ABSTRACT Propolis also known as "bee glue or bee resin" is a resinous mixture of bee saliva or bee wax and exudate from tree trunks and flowers, produced by honeybees. The composition of propolis varies depending on the vegetation the bees can access. It is therefore expected that propolis obtained from various localities may have different chemical profiles. In this study, the headspace volatiles of propolis (n = 39) collected from various locations in South Africa (Gauteng, Northern Cape and Western Cape Provinces) were explored for the first time using GCxGC–ToF–MS. Several GCxGC parameters were optimised including; incubation time, temperature and modulation period. Multivariate data analysis techniques (principal component and hierarchical cluster analyses) were applied on the GCxGC–ToF–MS data to investigate trends and clustering patterns within propolis samples. The results demonstrated that headspace volatiles of propolis varied between locations. The volatile profiles were dominated by monoterpenes such as α-pinene (1.2–46.5%), β-pinene (2.0–21.8%), dihydrosabinene (trace-17.8%), limonene (trace-11.6%), p-cymene (0.1–5.3%), 1,8-cineole (0.1–11.0%), 2,7-dimethyl-3-octen-5-yne (trace-11.7%), E-β-ocimene (trace-17.8%), octanal (trace-12.9%), styrene (trace-13.5%) and α-thujene (trace-11.0%). Principal component analysis revealed chemical variation within propolis from the various locations. The heatmap of the averages revealed dehydrosabinene, isopropentyltoluene, p-cymene, acetophenone and α-thujene as chemical markers for the Northern Cape propolis, while λ-terpinene, propanoic acid, furfural, 2-methoxy benzyl alcohol and hexanoic acid methylester were filtered out as markers for Gauteng propolis. The propolis samples originating from the Western Cape Province were dominated by prenal, cinnamaldehyde styrene, 1,8-cineole, decanal, prenyl acetate and butanoic acid. Using GCxGC–ToF–MS in combination with chemometrics, it was possible to profile headspace volatile constituents of propolis and further identify marker compounds that differentiate propolis from various provinces in South Africa.

ABSTRACT Recently there has been a renewed impetus in the search for novel ingredients to be used in the cosmetic industry and Baobab (Adansonia digitata L., Malvaceae) seed oil has received high interest. In this study, a commercial Baobab seed oil sample was characterised (fatty acid content) using GCxGC-ToF-MS and a pilot study on the safety and efficacy of the seed oil was performed. The safety and efficacy of Baobab seed oil after topical application was determined using healthy adult female caucasian participants (n = 20). A 2× magnifying lamp was used for visual analysis, while for monitoring and evaluation of the irritancy level, transepidermal water loss (TEWL) and hydration level of the skin, Chromameter®, Aquaflux® and Corneometer® instruments, respectively, were used. In addition, Aquaflux® and Corneometer® instruments were used to assess occlusive effects. Thirteen methyl esters were identified using GCxGC-ToF-MS. The major fatty acids included 36.0% linoleic acid, 25.1% oleic acid and 28.8% palmitic acid with 10.1% constituting trace fatty acids. The irritancy of sodium lauryl sulphate (SLS) in the patch test differed significantly compared to both de-ionised water (p < 0.001) and Baobab seed oil (p < 0.001) but the difference between the irritancy of Baobab seed oil and de-ionised water was not significant (p = 0.850). The moisture efficacy test indicated a reduced TEWL (p = 0.048) and an improved capacitance moisture retention (p < 0.001) for all the test products (Baobab oil, liquid paraffin, Vaseline® intensive care lotion and Vaseline®). The occlusivity wipe-off test indicated an increased moisture hydration (p < 0.001) and decreased TEWL particularly when Baobab oil was applied. Baobab possesses hydrating, moisturising and occlusive properties when topically applied to the skin. Baobab seed oil could be a valuable functional ingredient for cosmeceutical applications.

A hitherto unidentified medicinal plant is here identified for the first time as Pteronia camphorata (L.) L., an aromatic shrub of the Asteraceae family endemic to the western and southern coastal region of South Africa. The plant was described in this journal by Laidler¹ in 1928 as 'D/nhora buchu', and is one of the important types of buchu used by the Nama people. We report the traditional medicinal uses among San and Nama people, based on our interviews with rural participants. These include the treatment of colds, influenza, chest ailments and tuberculosis, as well as convulsions, haemorrhoids and inflammation of the neck. The major and minor chemical compounds of the essential oil that is produced by the plant are identified, together with the site of accumulation of this volatile oil within the leaf. We also investigated the plant's antimicrobial activity against a selection of a yeast and two Gram-negative and one Gram-positive bacteria, all of which are associated with respiratory infections. P. camphorata is scientifically poorly known but is an important San and Nama traditional remedy. Our study not only prevents the potential loss of historically important indigenous knowledge, but also provides the first scientific evidence to validate the traditional use of |nhora against upper and lower respiratory tract infections, including tuberculosis. This detailed study has wider application in demonstrating the fragility of the oral-traditional knowledge of a scientifically neglected indigenous group. It also highlights the scientific and practical importance of preserving traditional plant-use knowledge within a botanically diverse region. SIGNIFICANCE: • Reveals the botanical identity of |nhora, an important Nama medicinal plant. • Presents scientific evidence to validate the traditional uses. • Contributes to the cultural heritage of a scientifically neglected indigenous group. • Demonstrates the fragility of oral-traditional knowledge.