*Article* **Chemical Composition and Cosmeceutical Potential of the Essential Oil of** *Oncosiphon suffruticosum* **(L.) Källersjö**

**Selena O. Adewinogo 1, Rajan Sharma 1, Charlene W. J. Africa 2, Jeanine L. Marnewick <sup>3</sup> and Ahmed A. Hussein 1,\***


**Abstract:** The South African medicinal plant *Oncosiphon suffruticosum* (L.) Källersjö is an important remedy used to treat chronic, respiratory, and skin ailments. From the essential oil (EO) extracted by the hydrodistillation, sixteen constituent components were identified with oxygenated monoterpenes: camphor (31.21%), filifolone (13.98%), chrysanthenone (8.72%), 1,8-cineole (7.85%), and terpinen-4-ol (7.39%) as predominant constituents. In the antibacterial activity study, the EO was found most susceptible against *Pseudomonas aeruginosa* with an MIC of 6.4 mg/mL; however, it showed the same activity against *Staphylococcus aureus* and *Escherichia coli* with an MIC value of 12.8 mg/mL. The sun protecting factor (SPF) of the EO was found to be 2.299 and thus establishing it as a potentially important cosmeceutical for sunscreen applications. This is the first report investigating the essential oil of *O. suffruticosum* for its chemical composition and skin-related in vitro biological activities viz antibacterial, antioxidant capacity, antityrosinase, and sun protection factor.

**Keywords:** essential oils; *Oncosiphon suffruticosum*; antioxidant; antibacterial; tyrosinase inhibition; sun protection factor
