Search

Peptides are distinctive biomacromolecules that demonstrate potential cytotoxicity and diversified bioactivities against a variety of microorganisms including bacteria, mycobacteria, and fungi via their unique mechanisms of action. Among broad-ranging pharmacologically active peptides, natural marine-originated thiazole-based oligopeptides possess peculiar structural features along with a wide spectrum of exceptional and potent bioproperties. Because of their complex nature and size divergence, thiazole-based peptides (TBPs) bestow a pivotal chemical platform in drug discovery processes to generate competent scaffolds for regulating allosteric binding sites and peptide–peptide interactions. The present study dissertates on the natural reservoirs and exclusive structural components of marine-originated TBPs, with a special focus on their most pertinent pharmacological profiles, which may impart vital resources for the development of novel peptide-based therapeutic agents.

In the Indian traditional system of medicine, Streblus asper Lour (Moraceae) is prescribed for the treatment of diabetes mellitus.In the present study, α-amyrin acetate isolated from S. asper, and the petroleum ether extract of S. asper stem bark (PESA) was screened for their antidiabetic properties in streptozotocin (STZ)-induced diabetic rats.Successive Soxhlet extraction of the dried stem bark with petroleum ether and then with ethanol (95%) yielded petroleum ether and ethanol extracts, respectively, which were concentrated under reduced pressure. Hyperglycemia was induced in rats by STZ (50 mg/kg, b.w.). Twenty-four hours after STZ induction, respective groups of diabetic rats received PESA (100, 250 and 500 mg/kg, b.w.) and α-amyrin acetate (25, 50 and 75 mg/kg, b.w.) respectively, orally daily for 15 days. Glibenclamide (0.5 mg/kg, orally) served as a reference. Blood glucose levels were measured on every 5th day during the 15 days of treatment. The serum lipid profiles and biochemical parameters, viz., serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), insulin and glycosylated hemoglobin level, were measured.PESA significantly (p0.01) normalized blood-glucose levels and serum biochemical parameters as compared with those of STZ controls. α-Amyrin acetate (75 mg/kg, b.w.) exhibited maximum glucose lowering effect (71.10%) in diabetic rats compared to the other dose (25, 50 mg/kg) at the end of the study. The protective effect was further confirmed by histopathological examination of the liver.PESA and α-amyrin acetate demonstrated remarkable antidiabetic activity in STZ-induced diabetic rats.

Stigmast-5-en-3β-ol (β-sitosterol) was isolated from the chloroform extract of the aerial parts ofAristolochia indica (CEAI). The structure and relative configuration of Stigmast-5-en-3β-ol (β-sitosterol) was determined by spectroscopic methods (1H- and 13C-NMR, IR, and MS). CEAI was found to produce good antidiabetic activity in treated mice. It reversed the weight loss of diabetic mice and restored to normal blood sugar level. The efficacy of the extract was compared with standard drug, Glibenclamide (10 mg/kg p.o.) in diabetic mice. CEAI also showed significant antioxidant activity in the level of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide radicals with IC50 value being 7.325 and 8.498 µg/ml, respectively. The anti-hyperglycemic effect of the extract might be due to an increase in peripheral glucose consumption as well as protection against oxidative damaged in alloxanised diabetes. Key words: Aristolochia indica, antioxidant, antidiabetic activity, alloxan, glibenclamide, diabetes, 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion radical, β-sitosterol.

In the present study, the hepatoprotective activity of ethanolic extracts ofCassia sopheraLinn. leaves was evaluated against carbon-tetrachloride- (CCl4-) induced hepatic damage in rats. The extracts at doses of 200 and 400 mg/kg were administered orally once daily. The hepatoprotection was assessed in terms of reduction in histological damage, changes in serum enzymes, serum glutamate oxaloacetate transaminase (AST), serum glutamate pyruvate transaminase (ALT), serum alkaline phosphatase (ALP), total bilirubin, and total protein levels. The substantially elevated serum enzymatic levels of AST, ALT, ALP, and total bilirubin were restored towards the normalization significantly by the extracts. The decreased serum total protein level was significantly normalized. Silymarin was used as standard reference and exhibited significant hepatoprotective activity against carbon tetrachloride-induced hepatotoxicity in rats. The biochemical observations were supplemented with histopathological examination of rat liver sections. The results of this study strongly indicate thatCassia sopheraleaves have potent hepatoprotective action against carbon tetrachloride-induced hepatic damage in rats. This study suggests that possible activity may be due to the presence of flavonoids in the extracts.