Histomorphological Changes in the Ovary and Uterine Horn of Female Wistar Rats Following 28-Day Oral Administration of Acacia nilotica Pod Extract

Acacia nilotica pods are extensively used in Northern Nigeria for treating reproductive disorders, yet their morphological effects on female reproductive organs remain poorly characterized. This study evaluated dose-dependent histological changes in ovarian and uterine tissues following repeated oral administration. Fifty adult female Wistar rats were divided into five groups (n=10): control (normal saline), three treatment groups (125, 250, 500 mg/kg for 28 days), and one recovery group (500 mg/kg for 28 days followed by 14-day withdrawal). Ovaries and uterine horns were examined histologically using hematoxylin-eosin staining with semi-quantitative follicular assessment. Ovarian and uterine horn weights remained unchanged across groups (p>0.05), except for modest uterine horn index elevation at 250 and 500 mg/kg (p<0.05). Uterine architecture was preserved in all groups. Ovarian histology revealed dose-dependent increases in atretic follicle density (control: 2.4±0.6 vs. 500 mg/kg: 8.2±1.1 per high-power field; p<0.01), with reduced mature follicle counts. Recovery animals showed partial reversal (5.1±0.9 atretic follicles/HPF). Corpus luteum and developing follicles persisted across groups. Aqueous Acacia nilotica pod extract induces reversible, dose-dependent ovarian follicular atresia without affecting uterine morphology, suggesting selective reproductive toxicity requiring caution in traditional use.

Key Words: Follicular atresia, ovarian histology, medicinal plant toxicity, uterine morphology