In Vitro Chondroprotective Potential of Extracts Obtained from Various Phyllantus Species

has been proven to exhibit chondroprotection. Regarding the morphological similarities among species, we were attracted to evaluate the chondroprotective potential of species including obtained from Chiang Mai and Phuket, L., subsp, and using interleukin-1-induced degradation of cartilage explants. The ethanolic extracts of the plants were evaluated for major lignans, phyllanthin, and hypophyllanthin by HPLC and further measurements of the total contents of flavonoids and phenolic compounds along with the assays for antioxidant and anti-collagenase activities. The interleukin-1-induced cartilage explant degradation was performed with/without the extracts at concentrations of 50-250 µg/mL. After 4-14 days of incubation, the medium was assayed for the level of sulfated glycosaminoglycans while the explants were measured for the remaining content of uronic acid. Proteoglycan intensity in the explants was determined by safranin O staining. Diacerein, the antiarthritic agent, was used as the positive control. Although the two major lignans were found in from Chiang Mai, from Phuket, and L. extracts, similar chondroprotective activities were observed in all extracts. Total phenolic content and total flavonoid content of the extracts showed a correlation with antioxidation, whereas the total phenolic content correlated with anti-collagenase activity. Among the six extracts, showed the greatest antioxidant and collagenase inhibitory activities. The results revealed that chondroprotective activities of all of the extracts of species might result from an additive or synergistic influence of some constituents of these plants, which could be considered for antiarthritic purposes.