Assessment of anti-diabetic activity of the aqueous extract of leaves of Astilboides tabularis

Polyphenols: Secondary Metabolites with a Biological Impression

Polyphenols are natural compounds which are plant-based bioactive molecules, and have been the subject of growing interest in recent years. Characterized by multiple varieties, polyphenols are mostly found in fruits and vegetables. Currently, many diseases are waiting for a cure or a solution to reduce their symptoms. However, drug or other chemical strategies have limitations for using a treatment agent or still detection tool of many diseases, and thus researchers still need to investigate preventive or improving treatment. Therefore, it is of interest to elucidate polyphenols, their bioactivity effects, supplementation, and consumption. The disadvantage of polyphenols is that they have a limited bioavailability, although they have multiple beneficial outcomes with their bioactive roles. In this context, several different strategies have been developed to improve bioavailability, particularly liposomal and nanoparticles. As nutrition is one of the most important factors in improving health, the inclusion of plant-based molecules in the daily diet is significant and continues to be enthusiastically researched. Nutrition, which is important for individuals of all ages, is the key to the bioactivity of polyphenols.

Combined Treatment of Dendrosomal-Curcumin and Daunorubicin Synergistically Inhibit Cell Proliferation, Migration and Induce Apoptosis in A549 Lung Cancer Cells

Purpose

Chemotherapy drugs used to treat lung cancer are associated with drug resistance and severe side effects. There have been rising demands for new therapeutic candidates and novel approaches, including combination therapy. Here, we aimed to investigate the combinatorial effect of a dendrosomal formulation of curcumin (DNC) and daunorubicin (DNR) on the A549 lung cancer cell line.

Methods

We performed cytotoxicity, apoptosis, cell migration, colony-formation capacity, and gene expression analysis to interpret the mechanism of action for a combination of DNC and DNR on A549 cells.

Results

Our results revealed that the combination of DNC and DNR could synergistically inhibit the A549 cells' growth. This synergistic cytotoxicity was further approved by flow cytometry, migration assessment, colony-forming capacity and gene expression analysis. DNR combination with DNC resulted in increased apoptosis to necrosis ratio compared to DNR alone. In addition, the migration and colony-forming capacity were at the minimal range when DNC was combined with DNR. Combined treatment decreased the expression level of MDR-1, hTERT and Bcl-2 genes significantly. In addition, the ratio of Bax/Bcl2 gene expression significantly increased. Our analysis by free curcumin, dendrosomes and DNC also showed that dendrosomes do not have any significant cytotoxic effect on the A549 cells, suggesting that this carrier has a high potential for enhancing the curcumin's biological effects.

Conclusion

Our observations suggest that the DNC formulation of curcumin synergistically enhances the antineoplastic effect of DNR on the A549 cell line through the modulation of apoptosis/necrosis ratio, as well as Bax/Bcl2 ratio, MDR-1 and hTERT gene expression.

Subacute effects of hydroethanolic extracts of the pulp of Gambeya africana on glucose plasmatic levels and oxidative stress markers in diabetic rats

The management of hyperglycemia and oxidative stress is a key point in the control of diabetes and its complications. The work evaluated the hypoglycemiant and antioxidant properties of pulp extracts of Gambeya africana fruits. The acute toxicity was conducted for 14 days at the dose of 2000 mg/kg via oral gavage. Diabetes was induced in rats by intravenous administration of streptozotocin (50 mg/kg). The effect of the extract on blood glucose levels of diabetic rats was monitored at 2h after administration; and on the 7th and 14th days of treatment (single dose of 400 mg/kg/day). After 2 weeks of treatment, the rats were sacrificed. The oxidative stress markers (Hydroperoxides, Malonedialdehydes, Superoxide Dismutase, Catalase, and Total Antioxidant Capacity) and hepato/nephrotoxicity markers (Alanine Amino Transferase, urea, and creatinine) were determined. The hydroethanolic extract of G. africana fruits has a lethal dose upper than 2000 mg/kg. It significantly decreased glucose levels by 28.29% and 84.86% respectively after 2h and 14th days of treatment. The extract increased the antioxidant status and decrease oxidative stress, especially in the pancreas. This study suggests that the hydroethanolic pulp extract of G. africana fruits is a good hypoglycemiant and antioxidant agent and could be a potential source of compounds for diabetes management.

Tylophora hirsuta (Wall.) Extracts Ameliorate Diabetes Associated with Inflammation in Alloxan-induced Diabetic Rats

BACKGROUND

Tylophora hirsuta (Wall) has long been used as traditional medicine for the treatment of diabetes. The current study is designed to evaluate the anti-diabetic and anti-inflammatory activity of different extracts of aerial parts of Tylophora hirsuta.

METHODS

Sequential maceration was conducted to obtain extracts. Total phenolic contents were determined by the Folin-Ciocalteau method. The anti-oxidant activity was assessed by DPPH free radical scavenging assay. The extracts were tested for its inhibitory activity against α-amylase in-vitro. In-vivo anti-diabetic assay was conducted using alloxan-induced diabetic model and OGTT was conducted on normal rats. ELISA was used to determine the pro-inflammatory cytokines (TNF-α and IL-6). The polyphenolic composition of the extract was analyzed using an HPLC system.

RESULTS

Aqueous extract exhibited highest total phenolic contents (985.24± 3.82 mg GAE/100 g DW), antioxidant activity (IC50 = 786.70 ± 5.23 μg/mL), and alpha-amylase inhibition (IC50 =352.8 μg/mL). The aqueous extract of Tylophora hirsuta showed remarkable in-vivo anti-diabetic activity. Results were compared with standard drug glibenclamide. Alloxan induced diabetic mediated alterations in liver function enzymes, renal function determinants, and lipid parameters were significantly restored in aqueous extract treated diabetic rats. A significant reduction in pro-inflammatory cytokines (p<0.001) was observed when compared to the control group. HPLC analysis confirms the presence of quercetin, gallic acid, cinnamic acid, and p-coumaric acid.

CONCLUSION

These results showed that Tylophora hirsuta possesses strong anti-diabetic and anti-inflammatory potentials and justify its folklore use for the management of diabetes.

Biological Activities and Phenolic Compound Content of Astilboides tabularis (Hemsl.) Engler Extracts

INTRODUCTION

The plant, Astilboides tabularis (Hemsl.) Engler, is used in Chinese and Korean medicine to regulate blood sugar levels; however, little is known about its precise effects.

MATERIALS AND METHODS

In this study, we aimed to measure the composition as well as the antioxidant, and anti-proliferative capacities of A. tabularis. Various extracts were generated using different organic solvents, and in vitro antioxidant activities were evaluated using DPPH free radical-scavenging and reducing power assays. The extracts were also evaluated based on their ability to inhibit lipopolysaccharide (LPS)-induced Nitric Oxide (NO) production in RAW 264.7 cells.

RESULTS

Research shows that the A. tabularis ethyl acetate (EtOAc) extract showed significant antioxidant activity. Additionally, this extract could inhibit the LPS-induced expression of inflammatory mediators and pro-inflammatory cytokines in RAW 264.7 cells, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and interleukin-1 beta (IL-1ß). Notably, the A. tabularis EtOAc extract also displayed potent cytotoxic effects against MCF-7 and HeLa cancer cell lines, as determined by MTT assays. Lastly, total phenol and flavonoid content was measured for all extracts, and four flavonoid compounds-catechin, kaempferol, quercitrin, and isoquercetin were isolated from the EtOAc extract. Their structures were confirmed using mass spectrometry and nuclear magnetic resonance, and these isolated compounds were found to display potent DPPH free radical-scavenging activity.

CONCLUSION

Thus, our data suggest that phenolic compounds in A. tabularis extracts promote antioxidant activity, and furthermore, these extracts show numerous features that indicate potential for therapeutic development.

Synergistic inhibitory effects of capsaicin combined with cisplatin on human osteosarcoma in culture and in xenografts

BACKGROUND

The combination of phytochemicals with chemotherapy drugs is an emerging new strategy for cancer therapy to increase antitumor responses.

METHODS

The present study investigates the effect of the combination of capsaicin (CAP) with cisplatin (DDP) and the potential underlying anticancer mechanisms in osteosarcoma (OS) cells in vitro and in vivo.

RESULTS

Cell viability assays and isobolographic analyses demonstrated that the combination of CAP and DDP showed synergistic cytotoxic effects on OS cells. We chose relatively low concentrations of CAP (100 μM) and DDP (16.7 μM) for subsequent experiments. Generally, the combination of CAP and DDP had significant effects on apoptosis induction, cell cycle arrest and cell invasion inhibition in OS cells compared with the individual-treatment groups and the control group. Moreover, cotreatment with CAP and DDP triggered prosurvival autophagy through reactive oxygen species (ROS)/JNK and p-AKT/mTOR signaling in OS cells. The combination regimen of CAP and DDP also inhibited tumor growth in an OS xenograft model.

CONCLUSION

These results suggest that the combination of CAP and DDP has strong inhibitory effects on OS cells and identify CAP as a promising agent for supplementing standard chemotherapy and possible future targeted therapy in OS.

Mechanochemical preparation of kaempferol intermolecular complexes for enhancing the solubility and bioavailability

In this study, complexes of kaempferol (KF) with polysaccharide arabinogalactan (AG) and disodium glycyrrhizinate (Na₂GA) were prepared through mechanochemical technique to improve the solubility and bioavailability of KF. The physicochemical properties and the interactions of KF with AG/Na₂GA were investigated through dissolution, SEM, XRD, and DSC studies. The reduction of particle sizes and destruction of crystal forms revealed the formation of solid dispersion which may have assisted the dissolution of the drug. The accelerated stability study showed higher stability for KF-Na₂GA complex. In vivo pharmacokinetic study was performed to observe the plasma drug concentrations for KF complexes. Mechanochemical complexation of KF with AG/Na₂GA improved the pharmacological activity as evident by the inhibitory potential of the complexes towards carbohydrate metabolic enzymes. In vivo studies were performed in STZ-induced diabetic mice, where the group treated with KF-AG complex showed better liver and kidney function and lower blood glucose levels than pure KF. Therefore, mechanochemical complexes of KF with polysaccharide or glycyrrhizate may serve as a promising formulation for the treatment of diabetes.

Anti-Diabetic Effects of Phenolic Extract from Rambutan Peels (Nephelium lappaceum) in High-Fat Diet and Streptozotocin-Induced Diabetic Mice

Recent studies have shown that rambutan peel phenolic (RPP) extract demonstrate high antioxidant and antiglycation activities in vitro and in vivo. This study further evaluated the anti-diabetic activity of RPP in a mouse model of Type II diabetes induced by streptozotocin combined with high-fat diet. Results showed that RPP increased the body weight and reduced the fasting blood glucose level of the diabetic mice. RPP significantly reduced the serum levels of total cholesterol, triglyceride, creatinine, and glycated serum protein in diabetic mice in a dose-dependent manner. Glycogen content in mice liver was recovered by RPP, which further increased the activity of superoxide dismutase and glutathione peroxidase and reduced lipid peroxidation in diabetic mice. Histological analysis showed that RPP effectively protected the tissue structure of the liver, kidney, and pancreas. In addition, RPP decreased the mesangial index and inhibited the expression of TGF-β in the kidney of diabetic mice.