EVALUATION OF THE TOXIC EFFECTS OF THE BIO-COAGULANT MORINGA OLEIFERA (SEED POWDER) USING ZEBRA FISH AS A MODEL

摘要

Moringa oleifera (Moringaceae) seed powder contains polyelectrolytes which constitute active ingredients for water purification and is being employed as a bio-coagulant. Indiscriminate use of such materials to purify water can be toxic to various cultivable aquatic species. The present work assessed the lethal and sub-lethal effects of the aqueous suspension of M. oleifera seeds using zebra fish model. Static bioassays were carried out on Danio rerio exposed to different concentrations of aqueous extract and the 96-h median lethal concentration (LC_(50)) was found to be 308 mgL~(-1) and 1/10~(th) of this viz. 30.8 mgL~(-1) was considered as sub-lethal concentration. Toxic manifestations such as hyper secretion of mucus, surfacing, darting movements, loss of balance, irregular swimming patterns were noticed in the fish exposed to lethal concentration. M. oleifera seed extract was found to be toxic and induced mortality in fish from 24 h to 96 h, demonstrating a linear and positive correlation with both the concentration and duration of the exposure. The present study also examined the toxic effects of seed powder suspension on vital biochemical constituents such as glycogen and total protein content in gill and muscle tissues of the fish. Significant decrease (p<0.05) was observed in glycogen and protein at the end of 96 h in gill and muscle tissues both in lethal and sub-lethal exposures suggesting that aqueous extract of M.oleifera seeds is moderately toxic even at low doses.