The resazurin assay utilising microtitre-plate, described by Drummond and Waigh in 2000, has been modified to achieve more accuracy in the determination of the minimum inhibitory concentration (MIC) values of natural products, including crude extracts, chromatographic fractions or purified compounds against various bacterial strains. This modified resazurin method is simple, sensitive, rapid, robust and reliable, and could be used successfully to assess antibacterial properties of natural products.

Flavonoids are important natural compounds with diverse biologic activities. Citrus flavonoids constitute an important series of flavonoids. Naringin and its aglycone naringenin belong to this series of flavonoids and were found to display strong anti-inflammatory and antioxidant activities. Several lines of investigation suggest that naringin supplementation is beneficial for the treatment of obesity, diabetes, hypertension, and metabolic syndrome. A number of molecular mechanisms underlying its beneficial activities have been elucidated. However, their effect on obesity and metabolic disorder remains to be fully established. Moreover, the therapeutic uses of these flavonoids are significantly limited by the lack of adequate clinical evidence. This review aims to explore the biologic activities of these compounds, particularly on lipid metabolism in obesity, oxidative stress, and inflammation in context of metabolic syndrome.

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From a consideration of ethnobotanical and taxonomic information, seeds of 45 Scottish plant species encompassing 23 different families were obtained from authentic seed suppliers. The n-hexane, dichloromethane (DCM) and methanol (MeOH) extracts were assessed, both qualitatively and quantitatively, for free radical scavenging activity in the DPPH assay. The MeOH extracts of 37 species exhibited low to high levels of free radical scavenging activity (RC50 values ranging from 2.00 to 4.7 x 10(-4) mg/mL), and Alliaria petiolata, Prunus padus and Prunus spinosa were the most potent antioxidant extracts. The DCM extracts of 17 species showed similar levels of activity, and among those, Prunus padus and Prunus spinosa extracts were the most active with RC50 values of 2.5 x 10(-4) and 5.0 x 10(-4) mg/mL, respectively. The n-hexane extracts were much less active than the MeOH and DCM extracts, and 17 species, with the exception of Glechoma hederacea (RC50 = 1.94 x 10(-4)) displayed low to moderate levels of free radical scavenging property (RC50 values ranging from 2.00 to 8.7 x 10(-3) mg/mL).

More than 60 species of medicinal plants belong to the genus Angelica (Family: Apiaceae). Many of these species have long been used in ancient traditional medicine systems, especially in the far-east. Various herbal preparations containing Angelica species are available over-the-counter, not only in the far-eastern countries, but also in the western countries like USA, UK, Germany, etc. For centuries, many species of this genus, e.g. A. acutiloba, A. archangelica, A. atropupurea, A. dahurica, A. japonica, A. glauca, A. gigas, A. koreana, A. sinensis, A. sylvestris, etc., have been used traditionally as anti-inflammatory, diuretic, expectorant and diaphoretic, and remedy for colds, flu, influenza, hepatitis, arthritis, indigestion, coughs, chronic bronchitis, pleurisy, typhoid, headaches, wind, fever, colic, travel sickness, rheumatism, bacterial and fungal infections and diseases of the urinary organs. Active principles isolated from these plants mainly include various types of coumarins, acetylenic compounds, chalcones, sesquiterpenes and polysaccharides. This review evaluates the importance of the genus Angelica in relation to its traditional medicinal uses, alternative medicinal uses in the modern society and potential for drug development, and summarises results of various scientific studies on Angelica species or Angelica-containing preparations for their bioactivities including, antimicrobial, anticancer, antitumour, analgesic, anti-inflammatory, hepatoprotective, nephroprotective, etc.