ABSTRACT
Objective: To explore the effect of hydroalcoholic extract of Cynodon dactylon on the whole body radiation-induced oxidative status of the cerebellum and cognitive impairments in mice. Methods: Swiss albino mice were randomly divided into the control group, radiation control group, low dose and high dose Cynodon dactylon extract treated groups and pre-treated with Cynodon dactylon extract before irradiation. Cynodon dactylon extract was administered for 7 d daily in low dose (0.25 g/kg) and high dose (1 g/kg). On day 7, mice were irradiated with a sublethal dose of 5 Gy gamma rays. Motor coordination was assessed by elevated rotarod test and spatial memory was studied by water maze test. Subsequently, biochemical markers (glutathione, lipid peroxidation and nitric oxide levels) in the cerebellum were evaluated. Results: The gamma irradiated group showed significant impairment in motor coordination and spatial memory compared to normal mice. Mice treated by Cynodon dactylon extract prior to gamma radiation showed good improvement in both paradigms compared to the radiation control group. Moreover, glutathione level was increased, while lipid peroxidation and nitric oxide levels were significantly reduced in mice receiving low dose and high dose of Cynodon dactylon extract compared to the radiation control group. Conclusions: The present study suggests the neuroprotective role of Cynodon dactylon against radiation-induced cognitive impairment and oxidative stress on the cerebellum of mice.
ABSTRACT
In the present study we investigated the radioprotective activity of hydroalcoholic leaf extracts of Psidium guajava (P.G) against rats exposed to X rays. Exposure to ionizing radiation like X rays induces oxidative damage in normal tissues leading to their death or transforming them into cancerous tissues. To study the optimum dose of radioprotection, rats were administered with different doses (50,100,200,400 mg/kg body weight) of Psidium guajava leaf extracts daily for five consecutive days. One hour after last administration of leaf extracts the rats were treated with 6.6 Gy of x rays.200 mg/kg body weight was selected as an optimum dose for radioprotection based on survival analysis. Pretreatment of 200 mg/kg body weight of P.G leaf extract increased the levels of antioxidant enzymes such as superoxide dismutase, catalase, reduced glutathione and lowered the levels of lipid peroxidation, protein carbonyls and nitric oxide when compared to irradiated group in liver tissue homogenates. DNA damage indicators analyzed through comet assay showed a reduction in Olive tail movement and percentage DNA in tail significantly in P.G pretreated group when compared to irradiated group alone. Pretreatment of P.G leaf extract at a dose of 200mg/kg body weight protected cells from apoptosis which was analyzed microscopically by Ethidium bromide /Acridine orange staining. Our findings demonstrate the role of P.G leaf extract as a radio modulator in vivo, consequent to its powerful antioxidant activity in vitro and could be beneficial in combating radiation induced damage in living systems.