Study on cow ghee versus soybean oil on 7,12-dimethylbenz(a)-anthracene induced mammary carcinogenesis & expression of cyclooxygenase-2 & peroxisome proliferators activated receptor- γ in rats.

Background & objectives Breast cancer is a leading cause of cancer death in women; dietary fat is the one of the factors that influences its incidence. In the present study we investigated the effect of feeding cow ghee versus soybean oil on 7,12-dimethylbenz(a)anthracene (DMBA) induced mammary cancer in rat and expression of cyclooxygenase-2 and peroxisome proliferators activated receptor- γ (PPAR-γ) in mammary gland. Methods Two groups of 21 day old female rats (30 each) were fed for 44 wk diet containing cow ghee or soybean oil (10%). The animals were given DMBA (30mg/kg body weight) through oral intubation after 5 wk feeding. Another two groups (8 each) fed similarly but not given DMBA served as control for the gene expression study. Results In DMBA treated groups, the animal fed soybean oil had higher tumour incidence (65.4%), tumour weight (6.18 g) and tumour volume (6285 mm3) compared to those fed cow ghee (26.6%, 1.67 g, 1925 mm3, respectively). Tumour latency period was 23 wk on soybean oil compared to 27 wk on cow ghee. Histological analysis of tumours showed that the progression of carcinogenesis was more rapid on soybean oil than on cow ghee. The expression of cyclooxygenase-2 was observed only in DMBA treated rats and it was significantly less on cow ghee than on soybean oil. The expression of PPAR-γ was significantly more on cow ghee than on soybean oil. Interpretation & conclusions Our results show that dietary cow ghee opposed to soybean oil attenuates mammary carcinogenesis induced by DMBA; and the effect is mediated by decreased expression of cyclooxygenase-2 and increased expression of PPAR-γ in the former group.

In vivo alternative testing with zebrafish in ecotoxicology

Although rodents have previously been used in ecotoxicological studies, they are expensive, time-consuming, and are limited by strict legal restrictions. The present study used a zebrafish (Danio rerio) model and generated data that was useful for extrapolating toxicant effects in this system to that of humans. Here we treated embryos of the naive-type as well as a transiently transfected zebrafish liver cell line carrying a plasmid (phAhREEGFP), for comparing toxicity levels with the well-known aryl hydrocarbon receptor (AhR)-binding toxicants: 3,3',4,4',5-pentachlorobiphenyl (PCB126), 2,3,7,8-tetrachlorodibenzo-p-dioxin, and 3-methylcholanthrene. These toxicants induced a concentration-dependent increase in morphological disruption, indicating toxicity at early life-stages. The transient transgenic zebrafish liver cell line was sensitive enough to these toxicants to express the CYP1A1 regulated enhanced green fluorescent protein. The findings of this study demonstrated that the zebrafish in vivo model might allow for extremely rapid and reproducible toxicological profiling of early life-stage embryo development. We have also shown that the transient transgenic zebrafish liver cell line can be used for research on AhR mechanism studies.

Abnormal pattern of lung functions in rubber factory workers.

The influence of suspended particulate matter, benzo(e) pyrene, benzo(e) pyrene and benzo(a) anthracene concentration on pulmonary lung functions ie, residual volume, total lung capacity, residual volume/total lung capacity, forced residual capacity were studied in 667 rubber factory workers during 1990-91. The respirable fraction of the particulate size (< 0.5 micron) showed high mean concentration of suspended particulate matter, benzo(a) pyrene, benzo(e) pyrene and benzo(a) anthracene in the compounding section (group III), when compared with vulcanising (group II) and packing loading (group I) units. While comparing the lung functions amongst these groups, the higher results of residual volume, residual volume/total lung capacity ratio, forced respiratory capacity and lower values of total lung capacity were observed in group III workers as compared with other two groups. And also these results seem to be correlated with the high pollutant concentrations to which group III workers were exposed, and reflect a clear combination of obstructive and restrictive pattern of lung functions in them.