The study investigated the effects of Heracleum persicum L. extract (HPE) on oxidative damage caused by mercuric chloride (HgCl2) in rat testes. Sixty male Wistar rats were divided into six groups: a sham group, a HgCl2 group, three groups receiving HgCl2 with HPE at doses of 250, 500, and 750 mg/kg, and a control group treated with 750 mg/kg HPE alone over 50 days. HgCl2 was administered intraperitoneally for the first 10 days, followed by HPE gavage for 40 days. On day 51, hormone levels (testosterone, FSH, LH), nitric oxide levels, antioxidant enzyme activity, and pro-inflammatory cytokines were measured. Testicular tissue was analyzed for thiobarbituric acid reactive substances, ferric reducing capacity, thiol levels, and stereological indicators of seminiferous tubules. The study also examined the p53/Cas-3/Bax/Bcl-2 apoptotic pathway. LC-ESI/MS and SEM-EDS analysis detected 25 substances and 14 mineral elements. HgCl2 exposure significantly reduced LH, T, and FSH levels, while HPE improved these hormones, especially at higher doses. Inflammatory cytokines were elevated due to HgCl2, but HPE reduced (P < 0.05) these levels and enhanced (P < 0.05) antioxidant enzyme activity, indicating protective effects against oxidative stress. Testicular analysis showed significant (P < 0.05) damage from HgCl2, but HPE preserved tissue integrity and improved parameters. Weight measurements indicated that HgCl2 reduced (P < 0.05) body and reproductive weights, while HPE restored these weights. HPE also counteracted apoptotic changes, highlighting its potential as a therapeutic agent against HgCl2-induced damage.