Wild Yam Complex by MediHerb 40 tablets (Best By Date: October 2019)

There are some 600 species of Yam in the genus Dioscorea, many of them are wild species that flourish in damp woodlands and thickets. Dioscorea villosa, also known as Colic Root or Wild Yam, is a twining, tuberous vine native to eastern North America. The roots initially taste starchy, but soon after are bitter and acrid, nothing like the taste of Yam or Sweet Potato grown for the dinner table. Commercial Wild Yam extracts available for use as raw materials are often notDioscorea villosa but instead Dioscorea opposita (Chinese Yam Root) which has a different phytochemical profile.

It is widely misconstrued that Dioscorea villosa contains diosgenin and many products have this as a statement on their labels. However it does not contain diosgenin, but rather the diosgenin precursors. Traditionally Dioscorea villosawas believed to contain predominantly dioscin, however, the origin of this assignment is unclear (dioscin is a steroidal glycoside precursor of diosgenin). The phytochemical profile of Wild Yam is poorly-defined and based on scientific literature from the 1940s. MediHerb undertook a project in conjunction with Associate Professor James De Voss, Chemistry Department, from the University of Queensland, Australia to investigate the phytochemistry. Commercially available Dioscorea villosa is in the form of dried roots, usually harvested at the end of summer or fall when the plant is dying back to its rootstock. It was found that these roots contained only very small amounts of dioscin, not the predominance as previously thought. The major saponin found in the fall harvested roots were in fact the furostanol-based saponins, methylparvifloside and methylprotodeltonin, while the spirostanol-based saponins, Zingiberensis saponin I and deltonin were the major saponins for samples harvested in summer. The storage saponins from the fall differ from the summer saponins by the presence of an extra glucose at the C-26 position of the diosgenin base structure. The two main compounds found in commercial material – harvested in the fall – are significantly different from dioscin by having an extra one or two glucose residues in methylprotodeltonin and methylparvifloside respectively. All of these compounds have been reported from other Disocorea species, however, the profile of saponins was different in the other species.