Manilkara zapota Leaves and Anxiolytic Activity: Potential Benefits in Caffeine-Induced Experimental Animals with Anxiety

Background: One of the most popular drinks in the world is caffeine, which is known to produce anxiety symptoms that are clinical in nature. There are numerous classes of anxiolytics in the market. Still, there is always a need to find safe substitutes for medications because of their poor effectiveness and long-term side effects. This study aimed to investigate the anxiolytic effects of Manilkara zapota (MZ) leaf extract on caffeine-induced anxiety in mice. Methods: The study was conducted on albino mice, in which anxiety disease was induced with a caffeine dose of 25 mg/kg by intraperitoneal (i.p) route. The animals were pretreated with different drugs for 14 days and caffeine was administered during the last 7 days of the treatment. The mice were randomly divided into 6 groups with 6 animals each, including control, caffeine (used for inducing anxiety), diazepam (1 mg/kg by oral route, as reference standard), and three doses of MZ (150, 300, and 450 mg/kg orally). Various behavioral, biochemical, and histopathological parameters were evaluated in caffeine-induced anxiety. Results: MZ leaf extract demonstrated a significant increase in behavioral activity. In light/dark exploration (LDE), the extract significantly increased (p < 0.01) the duration spent in the light chamber and the number of switches from light to dark, which was otherwise diminished by caffeine. Similarly, in the open field test (OFT), the extract shows a significant increase (p < 0.001) in the number of rearing and the squares crossed. In the force swim test (FST), the extract showed an increase in the immobility time compared to the inducer. Compared to the caffeine-treated group, there was a significant increase (p < 0.01) in the levels of catalase, glutathione, and serotonin in the extract-treated groups. The histopathological changes showed a considerable decrease in the caffeine-induced damage in the brain and showed normal morphology in the hippocampus (dentate gyrus) region. Conclusion: In the present study, data suggested that MZ extract exhibited anxiolytic-like activity. The observed activity could be linked to enhanced antioxidant status that was responsible for restoring the serotonin level and preventing structural damage in the brain. More research might provide a cost-effective alternative source for treating anxiety disorders.