OBJECTIVE: This study aimed to determine the effects of garlic (Allium sativum) on N-Methyl-N-Nitrosourea induced transitional carcinoma in Wistar rats.

METHODOLOGY: Transitional cell carcinoma was induced in thirty male, age-matched Wistar rats (45-50 days old) through intravesical instillation of 0.1mL of N-Methyl-N-Nitrosourea. They were divided into five treatment groups (0.1 mL of NSS; 0.1 mL of Mitomycin C; 0.1 mL of aqueous garlic extract in 10 mg/kg, 20 mg/kg, and 40 mg/kg given daily for the duration of the study); with one rat sacrificed every week (starting two weeks from tumor induction) until all rats were sacrificed after one month. The urinary bladders of the rats were subjected to histopathologic examination by a single veterinary pathologist. One-way ANOVA was used to compare mitotic index, papillomatous growth and vascularization of the specimens at Day 14 (baseline), 21 and 28. A P-value of less than 0.05 was used to detect significant difference.

RESULTS: Statistical analysis comparing mitotic index, papillomatous growth and vascularization showed no significant difference in the indices between the five treatment groups. It can be seen through that the P-value (0.144) for papillomatous growth was the smallest, which may indicate a trend towards a decrease in tumor growth at Day 28 for Mitomycin C and Garlic 40 mg/kg.

CONCLUSIONS: This preliminary study showed a favorable trend towards decreased papillomatous growth in the MNU induced rat bladder carcinoma treated with aqueous extract of Garlic (Allium sativum) at a higher dose and longer duration of time.