Up-Regulation of TNF-α by Ethanol Extract of Moringa Oleifera in Benzene-Induced Leukemic Wister Rat: A Possible Mechanism of Anticancer Property

Abstract

Ethanol extract of Monringa oleifera (EMO) has been shown to possess anti-cancer properties in animal models. The mechanisms of action of its anticancer properties have not been fully demonstrated. We induced leukemia in two groups of seven rats each by intravenous injection of benzene chromasolv solution (0.2 mL) 48 hourly for 4 weeks. EMO (0.2 ml of 100 mg/mL) was administered orally by gavage, after leukemia induction, daily for 4 weeks to one of the groups while the other group was not treated. The third group served as the normal control. At the end of the treatment, the rats were immobilized by cervical dislocation and blood samples were collected by cardiac puncture. Plasma concentrations of Beta-2 Microglobulin (β₂M), Perforins (PF), Interleukin-2 (IL2), Interferon-gamma (IFN-γ) and Tumour Necrosis Factor-alpha (TNF-α) were determined by standard commercial ELISA. Results showed that leukemia was induced within 4 weeks as significantly elevated leukocyte count and plasma β₂M concentrations over the baseline were noted (p < 0.05). Plasma IL2 and TNF-α were also significantly elevated while IFN-γ decreased significantly in EMO treated rats compared with untreated groups. The plasma concentration of PF remained statistically unchanged. Since IL2 and PF are associated with cytotoxicity of CD8 T lymphocytes, reduced expression of PF in the face of increasing plasma concentration of IL-2 suggests that EMO may not exert its anticancer properties via direct cytotoxicity. We thus concluded that increased expression TNF-α would translate to enhanced apoptosis and may be a possible mechanism of action.

Keywords: Moringa oleifera, anticancer mechanism, cytokines