Antimicrobial activity and stability of medicinal plant extracts : effect of simulated gastrointestinal conditions

Thesis (MTech. degree in Pharmaceutical Sciences)--Tshwane University of Technology, 2008.The aim of the study is to investigate whether the chemical composition and antimicrobial activity of orally administered medicinal plants are affected by in vitro dissolution and gastrointestinal absorption processes. Few in vitro screening assays for biological activities of plant extracts consider the effect of the gastrointestinal system. This is an important factor for the bioavailability of plant extracts intended to be administered via the oral route. In this study, crude water and methanol extracts of selected plants (green tea, 'buchu', thyme, sage and wild camphor) were prepared and exposed to simulated gastric fluid and simulated intestinal fluid during dissolution studies. The crude extracts and resulting simulated gastric fluid and simulated intestinal fluid products were screened for antimicrobial activity

The Application of Vibrational Spectroscopy Techniques in the Qualitative Assessment of Material Traded as Ginseng

The name “ginseng” is collectively used to describe several plant species, including Panax ginseng (Asian/Oriental ginseng), P. quinquefolius (American ginseng), P. pseudoginseng (Pseudoginseng) and Eleutherococcus senticosus (Siberian ginseng), each with different applications in traditional medicine practices. The use of a generic name may lead to the interchangeable use or substitution of raw materials which poses quality control challenges. Quality control methods such as vibrational spectroscopy-based techniques are here proposed as fast, non-destructive methods for the distinction of four ginseng species and the identification of raw materials in commercial ginseng products. Certified ginseng reference material and commercial products were analysed using hyperspectral imaging (HSI), mid-infrared (MIR) and near-infrared (NIR) spectroscopy. Principal component analysis (PCA) and (orthogonal) partial least squares discriminant analysis models (OPLS-DA) were developed using multivariate analysis software. UHPLC-MS was used to analyse methanol extracts of the reference raw materials and commercial products. The holistic analysis of ginseng raw materials revealed distinct chemical differences using HSI, MIR and NIR. For all methods, Eleutherococcus senticosus displayed the greatest variation from the three Panax species that displayed closer chemical similarity. Good discrimination models with high R2X and Q2 cum vales were developed. These models predicted that the majority of products contained either /P. ginseng or P. quinquefolius. Vibrational spectroscopy and HSI techniques in tandem with multivariate data analysis tools provide useful alternative methods in the authentication of ginseng raw materials and commercial products in a fast, easy, cost-effective and non-destructive manner

Eugenol—From the Remote Maluku Islands to the International Market Place: A Review of a Remarkable and Versatile Molecule

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Hyperspectral Imaging as a Rapid Quality Control Method for Herbal Tea Blends

In South Africa, indigenous herbal teas are enjoyed due to their distinct taste and aroma. The acclaimed health benefits of herbal teas include the management of chronic diseases such as hypertension and diabetes. Quality control of herbal teas has become important due to the availability of different brands of varying quality and the production of tea blends. The potential of hyperspectral imaging as a rapid quality control method for herbal tea blends from rooibos (Aspalathus linearis), honeybush (Cyclopia intermedia), buchu (Agathosma Betulina) and cancerbush (Sutherlandia frutescens) was investigated. Hyperspectral images of raw materials and intact tea bags were acquired using a sisuChema shortwave infrared (SWIR) hyperspectral pushbroom imaging system (920–2514 nm). Principal component analysis (PCA) plots showed clear discrimination between raw materials. Partial least squares discriminant analysis (PLS-DA) models correctly predicted the raw material constituents of each blend and accurately determined the relative proportions. The results were corroborated independently using ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-MS). This study demonstrated the application of hyperspectral imaging coupled with chemometric modelling as a reliable, rapid and non-destructive quality control method for authenticating herbal tea blends and to determine relative proportions in a tea bag

Beauty in Baobab: a pilot study of the safety and efficacy of Adansonia digitata seed oil

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