The Antitumor Properties of a Metal-free Ligand and Local Herbal Remedy against N-methyl-N-nitrosourea (MNU)-induced Carcinomas in Albino Mice

Aims: We report a pilot study evaluating the antitumor properties of a Schiff base ligand, 3-[2,4-dihydro-1H-inden-4-yl imino)methyl] napthalen-2-ol] and aqueous herbal extract against N-methyl-N-Nitrosourea (MNU)-induced carcinomas in albino mice via hematology; and histology of the liver, thymus, spleen and small intestine.

Study Design: Twenty-three male and female mice respectively received a single intra-peritoneal dose of 60 mg/kg MNU. Seven males and seven females served as controls.

Place and Duration of Study: Department of Zoology, University of Ibadan, Ibadan, Nigeria; January-July 2012.

Methodology: Five months post-induction, four induced males and four females of surviving mice were given a single intra-peritoneal dose (25 mg/kg) of ligand; three induced males and three females served as negative control. Three induced mice of both sexes respectively received daily doses of 136 mg/mL extract orally at an innoculation volume of 0.3 mL/mouse for 30 days (total dosage= 4.08 g/30 ml;) and monitored for two months. Depending on mortality, 1-3 mice/group were sacrificed at experiment termination and subsequently processed for hematology and histology.

Results: Tumor incidence was 13% (male) and 17% (female) respectively. There was no significant difference (P= .05) between hematology of control and statistically comparable experimental groups. Histology of control organs showed no abnormal features. Hepatocytes of ligand-treated mice showed cytoplasmic disintegration and presence of pleomorphic nuclei; while the extract-treated group showed progressive reversal towards normal with hepatocytic regeneration, fairly uniformly-shaped nuclei and bi-nucleate cells. Spleen of the ligand-treated group showed moderate lymphoid depletion, while the extract-treated group showed a regeneration of the central artery and red pulp with no visible lesion. The extract-treated thymus showed a gradual reversal of some of its Hassall’s corpuscles. The small intestine of the ligand-treated mice showed gross erosion of the intestinal villi; while intestinal mucosa regeneration was observed in the extract-treated group.

Conclusion: The herbal extract may possess some antitumor properties, thus necessitating further investigations, while the ligand showed little or no activity in vivo.