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Mode of Action of Selected Botanicals That Lower Blood Glucose
Published in Robert Fried, Richard M. Carlton, Type 2 Diabetes, 2018
Robert Fried, Richard M. Carlton
A review published in the Journal of Agricultural and Food Chemistry, reported that glyceollins, a phytoalexin found in soybeans, may play an important role in glucose homeostasis by regulating glucose utilization in adipocytes, and improving β-cell function and survival. Glyceollins improved insulin-stimulated glucose uptake in 3T3-L1 adipocytes without activating the PPAR-γ agonist. They decreased triacylglycerol accumulation in adipocytes.
Nodulin Function and Nodulin Gene Regulation in Root Nodule Development
Published in Peter M. Gresshoff, Molecular Biology of Symbiotic Nitrogen Fixation, 2018
Plants are able to defend themselves against plant-pathogens by a variety of means.299,300 Some of the defenses are general, in that they provide protection from infection by a range of pathogens. These defenses include phytoalexin accumulation,301 extensin accumulation, and other responses collectively called the hypersensitive response.299 Other defense responses are highly specific, detected only in response to attack by a particular pathogen. Although root nodule development has repeatedly been considered as a special kind of plant-pathogen interaction,302-305 the establishment of a nitrogen-fixing root nodule does not appear to provoke any known defense response. In soybean root nodules the concentration of the phytoalexin glyceollin is even lower than in uninfected roots.306 In preliminary studies in our laboratory no increase of extensin-related RNA in nodules compared to uninoculated roots was observed. Also, stress-related RNA, detected by using a soybean general stress cDNA clone307 as probe, was not enhanced in concentration.49 These results suggest that the known defense mechanisms are not operating during normal root nodule development. Furthermore, none of the nodulins identified in vetch and pea nodules are detectable in tumors formed on the stem of vetch and pea plants by A. tumefaciens,47 while Agrobacterium is a well-recognized plant-pathogen. This result shows that none of the identified nodulins functions in defense mechanisms.
Molecular Mechanisms of Endocrine Disruption in Estrogen Dependent Processes
Published in Rajesh K. Naz, Endocrine Disruptors, 2004
Robert M. Bigsby, Minerva Mercado-Feliciano, Josephine Mubiru
It is worthwhile to note that some polyphenolic phytochemicals that are structurally similar to estradiol are antiestrogenic. Although largely unstudied, glyceollins have been shown to weakly inhibit estrogen-induced activity in ER-positive MCF-7 and Ishikawa cells at 10 nM to 1 µM, concentrations associated with ER agonist action of many phytoestrogens.84 In addition, the glyceollins essentially lacked the ER agonist capacity to induce cell proliferation.84 Furthermore, the glyceollins displayed greater affinity to, and preferential suppression of, ERα compared to ERβ The inability of the antiestrogen ICI 182,780 to suppress this effect suggested an ER-independent mechanism.
The transcriptional factors HIF-1 and HIF-2 and their novel inhibitors in cancer therapy
Published in Expert Opinion on Drug Discovery, 2019
Najah Albadari, Shanshan Deng, Wei Li
Glyceollins (a mixture of glyceollin I, II, and III, 6) are a group of phytoalexins that are synthesized de novo in soybean via the stimulatory action of elicitors as a protective mechanism against microbial invasion, ultraviolet radiation, and chemical stressors [135,136]. Glyceollins exhibit various biological functions including anti-estrogenic activity [137], anti-contractile activity in vascular smooth muscle [138], enhanced insulin sensitivity [139] and anti-melanin synthesis activity [140]. Most importantly, Glyceollins regulate tumor growth and inhibit the expression of VEGF in cancer cells through regulation of HIF-1α [141,142]. They perform their HIF-1 inhibitory action by two means: 1) they block HIF-1α translation via inhibiting the PI3K/AKT/mTOR pathway under hypoxic conditions. 2) They interfere with Hsp90 binding activity and thus decrease HIF-1α stability.