ABSTRACT
Objective: The present study was conducted to screen the cytotoxicity and initiation of apoptosis in MCF-7 human breast tumour cells using the Indian sponge Acanthostylotela cornuta of the Gulf of Mannar. Methods: The crude methanol extract of A. cornuta was fractionated using a reversed phase silica gel column chromatography. The purity of the active fraction of bromopyrrole alkaloids was confirmed with Gas Chromatography-Mass Spectrometry (GCMS). The bromopyrrole alkaloids induce apoptotic changes in MCF-7 cells were studied with electrophoresis, caspase assay, and different staining analysis. The MCF-7 cells were analyzed by Flow cytometry to determine their DNA content. Results: Bromopyrrole alkaloids of A. cornuta showed cytotoxicity against MCF-7 human breast tumour cells with the IC50 value of 8.0μg/ml. The bromopyrrole compounds induced cells exhibited scatted red fluorescence, showing the presence of several residual bodies and condensation of chromatin. Caspase-3, pro-caspase-9, caspase-9 and Poly-ADP-Ribose-Polymerase (PARP) activity were occurred in bromopyrrole alkaloids treated tumour cell. The cell cycle arrest is conceivable that the compound prevented the progression of cell cycle through the G phase resulting from inhibition of survival, leading them to undergo apoptosis. Conclusion: Bromopyrrole alkaloids of A. cornuta possess antitumor activity which was arrested the G phase in cell cycle that clearly indicated its nature as that of antitumour drugs.
ABSTRACT
The marine fish Therapon jarbua was exposed to acute concentration of mercuric chloride (HgCl2). In static acute toxicity bioassays at 24, 48, 72 and 96 hr LC50 values were estimated for each concentrations such as control, 2, 1, 0.5, 0.25 and 0.125 ppm, respectively. DNA damage (single-strand break) was also studied in gill, kidney and blood tissues at single-cell levels in the specimens exposed to different acute doses of HgCl2, by applying single-cell electrophoresis (comet assay). Dose- dependent responses were observed in DNA damage in all tissues. A comparison of DNA damage in all tissue at two concentration namely, 0.125 and 0.25 ppm indicated that the gill cells (maximum damage as 249.3 and 289.7 AU) were more sensitive to the heavy metal exposure than kidney (maximum 225.17 AU) and blood cells (maximum 200.3 AU). This study explored the utility of the comet assay for in vivo laboratory studies using fish for screening the genotoxic potential for various agents.
ABSTRACT
Lichens are lower group of plants. They accumulate heavy metals and have been used as bio-indicators in pollution monitoring. Nine lichen species were collected from urban, rural and hilly areas in the southern part of Tamilnadu. Accumulation of metals differed with species and also with respect to their locations. Among the nine species, Pyxine petricola collected from urban areas showed greater accumulation of the heavy metals i.e., copper, zinc, lead, nickel, chromium and cadmium.