The effect of scopoletin-standardized Morinda elliptica leaf extract against osteoarthritis was investigated in ex vivo explant culture and preclinical rodent model. Thirty male rats were grouped (n = 6) into untreated osteoarthritis (OA), OA + Diclofenac (5 mg/kg), and OA + extract (200 and 400 mg/kg) and compared with healthy control. Monosodium iodoacetate were injected into the right intra-articular knee joints to induce OA. The rats were evaluated for OA severity via physical (micro-CT and histological observations), biochemical, ELISA, and mRNA expression analysis (for inflammation and cartilage degradation biomarkers), after 28 days of treatment. The extract suppressed glycosaminoglycan release from the cartilage explant in the presence of Interleukin-1β. The 200 mg/kg dose appeared better than 400 mg/kg dose, at reducing cartilage and subchondral bone erosions in OA-induced rats, by significantly down-regulating the collagenases and aggrecanase. The extract dose-dependently reduced serum inflammation biomarkers and increased bone formation biomarkers to near normal levels in the OA-induced rats. M. elliptica leaf scopoletin-standardised extract alleviated OA progression and articular cartilage structure, by ameliorating cartilage degradation, nitric oxide levels, inflammation, bone /cartilage homeostasis, collagenase/aggrecanase activities, chondrocytes survival, subchondral bone structure and integrity.
The scopoletin (coumarin) and epicatechin (flavonoid) rich Morinda citrifolia L. (MC) Noni leaves are non-toxic (unlike the fruits) and consumed as vegetables. The anti-osteoarthritis effects of the MC leaf extract against joint cartilage degradation and inflammation were investigated through cartilage explant cultures and pre-clinical animal study. Osteoarthritis were induced by intra-articular monosodium iodoacetate injection into the right knee. The extract, scopoletin and epicatechin, suppressed glycosaminoglycan and nitric oxide release from the cartilage explant in the presence of Interleukin-1β. After 28 days, the extract treatment reduced the in vivo serum levels and joint tissues mRNA expressions for joint cartilage degradation, aggrecanase, and collagenase biomarkers. The extract increased the bone formation marker PINP levels, besides improving the articular cartilage structure and chondrocytes cellularity. The extract improved bone formation/repair, subchondral bone structure, strength and integrity, as well as cartilage synthesis by suppressing inflammation, nitric oxide production, joint catabolism by proteases, and oxidative stress. PRACTICAL APPLICATIONS: The scopoletin (coumarin) and epicatechin (flavonoid) rich Morinda citrifolia (Noni) leaves may be used as vegetables, functional food ingredient, or dietary supplements to suppress osteoarthritis progression against joint cartilage degradation and inflammation. The extract, scopoletin, or epicatechin, suppressed glycosaminoglycan, and nitric oxide release from the cartilage. The Morinda citrifolia leaf extract suppressed inflammation, nitric oxide production, tissues catabolism by proteases and oxidative stress to help reduce joint cartilage degradation, besides improving the articular cartilage structure, chondrocytes health, subchondral bone structure, bone formation/repair, and cartilage synthesis.