In vitro antioxidant studies in leaves of Annona species.

Antioxidant potential of leaves of three different species of Annona was studied by using different in vitro models eg., 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothizoline-6-sulphonate) (ABTS), nitric oxide, superoxide, hydroxy radical and lipid peroxidation. The ethanolic extract of A. muricata at 500 microg/ml showed maximum scavenging activity (90.05%) of ABTS radical cation followed by the scavenging of hydroxyl radical (85.88%) and nitric oxide (72.60%) at the same concentration. However, the extract showed only moderate lipid peroxidation inhibition activity. In contrast, the extract of A. reticulata showed better activity in quenching DPPH (89.37%) and superoxide radical (80.88%) respectively. A.squamosa extract exhibited least inhibition in all in vitro antioxidant models excepting hydroxyl radical (79.79%). These findings suggest that the extracts of A. muricata possess potent in vitro antioxidant activity as compared to leaves of A. squamosa and A. reticulata suggesting its role as an effective free radical scavenger, augmenting its therapeutic

Long-term effect of prenatal exposure to low level of gamma radiation on neurophysiology of mouse.

Abdominal region of pregnant Swiss mice were exposed to 0.25, 0.35 or 0.50 Gy of gamma radiation on days 11.5, 12.5, 14.5 or 17.5 post coitus (pc). Changes in locomotory activity and learning performance, and hippocampal biogenic amines (noradrenaline, NA; dopamine, DA; 5-hydroxytryptomine, 5-HT; and 5-HTs metabolite 5-hydroxyindolacetic acid, 5-HIAA) were studied at 12 (adult) and 18 months (old) of age. Significant change in locomotory activity and learning performance was observed after exposure to 0.50 Gy at late organogenesis day (11.5 pc), when tested at 12 months of age, but not observed much change at 18 months. Biogenic amines did not show any significant change after any exposure dose at any of the gestation days. It was inferred from the results that gamma irradiation (0.50 Gy) at the late organogenesis (day 11.5 pc) can impair the brain functions in adults when normal faculties are functional.

Changes in mouse behavior induced by fetal exposure to diagnostic ultrasound.

Pregnant Swiss albino mice were exposed to diagnostic ultrasound (3.5 MHz, 65mw, ISPTP = 1 W/cm2, ISATA = 240 W/cm2) for 10 min on day 14, 16 or 17 of gestation to assess any changes in physiological reflexes (pinna detachment, eye opening and fur development) and postnatal mortality. Changes in locomotor activity by open field test and dark/bright arena test and learning and memory by hole board test were also recorded. No change was observed in physiological reflexes and postnatal mortality. However there were significant alterations in behavior in all the three exposed groups. These results demonstrate that ultrasound exposure during the late fetal period can impair brain function in adult mouse.