Protective effects of pistachio pericarp essential oil against diazinon-induced oxidative stress and follicular damage in the ovaries of NMRI mice

BACKGROUND: Diazinon (DZN), a widely used agricultural pesticide, causes toxic effects on the reproductive system, leading to oxidative stress and impaired follicular development. OBJECTIVES: Due to its established antioxidant and anti-inflammatory properties, this experimental study aims to evaluate the potential protective effects of pistachio pericarp essential oil (PPEO) in mitigating DZN-induced ovarian damage in mice, with a focus on preserving ovarian structure and function. METHODS: Forty-eight female NMRI mice (10-12 weeks old) were randomly divided into six groups (n = 8 per group), receiving different treatments for 28 days. The control group was given a standard diet, while experimental groups received 30 mg/kg/day DZN, DZN combined with 5% or 10% PPEO, or 10% PPEO alone. The ovaries were processed for histomorphometric analysis on every fifth ovarian section, classifying follicles into primordial, primary, secondary, and antral stages. Follicular volume was estimated using the Cavalieri method, and follicle diameters were measured using specialized software. RESULTS: Ovary, cortex, and medulla volumes were significantly lower in the DZN group than those of the control group, and the decrease in all follicular stages (otoogonia, primordial, primary, secondary, and antral) was marked. On the other hand, the 10% PPEO group indicates statistically significant ovarian weight (1.9 ± 0.14 mg) and volumes. More importantly, co-administration of PPEO, especially at a 10% dose, exerted marked corrective effects against the DZN-induced loss in follicular counts by improving both follicular survival and ovarian structure. CONCLUSION: DZN disrupts ovarian function by inducing oxidative stress and damaging follicular development. PPEO offers productive protection against DZN by enhancing antioxidant defenses and successfully maintaining ovarian structure and folliculogenesis.