Bioactivity and modulatory functions of Napoleona vogelii on oxidative stress-induced micronuclei and apoptotic biomarkers in mice.

Napoleona vogelii is used in traditional medicine for the management of pain, inflammatory conditions and cancer. This study was conducted to investigate the modulatory mechanisms of methanol stem bark extract of N. vogelii on induction of micronuclei, apoptotic biomarkers and in vivo antioxidant enzymes in mice. Forty male albino mice were randomly divided into eight groups (n = 5) and were administered distilled water (DW, 5 mL/kg) as negative control, 100, 200 or 400 mg/kg of the extract respectively for 28 days before the injection of cyclophosphamide (CP, 40 mg/kg) i.p. on the 28th day. The remaining groups were administered 100, 200 or 400 mg/kg of the extract only for 28 days. Twenty four hours after injection of CP or administration of the last dose of extract, animals were euthanized by cervical dislocation and blood samples collected for determination of in vivo antioxidants, the spleen harvested for immunohistochemical expression of NFκB, Bcl-2, Bax and p53. Bone marrow smears were also made for the micronucleus assay. Treatment with the extract resulted in a significant (p < 0.0001) reduction in frequency of micronucleated polychromatic erythrocytes (MNPCEs) compared to CP exposed control conferring protection of 75.09, 94.74 and 96.84% at 100, 200 or 400 mg/kg respectively. In extract and CP exposed animals, there were significant (p < 0.05) increases in GSH, GST and SOD with a corresponding significant (p < 0.05) reduction in MDA. In addition, the extract significantly downregulated cytoplasmic levels of NFκB and Bcl-2 and upregulated Bax and p53. These findings demonstrate that N. vogelli may serve as an interesting lead for chemo-preventive drug development.