Atul Shrivastava

Antidyslipidemic effect and antioxidant activity of anthraquinone derivatives from Rheum emodi rhizomes in dyslipidemic rats

The aim of the present study was to evaluate the antidyslipidemic effect of ethanolic extract of Rheum emodi rhizomes and its constituents in Triton-WR-1339 and high-fat diet (HFD)-induced dyslipidemic rats. In preliminary screening, the ethanolic extract showed significant activity in Triton-treated rats. Bioassay-guided fractionation of the ethanolic extract resulted in the identification of four anthraquinone derivatives, viz. chrysophanol, emodin, chrysophanol 8-O-β-d-glucopyranoside and emodin 8-O-β-d-glucopyranoside as active constituents. All these compounds significantly reduced plasma lipid levels. The most active compound emodin showed significant lipid-lowering activity in the HFD-fed model. In addition, these compounds showed significant antioxidant activity. The effect of emodin on enzymes modulating lipid metabolism confirms and supports the efficiency of emodin as a potent antidyslipidemic agent.

Antidyslipidemic and antioxidant activity of the constituents isolated from the leaves of Calophyllum inophyllum.

In continuation of our drug discovery program on Indian medicinal plants, we isolated bioactive compounds (1-5) from the leaves of Calophyllum inophyllum and evaluated their antidyslipidemic activity in triton induced hyperlipidemia model. The calophyllic acid (1A) and isocalophyllic acid (1B) mixture, canophyllic acid (4) and amentoflavone (5) showed dose dependent lipid lowering activity in in vivo experiments. The compounds 1A+1B mixture and 3 also showed good in vitro antioxidant activity.

A mechanism-based pharmacological evaluation of efficacy of Trigonella foenum graecum (fenugreek) seeds in regulation of dyslipidemia and oxidative stress in hyperlipidemic rats.

Abstract: Alcoholic extract of Trigonella foenum graecum seeds [fenugreek seed extract (FSE)] was studied in triton-induced and high-fat diet–induced hyperlipidemia to evaluate antidyslipidemic effect. Plasma cholesterol (26.19%) and triglycerides (36.6%) were found to be lowered by FSE maximum at a dose of 200 mg/kg body weight in triton-treated hyperlipidemic rats. Chronic feeding of FSE (200 mg/kg body weight) caused lowering in plasma and hepatic lipid levels by activating lecithin–cholesterol acyltransferase (47%), postheparin lipolytic activity (35%), triglyceride lipase (34%), lipoprotein lipase (20.8%), and increased excretion of fecal bile acids (36%–45%). The FSE shows potent antioxidant activity in both in vitro and in vivo systems. It inhibited generation of superoxide anion and hydroxyl free radicals in both enzymatic and nonenzymatic systems significantly at 200 µM concentration. Furthermore, FSE normalizes the activities of antioxidant enzymes, that is, superoxide dismutase and catalase, and reduces plasma lipid peroxidation (33.9%), hepatic 4-hydroxynonenal (27%), and isoprostanes (28%). Data of the present study demonstrated that the T. foenum graecum seed extract has both antidyslipidemic and antioxidant properties.

A mechanism-based pharmacological evaluation of efficacy of Flacourtia indica in management of dyslipidemia and oxidative stress in hyperlipidemic rats.

Abstract Background: Flacourtia indica (Burm. f.) Merr. is a medicinal plant indigenous to India and is broadly used worldwide for the treatment of a variety of health ailments. The present study was experimented on hyperlipidemic Charles Foster rats with the aim to explore the possible mechanism responsible for the antidyslipidemic activity of the hydromethanolic extract from F. indica leaves (FIL). Methods: Hyperlipidemia was induced by a single intraperitoneal dose of Triton WR-1339 in Charles Foster rats. The plasma lipid levels were estimated in control and treated groups. The antioxidant potential of F. indica was assessed in both enzymatic and non-enzymatic systems. An acute toxicity study of high-performance liquid chromatography (HPLC)-fingerprinted extract was carried out in Swiss albino mice. Results: The F. indica extract at a dose of 150 mg/kg significantly lowers the plasma level of total cholesterol (17%), triglycerides (13%), and phospholipids (16%) by increasing post-heparin lipolytic activity (19%) and lecithin-cholesterol-acyltransferase activity (20%) in Triton-induced hyperlipidemic rats. In addition, the F. indica extract showed significant in vitro antioxidant and anti-adipogenic activity. HPLC analysis indicates the presence of flavanones and flavones in the extract, and the extract was found to be non-toxic up to a dose of 2000 mg/kg body weight in the acute oral toxicity study. Conclusions: These finding suggest that F. indica holds significant potential in preventing clinical deterioration induced by dyslipidemia along with oxidative stress.

Antidyslipidemic and antioxidant activity of an unusual amino acid (2-amino-5-hydroxyhexanoic acid) isolated from the seeds of Crotalaria juncea

In continuation of our drug discovery programme on Indian medicinal plants, we isolated an unusual amino acid, i.e. 2-amino-5-hydroxyhexanoic acid (1) from the seeds of Crotalaria juncea. The 2-amino-5-hydroxyhexanoic acid (1) showed dose dependent lipid lowering activity in the in vivo experiments and also showed good in vitro antioxidant activity. The cyclized compound, 3-amino-6-methyltetrahydro-2H-pyran-2-one (2) showed better lipid lowering and antioxidant profile than the parent compound 1.

Effects of Senna didymobotrya Root Extract and Compounds on Tritoninduced Hyperlipidaemic Rats and Differentiation of 3T3-Li Preadipocytes

The lipid lowering effects of Senna didymobotrya (Leguminoceae) root extract (250 mg/kg) and pure isolates (100 mg/kg) were investigated for hypolipidemic activity on Triton-induced hyperlipidemic rats (in-vivo). The extracts and isolates showed significant (p�0.01) reduction in serum lipid contents, and reactivation of the lipolytic enzymes, relative to the Triton-treated group. Ethyl acetate extract exhibited the highest lipid lowering (p�0.01) compared to other fractions. Seven anthraquinones, obtusifolin (1), 1,6-di-O-methylemodin (2), nataloemodin-8-methyl ether (3), chrysophanol (4), physcion (5), chrysophanol-10,10-bianthrone (6), physcion-10,10-bianthrone (7) and stigmasterol (8) were isolated from the ethyl acetate extract. Compounds 3, 5 and 7 displayed significant (p�0.01) lipid lowering effects. The hypolipidaemic activities prompted the determination of inhibition of differentiation of 3T3-L1 preadipocytes into adipocytes by the compounds 3, 5 and 7. Only compound 7 exhibited potent anti-adipogenic activity without significant cytotoxicity. The result indicated that extracts of S. didymobotrya root extract can provide good antidyslipidaemic and adipocytes maturation inhibitors.