The Ameliorative Effect of Bitter Leaf and Utazi Leaf Ethanolic Extract on the Antioxidant Responses of Claris Gariepinus Fingerlings Treated with Diclofenac

Abstract

Antioxidants are of great importance in controlling oxidative stress in fish and improving productivity. Synthetic antioxidants have been used traditionally in aquculture, but this have raised concern because of their potential adverse effect on human and the environment. However, there is growing interest in natural antioxidants derived from plants as safer and more sustainable alternatives. This study was designed to investigate the ameliorative effect of two medicinal plants; bitter leaf (Vernonia amygdalina) and utazi leaf (Gongronema latifolium) on the antioxidant responses of African catfish (Clarias gariepinus) fingerlings exposed to diclofenac (DCF). eight-week-old healthy C. gariepinus fingerlings with a mean weight of 1.31 ± 0.14 g were exposed to different concentrations of bitter leaf extract (BLE) (6% body weight) or utazi leaf extract (ULE) (6% body weight) and diclofenac (0.4 mg/L) after a series of range-finding tests. Groups A and B were fed with the control diet (CT) without and with exposure to 0.4 mg/l of DCF, respectively. Groups C and E were fed with 6% BLE-supplemented diets without and with exposure to 0.4 mg/l of DCF, respectively. Groups D and F were fed with 6% ULE-supplemented diets without and with exposure to 0.4 mg/l of DCF, respectively. Liver tissues of the experimental fishes were collected on day 14th and 28th for the assessment of antioxidant properties. MDA, hydroxyl radical, catalase, nitric oxide and pH increased significantly in fishes treated with BLE (6.30±0.14to 91.50±2.12), as compared to their control. MDA (30.53±0.44 to 43.35±3.47) and catalase (29.17±0.55 to 40.60±0.14) decreased in the fishes exposed to diclofenac. It can be deduced that the given concentration of BLE and ULE can cause significant alteration in the antioxidant parameter of C. gariepinus. This may suggest that they have antioxidant activity and / or free radical scavenging activity.