Fig. 4.

Effect of E. bonariensis on OVX/D-Gal-induced hippocampal histopathological changes. Representative H and E photomicrographs (hippocampal region) of all experimental groups (n = 2); magnification: H and E × 200 A SO group showing normal structure of hippocampus with normal structure of pyramidal cells (N); B OVX/D-Gal group showing vacuolated pyramidal cells (V) and pyknotic nuclei (P); C Donepezil group showing nearly normal architecture of the pyramidal cells of hippocampus with few pyknotic nuclei (P); D E. bonariensis 50 mg/kg group showing moderate vacuolated pyramidal cells (V) and pyknotic nuclei (P); E E. bonariensis 100 mg/kg group showing noticeable improvement of the hippocampus showed nearly normal appearance of most of the neurons, normal vesicular nucleoli. Some neurons showed minimal pyknotic nuclei (P); F E. bonariensis 200 mg/kg group showing nearly normal structure of pyramidal cells with mild pyknotic nuclei (P). Rats underwent either SO or OVX, and after 5 days, they received D-Gal (150 mg/kg/day, i.p) for 42 days. OVX/D-Gal-subjected rats were orally treated with donepezil (5 mg/kg/day) or the alcoholic extract of E. bonariensis at three different doses (50, 100, and 200 mg/kg/day) for 42 days, given 1 h prior to D-Gal. One day after behavioral testing (day 43), rats were decapitated, and the brains were separated for histopathological examination. OVX ovariectomy, D-Gal D-galactose, SO sham operation