Figure 6: Effect of exogenous melatonin on circulatory level of plasma testosterone in PCO rats showing significant decreased in plasma testosterone as compared to control groups of rats; Histogram represents Mean ± SE; n=6; Con=Control, L=Letrozole, L+Mel=Letrozole+Melatonin, Mel: Melatonin. Con vs. L=p<0.05; Con vs. L+Mel=p<0.05; Con vs. Mel=p<0.05; L vs. L+Mel= p<0.05.