Figure 4: Effect of exogenous melatonin on circulatory level of plasma estrogen level in PCO rats showing recovery of estrogen with significant increase as compared to control rat group. Histogram represents Mean+SE; n=6; Con: Control, L: Letrozole, L +Mel=Letrozole+Melatonin, Mel: Melatonin. Con vs. L=p<0.01, Con vs. L+Mel=p<0.01, Con vs. Mel=p<0.01, L vs. L+Mel=p<0.01.