Ganoderic acid A protects lens epithelial cells from UVB irradiation and delays lens opacity / 中国天然药物

A contributory role of oxidative stress and protection by antioxidant nutrients have been suspected in cataract formation. Ganoderic acid A (GAA), an effective lanostane triterpene, is widely reported as an antioxidant. The aim of this study is to investigate the potential effects of GAA on cataract formation. After lens epithelial cells (LECs) were exposed to UVB radiation for different periods, cell viability, apoptosis-related protein levels, malondialdehyde (MDA) and superoxide dismutase (SOD) activities were monitored. We found that cell viability, the Bcl-2/Bax ratio and SOD activity were increased, while Cleaved caspase-3 levels and MDA activity were decreased compared with those in UVB-impaired LECs after GAA treated. Furthermore, GAA activated PI3K/AKT in UVB-impaired LECs and effectively delayed the occurrence of lens opacity in vitro. In conclusion, these findings demonstrated that GAA exhibited protective functions in SRA01/04 cells and rat lenses against UVB-evoked impairment through elevating cell viability and antioxidant activity, inhibiting cell apoptosis, activating the PI3K/AKT pathway and delaying lens opacity.

Therapeutic effect of Aloe vera and silver nanoparticles on acid-induced oral ulcer in gamma-irradiated mice

Abstract Radiation combined injury, a life-threatening condition, has higher mortality than simple radiation injury. The aim of the present study was to analyze the efficiency of Aloe vera and silver nanoparticles in improving the healing of ulcerated oral mucosa after irradiation. Thirty male Albino mice were divided into five groups: control, radiation, Aloe vera (AV), silver nanoparticles (NS), and AV+NS. The mice were exposed to whole body 6Gy gamma-radiation. After one hour, 20% acetic acid was injected into the submucosal layer of the lower lip for ulcer induction. The animals received topical treatment with the assigned substances for 5 days. Lip specimens were subjected to hematoxylin and eosin and anti alpha-smooth muscle actin immunohistochemical staining. Results demonstrated occurance of ulcer three days post irradiation in all groups except in the AV+NS group where only epithelial detachment was developed. After seven days, data revealed persistent ulcer in radiation group, and almost normal epithelium in the AV+NS group. A significant reduction of epithelial thickness was detected in all groups at the third day as compared to control. At the seventh day, only the AV+NS group restored the epithelial thickness. Area percent of alpha-smooth muscle actin expression was significantly decreased in radiation group at the third day followed by significant increase at the seventh day. However, all treatment groups showed significant increase in alpha-smooth muscle actin at the third day, which decreased to normal level at the seventh day. Our study demonstrated the efficiency of Aloe vera and silver nanoparticles in enhancing ulcer healing after irradiation.

Analysis of micronuclei in buccal epithelial cells in patients subjected to panoramic radiography.

Context: Ionizing radiation is a well-known carcinogen in humans. Chromosomal aberrations and formation of micronuclei in cell cytoplasm are early biological evidence of carcinogenesis. Aims: This study was undertaken to assess the genotoxic effect of panoramic radiography in the buccal epithelial cells. Materials and Methods: The study included 60 healthy individuals (median age 23.5 years; age range 12-65 years) who underwent panoramic radiographic examination. Exfoliated buccal epithelial cells were obtained immediately before and 10 days after radiation exposure. The cells were stained with Giemsa and evaluated for micronuclei by scoring 1000 cells per sample. Statistical analysis used: The paired 't ' test was used to find out the significance of difference in the number of micronuclei before and after x-ray exposure. The Karl Pearson correlation coefficient was used to find out the correlation between age and micronucleated cell frequencies and number of micronucleus per 1000 cells. The ANOVA test was used to find out if there were significant differences in micronucleated cell frequencies between different age-groups. Student's unpaired 't' test was used to find out the significance of difference in micronucleated cell frequencies and number of micronucleus per 1000 cells between genders. Results: The paired 't' test showed that micronucleated cell frequencies (P = 0.02) and number of micronucleus per 1000 cells (P = 0.047) were significantly higher after radiographic exposure. The mean number of micronucleated cells before and after radiation exposure were 0.48 ± 0.14 and 0.51 ± 0.15, respectively. There was statistically significant increase in the frequency of micronuclei in buccal epithelial cells after exposure to panoramic radiography. The correlation of micronucleus frequency with age and gender was statistically nonsignificant. Conclusions: The results indicate that panoramic radiography may induce genotoxic effects in buccal epithelial cells. Considering this risk, panoramic radiography should be used cautiously.

Mechanisms of Apoptosis on Human Lens Epithelium after Ultraviolet Light Exposure

PURPOSE: The purpose of this study is to understand the mechanism of apoptosis occurring on a cultured human lens epithelial cell line after exposure to ultraviolet (UV) light. We intended to confirm the presence of cellular toxicity and apoptosis and to reveal the roles of p53, caspase 3 and NOXA in these processes. METHODS: Cells were irradiated with an ultraviolet lamp. Cellular toxicity was measured by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Hoechst staining and fluorescent anti-caspase 3 antibodies were used for apoptosis investigation. The quantities of p53, caspase 3, and NOXA were measured by Western blotting for to investigate the apoptosis pathway. RESULTS: Cellular toxicity on the human lens epithelium markedly increased with time after UV exposure. On Hoechst staining, we found that apoptosis also remarkably increased after exposure to ultraviolet light, compared with a control group. In the immunochemical study using anti-caspase 3 antibodies, active caspase 3 significantly increased after exposure to ultraviolet light. On Western blotting, p53 decreased, while caspase 3 and NOXA increased. CONCLUSIONS: Exposure of cultured human lens epithelial cell lines to ultraviolet light induces apoptosis, which promotes the expression of NOXA and caspase 3 increases without increasing p53. This may suggest that UV induced apoptosis is caused by a p53-independent pathway in human lens epithelial cells.

Protective Effects of Epigallocatechin Gallate After UV Irradiation of Cultured Human Lens Epithelial Cells

PURPOSE: To evaluate the protective effects of epigallocatechin gallate (EGCG) against UV irradiation of cultured human lens epithelial cells. METHODS: We irradiated cultured human lens epithelial cells with a 30-second pulse from a UV lamp with an irradiance of 0.6 mW/cm2. Five minutes and 1 hour after UV irradiation, we administered 0, 5, 10, 15, 25, 50, or 100 uM EGCG. The cell number was measured with a microscopic counting chamber and cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: Compared to untreated cells, the total number of cultured human lens epithelial cells was markedly higher after UV irradiation. In a dose-dependent manner, viability was also higher in EGCG-treated cells. CONCLUSIONS: EGCG increased the cell count and cell viability after UV irradiation of cultured human lens epithelial cells, indicating that EGCG can protect lens epithelium against UV damage.