Piscicidal activity of alcoholic extract of <i>Nerium indicum</i> leaf and their biochemical stress response on fish metabolism

Abstract

Laboratory evaluations were made to assess the piscicidal activity of ethyl alcohol extract of Nerium indicum leaf against predatory fish Channa punctatus and their ultimate mode of action on fish metabolism. Toxicity experiments show there was significant negative correlation between LC values and exposure periods i.e. LC₅₀ value decreased from 66.32 mg/L (24h) to 44.96 mg/L (96h). Biochemical studies show that after exposure to sub lethal doses of alcoholic extract, pyruvate level and activities of acetylcholinesterase and cytochrome oxidase significantly decreased while lactate level and activities of alanine aminotransferase and aspartate amino transferase were significantly enhanced in both liver and muscle tissues of Channa punctatus. The alterations in all the above biochemical parameters were significantly (P<0.05) time and dose dependent. There was a significant recovery observed in all the above biochemical parameters, in both liver and muscle tissues of fish after the seventh day of the withdrawal of treatment Thus it was believed that alcoholic extract of Nerium indicum leaf can be used in aquatic environment for controlling predatory fish Channa punctatus population. Their piscicidal activity may be due to their adverse effect on respiratory as well as energy production of fish. The reversible nature of the piscicidal action could be advantageous in aquatic environment.


Key Words: Piscicidal activity, Alcoholic extract, Nerium indicum, fish metabolism, Channa punctatus.


Afr. J. Trad. CAM (2004) 1: 15-29