Protective effect of Coleus aromaticus Benth (Lamiaceae) against naphthalene-induced hepatotoxicity.

OBJECTIVE: To investigate protective effect of Coleus aromaticus leaf extract against naphthalene induced hepatotoxicity in rats. METHODS: Eighteen male rats were divided into three groups. Group I rats were treated as control. Group II rats were intraperitoneally administered with naphthalene (435 mg/kg b.wt) dissolved in corn oil once a day for a period of 30 days. Group III rats were treated with leaf extract (100 mg/kg b.wt) dissolved in 0.9% saline and naphthalene (435 mg/kg b.wt) dissolved in corn oil once a day for a period of 30 days. RESULTS: Significant protective effect was observed against naphthalene induced liver damage, which appeared evident from the response levels of marker enzymes (aspartate transaminase, alanine transaminase, acid phosphatase, alkaline phosphatase and lactate dehydrogenase). The biochemical components viz. triglycerides, free fatty acids, cholesterol acyl transferase, high-density lipoprotein, low-density lipoprotein, cholesterol and bilirubin were found to be increased in liver and serum of naphthalene stressed rats when compared to control. CONCLUSION: Treatment of naphthalene intoxicated rats with plant extract reversed these distorted parameters to near normal levels. Liver histology showed supportive evidence regarding the protective nature of plant extract against fatty changes induced by naphthalene. The present study provides a scientific rationale for using C. aromaticus in the management of liver disorders.

Protective effect of Operculina turpethum against 7,12-dimethyl benz(a)anthracene induced oxidative stress with reference to breast cancer in experimental rats.

Reactive oxygen species (ROS) directly or indirectly involves in multistage process of carcinogenesis. Antioxidant activity of methanolic extract of Operculina turpethum stems (MEOT) on 7,12 dimethylbenz(a)anthracene (DMBA) induced breast cancer was investigated in female Sprague-Dawley rats. Changes in the levels of lipid peroxidation and antioxidants system was evaluated in addition to tumour development. Twenty four female rats were divided into four groups: control, DMBA, DMBA+MEOT and MEOT. In the DMBA group, rats were intragastrically administered with 20 mg of DMBA using corn oil as vehicle. Animals of DMBA+MEOT group received a single dose of 20 mg of DMBA dissolved in corn oil intragastrically followed by O. turpethum extract (100 mg/kg body weight), while MEOT group received O. turpethum extract (100 mg/kg body weight) intragastrically daily for a period of 45 days. After the experimental period of 45 days, oxidative stress parameters were assessed in serum, liver and breast of both control and experimental groups. In addition to this, tumour weight of breast was also assessed. A significant increase in lipid peroxidation levels were observed in the tested samples of cancer induced rats while the activities of enzymic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and non-enzymic antioxidants like glutathione (GSH), ascorbic acid (Vitamin C) and alpha-tocopherol (Vitamin E) were decreased in cancer-bearing animals when compared to control animals. A significant (P<0.05) increase in the tumour weight was observed in the breast of DMBA group and the breast tumour weight decreased significantly (P<0.05) in the DMBA+MEOT groups. Oral administration of MEOT remarkably reduced the lipid peroxidation activity and increased the antioxidants level in drug treated animals and decreased the tumour weight significantly (P<0.05). This result suggests that MEOT shows antioxidant activity and play a protective role against DMBA induced breast cancer.

Antioxidant effect of the marine algae Chlorella vulgaris against naphthalene-induced oxidative stress in the albino rats.

Alcoholic extract of the marine algae Chlorella vulgaris was examined for its free radical scavenging effect with reference to naphthalene-induced lipid peroxidation in serum, liver, and kidney of rats. Initially, upon naphthalene intoxication (435 mg/kg body weight, intraperitoneally), the lipid peroxidation activity increased significantly (P < 0.001), and in contrast, the enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase) and non-enzymic antioxidants (glutathione, ascorbic acid, and alpha-tocopherol) levels decreased remarkably. When the naphthalene stressed rats were treated with Chlorella vulgaris extract (70 mg/kg body weight, orally), the lipid peroxidation activity reduced significantly (P < 0.001) and the activities of both the enzymic and non-enzymic antioxidants increased reaching near control values. The minimum concentration (70 mg/l) of the extract that exhibited maximum (85%) free radical scavenging activity was chosen for the experimental study. The present results suggest that Chlorella vulgaris extract exerts its chemo-preventive effect by modulating the antioxidants status and lipid peroxidation during naphthalene intoxication.

Free radical scavenging activity of the marine mangrove Rhizophora apiculata bark extract with reference to naphthalene induced mitochondrial dysfunction.

Rhizophora apiculata bark extract was tested for its free radical scavenging activity and protective role against mitochondrial dysfunction in naphthalene stressed rats. Lipid peroxidation activity was increased and activity of mitochondrial enzymes (cytochrome-c-oxidase, NADH-dehydrogenase, alpha-ketoglutarate dehydrogenase and succinate dehydrogenase) and glutathione was decreased in the liver and kidney of rats intoxicated with naphthalene when compared to control rats. Intraperitoneal administration of plant extract significantly reduced the lipid peroxidation, increased the activity of mitochondrial enzymes and increased glutathione to near control levels. These results suggest that the sulfated polysaccharides in R. apiculata play a protective role through their free radical scavenging properties.