Investigating the Effect of Cumin (Cuminum cyminum L.) Hydroalcoholic Extract on the Incidence of Passive Avoidance Learning in Gonadectomized Male Wistar Rats

Abstract

Background: Learning and memory are fundamental to the survival of human life. In view of that, a relationship exists between age-related forgetfulness and changes in sex hormone levels. Objectives: Respecting the benefits of cumin (Cuminum cyminum L.) for sex hormones, this study investigated the effect of cumin hydroalcoholic extract (HAE) on learning and memory in gonadectomized (GDX) male Wistar rats. Methods: First, cumin seeds were purchased and identified by the herbarium affiliated with Islamic Azad University (IAU), Qom branch, Qom, Iran. The hydroalcoholic extract (HAE) was then extracted using a Soxhlet apparatus, and cumin powder was prepared using a drying oven. A total of 48 male Wistar rats (weighing 250 ± 50 g) were divided into eight groups: A normal group treated with dimethyl sulfoxide (DMSO), three normal groups receiving cumin HAE doses of 25, 50, and 100 mg/kg, a GDX group treated with DMSO, and three GDX groups receiving cumin HAE doses of 25, 50, and 100 mg/kg. Following the surgical procedure to remove both testes, intraperitoneal (IP) injections were administered. Half an hour later, learning and memory tasks were conducted using the Shuttle box, and the step-through latency (STL) as the standard index of passive avoidance learning (PAL) was recorded for 10 minutes. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey's test. Results: The GDX male Wistar rats receiving DMSO experienced a significant decline in STL compared to the normal group treated in the same manner (P < 0.001). The rats in the GDX groups receiving cumin HAE doses of 50 and 100 mg/kg also demonstrated a significant increase in STL compared to the GDX group treated with DMSO (P < 0.001). Conclusions: As evidenced, GDX decreased PAL, but cumin HAE boosted learning and memory in the GDX male Wistar rats.