Subchronic oral toxicity and growth-promoting effects of Morinda citrifolia (NONI) leaf extract in Wistar rats: biochemical, hematological, and histopathological evaluation

Abstract

With the increasing regulation of the use of antibiotic growth promoters in animal production around the world, medicinal plant extracts have garnered a significant amount of research interest as natural growth promoters and immunostimulants in laboratory and livestock animals. In the present study the subchronic orasl toxicity and growth promoting activity of leaf extract of Morinda citrifolia (noni) hydroethanolic extract were assessed in Wistar albino rats for 12 weeks. A total of 36 male Wistar rats (250 ± 10 g) were randomly divided into three groups as follows: Low Dose (50 mg/kg body weight), High Dose (100 mg/kg body weight) and Control (distilled water). Body weight gain, feed consumptison, FCR, haematological parameters, serum biochemical profile, and antioxidant enzyme activities of liver, relative organ weight and histopathological examination of the vital organs werse considered. sThe modulation of hemastological parameters had no negative effect on the physiological ranges. In the high dose group, the activity of hepatic antioxidant enzymes, i.e., superoxide dismutase, catalase and glutathione, were significantly increased (p<0.01) with a corresponding decrease in lipid peroxidation. There was mild increase in liver enzyme activities found after the administration of the drug, but there were no pathological changes in liver, kidney and spleen tissues that were due to the drug administration, except a very minor non-adverse effects were seen at the highest dose. The results showed that M. citrifolia leaf extract up to 100 mg/kg was safe and had an encouraging growth promoting and antioxidant activity, which might suggest its use as a phytogenic feed additive. A No Observed Adverse Effect Level of 100 mg/kg body weight/day is recommended for the species, sex and duration tested, thereby providing a preclinical basis for efficacy testing in target livestock species, and for the rational formulation of inclusion levels in commercial feeds.