Effects of Spearmint (Peppermint) on Morphological, Histological and Biochemical Aspects of Ovaries

Background and Objective: Spearmint (Peppermint), known for its aromatic and medicinal properties, is used in various products globally, including food, confectionaries, chewing gum, and toothpaste. While it has been known for its potential therapeutic benefits, this study aimed to investigate the effects of spearmint on the morphology, histology, and biochemistry of ovaries in Wistar albino rats.Methods: This Experimental animal study involved 30 adult female albino mice (200–250 g), divided into three equal groups. Group A (Control) received 15 ml/kg distilled water, Group B (Low Dose) received 0.3 g/kg body weight ethanol extract of peppermint leaves, and Group C (High Dose) received 0.6 g/kg body weight. Treatments were administered via gastric infusion for 30 days. Ovaries were dissected, weighed, and histological slides were prepared using H&E staining. Parameters, including capsule thickness, follicle diameter, and corpus luteum, were analyzed with ImageJ® software. Data were processed using SPSS 20.0, with significance level as p < 0.05.Results: Final ovarian weights (Group A: 0.19±0.02 g, Group B: 0.36±0.09 g, Group C: 0.49±0.05 g; p<0.001) and Relative Tissue Weight Index (RTWI; Group A: 0.08, Group B: 0.17, Group C: 0.27; p<0.001) increased significantly in experimental groups. Histological analysis revealed decrease in follicle diameters with higher doses of spearmint in both secondary and graafian follicle (secondary follicle; Group A 29.10±4.11 µm, Group B 22.31±5.51 µm, Group C 15.20±2.94 µm and Graafian follicle; Group A 53.75±8.01 µm, Group B 35.87±4.97 µm, group C 23.64±4.96 µm). Decreased corpus luteum size, along side significant reductions in serum progesterone levels post-experiment (Group A: 55.29±5.94 ng/ml, Group B: 23.01±8.89 ng/ml, Group C: 4.12±0.70 ng/ml; p<0.001) were also observed.Conclusion: This study reveals detrimental effects of excessive spearmint leaf consumption on rat ovarian histology, body weight, and progesterone levels. Caution, particularly during pregnancy, is advised due to potential risks to hormonal and ovarian function. Further research is essential to understand the mechanisms and assess the implications for human health.Key words: spearmint, ovarian morphology, progesterone level