Insulin-Mimetic Action of Rhoifolin and Cosmosiin Isolated from Citrus grandis (L.) Osbeck Leaves: Enhanced Adiponectin Secretion and Insulin Receptor Phosphorylation in 3T3-L1 Cells

Citrus grandis (L.) Osbeck (red wendun) leaves have been used in traditional Chinese medicine to treat several illnesses including diabetes. However, there is no scientific evidence supporting these actions and its active compounds. Two flavone glycosides, rhoifolin and cosmosiin were isolated for the first time from red wendun leaves and, identified these leaves are rich source for rhoifolin (1.1%, w/w). In differentiated 3T3-L1 adipocytes, rhoifolin and cosmosiin showed dose-dependent response in concentration range of o.oo1–5 μM and 1–20 μM, respectively, in biological studies beneficial to diabetes. Particularly, rhoifolin and cosmosiin at 0.5 and 20 μM, respectively showed nearly similar response to that 10 nM of insulin, on adiponectin secretion level. Furthermore, 5 μM of rhoifolin and 20 μM of cosmosiin showed equal potential with 10 nM of insulin to increase the phosphorylation of insulin receptor-β, in addition to their positive effect on GLUT4 translocation. These findings indicate that rhoifolin and cosmosiin from red wendun leaves may be beneficial for diabetic complications through their enhanced adiponectin secretion, tyrosine phosphorylation of insulin receptor-β and GLUT4 translocation

A new biflavonoid from <i style="">Cycas beddomei</i>

1933-1935Chemical investigation on the constituents of the cones of Cycas beddomei has been carried out which results in the isolation of a new biflavonoid, 2'',3''-dihydrohinokiflavone, along with 2,3,2'',3''-tetrahydrohinokiflavone, 2,3-dihydroamentoflavone, 2,3,2'',3''-tetrahydroamentoflavone, 2,3-dihydro-4'''-O-methyl-amentoflavone, and pinoresinol. The structure of the new compound has been established by detailed analysis of its spectral (mainly 1D and 2D NMR) data

<i>In Vitro</i> Production of Echioidinin, 7-<i>O</i>-Methywogonin from Callus Cultures of <i>Andrographis lineata</i> and Their Cytotoxicity on Cancer Cells

<div><p><i>Andrographis lineata</i> is an herbal medicinal plant used in traditional medicine as a substitute for <i>Andrographis paniculata</i>. Here, using mature leaf explants of <i>A</i>. <i>lineata</i> we demonstrate for the first time the callus induction established on MS medium containing 1.0 mg l^–1 IAA. Dried callus was subjected to solvent extraction with acetone. Further the acetone residue was separated by silica gel column chromatography, crystallized and characterized on the basis of nuclear magnetic resonance (proton and c13) and liquid chromatographic mass spectroscopy. This analysis revealed the occurrence of two known flavones namely, 7-<i>O</i>-methylwogonin (MW) and Echioidinin (ED). Furthermore, these compounds were tested for their cytotoxicity against leukemic cell line, CEM. We identify that ED and MW induced cytotoxicity in a time- and concentration-dependent manner. Further increase in the LDH release upon treatment with ED and MW further confirmed our cytotoxicity results against leukemic cell line. Strikingly, MW was more potent than ED when compared by trypan blue and MTT assays. Our results recapitulate the utility of callus cultures for the production of plant specific bioactive secondary metabolites instead of using wild plants. Together, our <i>in vitro</i> studies provide new insights of <i>A</i>. <i>lineata</i> callus cultures serving as a source for cancer chemotherapeutic agents.</p></div

Cytotoxicity analysis of 7-<i>O</i>-methylwogonin (MW) on leukemic cell line, CEM.

<p>(A) Structure of MW. (B) Evaluation of cell viability using trypan blue assay following 10, 50, 100 and 250 μM of MW or DMF (vehicle control) treatment. Cells were harvested, trypan blue stained and counted every 24 h until it reached stationary phase. (C) Determination of % cell viability by MTT assay in CEM cells. Cells were cultured with 10, 50, 100 and 250 μM of MWor vehicle control for 24, 48 and 72 h. The % of cell viability was calculated considering DMF treated cells as 100% and plotted with representation of error bars. (D) Measurement of LDH release following treatment with MW. After the exposure of CEM cells with MW at different concentrations (10, 50, 100 and 250 μM) for 24, 48 and 72 h, the release of LDH was measured at 490 nm. Results are presented as percentage of LDH release. Each experiment was done three independent times with good agreement.</p

Cytotoxicity analysis of echioidinin (ED) on leukemic cell line, CEM.

<p>(A) Structure of ED. (B) Evaluation of cell viability using trypan blue assay following 10, 50, 100 and 250 μM of ED or DMF (control) treatment. Cells were harvested, trypan blue stained and counted every 24 h until it reached stationary phase. (C) Determination of % cell viability by MTT assay in CEM cells. Cells were cultured with 10, 50, 100 and 250 μM of ED or vehicle control for 24, 48 and 72 h. The % of cell viability was calculated considering DMF treated cells as 100% and plotted with representation of error bars. (D) Measurement of LDH release following treatment with ED. After the exposure of CEM cells with ED at different concentrations (10, 50, 100 and 250 μM) for 24, 48 and 72 h, the release of LDH was measured at 490 nm. Results are presented as percentage of LDH release. Each experiment was done three independent times with good agreement.</p

Effect of auxins on callus induction from leaf explants of <i>Andrographis lineata</i> after 4 weeks of culture.

<p>NR indicates no response. Data represents 20 replicates and the values recorded after two weeks of culture initiation</p><p>Effect of auxins on callus induction from leaf explants of <i>Andrographis lineata</i> after 4 weeks of culture.</p

Structural elucidation of echioidinin (C₁₆H₁₂O₅) by spectral analysis.

<p>(A) ¹H NMR spectra (B) ¹³C NMR spectra (C) Liquid chromatography mass spectra (D) Structure of echioidinin.</p