Can curcumin provide an ideal contraceptive?

The population explosion, unintended pregnancies, sexually transmitted diseases, and cancer (cervical and breast) continue to cause major public health issues worldwide. Curcumin, diferuloyl methane, the yellow pigment component of the curry spice turmeric (Curcuma longa), has immense biological effects and has recently drawn considerable attention. Curcumin has antibacterial, antiviral, antiinflammatory, and anticancer properties. It has shown a lack of toxicity in animals and human clinical trials. Yet, its effect on reproduction has not been examined. The present study was conducted to examine if curcumin affects sperm function in vitro and fertility in vivo. Sperm (human and murine) were collected and incubated with curcumin to examine the effect on motility, capacitation/acrosome reaction, and in vitro fertilization. The effect on in vivo fertility using the mouse model was also examined. Incubation of sperm with curcumin caused a concentration-dependent decrease in sperm forward motility, capacitation/acrosome reaction, and murine fertilization in vitro. At higher concentrations, there was a complete block of sperm motility and function within 5-15 min. Administration of curcumin, especially intravaginally, caused a significant (P<0.001) reduction in fertility. The antifertility effect of curcumin was reversible. This is the first study to report the inhibitory effect of curcumin on sperm function, fertilization, and fertility. The findings suggest that curcumin may constitute a double-edged sword to block conception, infection, and cancer, thus providing an ideal contraceptive.