ABSTRACT
Insecticidal efficacy of oils from the leaves of Cassia occidentalisand Euphorbia milii on selected insect pests was studied. The oils were extracted via Soxhletapparatus with hexane, and test insects exposed to the oils at 3 dose levels (0.2mg, 0.4mg and 0.6mg) for 24 hours. The results showed contact insecticidal activity of E. miliioil at LD50s and LD90s (mg/kg) as 0.583 and 1.108 for Periplaneta americana, 0.681 and 1.215 for Tettigonia viridissima0.488 and 0.893 for Anopheles gambaie,C. occidentalisoil gave LD50s and LD90s (mg/kg) of 0.889 and 1.689 for P. americana, 1.013 and 1.973 for T. virdissima, and 0.722 and 1.847 for Anopheles gambaie. The corresponding values for the conventional insecticide; SWAN were 0.417 and 1.017 for P. americana, 0.607 and 1.111 for T. viridissimaand 0.40 and 0.743 for A. gambaie,respectively. The GC-MS analysis of plant oils revealed for E.milii,the presenceof hexadecanoic acid, 2 hydroxy-1-(hydroxymethyl) ethyl ester; 6, 9,12,15-docosatetraenic acid methyl ester. For C. occidentalis,the presence of:phthalic acid isobutyl octyl ester; hexadecanoic acid methyl ester; 9,12-octadecadienoic acid methyl ester; 9-octadecenoic acid (z)-methyl ester; methyl stearate; phthalic acid,2-ethylhexyl isohexyl ester; decane; oleic acid; 4,7,-methano-1h-indene,3a,4,7,7a-tetrahydro and n-hexadecanoic acid were revealed. Overall, data from this study provides strong evidence that these oils possess bioactive metabolites with commendable degrees of insecticidal efficacy.
ABSTRACT
In this study, the identification of secondary metabolites was carried out alongside acute toxicity evaluation on Corchorus olitorius leaf extract (COLE). Results of phytochemical analysis of the extract revealed the presence of flavonoids (4.00±0.035 mg/100 g), steroids (0.89±0.031 mg/100 g), terpenes (1.27±0.016 mg/100 g), phenolic compounds (2.05±0.514 mg/100 g), alkaloids (3.10±0.026 mg/100 g), saponins (4.00±0.054 mg/100 g), tannins (0.32±0.044 mg/100 g) and cardiac glycoside (1.61±0.068 mg/100 g) while GCMS analysis of the extract showed the presence of 46 compounds with 2-Dodecenal having the highest concentration. 3-Methyl-1-penten-4-yn-3-ol, 2,4-Decadienal and Ethanone were also found in higher amounts. No toxicity behaviour and mortality were observed during the acute toxicity study period, even at a dose of 5000 mg/kg body. From results obtained, we conclude that Corchorus olitorius leaf extract may be a potential source of antioxidant, anti-inflammatory, anticancer and cardiovascular system modulatory agent and may be safe for use as food and medicine.