The Effects of Mucuna pruriens and Basella alba Extracts on Sex Reversal in Rainbow Trout (Oncorhynchus mykiss)

Abstract

The use of synthetic steroids for sex reversal in various fish is widespread, but due to the potential dangers of these types of compounds, the use of phytochemicals has been explored as a suitable natural alternative. In this experiment, the effects of extracts of Mucuna pruriens seeds and Basella alba leaves on sex reversal in Oncorhynchus mykiss were investigated. Fifteen-days-old rainbow trout larvae (mean weight: 0.123 ± 0.001 g) were fed experimental diets containing 17 α-methyltestosterone (MT) (60, 90 mg/kg diet), ethanol extract of B. alba leaves (1.0, 2.0 g/kg diet), and methanol extract of M. pruriens seeds (0.1, 0.2 g/kg diet) for 90 days. After 90 days, the experimental diets were replaced with the basal diet until 10 months of age. The control group was fed the basal diet. At the end of the experiment, growth factors, survival (%), intersex (%), and masculinization (%) were measured. The feed conversion ratio and specific growth rate in all experimental groups were not significantly different from those in the control group ( $P>0.05$ ). The highest significant percentage of intersex (6.03 ± 3.53%) and the lowest percentage of survival (72.33 ± 2.51%) were observed in the treatment with 90 mg MT/kg compared with the other treatments ( $P>0.05$ ). The percentage of intersexuality was significantly lower in the groups fed with plant extract than in the groups fed with MT ( $P<0.05$ ). The percentage of intersexuality was significantly lower in the groups fed with plant extract than in the groups fed with MT. The highest percentage of masculinization was observed in the groups fed with M. pruriens extract (0.2 g/kg) (61.75 ± 17.16%) and MT (90 mg/kg) (68.62 ± 1.82%). Moreover, masculinization was significantly higher in all experimental groups than in the control group ( $P>0.05$ ). There were significantly more males (%) in all experimental groups than in the control group. In conclusion, extracts of M. pruriens and B. alba can be used as an environmentally friendly and safe alternative to MT to induce masculinization of rainbow trout.