Effect of Ocimum basilicum extract on cadmium-induced testicular histomorphometric and immunohistochemical alterations in albino rats

Abstract

The present study examined the efficacy of Ocimum basilicum (basil) extract, a natural herb, with antioxidant properties, against testicular toxicity induced by cadmium (Cd), which is one of the most important toxic heavy metals. The intoxicated rats showed significant alterations in the testicular tissue including decreased seminiferous epithelium height and changes in the arrangement of spermatogenic layers. Hypospermatogensis with cytoplasmic vacuolization and pyknotic nuclei were observed. Intertubular hemorrahage and absence of spermatozoa were noted. Decreased cell proliferation was reflected by a decrease in Ki-67 expression, whereas the increase in apoptotic rate was associated with a decrease in the Bcl/Bax ratio. Concomitant treatment with aqueous basil extract led to an improvement in histological, morphometrical and immunohistochemical changes induced by Cd. The beneficial effects of basil extract could be attributed to its antioxidant properties.

Keywords: Apoptosis; Cadmium; Ki-67; Ocimum basilicum; Rats; Testis.

Fig. 1

(A) Section in testis of a control rat showing normal seminiferous tubules. S, sperms; IT, interstitial tissue. (B) Section in testis of a rat treated with Cd showing intertubular hemorrhage (H) and large vacuoles (arrow). (C) Section in testis of a rat treated with Cd showing degenerated germ cells with pyknotic nuclei (p) and degenerated interstitial tissue (D). (D) Section in testis of a rat treated with Cd and Ocimum showing increase of spermatogenic cells (A-D, ×400).

Fig. 2

Change in diameter of seminiferous tubules (A) and germ epithelial height (B) of testes of different groups.

Fig. 3

Change in tunica albogenia (TA) and basal lamina (BL) in testes of different animal groups.

Fig. 4

(A) Weak expression of Bcl-2 in germ cells of a rat treated with Cd. (B) An increase in expression of Bcl-2 after treatment with Cd+Ocimum (A and B, ×400).

Fig. 5

(A) Section in testis of a rat treated with Cd showing increase of Bax expression in Leydig cells. (B) Section in testis of a rat treated with Cd+Ocimum showing decrease of Bax expression (A and B, ×400).

Fig. 6

(A) Section in testis of a control rat showing marked expression of Ki-67. (B) Section in testis of a rat treated with Cd showing decrease of Ki-67 expression (C). An increase in expression of Ki-67 after treatment with Cd+Ocimum (A-C, ×400).