Bakuchiol is a meroterpene in the class terpenophenol. It was first isolated in 1966 by Mehtaet al. from Psoralea corylifolia seed and was called Bakuchiol based on the Sanskrit name Bakuchi of the plant. Bakuchiol is mainly obtained from the seeds of the plant Psoralea corylifolia, which is widely used in Indian as well as in Chinese medicine to treat a variety of diseases. It has also been isolated from other plants, such as P. grandulosa, P. drupaceae, Ulmus davidiana, Otholobium pubescens, Piper longum and Aerva sangulnolenta Blum. Even though the first complete synthesis of Bakuchiol has been described in 1973, its first commercial use in topical applications did not occur until 2007 when it was introduced to the market under the trade name Sytenol® A by Sytheon Ltd. It has been reported to have anticancer activity in pre-clinical models, possibly due to its structural similarity with resveratrol. One study in rats suggested that bakuchiol and ethanol extracts of the Chinese medicinal plantPsoralea corylifolia could protect against bone loss. Bakuchiol possesses antioxidant, anti-inflammatory and anti-bacterial properties. Bakuchiol isolated from P. corylifolia has shown activity against numerous Gram-positive and Gram-negative oral pathogens. It was able to inhibit the growth of Streptococcus mutans under a range of sucrose concentrations, pH values and in the presence of organic acids in a temperature-dependent manner and also inhibited the growth of cells adhered to a glass surface. Despite having no structural resemblance to retinol, Bakuchiol was found to have retinol functionality through retinol-like regulation of gene expression. In 2018, a randomized, double-blind, 12-week clinical study with 44 volunteers demonstrated that Bakuchiol is comparable with retinol in its ability to improve photo-aging but has a better skin tolerance. Bakuchiol has been found to possess antiandrogenic activity in prostate cancer cells, which inhibited cell proliferation.
