Aqueous extract of Scabiosa atropurpurea counteracts oxidative stress and enhances spermatogenesis in rams under natural hot summer conditions

This study investigated the protective role of Scabiosa atropurpurea aqueous extract (AES) against natural heat stress in rams. Sixteen mature rams (4–6 years old, 61.2 ± 2.6 to 63.5 ± 0.3 kg) were monitored for 90 days (August–October 2022). Animals were divided into two groups: controls (C; n = 8) received 50 mL water daily, while the treated group (T; n = 8) received 50 mL AES (1 mg/kg body weight/day). The severity of heat stress was assessed using the temperature–humidity index (THI). Semen was collected every 10 days to assess sperm quality, oxidative status, ATP and calcium levels, and gene expression related to steroidogenesis. Plasma testosterone and LH concentrations were also determined. Under hot summer conditions, AES supplementation significantly enhanced individual sperm motility (93 ± 1.1% vs. 89 ± 0.9%; p = 0.006) and sperm concentration (3.77 ± 0.06 vs. 3.34 ± 0.05 × 10⁹ spz/mL; p = 0.02), while reducing abnormal forms (7.5 ± 0.4% vs. 12.9 ± 0.2%; p = 0.06) and DNA damage (15.2 ± 3.4% vs. 26.7 ± 2.4%; p = 0.008). Treated rams showed higher seminal antioxidant activity (6.4 ± 0.2 vs. 3.3 ± 0.08 mmol Trolox equiv/L; p < 0.0001), lower ROS levels (12.9 ± 0.29 vs. 21.3 ± 0.11 mmol H₂O₂; p = 0.03), and increased plasma testosterone. AES also improved LH secretion and upregulated key steroidogenic genes, including 3β-HSD, aromatase, StAR, LH, and FSHβ in testis. In conclusion, AES supplementation mitigates heat stress by improving sperm traits, antioxidant defenses, and endocrine activity in rams.