research_animalpaper2

                                        Effect of Thai bitter gourd fruits on colon carcinogenesis in rats

                     P. Kupradinun*, A. Tepsuwan*, N. Tantasi *,
                     N. Meesiripun*, A. Rungsipipat ** and WR. Kusamran *
                     *Research Division, National Cancer Institute, Bangkok, Thailand,2 Department of Veterinary Pathology, Faculty                      of Veterinary Science, Chulalongkorn University, Bangkok, Thailand,
                     *Corresponding author: E-mail : pkupradi@health.moph.go.th

                                                                                   Abstract

        Objective: Fruits of Thai bitter gourd (Mormordica charantia Linn., TBG) were widely used for food and herbal medicine for its anti-diabetes, anti-tumor, anti-viral and anti-hypertension activities. It has been previously demonstrated in our laboratory that it possesses phase II detoxificating enzymes inducing property, as well as the ability to reduce phase I carcinogen activating enzyme activities in rat liver (1). In addition, they were able to prevent micronucleus formation in mouse peripheral reticulocytes induced by cyclophosphamide, an indirect-acting clastogen (2) and also partially inhibited 7,12-dimethylbenz(a)anthracene-induced mammary gland carcinogenesis in female Sprague-Dawley rats (3). In this study, we therefore examined the chemopreventive effect of Thai bitter gourd fruits on azoxymethane (AOM)-induced colon carcinogenesis in rats.
        Methods: Male Wistar rats, 5-6 weeks old, were fed with AIN-76 semi-purified diets containing 5% and 10% ground freeze-dried TBG for 2 weeks prior to, during and 1 week after the completion of AOM administration (15 mg/kg once a week for 2 weeks). All animals were sacrificed 8 months later. The colon was visually observed for any tumor and the tumors were counted and measured for the size and processed for histopathological examination by conventional methods. The significant difference in the incidence of tumor between experimental and control groups was assessed by statistical techniques described by Peto et al. 1980, where as that of the number of tumors per rat, body and liver weights were analyzed using One-Way ANOVA.
        Results: It was found that rats fed diet containing TBG developed significantly higher incidence as well as the multiplicities of colon tumors than the control group.
        Conclusions: These results demonstrated that Thai bitter gourd fruits had no preventive potential against AOM-induced colon carcinogenesis in rat. On the contrary, it may promote colon tumor development in rat. These findings also suggest that Thai bitter gourd fruits may have different chemopreventive potential on different organs.
        References:

Kusamran WR, Ratanavila A, Tepsuwan A. Effects of neem flowers, Thai and Chinese bitter gourd fruits and sweet basil leaves on hepatic mono-oxygenase and glutathione-S-transferase activities and in vitro metabolic activation of chemical carcinogens in rats. Food Chem Toxicol 1998; 36: 475-37.
Kupradinun P, Tepsuwan A, Kusamran WR. Anticlastogenic potentials of neem flowers, cassia leaves and Thai bitter gourd fruits in erythrocyte micronucleus assay in the mouse. Abstract of The 3rd International Conference on Environmental Mutagens in Human Populations, November 29-December 4, 1998, p.121.
Kusamran WR, Tepsuwan A, Kupradinun P. Antimutagenic and anticarcinogenic potential of some Thai vegetables. Mutat Res 1998; 402: 247-58.

Key words: Thai bitter gourd , Mormordica charantia Linn., colon carcinogenesis, AOM

Presented at The Second International Conference on Natural Products for Health and Beauty (NATPRO), 17-19 December, 2008