Androgen disruption and toxicity tests of Butea superba Roxb., a traditional herb used for treatment of erectile dysfunction, in male rats
Introduction
Hormonal disruption is currently being investigated because it may initiate a biphasic response in the human body, disturbance of endocrine function and/or hormonal replacement action. Estrogen disruption is the most investigated case, especially that resulting from phytoestrogens [1], which can cause an adverse animal physiology such as sex hormone fluctuation [2]. Phytoestrogens initiate hormonal replacement actions in impaired estrogen synthesis animals for example, ovariectomized rats [3], [4], [5] and aging monkeys [6], [7], but also initiate hormonal disruption in normal female including monkeys [8], [9], [10] and rats [11]. Androgen disruption was first recorded in fish, caused by either androgenic or anti-estrogenic substance in the environment [12] but currently no significant effect in higher vertebrates has been reported.
Butea superba Roxb. (Leguminosae) is commonly found in Thai deciduous forests and has the domestic name of “Red Kwao Krua”. The plant tubers have long been consumed as a traditional medicine for the promotion of male sexual vigor. The efficacy of the plant powder has been demonstrated in a human clinical trial with effective treatment of erectile dysfunction (ED) in Thai males [13] comparable to that seen in a worldwide clinical trial-based evaluation of sildenafil [14]. Recently, the plant products are becoming popular as traditional and alternative medicines, dietary supplements and topical products including for the promotion of male vigor. The Thai FDA has approved many traditional recipes that are comprised of B. superba as a major ingredient with limited claims for tonic purposes. We therefore setup a rat subchronic study to evaluate the possible toxicity and hormonal, especially testosterone and luteinizing hormone (LH) disruption. The results might open the possibility of not only to fix a safe dose for human consumption but also to establish the first record of androgen disruption in higher vertebrate studies.
Section snippets
Plant materials
Fresh tubers of B. superba were collected in Lampang Province, Thailand. The identification of the plant was done in comparison with the voucher specimen no. BCU 1046 [15]. The tubers were washed, sliced, oven-dried at 70 °C, and powdered to a size of 100 mesh. The freshly prepared suspension, by dissolving plant powder with distilled water in a final volume of 0.7 ml, was used for oral administration.
Animals and treatment
Adult male Wistar rats, 130 ± 10 days of age, were obtained from the National Laboratory Animal
Animal growth and histology analysis
There was no significant difference in either the growth rate measured by living body weight (Fig. 1) or the relative weight of the main body organs of male rats treated with all doses of B. superba, when compared with the control except for the increase in relative weight of the spleen (13.67%) in rats treated with 150 mg/kg BW (Table 1). However, the apparent increase in spleen weight showed no apparent dose-dependency and remains to be confirmed. The histology of the spleen, liver, kidney and
Discussion
Treatment with B. superba powder as an oral administered suspension showed no discernable adverse effect upon male rat growth rates at the doses (0–200 mg/kg BW) and duration (0–90 days) administered in this study. The results from the haematology showed a significant adverse effect on blood neutrophil and eosinophil at high (200 mg/kg BW) doses. It is possible that the high doses of plant chemicals could either influence the respective blood stem cell lineage division and differentiation within
Acknowledgements
The authors wish to thank the Graduate School and Ratchadaphiseksomphot Endowment Fund of the Research affairs of Chulalongkorn University, and the National Center for Genetic Engineering, National Science and Technology Development Agency, Ministry of Science and Technology, for grant supports.
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