Toxicity of lime juice on cervicovaginal and penile tissue. (A) Human cervicovaginal and (B) penile tissue explants were exposed to LiJ (diluted using normal saline) for 5, 30, 60 or 120 minutes. Juice was then removed by washing and tissue viability assessed by the method of MTT dye reduction. Data shown are expressed as percentage viability (when compared to an untreated control) andrepresent the mean ± SEM of n = 2 (cervicovaginal) or n = 3 (penile) independent tissue donors where each condition was tested in triplicate. Statistical analysis (ANOVA with Bonferroni post tests) was performed comparing LiJ treated samples with an untreated control. Those conditions causing statistically significant differences are marked with an asterisk (* p < 0.05; ** p < 0.01; *** p < 0.001). (C) The 50% toxic dose (TD50) of LiJ was determined using non-linear regression analysis for cervicovaginal (red circles) and penile (blue circles) tissue.