The South African medicinal plant, Oncosiphon suffruticosum (L.) Källersjö is known to treat chronic, respiratory, and skin ailments. Essential oil (EO) was extracted by the hydrodistillation, showed sixteen constituent components totalling 85.09% of the composition.

The monoterpenoids were found to predominate the chemical composition of the essential oil by 84.64%. The major compounds were discovered to be ketone and alcohol monoterpenes, camphor 31.21%, filifolone 13.98%, chrysanthenone 8.72%, 1,8-cineole 7.85%, and terpinen-4-ol 7.39%.

The antibacterial activity study showed that the EO was most susceptible against Pseudomonas aeruginosa with a MIC of 6.4 mg/mL; however, it showed the same activity against Staphylococcus aureus and Escherichia coli with a MIC value of 12.8 mg/mL. 

The sun protecting factor (SPF) of the EO was observed to be 2.299 and thus rendering it to be a potentially important cosmeceutical for sunscreen applications. 

A report, thought to be the first of its kind, investigated 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. It explored its cosmeceutical potential in selected biological activities of dermatological relevance. 

According to the in vitro biological evaluations conducted, it was concluded that O. suffruticosum essential oil possesses low tyrosinase inhibitory activity, low to moderate antibacterial and antioxidant activity, but a promising sun protection ability as per the calculated SPF value. It was proposed that the therapeutic properties of this essential oil can be improved by the application of nanotechnologies such as nanoencapsulation and nanostructured lipid carriers. 

Thus this study establishes O. suffruticosum essential oil to be used as a complementary ingredient to boost the performance of cosmeceuticals with a prominent potential to be used in sunscreen formulations.

Source: Adewinogo SO, Sharma R, Africa CWJ, Marnewick JL, Hussein AA. Chemical Composition and Cosmeceutical Potential of the Essential Oil of Oncosiphon suffruticosum (L.) Källersjö. Plants (Basel). 2021 Jun 28;10(7):1315. doi: 10.3390/plants10071315. PMID: 34203514.