Evaluating the estrogenic activity and toxicity of Tectona grandis leaf extract on the reproductive and endocrine system of female wistar rats

Abstract

Female reproductive complications continue to be a major health challenge worldwide. Medicinal plants richer in secondary metabolites such as phytoestrogens have been used over decades for the treatment of reproductive health problems like infertility, with limited knowledge on their toxicities. The present study was designed to evaluate the estrogenic potential and safety of Tectona grandis leaves extract on female wistar rats. Following acclimatization and pre-evaluation of the estrous cycle, female wistar rats, 6 weeks old were placed in groups of 3 animals each and T. grandis extracts administered daily in graded doses of 500, 1000, 2000mg/Kg body weight against controls for 28 days (Sub-acute toxicity). A dose dependent increase in 17-Beta estradiol was observed in the serum and ovary homogenates versus an increase in cholesterol when compared to the control groups. Results from the three animals per group showed an increase in the weights of the animals and a non-significant increase in alanine aminotransferase (ALT), white blood cells, haemoglobin and haematocrit at the dose of 2000 mg/kg. Also, there was no significant difference in the organ weights and histopathological examinations of necropsied animals showed no abnormalities in the various organs. T. grandis leave extract contains phytochemicals such as lignans that can be converted by microflora to phytoestrogens, which can compete with endogenous estrogen for the estrogen receptor potentiating similar activities like estrogens. This indicates that T. grandis could be explored as hormonal replacement therapies in infertility, menopausal and/or breast cancer related problems. Keywords: 17-β-estradiol, Tectona grandis, lignans, phytoestrogens, toxicity, hormonal replacement therapy