Amelioration of chemical-induced skin carcinogenesis by Aegle marmelos, an Indian medicinal plant, fruit extract.

Chemoprevention is a novel approach to study the anti-initiating and anti-tumor-promoting efficacy of medicinal plants and their active principles. The present study investigated the chemopreventive potential of Aegle marmelos fruit extract in 7,12-dimethylbenz[a]anthracene-induced skin carcinogenesis and its influence on oxidative stress and the antioxidant defense system. The oral administration of A marmelos at 100 mg/kg body weight/day during peri-initiational, postinitiational, and peri- & postinitiational phases of papillomagenesis showed significant reduction in tumor incidence, tumor yield, tumor burden, and cumulative number of papillomas when compared with carcinogen-treated control. The average latent period significantly increased (7.88 weeks; control group) to 9.45, 11.11, and 11.54 weeks in different A marmelos extract (AME) experimental groups. Enzyme analysis of skin and liver showed a significant elevation in antioxidant parameters such as superoxide dismutase, catalase, glutathione, and vitamin C in AME-treated groups when compared with the carcinogen-treated control. The elevated level of lipid peroxidation in the positive control was significantly inhibited by AME administration. These results indicate that AME has the potential to reduce chemical-induced skin papillomas by enhancing the antioxidant defense system.

Protective effect of an extract of Emblica officinalis against radiation-induced damage in mice.

The radioprotective effect of Emblica officinalis extract (EOE) was studied in mice. Swiss albino mice were exposed to gamma rays (5 Gy) in the absence (control) or presence (experimental) of EOE, orally 100 mg/kg body weight, once daily for 7 consecutive days. A specimen of small intestine (jejunum) was removed from the mice and studied at different autopsy intervals from 12 hours to 30 days. In control animals, crypt cell population, mitotic figures, and villus length were markedly reduced on day 1; these later started to increase progressively but did not attain the normal level even at the last autopsy interval. The animals receiving EOE prior to irradiation had a higher number of crypt cells and mitotic figures when compared with non-drug-treated control at all the autopsy intervals. Irradiation of animals resulted in a dose-dependent elevation in lipid peroxidation and a reduction in glutathione as well as catalase concentration in the intestine at 1 hour post-irradiation. In contrast, EOE treatment before irradiation caused a significant depletion in lipid peroxidation and elevation in glutathione and catalase levels.

Modulation of radiation-induced biochemical alterations in mice by rosemary (Rosemarinus officinalis) extract.

Radioprotective effect of leaves extract of Rosemarinus officinalis (ROE) has been studied against 6 Gy gamma-radiations in the liver of Swiss albino mice at various post-irradiation intervals between 12 h and 30 days. In control animals (without ROE treated irradiated), an elevation in glycogen, protein, acid and alkaline contents was found till day 5th, but thereafter decreased at successive intervals without returning to normal. Cholesterol level was found to be lower than normal till 10th day, then increased up to 20th day but later declined without restoring normal level. A similar trend of variation in these biochemical parameters was observed in experimental group (ROE pretreated irradiated) also but to a lower extent. ROE significantly delayed and inhibited the rise in these biochemical parameters. Almost normal values of such constituents were regained by day 30th in experimental animals; whereas in control animals, normal values were not ever attained. In control animals, there was an elevation in lipid peroxidation (LPx) and a decrease in glutathione (GSH) in blood and liver; whereas in experimental group, decline in LPx accompanied by an increase in GSH concentration was observed.

Radioprotective potential of Rosemarinus officinalis against lethal effects of gamma radiation : a preliminary study.

The radioprotective effect of Rosemarinus officinalis extract (ROE) was studied in mice exposed to 8 Gy of gamma radiation. The optimum dose for radioprotection was determined by administering 100, 200, 400, 800, 1000, 1500, and 2000 mg/kg body weight of ROE orally once daily, consecutively for five days before irradiation. Treatment of mice with ROE, delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug-treated irradiated controls. The dose of ROE found to be most effective against radiation was 1000 mg/kg body weight because this dose increased the survival time and reduced the mortality rate of mice significantly. Body weight loss in ROE administered irradiated animals was significantly less in comparison with animals who were given radiation treatment alone. Furthermore, irradiation of animals resulted in an elevation in lipid peroxidation (LPx) and a significant decrease in glutathione (GSH) in blood and liver. Conversely, administration of animals with ROE before irradiation caused a significant decline in LPx accompanied by a significant increase in GSH concentration. The present study demonstrates that Rosemarinus officinalis leave extract is a good radioprotector.

Emblica officinalis (Linn.) fruit extract provides protection against radiation-induced hematological and biochemical alterations in mice.

Oral administration of Emblica officinalis (Linn.) before exposure to gamma radiation was found to be effective in protecting mice against the hematological and biochemical modulation in peripheral blood. A significant increase in the RBC, WBC, hemoglobin, and hematocrit values was observed in the animals pretreated with E. officinalis extract as compared to the hematological values observed in the irradiated group. Furthermore, radiation sickness was greatly inhibited in those mice that were irradiated with prior treatment of E. officinalis. A significant decrease in glutathione (GSH) content and increase in lipid peroxidation (LPx) level were also observed in irradiated animals; whereas E. officinalis pretreated irradiated animals exhibited a significant increase in GSH content and decrease in LPx level, but such remained below the normal. The results from the present study suggest that E. officinalis pretreatment provides protection against irradiation to Swiss albino mice.