Exploring the phytochemical variation of non-volatile metabolites within three South African Salvia species using UPLC-MS fingerprinting and chemometric analysis.

The South African Salvia species, Salvia africana-lutea, S. lanceolata and S. chamelaeagnea, are widely used to treat fever and inflammation associated with skin and lung infections. The aim of this study was to explore the non-volatile secondary metabolites and the phytochemical variation within these lesser known species, to support product development and commercialisation. Chemical profiles of the methanol extracts of 81 wild-harvested samples were obtained using ultra performance-quadrupole-Time-of-Flight-mass spectrometry (UPLC-qToF-MS). Forty-one compounds, including caffeic acid, rosmarinic acid, carnosol, carnosic acid and ursolic acid, were detected and confirmed across the three species. Nineteen compounds were tentatively identified of which 14 have not been reported in these species. Principal component analysis revealed distinct clusters corresponding to the three species, confirming chemical differences. Marker compounds for each species were revealed using orthogonal projection to latent structures-discriminant analysis. Further chemometric analysis reflected a degree of intraspecies variation, although the chemistry within populations was mostly conserved. Potential chemotypes for each species were identified through unique compounds associated with each group. The concentrations of medicinally important metabolites, namely, rosmarinic acid, carnosol, carnosic acid and ursolic acid, were determined, using validated UPLC-PDA methods. Ursolic acid was present at levels up to 38.2 mg/g, confirming that these species are a rich source of this compound. No similar studies combining liquid chromatography with chemometric analysis, and utilising a large sample size from various habitats, have been reported for these three Salvia species. The results will guide selection of cultivars with the best attributes for the intended therapeutic application, thereby protecting wild populations from over-exploitation.

A chemometric assessment of essential oil variation of three Salvia species indigenous to South Africa.

Indigenous Salvia species from southern Africa are popular traditional medicines for the treatment of a variety of conditions. They produce fragrant volatiles that can be isolated as essential oils. Some of these volatile organic compounds may play a role in the biological activities of the extracts. Three indigenous Salvia species, Salvia africana-lutea, S. lanceolata and S. chamelaeagnea, were selected for this study as they are commonly used in traditional medicine in South Africa, and the essential oils from these species have potential for commercialisation. Although some studies have described the essential oil compositions and some biological activities, only single composite samples were used. The aim of this study was to investigate the intra- and interspecies variation of the essential oils, sampled over a wide geographical area and using a representative sample size, to encourage commercialisation of the essential oil. Essential oils were isolated from individual plants using conventional hydrodistillation of the aerial parts, harvested from several localities. Gas chromatography coupled simultaneously to mass spectrometry/flame ionisation detection (GC-MS/FID) was used to identify and quantify the volatile constituents. The essential oils of S. africana-lutea consisted mainly of terpinene-4-ol + ß-caryophyllene (1.4 - 29.0%), T-cadinol (1.2 - 20.0%), α-eudesmol (trace - 23.0%) and ß-eudesmol (trace - 26.0%), those of S. lanceolata comprised mainly terpinene-4-ol + ß-caryophyllene (4.3 - 31.0%), α-humulene (2.3 - 15.0%), bicyclogermacrene (trace - 37.0%) and spathulenol (trace - 25.0%), while the essential oils of S. chamelaeagnea were characterised by δ-3-carene (trace - 18.0%), limonene (1.6 - 36.0%), viridiflorol (9.8 - 61.0%) and 1,8-cineole (not detected - 11.0%). The compounds identified in the essential oils of the three selected Salvia species have been identified in other Salvia essential oils. To add to the novelty of this study, the superior resolving power of two-dimensional gas chromatography was demonstrated through analysis of selected essential oils. Many additional compounds were identified, and previously co-eluting compounds were clearly separated. Chemometric modelling of the GC-MS data using SIMCA P+ 14 software allowed distinct clustering patterns to be discerned. The unsupervised principal component analysis model revealed separate clusters for the three species, confirming substantial chemical differences between their essential oils. Quantitative, rather than qualitative differences were evident when individual essential oil samples representing the same species, were compared. For each species, two chemically distinct groups were observed and unique marker compounds could be identified. This study has contributed detailed information on the major and minor volatile compounds present in the essential oils of the three Salvia species investigated.

The additive and synergistic antimicrobial effects of select frankincense and myrrh oils--a combination from the pharaonic pharmacopoeia.

AIMS: The in vitro antimicrobial activity of three essential oil samples of frankincense (Boswellia rivae, Boswellia neglecta and Boswellia papyrifera) and two essential oil samples of myrrh and sweet myrrh (Commiphora guidotti and Commiphora myrrha), collected from different regions of Ethiopia, was investigated independently and in combination to determine their anti-infective properties. METHODS AND RESULTS: The microdilution minimum inhibitory concentration (MIC) assay was performed, whereby it was noted that generally Cryptococcus neoformans (MIC values in the range of 0·8-1·4 mg ml(-1)) and Pseudomonas aeruginosa (MIC values in the range of 0·5-1·3 mg ml(-1)) often appeared to be the most susceptible micro-organisms against oils of both Boswellia and Commiphora spp. When assayed in various combinations, the frankincense and myrrh oils displayed synergistic, additive and noninteractive properties, with no antagonism noted. When investigating different ratio combinations against Bacillus cereus, the most favourable combination was between B. papyrifera and C. myrrha. The composition of the oils was determined by gas chromatography coupled to mass spectrometry (GC-MS) to document the specific chemotypes used in the study, and the chemical profiles were found to be congruent with previously reported data. CONCLUSIONS: The majority of interactions identified synergistic and additive effects, with strong synergism noted between B. papyrifera and C. myrrha. SIGNIFICANCE AND IMPACT OF THE STUDY: Frankincense and myrrh essential oils have been used in combination since 1500 bc; however, no antimicrobial investigations have been undertaken to confirm their effect in combination. This study validates the enhanced efficacy when used in combination against a selection of pathogens.

South African Salvia species: a review of biological activities and phytochemistry.

The genus Salvia (sage) belongs to the Lamiaceae and encompasses 900 species worldwide of which ca. 26 indigenous species are found in southern Africa. Salvia is the largest genus in this family and constitutes almost one quarter of the Lamiaceae. In South Africa, the majority of Salvia species are distributed predominantly in the Cape region. Salvia species are used in many parts of the world to treat various conditions. Many sages, if not all, form an integral part of traditional healing in South Africa particularly in regions where they occur in abundance. Several species are used to treat microbial infections, cancer, malaria, inflammation, loss of memory and to disinfect homes after sickness. Despite the extensive traditional use and the general interest in phytoconstituents of Salvia it remains ironic that research on the South African counterparts has until recently been neglected. The review aims to collate recent research results on the phytochemistry and pharmacological properties of indigenous species. Bio-active compounds with antiplasmodial and antibacterial activities have been isolated and structurally elucidated from Salvia chamelaegnea, Salvia radula and Salvia verbenaca. The essential oil composition of Salvia showed the dominance of monoterpene hydrocarbons, oxygen-containing monoterpenes and oxygen- containing sesquiterpenes. Salvia runcinata is identified as an alternative source of natural alpha-bisabolol. Many pharmacological activities are summarised (anti-oxidant, antimicrobial, antiplasmodial, analgesic, antipyretic, anticancer, anti-inflammatory and antinociceptive) as a first attempt to provide scientific support for past and present local traditional uses.

The in vitro pharmacological activities and a chemical investigation of three South African Salvia species.

Salvia species (sage) are well known in folk medicine throughout the world. In South Africa sage is used against fever and digestive disorders. Three closely related South African species (Salvia stenophylla, Salvia repens and Salvia runcinata) were investigated for their anti-oxidant (DPPH assay); anti-inflammatory (5-lipoxygenase and cyclo-oxygenase assays); antimalarial (tritiated hypoxanthine incorporation assay); antimicrobial (disc diffusion and micro-dilution assays) properties and toxicity profile (tetrazolium-based assay). The solvent extracts exhibited anti-oxidant, antimalarial and antibacterial and poor anti-inflammatory properties. The essential oils exhibited anti-inflammatory and antimalarial properties, but displayed poor anti-oxidant and antimicrobial activity. The extract of Salviastenophylla and the essential oil of Salvia runcinata displayed the highest toxicity profile. Overall, Salvia runcinata displayed the most favorable activity of all three taxa tested with an IC(50) value of 6.09 (anti-oxidant); 29.05 (antimalarial) and 22.82 microg/ml (anti-inflammatory). Analytical procedures (GC-MS and HPLC-UV) were employed to generate chromatographic profiles for the essential oils and solvent extracts respectively. The HPLC analysis revealed the presence of rosmarinic acid in all three taxa while carnosic acid was only present in Salvia repens and Salvia stenophylla. The GC-MS analysis showed that oils were qualitatively and quantitatively variable. beta-Caryophyllene was present in large amounts in all three taxa. Other components present include camphor, alpha-pinene and alpha-bisabolol. The results of the in vitro pharmacological activities provide a scientific basis to validate the use of these Salvia species in traditional medicine in South Africa.