Phenolic composition, antioxidant and enzyme inhibitory activities of Eryngium bornmuelleri leaf.

Eryngium bornmuelleri Nab. (Tusî) is an endemic botanical from the Eastern Anatolia region of Turkey traditionally used for preparation of herbal tea. Within this study, phenolic composition, antioxidant capacities and inhibitory activities towards selected digestive enzymes of E. bornmuelleri leaf were investigated. Sequential extracts, obtained by extraction of plant tissue by ethanol, acetone and water exhibited pronounced antioxidant capacities and in a dose-dependent manner suppressed the metabolic syndrome related enzymes: α-amylase, α-glucosidase and pancreatic lipase. All extracts contained high levels of phenolic compounds. Flavonoid glycosides were the main phytochemicals detected, with rutin as the major compound (70% of total phenolics). Chlorogenic, hydroxybenzoic and caftaric acids as well as traces of caffeic, ferulic and rosmarinic acids were also detected. Correlation analysis indicated that phenolic compounds were the major sources of the enzyme-inhibitory activities. This study suggests that E. bornmuelleri leaf extracts can modulate the metabolism of sugars and fats through inhibition of the relevant digestive enzymes.

Phytohormone levels in germinating seeds of Zea mays L. exposed to selenium and aflatoxines.

Seeds of Zea mays L. were exposed to aflatoxine B1 (AFB1), aflatoxine G1 (AFG1) and selenium (Se) alone and in combination and allowed to germinate. Phytohormone levels of GA-like substances (GAs), trans-Zeatin (t-Z) and Indole-3-acetic acid (IAA) were determined by High Performance Liquid Chromatography (HPLC) when the roots of the germinating seeds reach 1.5-3.0 cm in length. The levels of endogenous hormones decreased in seeds treated with AFB1 and AFG1 compared to control; however an increase was noted in seeds exposed to AFG1 and Se together. AFB1 and Se treatment caused reduced hormone levels in most of the treatments. When plants were exposed to Se alone, the highest levels of GAs, t-Z and IAA were observed in the application of 800 ppm Se. The highest levels of GAs, t-Z and IAA were observed when seeds were treated with 0.2 ppm AFG1 + 8 ppm Se, 0.2 ppm AFG1 + 8 ppm Se and 0.2 ppm AFG1 + 0.08 ppm Se, respectively, whereas the lowest levels of the hormones were observed in 0.2 ppm AFB1 + 8 ppm Se, 0.2 ppm AFB1 + 0.08 ppm Se and 0.1 ppm AFB1, respectively. In conclusion, the levels of phytohormones were reduced by the treatment of AFB1 and AFG1 alone. However Se removed the negative effect of AFB1 on phytohormones, but not AFB1.