<i>Moringa oleifera</i> alleviates lead nitrate induced hepatotoxicity in <i>Oreochromis niloticus</i> through regulating JAK/STAT signaling pathway, hematological, histological, immunological and antioxidant parameters

Abstract Nile Tilapia (Oreochromis niloticus) is a freshwater fish which is widely consumed as a food source. However, the exposure of these fish to environmental toxicants such as heavy metals may cause significant damage and result in mortality. Moringa (Moringa oleifera) is a widely used plant for its nutritional and medicinal uses. The current study was designed to assess the protective efficacy of Moringa extract against lead nitrate (LN) induced hepatotoxicity in O. niloticus. For this purpose, 160 adult tilapia fish were randomly assorted into four groups i.e. control, Moringa supplemented, LN treated and LN + Moringa co-treated groups. Fish were exposed to LN at the concentration of 8.8 mg/L, while Moringa was supplemented at the rate of 1% of fish body weight daily for 30 days. The results of our experiment revealed that LN exposure significantly disturbed hematological parameters of tilapia. Moreover, it was observed that LN treatment increased hepatic enzymes (AST, ALT and ALP) and metabolic markers (glucose and cortisol) while reducing serum protein (total protein, albumin, globulin) levels. Furthermore, it reduced the activities of antioxidant enzymes (SOD, TAC, CAT and GSH) and increased lipid peroxidation marker (MDA) and immunological parameters (LYZ, RBA, IgM) levels as well as induced multiple histopathological damages in hepatic tissues. It was also observed that LN disturbed JAK/STAT signaling pathway and increased the expressions of JAK2, STAT3, Bax, Caspase-3 and Caspase-9 and reduced Bcl-2 expressions. Nevertheless, Moringa supplementation mitigated all these damages in O. niloticus. This protective efficacy of Moringa may be attributed to its antioxidant and JAK/STAT signaling pathway regulating characteristics.