Comparison of Cosmos caudatus extract and vitamin C effects on antioxidant response and bone metabolism in rats under high-intensity exercise-induced oxidative stress

다국어 초록 (Multilingual Abstract)

[Purpose] High-intensity exercise increases oxidative stress, disrupts bone remodeling and accelerate bone loss. While vitamin C is commonly used to counteract these effects, high doses may act as pro-oxidants. <i>Cosmos caudatus</i>, a traditional herb rich in antioxidants, may serve as a natural alternative. In this study compared the effects of <i>C. caudatus</i> extract and vitamin C on oxidative stress and bone health in a rat model of exercise-induced oxidative stress.[Methods] Fifty-four male Sprague-Dawley rats (3–4 months old, 200–300 g) were divided into five groups (10–11 rats each). Group P1 received distilled water, whereas groups P2–P4 received <i>C. caudatus</i> extract at 0.91, 1.82, and 3.64 mg/0.5 mL/200 g BW. Group P5 was administered vitamin C at 9 mg/0.5 mL/200 g BW. Treatments were administered orally for 28 days. Rats underwent high-intensity swimming with an 18% BW load at 90% maximal swim time (T₉₀), twice daily, three times weekly. Femoral and blood samples were collected for malondialdehyde (MDA), osteocalcin (OC), C-telopeptide (CTX), trabecular bone ratio, and bone cell analyses.[Results] MDA levels were significantly elevated across all groups (p = 0.007), particularly in the high-dose <i>C. caudatus</i> and vitamin C. However, trabecular bone ratio improved significantly in medium-dose Cosmos caudatus and vitamin C groups (p = 0.016).[Conclusion] These findings suggested that medium-dose <i>C. caudatus</i> supports bone integrity comparably to vitamin C and may exert osteoprotective effects beyond direct reactive oxygen species (ROS) scavenging, offering a potentially safer alternative for bone health under oxidative stress.