Effect of Triptolide on Vital Organs, Blood Biochemical Parameters and Histomorphology of Testis in Male Bandicota Bengalensis

Present study reports the effect of triptolide in male Bandicota bengalensis. One group of rats was kept as vehicle control and the other three groups were fed on bait containing 0.15, 0.2 and 0.25% triptolide. Autopsy of rats immediately after 15 days of treatment period revealed no significant effect on weights of vital organs. A significant (P ≤ 0.05) increase in plasma levels of total proteins, alkaline and acid phosphatases and alanine and aspartate aminotransferases in response to stress induced by triptolide was observed in treated groups of rats. A significant (P ≤ 0.05) effect of treatment was also observed on histomorphology of testis in the form of decrease in seminiferous tubule diameter and number of various spermatogenic cells. Giant cells containing several round nuclei within a single cytoplasmic boundary were also observed in treated rats. Present studies suggest the antifertility potential of triptolide against male B. bengalensis. Introduction Rodents constitute the largest and most successful group of mammals worldwide. Among different rodent species, lesser bandicoot rat, Bandicota bengalensis Gray and Hardwicke has been reported as the most detrimental pest. It is the predominant species inhabiting irrigated crop fields and causing heavy losses in Punjab, India (Singla and Parshad 2010, Singla and Babbar 2010, 2012). The species also acts as reservoir of a number of parasites of zoonotic importance (Singla et al 2008, 2013). The economic losses and health problems associated with this pest species emphasize the need to develop techniques for its management. The use of rodenticides is the main approach being followed to tackle rodent problems all over the world. However, the excessive use of rodenticides have resulted in non target toxicity hazards (Brakes and Smith, 2005) in addition to development of resistance among animals (Pelz and Klemann 2004). Moreover, due to their high rate of reproduction, rodents rapidly rebuildup their population after a successful control operation with rodenticides (Shilova and Tchabovsky 2009). So the challenge is to develop strategies which can reduce the reproductive output of rodents and be effective in long term. Triptolide, a diterpenoid triepoxide obtained from Tripterygium wilfordii Hook, has several forms of pharmacological activities including anti-inflammatory, anti-fertility and anticancer activities (Zhang et al 2010). However, the clinical use of triptolide is known to present several practical disadvantages mainly due to its lower water solubility such as toxicity towards the heart, liver and kidney; reproductive dysfunction and hematopoietic dysfunction (Yang et al 2012, Zhang et al 2011). Earlier studies on antifertility effects of triptolide were conducted in laboratory rats and mice keeping in view the development of an oral human contraceptive (Lue et al 1998, Sinha Hikim et al 2000, Huynh et al 2000, Ni et al 2008, Liu et al 2010). Deng et al (2011) studied antifertility potential of oral doses of extracts of T. hypoglaucum containing triptolide against Mongolian gerbils keeping in view their management. In India, for the first time, Singla et al (2013) reported antifertility potential of triptolide fed in cereal based bait against house rat, Rattus rattus. Our previous studies (Dhar and Singla 2013) have reported complete inhibition of reproduction in female B. bengalensis paired with male rats treated with 0.2 and 0.25% triptolide in bait immediately after treatment withdrawal. Autopsy of rats immediately after termination of treatment have revealed significant effect of triptolide treatment on weights reproductive organs, sperm motility, viability, density and sperm morphology. Present studies report the effect of triptolide treatment on weights of vital organs, blood biochemical parameters and histomorphology of testes in male B. bengalensis. Material and Methods The present study was carried out in the Animal House Laboratory, Department of Zoology, Punjab Ag ricultural University, Ludhiana, India. Collection and maintenance of animals Mature and healthy male lesser bandicoot rat, B. bengalensis were live-trapped with multi-catch rat traps from crop fields in and around Ludhiana. In the laboratory, rats were acclimatized individually in cages for 10-15 days before the experiment with food and water provided ad libitum. Food consisted of a loose mixture of cracked wheat, powdered sugar and groundnut oil (WSO bait) at a ratio of 96:2:2. Proper hygienic conditions were maintained. Approval of the Institutional Animal Ethics Committee was obtained for the use of animals. Treatment Triptolide (molecular formula C20H24O6, molecular weight 360.41) was kindly supplied by Pidilite Indus tries, New Delhi, India. Rats (n = 20) were divided into 4 groups of 5 rats each. The average body weight of rats in different groups ranged from 248 to 311.2 g. There was no significant difference in average body weight of rats among the four groups. Rats of groups II–IV were fed on bait containing 0.15, 0.2 and 0.25% triptolide, respectively for 15 days in bi-choice with WSO bait. Treatment bait was prepared by mixing the de sired concentration of triptolide in a mixture of cracked wheat and powdered sugar (98:2). Triptolide was mixed in bait after being dissolved in vehicle (1% sodium carboxy methyl cellulose solution). Rats of group I, fed on WSO bait containing vehicle were kept as untreated control. Water was provided ad libitum throughout the treatment. Effect on weights of vital organs At autopsy of rats immediately after termination of treat