Biology, chemistry, and pharmacological activity of Kigelia africana (Bignoniaceae) and Garcinia kola (Clusiaceae) - a review.

Kigelia africana and Garcinia kola are two West African medicinal plants traditionally used to treat or alleviate various medical conditions such as skin ailments, respiratory disorders, and digestive problems. Phytochemical analyses indicated the presence of bioactive constituents, including flavonoids and phenolic acids, suggesting that the extracts of these two plants can interfere with reactive oxygen species-induced oxidative stress, inflammation, and microbial growth. This paper reviews the biochemical properties and the antioxidant, anti-inflammatory, and antibacterial activities of these two relevant West African medicinal plants.

An improved clearing and mounting solution to replace chloral hydrate in microscopic applications.

PREMISE OF THE STUDY: This study presents Visikol™, a new proprietary formulation that can be used as an efficient replacement for chloral hydrate as a clearing agent for microscopic examination. In the United States, chloral hydrate is regulated and therefore difficult to acquire. • METHODS AND RESULTS: Fresh and dry samples of the following plants: ginger (Zingiber officinale), maté (Ilex paraguariensis), lime basil (Ocimum americanum), oregano (Origanum vulgare), and mouse-ear cress (Arabidopsis thaliana), were cleared using Visikol or chloral hydrate solution and compared using a light microscope. • CONCLUSIONS: This new method can be used successfully to clear specimens, allowing identification of diagnostic characteristics for the identification of plant materials. Visikol is as effective as chloral hydrate in providing clarity and resolution of all tissues examined. Tissues become transparent, allowing observation of deeper layers of cells and making it effective in research, botanical and quality control, and for educational applications.

Rapid staining method to detect and identify downy mildew (Peronospora belbahrii) in basil.

PREMISE OF THE STUDY: Demand for fresh-market sweet basil continues to increase, but in 2009 a new pathogen emerged, threatening commercial field/greenhouse production and leading to high crop losses. This study describes a simple and effective staining method for rapid microscopic detection of basil downy mildew (Peronospora belbahrii) from leaves of basil (Ocimum basilicum). • METHODS AND RESULTS: Fresh leaf sections infected with P. belbahrii were placed on a microscope slide, cleared with Visikol™, and stained with iodine solution followed by one drop of 70% sulfuric acid. Cell walls of the pathogen were stained with a distinct coloration, providing a high-contrast image between the pathogen and plant. • CONCLUSIONS: This new staining method can be used successfully to identify downy mildew in basil, which then can significantly reduce its spread if identified early, coupled with mitigation strategies. This technique can facilitate the control of the disease, without expensive and specialized equipment.

Application of near-infrared spectroscopy in quality control and determination of adulteration of African essential oils.

An evaluation has been made of the potential of near-infrared (NIR) technologies in the assessment of essential oil components and in the identification of individual essential oils. The results showed that cross-validation models are able to predict accurately almost all of the components of essential oils. In different cinnamon (Cinnamomum zeylanicum) and clove (Syzygium aromaticum) essential oils, which showed a similar composition, 23 components (representing 97.8-99.9% of the oil) were accurately predicted, as well as 20 components (93.0-99.1%) in Cinnamomum camphora (ravintsara), 32 components (92.3-98.1%) in Ravensara aromatica (ravensara), and 26 components (96.6-98.4%) in Lippia multiflora. For almost all of the components, the modelled and reference values obtained by GC-FID were highly correlated (r2 > or = 0.985) and exhibited a low variance (less than 5%). The model was also able to discriminate between the ravintsara and ravensara essential oils. It was shown that two commercial oils labelled as R. aromatica were actually ravintsara (C. camphora), revealing the misidentification of these essential oils in the marketplace. The study demonstrates the application of NIR technology as a quality control tool for the rapid identification of individual essential oils, for product authentication, and for the detection of adulteration.

Chemical constituents and antimicrobial activity of the essential oil of Lantana xenica.

The aim of this work was to evaluate the chemical composition of Lantana xenica essential oil and its antimicrobial activity. The oil from the aerial parts of Lantana xenica Mold. (Verbenacea) was obtained by steam distillation and analyzed by gas chromatography/mass spectrometry. The major constituent of the oil was (E)-caryophyllene (35.2 %), with minor amounts of gamma-cadinene (13.3 %), alpha-pinene (9.3 %), ocimene (9.2 %) and germacrene D (6.6 %). The antimicrobial assays showed that the essential oil of L. xenica inhibited the growth of Bacillus cereus and Proteus mirabilis and both bacteria were inhibited by (E)-caryophyllene, the major component of the oil. Enterococcus faecalis, Staphylococcus epidermidis and S. aureus showed a lower inhibition. The bacteria Micrococcus luteus, Klebsiella sp., Escherichia coli and the yeast Candida albicans were insensitive to both the oil and (E)-caryophyllene.