Fig. 4.

Masson's trichrome staining of male rat penile tissue (corpus cavernosum smooth muscle) as seen under light microscope (40×). Smooth muscle was stained as pink and collagen was stained as blue. In aged rat penile tissue collagen level had increased (intensity of blue color was more) and smooth muscle level had decreased in comparison to young rats. Cinnamomum cassia methanol extract (CCME) and sildenafil treatment decreased collagen level and increased smooth muscle level in aged rat penile tissue in comparison to age matched control.