Oldrich Lapcik

The relationship between structure and in vitro antibacterial activity of selected isoflavones and their metabolites with special focus on antistaphylococcal effect of demethyltexasin.

In this study, we tested 15 naturally occurring isoflavones and their metabolites for their possible antibacterial properties against nine Gram‐positive and Gram‐negative bacteria. The in vitro antibacterial activity was determined using the broth microdilution method, and the results were expressed as minimum inhibitory concentrations (MICs). 6,7,4′‐trihydroxyisoflavone (demethyltexasin), 7,3′,4′‐trihydroxyisoflavone (hydroxydaidzein), 5,7‐dihydroxy‐4′‐methoxyisoflavone (biochanin A), 7,8,4′‐trihydroxyisoflavone (demethylretusin) and 5,7,4′‐trihydroxyisoflavone (genistein) produced significant antibacterial activity (MICs ≥ 16 μg ml−1). The most effective compound, demethyltexasin, was subsequently tested for its growth‐inhibitory effect against Staphylococcus aureus, and it exhibited significant antistaphylococcal effects against various standard strains and clinical isolates, including methicillin and tetracycline resistant ones with the MICs ranging from 16 to 128 μg ml−1.

Screening of medicinal plants traditionally used in Peruvian Amazon for in vitro antioxidant and anticancer potential

Abstract Plants mentioned in this study have numerous records in traditional Peruvian medicine being used in treatment of cancer and other diseases likely to be associated with oxidative stress. Amongst the eight plant species tested, only Dysphania ambrosioides exhibited combinatory antioxidant and anti-proliferative effect on a broad spectrum of cancer cells (DPPH and ORAC values = 80.6 and 687.3 μg TE/mg extract, respectively; IC50 against Caco-2, HT-29 and Hep-G2 = 129.2, 69.9 and 130.6, respectively). Alkaloids and phenolic compounds might significantly contribute to anticancer/antioxidant activity of this plant. The results justify the traditional medicinal use of this plant. Our findings further suggest that D. ambrosioides might serve as a prospective material for further development of novel plant-based antioxidant and/or anti-proliferative agents. Detailed analysis of chemical composition together with toxicology assessments and in vivo antioxidant/anti-proliferative activity of this plant should be carried out in order to verify its potential practical use.

Fatty acids, minerals, phenolics and vitamins in the seeds of Inocarpus fagifer , a Pacific Island underutilized legume

Recently, Pacific nations have faced to alarming increase in prevalence of noncommunicable diseases connected with consumption of non-traditional processed food. It is believed that re-introduction of native diet may mitigate these negative trends. One of the traditional staple food of Pacific region are seeds of underutilized leguminous tree Inocarpus fagifer . Nevertheless, information on their chemical composition and nutritional properties are missing. Therefore we decided to analyze this crop for the presence of fatty acids, minerals, phenolics and vitamins. Performed analyses revealed a slightly predominating portion of unsaturated (e.g. 18:2 n-6; 18:1 n-9 and 18:3α n-3) over saturated (e.g. C18 and C16) fatty acids. Considering minerals, the substantial concentrations of copper, magnesium, manganese, potassium and zinc (19.32; 1823.21; 8.44; 23308.41 and 77.99 mg kg-1 of dry matter respectively) were recorded. Ferulic and coumaric acids were the most abundant phenolics (3.23 and 1.48 mg kg-1 of dry matter respectively), whereas flavonoids, isoflavonoids and coumestrol were also present. Regarding vitamins, niacin and riboflavin were found in respective concentrations 131.80 and 4.47 mg kg-1 of dry matter. Our findings suggest I. fagifer seeds as a prospective food source of several health-beneficial constituents which might contribute to the well-being of Pacific islanders. The online version of this article (doi: 10.5073/JABFQ.2016.089.034) contains a supplementary file .