A simple method for the rapid production of atherosclerosis in rats

Glutathione-redox status on hydro alcoholic root bark extract of Premna integrifolia Linn in high fat diet induced atherosclerosis model

BACKGROUND

Premna integrifolia Linn. is a medicinal plant of an Ayurvedic importance and proved to have an anti-inflammatory, anti-diabetic, anti-microbial and hypo-lipidemic activity. Glutathione (GSH) redox status is an important parameter to assess the antioxidant activity of any neutraceuticals.

OBJECTIVE

In order to assess the anti-oxidant potential of hydro alcoholic extract (HAE) of P. integrifolia, this study was aimed to evaluate the GSH redox status in high fat diet induced experimental atherosclerosis.

MATERIALS AND METHODS

The present study comprises sixty Wistar rats and they were divided into six groups: the first group served as control, the second group was fed with high fat diet and the third, fourth and fifth groups were fed with high fat diet along with various concentrations of HAE of 200, 400 and 500 g/kg.b.wt respectively and the sixth group was administered high fat diet along with 10 mg/kg b.wt of atorvastatin for 30 days. GSH-dependent enzymes like GSH-peroxidase (GPx), GSH-reductase (GR) and glucose 6-phosphate dehydrogenase (G6PD) were estimated in hemolysate, kidney, heart and liver of experimental rats.

RESULTS

Analysis of GSH levels showed a significant decrease in hemolysate, heart and kidney (p < 0.05) and liver (p < 0.01) in high fat-fed rats when compared to control. Activities of GPx, GR and G6PD in hemolysate and heart (p < 0.001), liver and kidney (p < 0.05) in high fat-fed rats when compared to control. Dose-dependent increase was observed in rats treated with various concentrations of HAE.

CONCLUSION

The HAE of root bark of P. integrifolia is proved to have a protective role on antioxidant defense in high fat diet induced atherosclerosis model. As a whole P. integrifolia increases the GSH content in a dose-dependent manner and in turn altered the redox cycle.

Anti-atherosclerotic activity of root bark of Premna integrifolia Linn. in high fat diet induced atherosclerosis model rats

Premna integrifolia Linn. is a medicinal plant used in “Dhasamula” drug preparation of Ayurvedic systems of medicine in the treatment of various ailments like bronchitis, dyspepsia, liver disorders, piles, constipation, hyperlipidemia and fever. The anti-atherosclerotic activity of hydroalcoholic extract (HAE) of root bark of P. integrifolia was evaluated in high fat diet induced atherosclerosis rats. Sixty Wistar rats were divided into six groups: the first group served as control, the second group was fed with high fat diet and the other three groups were fed with high fat diet along with various concentrations of HAE and the last group was treated with atorvastatin for 30 days. Lipid and lipoprotein profile, atherogenic index, and cardiac markers and histopathological evaluation of aorta were determined in high fat diet induced atherosclerosis rats. HAE of P. integrifolia produced a significant and dose-dependent anti-atherosclerotic activity in terms of reduction in lipids and lipoprotein profile, atherogenic index, HMG-CoA reductase activity, marker enzymes such as lactate dehydrogenase (LDH), creatine phosphokinase (CPK), aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP), alteration in collagen and calcium contents, mild mineralization and focal rupture of intima and media of aorta was noticed in treated groups as compared to the control. The results suggested that anti-atherosclerotic activity of HAE of P. integrifolia Linn. was due to its modulatory activity on metabolic pathway of lipid. The results contribute to the validation of the traditional use of Agnimantha in high fat diet induced atherosclerosis rats.

A comparative study on dyslipidaemia inducing diets in various rat strains

In our experiments we compared the serum lipoprotein lipid composition of Fischer 344 (F344) and Long-Evans (LE) inbred rats as well as of their hybrid FLF(1) from both sexes after feeding them for 2, 4 and 8 weeks with different diets. The following diets were used: 1) standard diet marked as CRLT/N; 2) diet reach in butter marked as BR; 3) diet containing cholesterol, sodium cholate and methylthiouracil marked as CR; 4) diet marked as BRC, which is the Hartroft-Sós diet modified by our research group consisting of the diets BR and CR. The latter diet was the most effective, because within two weeks the level of serum total cholesterol, LDL-cholesterol, HDL-cholesterol and triglyceride in the F344 female rats increased 8, 30, 4 and 8 times, respectively. The male rats of the Long-Evans strain showed moderately increased values while the FLF(1) female hybrids derived from the hybridization of LE males and F344 females had values closer to those of the mother strain. Despite the fact that during this time the LDL/HDL ratio increased from 0.06 to 2.97 and the PON-1 activity decreased to one-third, a significant lipid deposition could not be shown in the wall of the abdominal aorta even two months later. Our experimental model is suitable for the chemoprevention of dyslipidaemia or rapid testing of molecules chosen for its treatment.

Atherosclerosis mouse model induced by a high-cholesterol diet supplemented with beta-aminopropionitrile: effects of various anti-atherosclerotic agents on the biochemical parameters

A mouse model of atherosclerosis was produced by feeding a 1.5% cholesterol diet with 0.4% beta-aminopropionitrile (BAPN) fumarate, a chemical lathyrogen, for 10 weeks, and the pharmacological sensitivity and specificity of this model were evaluated biochemically with various hypolipidemic drugs and calcium antagonists. Histological findings on this model showed typical angiolathyrism with foam cells in the media of the thoracic aorta. Uniform and marked accumulation of cholesterol, notably esterified cholesterol, in the aorta was observed, although it was much less in mice receiving a high-cholesterol diet or BAPN alone. The reduction in elastin contents in the aorta was a characteristic feature of this model. Clofibrate, cetaben and elastase tended to prevent the increase of cholesterol contents in the aorta, together with their significant hypocholesterolemic effects. Nifedipine, diltiazem and verapamil showed a slight preventive effect on the cholesterol accumulation and on the reduction of elastin content in the aorta without a cholesterol lowering effect in the serum. MgCl2 was more effective than other calcium antagonists and even had a hypocholesterolemic effect. The results indicate that this mouse atherosclerosis model may be usable for primary drug evaluation.

Tissue lipid responses to 3-hydroxy-3-methylglutaric acid with different dietary fats

Simultaneous administration of 3-hydroxy-3-methylglutaric acid (HMG) for 4 weeks to rats fed 20% saturated fats prevented rise of serum cholesterol, triglycerides, and phospholipids. Except phospholipids, other liver lipids were significantly decreased. HMG administration for 4 weeks along with atherogenic diet significantly decreased cholesterol and phospholipids of serum, liver, aorta, and heart. The phospholipids of epididymal fat and brain were also significantly lowered. The triglyceride levels in serum, liver, and epididymal fat were significantly decreased. The maximal hypolipidemic effect of HMG was observed in serum.

3-hydroxy-3-methylglutaric acid and experimental atherosclerosis in rats

In rats 3-hydroxy-3-methylglutaric acid effectively counteracts the lipemic and atherosclerotic response of massive doses of vitamin D2. It regressed the formation of atheromatous arterial lesions. Furthermore the significant decrease in serum beta-lipoprotein levels on HMG treatment could be due to decrease in VLDL triglyceride and cholesterol levels.