potential α-Glucosidase and α-Amylase Inhibitors

A series of benzylidene analogs of oleanolic acid 4a∼4s were synthesized and assessed for their α-glucosidase and α-amylase inhibitory activities. The results presented that all synthesized analogs exhibited excellent-to-moderate inhibitory effects on α-glucosidase and α-amylase. Analog 4i showed the highest α-glucosidase inhibition (IC50: 0.40 μM), and analog 4o presented the strongest α-amylase inhibition (IC50: 9.59 μM). Inhibition kinetics results showed that analogs 4i and 4o were reversible and mixed-type inhibitors against α-glucosidase and α-amylase, respectively. Simulation docking results demonstrated the interaction between analogs and two enzymes. Moreover, analogs 4i and 4o showed a high level of safety against 3T3-L1 and HepG2 cells.

Antihyperglycemic Effects of Salvia polystachya Cav. and Its Terpenoids: α-Glucosidase and SGLT1 Inhibitors

The antihyperglycemic activity of ethanolic extract from Salvia polystachya (EESpS) and its products was evaluated using in vivo, ex vivo and in silico assays; additionally, an acute toxicity assay was evaluated. EESpS was classified as a nontoxic class 5 drug. EESpS, ethyl acetate fraction (EtOAcFr), secondary-6-fraction (SeFr6), ursolic acid (UA), and oleanolic acid (OA) reduced the hyperglycemia in DM2 mice. α-glucosidase inhibition was evaluated with oral sucrose and starch tolerance tests (OSuTT and OStTT), an intestinal sucrose hydrolysis (ISH) assay and molecular docking studies using acarbose as control. SGLT1 inhibition was evaluated with oral glucose and galactose tolerance tests (OGTT and OGaTT), an intestinal glucose absorption (IGA) assay and molecular docking studies using canagliflozin as the control. During the carbohydrate tolerance tests, all the treatments reduced the postprandial peak, similar to the control drugs. During the ISH, IC₅₀ values of 739.9 and 726.3 µM for UA and OA, respectively, were calculated. During the IGA, IC₅₀ values of 966.6 and 849.3 for UA, OA respectively, were calculated. Finally, during the molecular docking studies, UA and OA showed ∆G values of -6.41 and -5.48 kcal/mol^-1, respectively, on α-glucosidase enzymes. During SGLT1, UA and OA showed ∆G values of -10.55 and -9.65, respectively.

Oleanolic Acid: Extraction, Characterization and Biological Activity

Oleanolic acid, a pentacyclic triterpenoid ubiquitously present in the plant kingdom, is receiving outstanding attention from the scientific community due to its biological activity against multiple diseases. Oleanolic acid is endowed with a wide range of biological activities with therapeutic potential by means of complex and multifactorial mechanisms. There is evidence suggesting that oleanolic acid might be effective against dyslipidemia, diabetes and metabolic syndrome, through enhancing insulin response, preserving the functionality and survival of β-cells and protecting against diabetes complications. In addition, several other functions have been proposed, including antiviral, anti-HIV, antibacterial, antifungal, anticarcinogenic, anti-inflammatory, hepatoprotective, gastroprotective, hypolipidemic and anti-atherosclerotic activities, as well as interfering in several stages of the development of different types of cancer; however, due to its hydrophobic nature, oleanolic acid is almost insoluble in water, which has led to a number of approaches to enhance its biopharmaceutical properties. In this scenario, the present review aimed to summarize the current knowledge and the research progress made in the last years on the extraction and characterization of oleanolic acid and its biological activities and the underlying mechanisms of action.

The Use of Bioactive Compounds in Hyperglycemia- and Amyloid Fibrils-Induced Toxicity in Type 2 Diabetes and Alzheimer’s Disease

It has become increasingly apparent that defective insulin signaling may increase the risk for developing Alzheimer’s disease (AD), influence neurodegeneration through promotion of amyloid formation or by increasing inflammatory responses to intraneuronal β-amyloid. Recent work has demonstrated that hyperglycemia is linked to cognitive decline, with elevated levels of glucose causing oxidative stress in vulnerable tissues such as the brain. The ability of β-amyloid peptide to form β-sheet-rich aggregates and induce apoptosis has made amyloid fibrils a leading target for the development of novel pharmacotherapies used in managing and treatment of neuropathological conditions such as AD-related cognitive decline. Additionally, deposits of β-sheets folded amylin, a glucose homeostasis regulator, are also present in diabetic patients. Thus, therapeutic compounds capable of reducing intracellular protein aggregation in models of neurodegenerative disorders may prove useful in ameliorating type 2 diabetes mellitus symptoms. Furthermore, both diabetes and neurodegenerative conditions, such as AD, are characterized by chronic inflammatory responses accompanied by the presence of dysregulated inflammatory biomarkers. This review presents current evidence describing the role of various small bioactive molecules known to ameliorate amyloidosis and subsequent effects in prevention and development of diabetes and AD. It also highlights the potential efficacy of peptide–drug conjugates capable of targeting intracellular targets.

Synthesis and bioactivities evaluation of oleanolic acid oxime ester derivatives as α-glucosidase and α-amylase inhibitors

Different oleanolic acid (OA) oxime ester derivatives (3a-3t) were designed and synthesised to develop inhibitors against α-glucosidase and α-amylase. All the synthesised OA derivatives were evaluated against α-glucosidase and α-amylase in vitro. Among them, compound 3a showed the highest α-glucosidase inhibition with an IC₅₀ of 0.35 µM, which was ∼1900 times stronger than that of acarbose, meanwhile compound 3f exhibited the highest α-amylase inhibitory with an IC₅₀ of 3.80 µM that was ∼26 times higher than that of acarbose. The inhibition kinetic studies showed that the inhibitory mechanism of compounds 3a and 3f were reversible and mixed types towards α-glucosidase and α-amylase, respectively. Molecular docking studies analysed the interaction between compound and two enzymes, respectively. Furthermore, cytotoxicity evaluation assay demonstrated a high level of safety profile of compounds 3a and 3f against 3T3-L1 and HepG2 cells.

Highlights

Oleanolic acid oxime ester derivatives (3a–3t) were synthesised and screened against α-glucosidase and α-amylase.

Compound 3a showed the highest α-glucosidase inhibitory with IC50 of 0.35 µM.

Compound 3f presented the highest α-amylase inhibitory with IC50 of 3.80 µM.

Kinetic studies and in silico studies analysed the binding between compounds and α-glucosidase or α-amylase.

In Silico Screening of Potential Phytocompounds from Several Herbs against SARS-CoV-2 Indian Delta Variant B.1.617.2 to Inhibit the Spike Glycoprotein Trimer

In October 2020, the SARS-CoV-2 B.1.617 lineage was discovered in India. It has since become a prominent variant in several Indian regions and 156 countries, including the United States of America. The lineage B.1.617.2 is termed the delta variant, harboring diverse spike mutations in the N-terminal domain (NTD) and the receptor-binding domain (RBD), which may heighten its immune evasion potentiality and cause it to be more transmissible than other variants. As a result, it has sparked substantial scientific investigation into the development of effective vaccinations and anti-viral drugs. Several efforts have been made to examine ancient medicinal herbs known for their health benefits and immune-boosting action against SARS-CoV-2, including repurposing existing FDA-approved anti-viral drugs. No efficient anti-viral drugs are available against the SARS-CoV-2 Indian delta variant B.1.617.2. In this study, efforts were made to shed light on the potential of 603 phytocompounds from 22 plant species to inhibit the Indian delta variant B.1.617.2. We also compared these compounds with the standard drug ceftriaxone, which was already suggested as a beneficial drug in COVID-19 treatment; these compounds were compared with other FDA-approved drugs: remdesivir, chloroquine, hydroxy-chloroquine, lopinavir, and ritonavir. From the analysis, the identified phytocompounds acteoside (−7.3 kcal/mol) and verbascoside (−7.1 kcal/mol), from the plants Clerodendrum serratum and Houttuynia cordata, evidenced a strong inhibitory effect against the mutated NTD (MT-NTD). In addition, the phytocompounds kanzonol V (−6.8 kcal/mol), progeldanamycin (−6.4 kcal/mol), and rhodoxanthin (−7.5 kcal/mol), from the plant Houttuynia cordata, manifested significant prohibition against RBD. Nevertheless, the standard drug, ceftriaxone, signals less inhibitory effect against MT-NTD and RBD with binding affinities of −6.3 kcal/mol and −6.5 kcal/mol, respectively. In this study, we also emphasized the pharmacological properties of the plants, which contain the screened phytocompounds. Our research could be used as a lead for future drug design to develop anti-viral drugs, as well as for preening the Siddha formulation to control the Indian delta variant B.1.617.2 and other future SARS-CoV-2 variants.

Oleanolic Acid Provides Neuroprotection against Ischemic Stroke through the Inhibition of Microglial Activation and NLRP3 Inflammasome Activation

Oleanolic acid (OA), a natural pentacyclic triterpenoid, has been reported to exert protective effects against several neurological diseases through its anti-oxidative and anti-inflammatory activities. The goal of the present study was to evaluate the therapeutic potential of OA against acute and chronic brain injuries after ischemic stroke using a mouse model of transient middle cerebral artery occlusion (tMCAO, MCAO/reperfusion). OA administration immediately after reperfusion significantly attenuated acute brain injuries including brain infarction, functional neurological deficits, and neuronal apoptosis. Moreover, delayed administration of OA (at 3 h after reperfusion) attenuated brain infarction and improved functional neurological deficits during the acute phase. Such neuroprotective effects were associated with attenuation of microglial activation and lipid peroxidation in the injured brain after the tMCAO challenge. OA also attenuated NLRP3 inflammasome activation in activated microglia during the acute phase. In addition, daily administration of OA for 7 days starting from either immediately after reperfusion or 1 day after reperfusion significantly improved functional neurological deficits and attenuated brain tissue loss up to 21 days after the tMCAO challenge; these findings supported therapeutic effects of OA against ischemic stroke-induced chronic brain injury. Together, these findings showed that OA exerted neuroprotective effects against both acute and chronic brain injuries after tMCAO challenge, suggesting that OA is a potential therapeutic agent to treat ischemic stroke.

Anti-Diabetic Potential of Plant-Based Pentacyclic Triterpene Derivatives: Progress Made to Improve Efficacy and Bioavailability

Diabetes mellitus (DM) results from the inability of the pancreas to produce sufficient insulin or weakened cellular response to the insulin produced, which leads to hyperglycemia. Current treatments of DM focus on the use of oral hypoglycemic drugs such as acarbose, alpha-glucose inhibitors, sulphonylureas, thiazolidinediones, and biguanides to control blood glucose levels. However, these medications are known to have various side effects in addition to their bioavailability, efficacy, and safety concerns. These drawbacks have increased interest in the anti-diabetic potential of plant-derived bioactive compounds such as oleanolic and maslinic acids. Although their efficacy in ameliorating blood glucose levels has been reported in several studies, their bioavailability and efficacy remain of concern. The current review examines the anti-diabetic effects of oleanolic, maslinic, asiatic, ursolic, and corosolic acids and their derivatives, as well as the progress made thus far to enhance their bioavailability and efficacy. The literature for the current review was gathered from leading academic databases-including Google Scholar and PubMed-the key words listed below were used. The literature was searched as widely and comprehensively as possible without a defined range of dates.

Novel Triterpenoids from Cassia fistula Stem Bark Depreciates STZ-Induced Detrimental Changes in IRS-1/Akt-Mediated Insulin Signaling Mechanisms in Type-1 Diabetic Rats

Here, we identified the mechanisms of action of antidiabetic activity of novel compounds isolated from Cassia fistula stem bark in STZ-diabetic animals. Novel triterpenoid compounds (C1, C2 and C3) were treated to STZ-administered diabetic animals at a concentration of 20mg/kg body weight orally for 60 days to assess their effects on plasma glucose, plasma insulin/C-peptide, serum lipid markers and the enzymes of carbohydrate metabolism, glucose oxidation and insulin signaling molecules. Oral administration of novel triterpenoid compounds to STZ-diabetic animals significantly decreased (p < 0.05) the plasma glucose concentration on the 7th, 15th, 30th, 45th and 60th daysin a duration-dependent manner (p < 0.05). Plasma insulin (p < 0.0001)/C-peptide (p < 0.0006), tissue glycogen (p < 0.0034), glycogen phosphorylase (p < 0.005), glucose 6-phosphatase (p < 0.0001) and lipid markers were significantly increased (p < 0.0001) in diabetic rats, whereas glucokinase (p < 0.0047), glycogen synthase (p < 0.003), glucose oxidation (p < 0.001), GLUT4 mRNA (p < 0.0463), GLUT4 protein (p < 0.0475) and the insulin-signaling molecules IR mRNA (p < 0.0195), IR protein (p < 0.0001), IRS-1 mRNA (p < 0.0478), p-IRS-1Tyr612 (p < 0.0185), Akt mRNA (p < 0.0394), p-AktSer473 (p < 0.0162), GLUT4 mRNA (p < 0.0463) and GLUT4 (p < 0.0475) were decreased in the gastrocnemius muscle. In silico analysis of C1-C3 with IRK and PPAR-γ protein coincided with in vivo findings. C1-C3 possessed promising antidiabetic activity by regulating insulin signaling mechanisms and carbohydrate metabolic enzymes.

Immunomodulatory Effects of a Concoction of Natural Bioactive Compounds-Mechanistic Insights

Natural bioactive compounds derived from plant-based products are known for their biological immunomodulatory activities. They possess systemic pleiotropic effects, minimal side effects, and very low toxicities. Plant-based bioactive compounds have tremendous potential as natural therapeutic entities against various disease conditions and act as anti-inflammatory, antioxidant, anti-mutagenic, anti-microbial, anti-viral, anti-tumour, anti-allergic, neuroprotective, and cardioprotective agents. A herbal formulation extract including five biologically active compounds: Apigenin, Quercetin, Betulinic acid, Oleanolic acid, and β-Sitosterol can impart several immunomodulatory effects. In this review, we systematically present the impact of these compounds on important molecular signaling pathways, including inflammation, immunity, redox metabolism, neuroinflammation, neutropenia, cell growth, apoptosis, and cell cycle. The review corroborates the beneficial effect of these compounds and shows considerable potential to be used as a safer, more cost-effective treatment for several diseases by affecting the major nodal points of various stimulatory pathways.

Oleanolic Acid-Enriched Olive Oil Alleviates the Interleukin-6 Overproduction Induced by Postprandial Triglyceride-Rich Lipoproteins in THP-1 Macrophages

Oleanolic acid (OA), a triterpene that is highly present in olive leaves, has been proposed as a component of functional foods for the prevention of metabolic syndrome, due to its anti-inflammatory activity. We analyzed the effects of OA on inflammatory parameters and signaling proteins in LPS-stimulated THP-1 macrophages. Thus, THP-1 macrophages were incubated with LPS for 48 h after pretreatment with OA at different concentrations. Pretreatment with OA was significantly effective in attenuating IL-6 and TNF-α overproduction induced by LPS in macrophages, and also improved the levels of AMPK-α. We also evaluated the effects of human triglyceride-rich lipoproteins (TRLs) derived from individuals consuming an OA-enriched functional olive oil. For this purpose, TRLs were isolated from healthy adolescents before, 2 and 5 h postprandially after the intake of a meal containing the functional olive oil or common olive oil, and were incubated with THP-1 macrophages. THP-1 macrophages incubated with TRLs isolated at 2 h after the consumption of the OA-enriched olive oil showed significant lower levels of IL-6 compared to the TRLs derived from olive oil. Our results suggest that OA might have potential to be used as a lipid-based formulation in functional olive oils to prevent inflammatory processes underlying metabolic syndrome in adolescents.

Biological activity of 2α,3β,23-trihydroxyolean-12-ene on glucose homeostasis

We studied the effect and the mechanisms of action of 2α,3β,23-trihydroxyolean-12-ene (THO), from Croton heterodoxus Baill. (Euphorbiaceae), in glucose uptake in hyperglycemic rats. The effect of in vivo pretreatment with THO in hyperglycemic rats was analyzed. The in vitro effects of THO were observed in adipocytes and in adipose tissue. THO reduced glycemia, in part by increasing serum insulin and augmenting the disposal of glucose as glycogen in hepatocytes but did not change the serum concentration of glucagon-like peptide-1. THO increased glucose uptake in adipocytes and in adipose tissue by a mechanism dependent on phosphatidylinositol 3-kinase vesicular traffic and on the process of vesicle fusion at the plasma membrane in regions containing cholesterol, indicating the involvement of glucose transporter-4 (GLUT4). This triterpene may act solely via the activation and translocation of GLUT4 (rather than via nuclear actions, such as upregulation of GLUT4 synthesis), since THO did not alter the amount of GLUT4 mRNA or the content of GLUT4. Consistent with these data, the stimulatory effect of this triterpene on the quantity of GLUT4 in the membrane fraction was dependent upon p38 phosphorylation. In this experimental model, orally administered 10 mg/kg THO did not modulate extracellular serum lactate dehydrogenase. In conclusion, THO decreases hyperglycemia by increasing serum insulin and hepatic glycogen content. The THO mechanism of action on adipose tissue for glucose uptake is suggested to be via GLUT4 translocation stimulation mediated by a p38-dependent mechanism. THO is a potential antihyperglycemic agent that acts in a target tissue for glucose homeostasis.

Novel A-Ring Chalcone Derivatives of Oleanolic and Ursolic Amides with Anti-Proliferative Effect Mediated through ROS-Triggered Apoptosis

A series of A-ring modified oleanolic and ursolic acid derivatives including C28 amides (3-oxo-C2-nicotinoylidene/furfurylidene, 3β-hydroxy-C2-nicotinoylidene, 3β-nicotinoyloxy-, 2-cyano-3,4-seco-4(23)-ene, indolo-, lactame and azepane) were synthesized and screened for their cytotoxic activity against the NCI-60 cancer cell line panel. The results of the first assay of thirty-two tested compounds showed that eleven derivatives exhibited cytotoxicity against cancer cells, and six of them were selected for complete dose-response studies. A systematic study of local SARs has been carried out by comparative analysis of potency distributions and similarity relationships among the synthesized compounds using network-like similarity graphs. Among the oleanane type triterpenoids, C2-[4-pyridinylidene]-oleanonic C28-morpholinyl amide exhibited sub-micromolar potencies against 15 different tumor cell lines and revealed particular selectivity for non-small cell lung cancer (HOP-92) with a GI50 value of 0.0347 μM. On the other hand, superior results were observed for C2-[3-pyridinylidene]-ursonic N-methyl-piperazinyl amide 29, which exhibited a broad-spectrum inhibition activity with GI50 < 1 μM against 33 tumor cell lines and <2 μM against all 60 cell lines. This compound has been further evaluated for cell cycle analysis to decipher the mechanism of action. The data indicate that compound 29 could exhibit both cytostatic and cytotoxic activity, depending on the cell line evaluated. The cytostatic activity appears to be determined by induction of the cell cycle arrest at the S (MCF-7, SH-SY5Y cells) or G0/G1 phases (A549 cells), whereas cytotoxicity of the compound against normal cells is nonspecific and arises from apoptosis without significant alterations in cell cycle distribution (HEK293 cells). Our results suggest that the antiproliferative effect of compound 29 is mediated through ROS-triggered apoptosis that involves mitochondrial membrane potential depolarization and caspase activation.

Ethnopharmacological, Phytochemical, Pharmacological, and Toxicological Review on Senna auriculata (L.) Roxb.: A Special Insight to Antidiabetic Property

Avartaki (Senna auriculata (L.) Roxb. syn. Cassia auriculata L.; Family- Fabaceae ) is a traditional medicinal plant, widely used for the treatment of various ailments in Ayurveda and Siddha system of medicine in India. Almost all the parts of the plant, such as flowers, leaves, seeds, barks, and roots have been reported for their medicinal uses. Traditionally, it has been used in the treatment of diabetes, asthma, rheumatism, dysentery, skin disease, and metabolic disorders. The principle phytochemicals in Senna auriculata (L.) Roxb. are alkaloids, anthraquinone, flavone glycosides, sugar, saponins, phenols, terpenoids, flavonoids, tannins, steroids, palmitic acid, linoleic acid, benzoic acid 2-hydroxyl methyl ester, 1-methyl butyl ester, resorcinol, α-tocopherol-β-D-mannosidase, epicatechin, ferulic acid, quercetin-3-O-rutinoside, quercetin, proanthocyanidin B1. The extracts from its different parts and their isolated compounds possess a wide range of pharmacological activities such as antidiabetic, antioxidant, anti-inflammatory, antihyperlipidemic, hepatoprotective, nephroprotective, cardioprotective, anti-atherosclerotic, anticancer, antimutagenic, antimicrobial, antiulcer, antipyretic, anthelmintic, immunomodulatory, antifertility, anti-venom, and anti-melanogenesis. The toxicological findings from preclinical studies ensured the safety of the plant, but comprehensive clinical studies are required for the safety and efficacy of the plant in humans. The current review article aimed to provide up-to-date information about Senna auriculata (L.) Roxb. covering its ethnomedicinal, phytochemical, pharmacological, and toxicological aspects with special emphasis on its clinical implications in diabetes.

Neuroprotective effects of oleanolic acid against cerebral ischemia-reperfusion injury in mice

BACKGROUND/AIM

Stroke is among the most common causes of disability and death in highly developed countries and China. We sought to study the role of oleanolic acid in cerebral ischemia-reperfusion injury.

METHODS

Middle cerebral artery occlusion (MCAO) was performed to induce cerebral ischemia-reperfusion injury in mice. For the short-term effects of oleanolic acid (OA) against MCAO, mice administrated with OA (6 mg/kg /d) for 3 days before the injury were evaluated the infarct volume, neurological scores, blood brain barrier permeability and oxidative stress level, while for the long-term effects, MCAO mice were injected daily with OA for 6 weeks, followed by assessments of motor function, behavior and cerebral infarction area.

RESULTS

Pretreatment of oleanolic acid alleviated MCAO-induced ischemia-reperfusion injury as indicated by the significant decreases in cerebral infarction area and neurological symptom score at 24 h post injury, Evans blue leakage, expression of matrix metalloproteinase 9 (MMP9) and occludin, dihydroethidium fluorescence, and block malonaldehyde generation. In the long run, OA significantly reduced brain loss, enhanced the motor function, promoted the recovery of nerve function, and improved the learning and memory ability 9 weeks after the ischemia-reperfusion injury. OA also inhibited astrocytes proliferation and microglia activation, promoted the expression of synapse-related proteins, and increased the number of DCX+ cells in the hippocampus.

CONCLUSIONS

OA exhibits both short-term and long-term protective effects against the cerebral ischemia-reperfusion injury in mice. The short-term protective mechanism is related to the anti-oxidation of blood-brain barrier, while the long-term protective effect lies in neuroglia modulation, promotion of synaptic connection and neuroregeneration.

Chromolaena odorata (Siam weed): A natural reservoir of bioactive compounds with potent anti-fibrillogenic, antioxidative, and cytocompatible properties

Protein fibrillation and oxidative damage are closely associated with the development of many chronic diseases such as Alzheimer's disease, Parkinson's disease and transthyretin amyloidoses. This work aimed at evaluating the fibrillogenic, antioxidant, anti-oxidative, hemolytic and cytotoxic activities of phenolic-rich extract from Chromolaena odorata (L) R.M. King & H. Rob aerial parts (COPE). As revealed by Thioflavin-T fluorescence, transmission electron microscopy, NBT redox cycling and ANS fluorescence analyses, COPE suppressed the fibril formation of hen egg-white lysozyme by directly binding to the protein and preventing surface exposure its of hydrophobic clusters. In addition, COPE demonstrated potent radical scavenging activities against DPPH˙ and ABTS˙⁺, chelated ferrous ions, and inhibited metal-catalyzed oxidation of bovine serum albumin. The observed effects could be explained by the high content of flavonoids (22.82 QE/g) and phenolics (190 mg GAE/g) present in COPE. UHPLC-ESI-QTOF-MS/MS analysis of COPE in negative ionization mode revealed that the predominant compounds were phenolics and terpenoids. Furthermore, COPE was found to exert very minimal cytotoxic effects against human red blood cells (≤ 5% hemolysis) and human embryonic kidney (HEK-293) cells (≥ 80% viability). These findings suggested that with further investigations, phenolic-rich extract from C odorata could be effectively valorized for pharmacological applications against protein fibrillogenic and oxidative damage related conditions.

Epigenetic Remodeling in Obesity-Related Vascular Disease

Significance: The prevalence of obesity and cardiometabolic phenotypes is alarmingly increasing across the globe and is associated with atherosclerotic vascular complications and high mortality. In spite of multifactorial interventions, vascular residual risk remains high in this patient population, suggesting the need for breakthrough therapies. The mechanisms underpinning obesity-related vascular disease remain elusive and represent an intense area of investigation. Recent Advances: Epigenetic modifications-defined as environmentally induced chemical changes of DNA and histones that do not affect DNA sequence-are emerging as a potent modulator of gene transcription in the vasculature and might significantly contribute to the development of obesity-induced endothelial dysfunction. DNA methylation and histone post-translational modifications cooperate to build complex epigenetic signals, altering transcriptional networks that are implicated in redox homeostasis, mitochondrial function, vascular inflammation, and perivascular fat homeostasis in patients with cardiometabolic disturbances. Critical Issues: Deciphering the epigenetic landscape in the vasculature is extremely challenging due to the complexity of epigenetic signals and their function in regulating transcription. An overview of the most important epigenetic pathways is required to identify potential molecular targets to treat or prevent obesity-related endothelial dysfunction and atherosclerotic disease. This would enable the employment of precision medicine approaches in this setting. Future Directions: Current and future research efforts in this field entail a better definition of the vascular epigenome in obese patients as well as the unveiling of novel, cell-specific chromatin-modifying drugs that are able to erase specific epigenetic signals that are responsible for maladaptive transcriptional alterations and vascular dysfunction in obese patients. Antioxid. Redox Signal. 34, 1165-1199.

Ursolic Acid Lactone Obtained from Eucalyptus tereticornis Increases Glucose Uptake and Reduces Inflammatory Activity and Intracellular Neutral Fat: An In Vitro Study

Obesity has a strong relationship to insulin resistance and diabetes mellitus, a chronic metabolic disease that alters many physiological functions. Naturally derived drugs have aroused great interest in treating obesity, and triterpenoids are natural compounds with multiple biological activities and antidiabetic mechanisms. Here, we evaluated the bioactivity of ursolic acid lactone (UAL), a lesser-known triterpenoid, obtained from Eucalyptus tereticornis. We used different cell lines to show for the first time that this molecule exhibits anti-inflammatory properties in a macrophage model, increases glucose uptake in insulin-resistant muscle cells, and reduces triglyceride content in hepatocytes and adipocytes. In 3T3-L1 adipocytes, UAL inhibited the expression of genes involved in adipogenesis and lipogenesis, enhanced the expression of genes involved in fat oxidation, and increased AMP-activated protein kinase phosphorylation. The range of biological activities demonstrated in vitro indicates that UAL is a promising molecule for fighting diabetes.

The Influence of Plant Extracts and Phytoconstituents on Antioxidant Enzymes Activity and Gene Expression in the Prevention and Treatment of Impaired Glucose Homeostasis and Diabetes Complications

Diabetes is a complex metabolic disorder resulting either from insulin resistance or an impaired insulin secretion. Prolonged elevated blood glucose concentration, the key clinical sign of diabetes, initiates an enhancement of reactive oxygen species derived from glucose autoxidation and glycosylation of proteins. Consequently, chronic oxidative stress overwhelms cellular endogenous antioxidant defenses and leads to the acute and long-standing structural and functional changes of macromolecules resulting in impaired cellular functioning, cell death and organ dysfunction. The oxidative stress provoked chain of pathological events over time cause diabetic complications such as nephropathy, peripheral neuropathy, cardiomyopathy, retinopathy, hypertension, and liver disease. Under diabetic conditions, accompanying genome/epigenome and metabolite markers alterations may also affect glucose homeostasis, pancreatic β-cells, muscle, liver, and adipose tissue. By providing deeper genetic/epigenetic insight of direct or indirect dietary effects, nutrigenomics offers a promising opportunity to improve the quality of life of diabetic patients. Natural plant extracts, or their naturally occurring compounds, were shown to be very proficient in the prevention and treatment of different pathologies associated with oxidative stress including diabetes and its complications. Considering that food intake is one of the crucial components in diabetes’ prevalence, progression and complications, this review summarizes the effect of the major plant secondary metabolite and phytoconstituents on the antioxidant enzymes activity and gene expression under diabetic conditions.

Therapeutic Potential of RTA 404 in Human Brain Malignant Glioma Cell Lines via Cell Cycle Arrest via p21/AKT Signaling

Background

Glioblastoma multiforme (GBM) is the most common malignant brain tumor in the world. Despite advances in surgical resection, radiotherapy, and chemotherapy, GBM continues to have a poor overall survival. CDDO (2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid), a synthetic triterpenoid, is an Nrf2 activator used to inhibit proliferation and induce differentiation and apoptosis in various cancer cells. One new trifluoroethylamide derivative of CDDO, RTA 404, has been found to have increased ability to cross the blood-brain barrier. However, it is not clear what effect it may have on tumorigenesis in GBM.

Methods

This in vitro study evaluated the effects of RTA 404 on GBM cells. To do this, we treated GBM840 and U87 MG cell lines with RTA 404 and assessed apoptosis, cell cycle, cell locomotion, and senescence. DNA content and induction of apoptosis were analyzed by flow cytometry and protein expression by Western blot analysis.

Results

RTA 404 significantly inhibited the proliferation of tumor cells at concentrations higher than 100 nM (p < 0.05) and reduced their locomotion ability. In addition, treatment with RTA 404 led to an accumulation of RTA 404-treated G₂/M phase cells and apoptosis. An analysis of the p21/AKT expression suggested that RTA 404 may not only help prevent brain cancer but it may also exert antitumor activities in established GBM cells.

Conclusion

RTA404 can inhibit proliferation, cell locomotion, cell cycle progression, and induce apoptosis in GBM cells in vitro, possibly through its inhibition of N-cadherin and E-cadherin expression via its inhibition of the AKT pathway.

Nutrigenomics for the prevention and treatment diabetes

Diabetes mellitus is a metabolic disease that manifest itself hyperglycemia It is estimated that about 422 million people worldwide are affected by this disease. Great hopes in the prevention and support of pharmacological treatment of diabetes are associated with a new scientific discipline, which is nutrigenomics. Lowering the reports in the field of physiology, bromatology, genomics, proteomics, biochemistry or epigenetics, this field searches for and explains the interactions of genes with food components at the molecular level. The article presents the most important information on the bioactive effects of food (flavonoids, amino acids, vitamins, fatty acids) on the expression of genes connected with secretion/action of insulin and the metabolism of the glucose in the body. The article discusses the functions of genes that work on the pathogenesis of diabetes development, and presents experimental models in empirical research. In addition, it article presents the importance of epigenetic factor in the development of type 2 diabetes mellitus, as well as basic informations in the field of its diagnosis and differentiation.

Boswellia serrata Resin Extract in Diets of Nile Tilapia, Oreochromis niloticus: Effects on the Growth, Health, Immune Response, and Disease Resistance to Staphylococcus aureus

Simple Summary

The current study evaluated the effects of Boswellia serrata resin extract (BSRE) as a feed additive on the growth performance, immune response, antioxidant status, and disease resistance of Nile tilapia, Oreochromis niloticus. Fish were fed on four basal diets complemented with four levels of BSRE 0, 5, 10, or 15 g kg⁻¹. The results of this study proposed that BSRE addition can enhance the antioxidant activity, immune status, and disease resistance of O. niloticus to S. aureus infection. The level of 5 g kg⁻¹ BSRE can improve fish growth without causing harmful effects on fish health. Higher levels of BSRE are not recommended as they badly affected the histoarchitecture of many vital organs.

Abstract

The influences of Boswellia serrata resin extract (BSRE) as a feed additive on the growth performance, immune response, antioxidant status, and disease resistance of Nile tilapia, Oreochromis niloticus L. were assessed. One hundred-forty four fingerlings (initial weight: 21.82 ± 0.48 g) were randomly allotted into four groups with three replicates where they were fed on one of four treatments with four levels of Boswellia serrata resin extract 0, 5, 10, or 15 g kg⁻¹, BSRE0, BSRE5, BSRE10, BSRE15, respectively for eight weeks. After the end of the feeding trial, the fish were challenged with Staphylococcus aureus, and mortalities were noted. The final body weight, total body weight gain, and the total feed intake were quadratically increased in BSRE5 treatment (p < 0.01). The protein productive efficiency (PPE) was linearly and quadratically increased in all BSRE supplemented treatments (p < 0.01). Dietary addition of BSRE raised the fish crude protein content and reduced the fat content in a level-dependent manner (p < 0.01). The ash content was raised in the BSRE15 group (p < 0.01). Dietary BSRE supplementation decreased the serum levels of glucose, total cholesterol, triglycerides, and nitric oxide. It increased the serum levels of total protein, albumin, total globulins, α1 globulin, α2 globulin, ß globulin, ɣ globulin, Catalase, and SOD (superoxide dismutase) activity, GSH (reduced glutathione), lysozyme activity, and MPO (myeloperoxidase) in a level-dependent manner (p < 0.05). The BSRE15 diet increased the serum level of ALT (alanine aminotransferase) and decreased creatinine serum level (p < 0.05). Dietary BSRE supplementation increased the relative percentage of survival % (RPS) of S. aureus challenged fish. The histoarchitecture of the gills and kidney was normal in the BSRE5 treatment and moderately changed in BSRE10 and BSRE15 treatments. The splenic lymphoid elements were more prevalent, and the melano-macrophage centers (MMC) were mild to somewhat activated in BSRE supplemented treatments. Dietary BSRE supplementation improved the intestinal histomorphology. It can be concluded that BSRE addition can enhance the antioxidant activity, immune status, and disease resistance of O. niloticus to S. aureus infection. The level of 5 g kg⁻¹ BSRE can improve fish growth without causing harmful effects on fish health. The highest levels of BSRE are not recommended as they badly affected the histoarchitecture of many vital organs.

Potential Application of Some Lamiaceae Species in the Management of Diabetes

Diabetes is one of the most dangerous metabolic disorders, with high rates of mortality worldwide. Since ancient times, medicinal plants have been used in traditional medicine to treat many diseases, including diabetes and its related complications. Plants are widely accepted, affordable, and perceived to have minimal adverse side effects. The Lamiaceae family is a potential source of therapeutic agents for the management of metabolic disorders, including diabetes. Hence, this review paper summarizes the antidiabetic use of Lamiaceae species in folk medicine globally. Furthermore, we present the antidiabetic activities and phytochemical constituents of twenty-three (23) Lamiaceae species and the antidiabetic activity of some notable chemical constituents isolated from some of these Lamiaceae species.

The herbal extract ALS-L1023 from Melissa officinalis reduces weight gain, elevated glucose levels and β-cell loss in Otsuka Long-Evans Tokushima fatty rats

ETHNOPHARMACOLOGICAL RELEVANCE

Melissa officinalis L. (Labiatae; lemon balm) is a traditional medicinal plant with hypoglycemic and hypolipidemic effects; however, how it imparts its beneficial effects remains unclear. We thus hypothesized that the herbal extract ALS-L1023, isolated from Melissa officinalis, inhibits obesity and diabetes, and tested our hypothesis using Otsuka Long-Evans Tokushima fatty (OLETF) rats, which are an established animal model of type 2 diabetes.

MATERIALS AND METHODS

In this study, 28-week-old OLETF rats were fed a high-fat diet for 4 weeks to induce a marked impairment of the insulin response and were treated with or without ALS-L1023. Subsequently, the variables and determinants of glucose metabolism and pancreatic function were assessed via blood analysis, histology, immunohistochemistry, and real-time polymerase chain reaction.

RESULTS

The administration of ALS-L1023 resulted in a weight reduction without changes in food intake. It also markedly inhibited hyperglycemia and hypoinsulinemia, and restored β-cell mass that was severely impaired in OLETF rats. There was a decrease in lipid accumulation in the liver and skeletal muscle of the obese rats after treatment with ALS-L1023. Concomitantly, there was an increase in the expression levels of fatty acid-oxidizing enzymes (AMPKα2, ACOX, MCAD, and VLCAD) in the liver and skeletal muscle after ALS-L1023 treatment. Furthermore, ALS-L1023 attenuated the pancreatic inflammation including the infiltration of CD68-positive macrophages and mast cells, in addition to attenuating the expression of inflammatory factors (IL-6 and CD68).

CONCLUSIONS

These results suggest that treatment with ALS-L1023 may reduce weight gain, elevated glucose levels, and β-cell loss, by changing the expression of fatty acid-oxidizing enzymes in the liver and skeletal muscle, including inflammatory factors in the pancreas. These findings indicate that ALS-L1023 may be an effective therapeutic strategy to treat human obesity and type 2 diabetes.

Evaluation of Acute and Chronic Antidiabetic Activity of Ivy (<i>Hedera helix</i> L.) Aqueous Leaf Extract in Rat Model

BACKGROUND AND OBJECTIVE

Hedera helix L. (Ivy) has been utilized as an alternative medicine for cough however, through extensive literature search; we found no reported activity of ivy on α-glucosidase inhibition, HbA1c levels and its protective effect on vital organs. Therefore, the present study aimed to evaluate the antidiabetic and protective effect of ivy in alloxan induced rat model.

MATERIALS AND METHODS

The hypoglycemic activity of ivy was examined in normoglycemic, glucose overloaded and alloxan-induced rats. The antidiabetic potential was also confirmed by estimation of HbA1c and α-glucosidase inhibitory activity.

RESULTS

Results of acute and chronic study revealed that ivy produced highly significant decline (p<0.01) in fasting and post-prandial blood sugar levels as compared to diabetic control and standard group respectively. Furthermore, highly significant decline (p<0.01) in HbA1c levels were seen after chronic administration of ivy indicating its therapeutic effect in lowering HbA1c levels during long term use. It was found that ivy produced stronger and highly significant (p<0.05) inhibition of α-glucosidase activity than the standard agent acarbose at 500 μg mL-1.

CONCLUSION

The histopathological studies of vital organs revealed protective effect of ivy via maintaining the normal architecture as compared to alloxan model. Hence, our findings support the potential use of ivy for diabetes management.