In the present study, various solvent fractions were prepared from the root of Smilax china (Liliaceae), which was collected during the autumn, and their radical-scavenging activity and several antioxidant activities were evaluated. The ethyl acetate fractions exhibited the highest antioxidant activities in all assays. In addition, the ethyl acetate fraction had the highest amount of total phenolics (401.62 mg/g). High-performance liquid chromatography analyses showed that catechin and epicatechin were the predominant phenolic compounds in the ethyl acetate fraction. Consequently, our research presented that the ethyl acetate fraction has the strongest antioxidant activities, which are correlated with its high level of phenolics, particularly catechin and epicatechin. Therefore, these results suggest that the ethyl acetate fraction of S. china root possess excellent antioxidant activities, and thus it has a great potential as a source of natural antioxidant.
Smilax china is commonly known as “Ba Qia” (or “Jin Gang Teng”) in China, while in Pakistan, it is locally called “Bilri.”Smilax has 350 species and is distributed widely in tropical and temperate regions throughout the world, especially in East Asia and North America. In traditional Chinese medicine, it is used for the treatment of several diseases, especially for the management of chronic pelvic inflammation, syphilis, acute bacillary dysentery and chronic nephritis. In Korea, S. china has been used as a traditional remedy for inflammatory diseases and ischuria. It has been well known that the rhizome of the genus Smilax has various pharmacological activities. As for S. china, several reports describe the antimicrobial, antimutagenic, antioxidant, anti-inflammatory, anticancer and neuroprotective effect. According to our results, the high antioxidant properties of the root of S. china might be beneficial to the antioxidant protection system of the human body against oxidative damage.