Prophylactic and therapeutic potential of tender coconut water intervention on antioxidant status in electron beam irradiated Swiss albino mice

Ionizing radiation induces oxidative stress due to free radicals production. The in vitro study has shown that tender coconut water (TCW) of West Coast tall variety exhibits potent antioxidant property. Here, we attempted to evaluate the potency of TCW in reducing radiation induced oxidative stress in the mice model. The LD50/30 dose of electron beam radiation (EBR) for Swiss albino mice was assessed and was found to be 9.33Gy. Therefore, a sublethal dose of 6Gy was selected for further intervention studies to assess the levels of antioxidants. To evaluate the effective dose, the mice were irradiated with a lethal dose of 10Gy with the oral intervention of 50, 100 and 200 µL of TCW/20 g body wt. of mice. Findings of the study suggest that 100 µL/20 g body wt. was found to be effective in decreasing the mortality of irradiated mice. Further, intervention with TCW significantly increased the antioxidant levels compared to that of radiation control group. The results suggest that TCW exhibits radioprotective activity by potentiating the antioxidant levels in mice exposed to a sublethal dose of whole body EBR.

Comparison of cardiac autonomic activity between pre and post menopausal women using heart rate variability.

Ageing is associated with a decline in short-term indexes of heart rate variability (HRV). But there is little evidence regarding the extent to which age-related changes in HRV depend on simultaneous changes in levels of estrogen and body composition as it occurs from pre menopausal state to postmenopausal state. The purpose of this study was (i) to compare HRV between pre and postmenopausal women, (ii) to determine whether difference in age, estrogen level and body composition could account for the difference in HRV between these two groups. HRV was assessed using spectral. analysis and estrogen level was estimated using radioimmunoassay technique. The body composition, in terms of percent fat, was assessed using measurement of skin fold thickness. Data was analyzed both before and after adjusting for age, estrogen level and body composition. It was found that the total power, high frequency (HF) and the low frequency (LF) power spectrum of HRV in absolute units were significantly lower (P<0.001) in postmenopausal women compared to that of premenopausal women. Postmenopausal women had significantly lower HF (P<0.01) and higher LF (P<0.01) when expressed in normalized units. The ratio of LF/HF, the index of sympathovagal balance was significantly higher (P<0.01) among postmenopausal women. Analysis after adjusting for age, revealed that age was one of the important confounder, responsible for the differences in all the components of power spectrum between the two study groups. Difference in estrogen level contributed for the difference in relative values of HF and LF components of HRV. Difference in body composition did not explain the difference in HRV between the groups. The study concludes that both ageing and declined estrogen levels are associated with the autonomic alterations seen among postmenopausal women.