The Effects of Increasing Doses of Nigella Sativa and Conjugated Estrogen on Bone-Specific Alkaline Phosphatase (B-ALP), Procollagen Type 1 N-Terminal Propeptide (P1NP), Carboxy Terminal Crosslinked Telopeptide of Type 1 Collagen (CTX-1), and Osteoprotegerin (OPG) in an Osteoporosis Rat Model

Introduction: Osteoporosis is characterized by decreased bone density, increasing the risk of fractures. Hormone therapy for post-menopausal osteoporosis has side effects, prompting the development of Nigella sativa (black cumin) as an alternative treatment. Objective: This study aims to determine the effect of administering Nigella sativa and conjugated estrogen as osteoporosis therapy in rats treated with bilateral oophorectomy, which have been verified as having osteoporosis based on bone biomarkers. Materials and Methods: This study involved 72 female Wistar rats divided into six groups: K+ (positive control), K- (negative control), P1 (receiving conjugated estrogen), P2 (receiving 100 mg/kg BW of Nigella sativa), P3 (receiving 200 mg/kg BW of Nigella sativa, and P4 (receiving 400 mg/kg BW of Nigella sativa. After inducing post-menopausal osteoporosis through bilateral oophorectomy, the treatment groups received therapy for 28 days. Bone biomarkers such as bone-specific alkaline phosphatase (bALP), procollagen type 1 n-terminal propeptide (P1NP), carboxy-terminal crosslinked telopeptide of type 1 collagen (CTX-1), and osteoprotegerin (OPG) were measured using ELISA. Results: The 400 mg/kg BW administration of Nigella sativa significantly increased bALP and P1NP levels, indicating higher osteoblast activity. At the same dose, Nigella sativa also increased OPG levels, suppressing osteoclastogenesis in bone resorption. However, 100-400 mg/kg BW/day of Nigella sativa did not reduce CTX-1 levels, nor did it inhibit osteoclasts in bone resorption. Estrogen conjugation also increased OPG levels but did not significantly affect bALP and P1NP levels. Conclusion: Nigella sativa at a dose of 400 mg/kg BW significantly increases osteoblast activity and OPG levels. Estrogen conjugation increases OPG levels but does not affect bALP and P1NP. Nigella sativa can potentially serve as an effective alternative therapy for osteoporosis through a mechanism different from conjugated estrogen.