The protective effects of the antioxidative compound sesamol against radiation were reported as early as 1991.1 The water-soluble lignan sesamol, a natural phenolic compound derived from Sesamum indicum (sesame) seed oil, has since become known as a potent antioxidant with significant anticancer potential.2,3 As a constituent found in food oils such as sesame and sunflower oil, sesamol has been studied for the dietary benefits that it has been said to impart. Sesame oil, in particular, has been used in Ayurveda, traditional Chinese medicine, as well as in folk medicine in Nigeria and other African countries.Data on its antioxidant and chemopreventive properties also have prompted investigations into its potential in the dermatologic realm because sesamol has demonstrated an increasingly wide array of cutaneous applications.
Antibacterial effects
In 2007, Bankole et al. ascertained the synergistic antimicrobial properties of the essential oils and lignans found in the leaf extracts of S. radiatum and S. indicum. Phytochemical screening of methanolic extracts revealed the presence of phenolic compounds such as the potent antioxidants sesamol, sesamolin, and sesamin, as well as carboxylic acids. Methanolic and ethanolic extracts were shown to exhibit broad-spectrum antimicrobial effects against all of the pathogens tested except Streptococcus pneumoniae (methanolic extracts) and Staphylococcus aureus (ethanolic extracts). The investigators concluded that their results buttressed long-held traditional claims in multiple regions in Nigeria where consumption of sesame leaf extracts has been known to confer antibacterial effects with effectiveness reported for common skin infections.4
Anticancer activity
Kapadia et al. studied the dietary components resveratrol, sesamol, sesame oil, and sunflower oil in various protocols, including a murine two-stage skin cancer model, for their potential as cancer chemopreventive agents. In this 2002 study, the mouse skin tumor model, sesamol was found to provide a 50% reduction in skin papillomas at 20 weeks after promotion with 12-O-tetradecanoylphorbol 13-acetate. The researchers concluded that all of the dietary constituents appeared to provide chemopreventive effects.5
In 2010, Ramachandran et al. observed that pretreating human skin dermal fibroblast adult cells with sesamol before irradiation with UVB yielded significant reductions in cytotoxicity, intracellular reactive oxygen species levels, lipid peroxidation, and apoptosis. In noting increases in enzymatic and nonenzymatic antioxidant activity in sesamol-pretreated UVB-exposed fibroblasts, the investigators ascribed the apparent protective effects of sesamol to its antioxidant scavenging of reactive oxygen species.6
Seven years later, Bhardwaj et al. evaluated the chemopreventive efficacy of free and encapsulated sesamol in a 7,12-dimethylbenz[a]-anthracene–induced skin cancer animal model. The investigators found that in both forms sesamol significantly reduced tumor burden and lipid peroxidation while raising antioxidant levels. This resulted in the inhibition of skin tumor development and promotion. Apoptosis in tumor cells also was found to result from the down-regulation of Bcl-2 and stimulation of Bcl-2–associated X protein expression from administration of both free and encapsulated sesamol. Furthermore, the irritant qualities of sesamol were mitigated by encapsulation, which also aided in direct targeting of the skin.2