Effect of <i>Stachytarpheta cayennensis</i> essential oil on liver function and oxidative stress markers in Calabar, Nigeria

The effect of essential oil from the leaves of Stachytarpheta cayennensis (a potential bio-pesticidal agent) on some biochemical indices of Wistar rats was tested to determine the safety of this oil on non-target organisms. Twenty-eight (28) albino Wistar rats weighing between 150-180g were divided into seven groups of four rats each. Group A served as negative control, B1, B2, and B3 were exposed to 500 mg, 300 mg and 150 mg/kg body weight of a synthetic insecticide (BNC) while S1, S2, S3 were exposed to 5000, 3000 and 1500 mg/kg body weight of Stachytarpheta cayennensis essential oil. After twenty-eight days, blood samples were collected and tested for liver function markers: aspartate transaminase, alanine transaminase, alkaline phosphatase, and oxidative stress markers: superoxide dismutase, catalase, glutathione peroxidase, and hydrogen peroxide. Liver enzyme activities were higher (p < 0.05) in the BNC exposed rats compared to the control and essential oil exposed groups. Superoxide dismutase (SOD) and catalase (CAT) activities decreased significantly (p < 0.05) while glutathione peroxidase and hydrogen peroxide concentrations increased in the BNC exposed groups relative to the control group. The essential oil was milder in its effects on tested biochemical indices, and may hold better promises than the synthetic pesticide in terms of safety.