Novel D-ring analog of epigallocatechin-3-gallate inhibits tumor growth and VEGF expression in breast carcinoma cells.

The cancer chemopreventive activity of green tea and its major polyphenolic constituent, epigallocatechin-3-gallate (EGCG) have been attributed to its antioxidant, antiproliferative and antiangiogenic effects. Several new molecular targets for EGCG's anticarcinogenic activity have been proposed in the recent literature. However, the understanding of the molecular mechanisms of EGCG's activity in vivo have been confounded by its low oral bioavailability and low plasma levels. Studies of EGCG would be greatly aided by the availability of synthetic analogs of EGCG designed to understand the contributions of the A, B, and D-rings and the phenolic hydroxyl groups of EGCG to its molecular mechanisms of action. We recently reported the de novo synthesis of a D-ring analog of EGCG, with the objective of using such analogs to understand the molecular mechanisms of EGCG action. We report here the first studies with a synthetic D-ring analog of EGCG. We examined the ability of the synthetic D-ring analog to inhibit tumor cell proliferation in breast carcinoma cells. We also investigated the effect of the analog on stress-induced VEGF production in breast carcinoma cells using Northern analysis and quantitative RT-PCR. We report here that the synthetic D-ring analog inhibits breast cancer cell growth in vitro with potencies equivalent to those of EGCG. Our results also show that, like EGCG, the synthetic analog inhibits hypoxia- and serum starvation-induced production of VEGF mRNA in breast cancer cells. Such synthetic analogs are valuable for understanding the structure-function relationship of EGCG and identifying relevant mechanisms of the chemopreventive action of EGCG

Novel D-ring analog of epigallocatechin-3-gallate inhibits tumor growth and VEGF expression in breast carcinoma cells.

The cancer chemopreventive activity of green tea and its major polyphenolic constituent, epigallocatechin-3-gallate (EGCG) have been attributed to its antioxidant, antiproliferative and antiangiogenic effects. Several new molecular targets for EGCG's anticarcinogenic activity have been proposed in the recent literature. However, the understanding of the molecular mechanisms of EGCG's activity in vivo have been confounded by its low oral bioavailability and low plasma levels. Studies of EGCG would be greatly aided by the availability of synthetic analogs of EGCG designed to understand the contributions of the A, B, and D-rings and the phenolic hydroxyl groups of EGCG to its molecular mechanisms of action. We recently reported the de novo synthesis of a D-ring analog of EGCG, with the objective of using such analogs to understand the molecular mechanisms of EGCG action. We report here the first studies with a synthetic D-ring analog of EGCG. We examined the ability of the synthetic D-ring analog to inhibit tumor cell proliferation in breast carcinoma cells. We also investigated the effect of the analog on stress-induced VEGF production in breast carcinoma cells using Northern analysis and quantitative RT-PCR. We report here that the synthetic D-ring analog inhibits breast cancer cell growth in vitro with potencies equivalent to those of EGCG. Our results also show that, like EGCG, the synthetic analog inhibits hypoxia- and serum starvation-induced production of VEGF mRNA in breast cancer cells. Such synthetic analogs are valuable for understanding the structure-function relationship of EGCG and identifying relevant mechanisms of the chemopreventive action of EGCG

A comprehensive evaluation of the chemical profiles and biological properties of six geophytes from Turkey: Sources of bioactive compounds for novel nutraceuticals

Geophytes are gaining interest as sources of natural ingredients in nutraceutical and pharmaceutical area. In this sense, six bulbous plant species from Turkey are investigated, namely Hyacinthella campanulata K.Perss. & Wendelbo, Muscari neglectum Guss. ex Ten., Tulipa humilis herb., Iris stenophylla Hausskn. ex Baker, Galanthus elwesii Hook. f. and Crocus danfordiae Maw. with the aim to highlight their chemical compositions and biological properties. Polyphenolic profiles of the different plant parts (flower, bulb and leaf) of the six genotypes were evaluated using colorimetric methods as well LC–MS/MS. The antioxidant properties and enzymes inhibitory potential (α-amylase, α-glucosidase, tyrosinase and cholinesterases) of the extracts were determined. Overall, highest total phenolic content and total flavonoid content were observed in the leaf extracts of the studied species, except for M. neglectum (flower extract) and T. humilis (flower extract). LC–MS/MS analysis revealed the abundance of some phenolic compounds including quinic acid, hesperidin and chlorogenic acid in selective extracts. The extracts showed significant antioxidant potentials, with leaf extract of the I. stenophylla being more potent, which is linked to its high phenolic contents. All the extracts displayed notable anti-acetylcholinesterase (1.77 – 2.53 mg GALAE/g) and tyrosinase (54.9–67.20 mg KAE/g). Selective extracts have showed activity against butyrylcholinesterase, with bulb extract of M. neglectum (2.99 mg GALAE/g), I. stenophylla (2.53 mg GALAE/g) and G. elwesii (2.52 mg GALAE/g) showing highest activity. Modest activity was observed against α-amylase and α-glucosidase. The experimental data gathered herein is the first report on the phytochemical and biological attributes of these bulbous plant species which project them as potential sources of biologically active compounds for phytomedicines and nutraceuticals development

A comparative bio-evaluation and chemical profiles of Calendula officinalis L. extracts prepared via different extraction techniques

Calendula officinalis L., (marigold), well known for its medicinal properties, has been extensively studied for its therapeutic properties. Nonetheless, as far as the literature could establish, no study has attempted to comparatively assess the biological (antioxidant and enzyme inhibitory potential) of the flowers, leaves, and roots of C. officinalis extracted using conventional (maceration and Soxhlet extraction (SE)) and non-conventional extraction (homogenizer (HAE) and ultrasound (UAE) assisted extraction) techniques. The detailed phytochemical profile of each extract along with the concentration of specific bioactive compounds has also been established. Total phenolic content was highest for the flower extracts while flavonoid content was highest in the leaf extracts. Phytochemical profiling showed that the extraction method influenced the phytochemical composition of the extract. Nicotiflorin was identified in the flower extracts only while amentoflavone occurred only in the roots, inferring that the occurrence of bioactive compounds varies within a plant. The flower extracts showed highest antioxidant potential while the roots extracts were potent inhibitors of cholinesterase and tyrosinase. This study provides valuable data on the influence of extraction techniques on the recovery of bioactive compounds from plants. In an endeavor to scale-up extraction from plant considering the more efficient extraction method is of paramount importance. Moreover, the study highlighted the necessity to thoroughly examine the biological activities of various parts of a plant obtained via different extraction protocols