Curcumin as a potential non-steroidal contraceptive with spermicidal and microbicidal properties

Objective Curcumin, a component of the curry powder turmeric, has immense biological properties, including anticancer effects. The objective of this study was to determine if curcumin can provide a novel non-steroidal contraceptive having both spermicidal and microbicidal properties. Study design The effect of curcumin, with and without photosensitization, was examined on human sperm forward motility and growth of several aerobic (n = 8) and anaerobic bacteria (n = 4) and yeast (n = 7) strains implicated in vaginosis, vaginitis, and vaginal infections in women. The effect of various concentrations of curcumin on human sperm and microbes (aerobic and anaerobic bacteria and yeast) was tested. The effect on sperm was examined by counting the sperm forward motility, and on microbes by agar and broth dilutions and colony counting. Each experiment was repeated using different semen specimens, and bacteria and yeast stocks. Results Curcumin caused a concentration-dependent inhibition of sperm forward motility with a total block at ≥250 μM concentration. After photosensitization, the effective concentration to completely block sperm forward motility decreased 25-fold, now requiring only 10 μM concentration for total inhibition. Curcumin concentrations between 100 and 500 μM completely blocked the growth of all the bacteria and yeast strains tested. After photosensitization, the effective concentration to completely inhibit microbial growth decreased 10-fold for aerobic bacteria and yeast, and 5-fold for anaerobic bacteria. Conclusions These findings suggest that curcumin can block sperm function and bacteria/yeast growth. It can potentially provide an ideal non-steroidal contraceptive having both spermicidal and microbicidal properties against vaginal infections.