In continuation of our natural and medicinal research programme on tropical rainforest plants, a bioassay guided fractionation of ethanolic extract of leaves of Canarium patentinervium Miq. (Burseraceae Kunth.) led to the isolation of scopoletin (1), scoparone (2), (+)-catechin (3), vomifoliol (4), lioxin (5), and syringic acid (6). All the compounds exhibited antiacetylcholinesterase activity with syringic acid, a phenolic acid exhibiting good AChE inhibition (IC50 29.53 ± 0.19 μ g/mL). All compounds displayed moderate antileishmanial activity with scopoletin having the highest antileishmanial activity (IC50 163.30 ± 0.32 μ g/mL). Given the aforementioned evidence, it is tempting to speculate that Canarium patentinervium Miq. represents an exciting scaffold from which to develop leads for treatment of neurodegenerative and parasitic diseases.
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.