Thiruvengadam Devaki

Cardioprotective effects of Picrorrhiza kurroa against isoproterenol-induced myocardial stress in rats

The cardioprotective effect of the ethanol extract of Picrorrhiza kurroa rhizomes and roots (PK) on isoproterenol-induced myocardial infarction in rats with respect to lipid metabolism in serum and heart tissue has been investigated. Oral pre-treatment with PK (80 mg kg(-1) day(-1) for 15 days) significantly prevented the isoproterenol-induced myocardial infarction and maintained the rats at near normal status.

Anti-peroxidative and anti-hyperlipidemic nature of Ulva lactuca crude polysaccharide on D-Galactosamine induced hepatitis in rats

To find whether pretreatment of Ulva lactuca polysaccharide (ULP) extract could be effective against D-Galactosamine (500 mg/kg body weight, i.p.) induced anomaly in rat. Serum total cholesterol (TC), triglycerides (TG), free fatty acid (FFA), phospholipids (PL), high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), tissue lipoperoxides (LPO), hepatic protein thiols, non-enzymatic anti-oxidants glutathione (GSH) and vitamins (E and C) were examined using spectrophotometer. The ultra structural changes of liver during D-Galactosamine and protection offered by ULP were examined by electron microscopy. Seaweed histology and chemical composition of polysaccharides in seaweed were examined. Alcian blue staining showed the presence of sulphated polysaccharide with total sugar (65.4%), sulphate (17.4%), and uronic acid (17.2%) content. D-Galactosamine intoxicated rats showed significant (p<0.01) liver damage with acute aberration in serum lipid profile, hepatic protein thiols and tissue non-enzymatic anti-oxidants. Assorted deposits of lipid droplets and abnormal appearance of mitochondria was observed in electron microscopy study. Rats pretreated with ULP (30 mg/kg body weight/day/for 21 days) showed a significant inhibition (p<0.05) against abnormality induced by d-Galactosamine. U.lactuca exhibit anti-peroxidative and anti-hyperlipidemic property.

Antiproliferative potential of gallic acid against diethylnitrosamine-induced rat hepatocellular carcinoma

One of the focuses in current cancer chemoprevention studies is the search for nontoxic chemopreventive agents that inhibit the initiation of malignant transformation. Cancer biomarkers are quantifiable molecules involved in the physiologic or pathologic events occurring between exposure to carcinogens and the development, progression of cancer. Biomarkers may be the consequence of a continuous process, such as increased cell mass, or a discrete event, such as genetic mutation. Analysis of tumor markers can be used as an indicator of tumor response to therapy. Gallic acid is a naturally available polyphenol, possess strong antioxidant activity with a capacity to inhibit the formation of tumors in several cancer models. In the present study, we investigated the antiproliferative effect of gallic acid during diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC) in male wistar albino rats. DEN treatment resulted in increased levels of aspartate transaminase, alanine transaminase, alkaline phosphatase, acid phosphatase, lactate dehydrogenase, gamma-glutamyltransferase, 5′-nucleotidase, bilirubin, alpha-fetoprotein, carcinoembryonic antigen, argyophillic nucleolar organizing regions, and proliferating cell nuclear antigen. Gallic acid treatment significantly attenuated these alterations and decreased the levels of AgNORs and PCNA. These finding suggests that gallic acid is a potent antiproliferative agent against DEN-induced HCC.

Protective effect of Hemidesmus indicus against rifampicin and isoniazid-induced hepatotoxicity in rats.

Oral treatment with the ethanol extract of Hemidesmus indicus roots (100 mg/kg, for 15 days) significantly prevented rifampicin and isoniazid-induced hepatotoxicity in rats.

Effect of Sargassum polycystum (Phaeophyceae)-sulphated polysaccharide extract against acetaminophen-induced hyperlipidemia during toxic hepatitis in experimental rats.

The effect of Sargassum polycystum crude extract on lipid metabolism was examined against acetaminophen-induced (800 mg/kg body wt., intraperitoneally) hyperlipidemia during toxic hepatitis in experimental rats. The animals intoxicated with acetaminophen showed significant elevation in the levels of cholesterol, triglycerides and free fatty acid in both serum and liver tissue. The levels of tissue total lipids and serum LDL-cholesterol were also elevated with depleted levels of serum HDL-cholesterol and tissue phospholipid. The acetaminophen-induced animals showed significant alterations in the activities of lipid metabolizing enzymes serum lecithin cholesterol acyl transferase (LCAT) and hepatic triglyceride lipase (HTGL). The levels of liver tissue fatty acids (saturated, mono and polyunsaturated) such as palmitic acid, stearic acid, oleic acid, linoleic acid, arachidonic acid and linolenic acid monitored by gas chromatography were considerably altered in acetaminophen intoxicated animals when compared with control animals. The prior oral administration of Sargassum polycystum (200 mg/kg body wt./day for a period of 15 days) crude extract showed considerable prevention in the severe disturbances of lipid profile and metabolizing enzymes triggered by acetaminophen during hepatic injury. Liver histology also showed convincing supportive evidence regarding their protective nature against fatty changes induced during acetaminophen intoxication. Thus the present study indicates that the protective nature of Sargassum polycystum extract may be due to the presence of active compounds possessing antilipemic property against acetaminophen challenge. (Mol Cell Biochem 276: 89–96, 2005)

Synergistic effect of Nicorandil and Amlodipine on tissue defense system during experimental myocardial infarction in rats.

The synergistic protective effect of Nicorandil (KATP channel opener) and Amlodipine (calcium channel blocker) on heart tissue antioxidant defense system and lipid profile were examined on isoproterenol induced myocardial infarction in rats. The rats given isoproterenol (150 mg kg−1 daily, i.p.) for 2 days showed significant changes in antioxidant defense system and lipid profile levels. Pretreatment with Nicorandil (2.5 mg kg−1 daily, p.o.) and Amlodipine (5.0 mg kg−1 daily, p.o.) for 3 days significantly prevented these alterations and restored the enzyme activities to near normal. These findings indicate the synergistic protective effect of Nicorandil and Amlodipine on tissue defense system and lipid metabolism during isoproterenol induced cardiac damage.

Silymarin downregulates COX-2 expression and attenuates hyperlipidemia during NDEA-induced rat hepatocellular carcinoma

Silymarin is a naturally available bioflavonoid and is a strong antioxidant with a capacity to inhibit the formation of tumors in several cancer models. In the present study, we investigated whether dietary supplementation of silymarin has any role in lipid components, lipid-metabolizing enzymes, free fatty acid profile, and expression of cyclooxygenase-2 (COX-2) in N-nitrosodiethylamine (NDEA)-induced hepatocellular carcinoma in rats. NDEA-induced rats showed severe hyperlipidemia along with upregulated expression of COX-2 as revealed by western blotting and immunohistochemistry. Dietary silymarin supplementation attenuated this hyperlipidemia and downregulated the expression of COX-2. Thus we conclude that compounds like silymarin with potent hypolipidemic effect are strong candidates as chemopreventive agents for the treatment of liver cancer.

Capsaicin modulates pulmonary antioxidant defense system during benzo(a)pyrene-induced lung cancer in Swiss albino mice.

The effect of a pungent ingredient of red pepper, capsaicin, on oxidative stress induced changes in the antioxidant defense system by benzo(a)pyrene in the lungs of mice was studied. Oral gavage administration of benzo(a)pyrene (50 mg/kg body weight) to mice led to a marked increase in oxidative stress indicated by alterations in pulmonary lipid peroxidation, enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione‐S‐transferase and glucose‐6‐phosphate dehydrogenase) and non‐enzymic antioxidants (reduced glutathione, vitamin C, vitamin E and vitamin A). Pre‐co‐treatment with capsaicin (10 mg/kg body weight i.p.) restored cellular normalcy, highlighting the antioxidant potential of capsaicin in mitigating the oxidative stress mediated damage produced during benzo(a)pyrene‐induced lung cancer. Copyright

Protective effect of Nardostachys jatamansi on oxidative injury and cellular abnormalities during doxorubicin induced cardiac damage in rats

Nardostachys jatamansi is a medicinally important herb of Indian origin. It has been used for centuries in the Ayurvedic and Unani systems of medicine for the treatment of various ailments. We have evaluated the effect of N. jatamansi (rhizomes) on the biochemical changes, tissue peroxidative damage and abnormal antioxidant levels in doxorubicin (adriamycin)‐induced cardiac damage. Preliminary studies on the effect of the graded dose of extract showed that 500 mg kg−1 orally for seven days was found to be optimum and hence all further study was carried out with this particular dose. Rats administered doxorubicin (15 mg kg−1, i.p.) showed myocardial damage that was manifested by the elevation of serum marker enzymes (lactate dehydrogenase, creatine phosphokinase, aspartate aminotransaminase and alanine aminotransaminase). The animals showed significant changes in the antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase and glutathione‐S‐transferase) and lipid peroxidation levels. Pretreatment with N. jatamansi extract significantly prevented these alterations and restored the enzyme activity and lipid peroxides to near normal levels. Restoration of cellular normality accredits the N. jatamansi with a cytoprotective role in doxorubicin‐induced cardiac damage.

Effect of Tridax procumbens on liver antioxidant defense system during lipopolysaccharide-induced hepatitis in D-galactosamine sensitised rats

The present study was carried out to assess the effect of chloroform insoluble fraction of ethanolic extract of Tridax procumbens (TP) against D-Galactosamine/Lipopolysaccharide (D-GalN/LPS)-induced hepatitis in rats. Induction of rats with D-GalN/LPS (300 mg/kg body weight/30 μg/kg body weight) led to a marked increase in lipid peroxidation as measured by thiobarbituric acid reactive substances (TBARS) in liver. Further there was a decline in the activities of enzymic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, glutathione s-transferase and the levels of non-enzymic antioxidants namely reduced glutathione, vitamin C and vitamin E. These biochemical alterations were normalised upon pretreatment with TP extract. Thus, the above results suggest that TP (300 mg/kg body weight orally for 10 days) is very effective in allievating the D-GalN/LPS-induced oxidative stress suggesting its antioxidant property. (Mol Cell Biochem 269: 131–136, 2005)