The scientific merit of Carpobrotus mellei L. based on antimicrobial activity and chemical profiling

Species of the genus Carpobrotus are similar in appearance and have been used for medicinal purposes over many generations. Carpobrotus mellei is endemic to the south-Western Cape of South Africa, and also used for various ailments. To date no scientific validation and information has been reported on C. mellei. This study investigated the antimicrobial potential of C. mellei against Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Mycobacterium smegmatis, and determined the minimum inhibitory concentrations (MIC) by two-fold serial dilution. C. mellei showed antimicrobial activity against S. aureus and M. smegmatis in the disc diffusion method. Eight chemical compounds showed clear zones of inhibition in the bioautograms, seven against S. aureus and three compounds were active against M. smegmatis. The ethyl acetate extracts have MIC values of 7.5 mg/ml and 15 mg/ml against S. aureus and M. smegmatis, respectively. Phytochemical tests indicated the presence of flavonoids, hydrolysable tannins, phytosterols and aromatic acids. High performance liquid chromatography (HPLC) showed a species-specific spectrum at a wavelength of 280nm. The results confirm that C. mellei has scientific merit, and can substitute one of the other Carpobrotus species for antimicrobial usage within the south-Western Cape of South Afric

Antimicrobial activities of four plant species from the Southern Overberg region of South Africa

Four plant species used for medicinal purposes in the Bredasdorp/Elim (Southern Overberg) region of the Western Cape Province in South Africa, were screened for their antimicrobial activity. Theantimicrobial activity of aqueous, methanol, ethanol and ethyl-acetate leaf extracts of Bulbine lagopus (Asphodelaceae), Chironia baccifera (Gentianaceae), Conyza scabrida (Asteraceae) and Dodonaeaviscosa var. angustifolia (Sapindaceae), were tested against Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Mycobacterium smegmatis. In the disc-diffusion assay, 20 out of the 80 extracts showed activity. Better activity was observed in the liquid dilution assay with all extracts showing a degree of activity. The best activity was observed in the ethanol extract of B. lagopus and themethanol extract of C. scabrida both having an MIC value of 0.3125 mg/ml. In the bioautography, M. smegmatis was chosen as the test organism along with the ethanol, ethyl-acetate and methanolextracts of C. scabrida and D. viscosa var. angustifolia. All six extracts showed at least two zones of inhibition on the TLC plates overlaid with M. smegmatis

Recent technological developments in MALDI-MSI based hair analysis

Hair is a common piece of trace evidence found at a crime scene, however, often it is not possible to obtain DNA (due to the lack of a follicular root). These hair samples could potentially provide other intelligence, based on the molecular history of an individual that it contains. Currently, this type of analysis is performed using traditional hyphenated techniques gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS). However, these techniques require a large amount of hair, not a few single strands such as those typically found at a crime scene and also involve extensive sample preparation. Recently new technologies such as matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) have been used to monitor the distribution of drugs of abuse in single hair strands. Using this technology it is possible to reveal the distribution of compounds in the hair more accurately and in single strands as opposed to milligram quantities required by traditional hyphenated methods. The use of MALDI-MSI could provide law enforcement agencies with lifestyle information on an individual and help to narrow down the pool of suspects