Embryotoxic and teratogenic effects of nickel in Swiss albino mice during organogenetic period.

The present study evaluates potential hazardous of nickel (Ni(+2) as NiCl2 ·6H2O) to Swiss albino mice fetus. Ni was administered orally on body weight base from days 6 to 13 of gestation period. Based on LD50, Ni doses (46.125, 92.25, and 184.5) mg Ni/kg b.wt. were used. On day 18 of gestation, uteri of the sacrificed dams were examined. A dose-dependent decrease (P < 0.01) in the body weight of the pregnant females and fetuses during the gestation period was observed. Number of implant sites and placental weight at all the three dose levels was lower compared with their respective control groups. Average number of live fetuses/dams reduced significantly (P < 0.01) at 184.5 mg Ni/kg b.wt. with concomitant increase in the percentage of postimplantation death and percentage of resorbed, macerated, and dead fetuses, respectively. Exposure increased the fetal malformations, namely, hydrocephaly, open eyelids, microphthalmia, exophthalmia, club foot, umbilical hernia, and skeletal anomalies. Reduced ossification of nasal, frontal, parietal, intraparietal, and supraoccipital bones, absence/gap between the ribs, reduced/fused sternebrae, vertebral centra, and caudal vertebrae, reduced pelvic elements, absence of carpals, metacarpals, tarsals, metatarsals, and phalanges were distinct. This indicates vulnerability of the mice fetus to nickel during prenatal exposure.

Evaluation of radioprotective efficacy and possible mechanism of action of Aloe gel.

The present study was undertaken to determine the optimum effective dose, dose reduction factor (DRF) and possible mechanism of action of Aloe gel. Three different doses of gel (250, 500 and 750 mg/kg body weight) were tested against 8 Gy induced damage in Swiss albino mice. A dose of 750 mg/kg body weight of Aloe was found the most effective while, 250 mg/kg body weight was the least effective in providing protection, as observed in the form of higher concentrations of blood GSH and vitamin C and lower level of serum LPO than irradiated animals at 1h post irradiation and higher percent of survivors up to day 30 post irradiation. Treatment of mice with Aloe before irradiation with different doses of gamma radiation (6-12 Gy) delayed the onset and reduced the severity of signs of radiation sickness. The LD(50/30) was calculated as 6.77 and 10 Gy for untreated irradiated and Aloe treated irradiated animals, respectively and its dose reduction factor was also calculated as 1.47. Aloe gel scavenged the free radicals, DPPH•, ABTS(+•) and NO in a concentration dependent manner in vitro and therefore, scavenging of free radicals seems to be its important mechanism of action.

Chemopreventive potential of Aloe vera against 7,12-dimethylbenz(a)anthracene induced skin papillomagenesis in mice.

The present investigation was undertaken to explore the antitumor-promoting activity of Aloe vera on 2-stage skin carcinogenesis, induced by a single topical application of 7,12-dimethylbenz(a)anthracene and promoted by treatment of croton oil for 16 weeks in Swiss albino mice. Oral administration of aloe leaf extract at a dose of 1000 mg/kg body weight/d and aloe gel treatment at a dose of 1 mL/9 cm(2)/mice/d was found to be effective in decreasing the number and size of the papillomas. A significant reduction in tumor incidence (40.00+/-5.10, 30.00+/-3.25, and 40.00+/-4.12 for aloe gel, aloe gel and aloe leaf extract combined, and aloe leaf extract alone, respectively) was observed in animals in the aloe extract- and aloe gel-treated groups compared with 100% tumor incidence in the control group. The cumulative number of papillomas during an observation period of 16 weeks was significantly reduced in the aloe-treated groups (8.0+/-0.34, 6.00+/-1.10, and 9.00+/-1.41 for aloe gel, aloe gel and leaf extract, and aloe leaf extract, respectively) compared with a 36+/-0.98 cumulative number of papillomas in the control group. The average latent period was significantly increased from 4.9+/-0.10 weeks in the control group to 6.37+/-0.12, 6.8+/-0.25, and 6.2+/-0.21 weeks in the aloe-treated groups, respectively. The tumor burden and tumor yield were significantly decreased (2.0+/-0.25, 2.00+/-0.30, and 2.25+/-0.2 and 0.8+/-0.25, 0.6+/-0.32, and 0.9+/-0.28, respectively) as compared with the 7,12-dimethylbenz(a)anthracene-treated control group (3.6+/-0.10 and 3.6+/-0.19). Furthermore, treatment with aloe gel and/or extract by topical and/or oral administration resulted in a significant increase in the reduced glutathione (P< .05), DNA (P< .001), catalase (P< .05), and protein (P< .001) in the skin of mice. Conversely, lipid peroxidation levels were significantly decreased (P< .001) in the skin of mice.