Correction: Simultaneous quantification of five biomarkers in ethanolic extract of Cassia occidentalis Linn. stem using liquid chromatography tandem mass spectrometry: application to its pharmacokinetic studies.

[This corrects the article DOI: 10.1039/C9RA07482A.].

Simultaneous quantification of five biomarkers in ethanolic extract of Cassia occidentalis Linn. stem using liquid chromatography tandem mass spectrometry: application to its pharmacokinetic studies.

Cassia occidentalis L. stem extract is used as a purgative, febrifuge, and diuretic, and in the treatment of flu, fever, fracture and bone diseases. Pharmacological studies prove the osteogenic and antiresorptive effects of Cassia occidentalis L. ethanolic extract (COEE), which may be due to apigenin, apigenin-6-C-glucopyranoside, luteolin, 3',4',7-trihydroxyflavone and emodin. The objectives of this study was to develop a selective and sensitive LC-MS/MS method and validate for the simultaneous determination of the above five biomarkers in rat plasma after oral administration of COEE at a dose of 500 mg kg-1. The analytes were separated on a Phenomenex Luna C18 column (4.6 × 150 mm, 3.0 µm) with an isocratic mobile phase consisting of methanol-10 mM ammonium acetate buffer (95 : 05, v/v). Run time was for 5.5 min with LLOQ of 1 ng mL-1 for all the analytes. The mass spectrometer was operating in negative ionization mode for quantification of the analytes. The calibration curves were linear (r 2 > 0.99) for all the analytes. The intra- and inter-day precisions were less than 8.17% and the relative error was between -8.57% and 7.28%. Analytes were rapidly absorbed in the oral pharmacokinetic study. The biomarkers were stable in simulated gastric and intestinal fluids but underwent metabolism in rat liver microsomes. This is the first report on in vivo oral pharmacokinetics and in vitro stability studies of osteogenic compounds present in COEE. These results will be helpful for further understanding of pharmacodynamic behaviour of COEE and the bioanalytical method will be useful for further preclinical/clinical trials.

Aegeline inspired synthesis of novel ß3-AR agonist improves insulin sensitivity in vitro and in vivo models of insulin resistance.

BACKGROUND AND PURPOSE: In our drug discovery program of natural product, earlier we have reported Aegeline that is N-acylated-1-amino-2- alcohol, which was isolated from the leaves of Aeglemarmelos showed anti-hyperlipidemic activity for which the QSAR studies predicted the compound to be the ß3-AR agonist, but the mechanism of its action was not elucidated. In our present study, we have evaluated the ß3-AR activity of novel N-acyl-1-amino-3-arylopropanol synthetic mimics of aegeline and its beneficial effect in insulin resistance. In this study, we have proposed the novel pharmacophore model using reported molecules for antihyperlipidemic activity. The reported pharmacophore features were also compared with the newly developed pharmacophore model for the observed biological activity. EXPERIMENTAL APPROACH: Based on 3D pharmacophore modeling of known ß3AR agonist, we screened 20 synthetic derivatives of Aegeline from the literature. From these, the top scoring compound 10C was used for further studies. The in-slico result was further validated in HEK293T cells co-trransfected with human ß3-AR and CRE-Luciferase reporter plasmid for ß3-AR activity.The most active compound was selected and ß3-AR activity was further validated in white and brown adipocytes differentiated from human mesenchymal stem cells (hMSCs). Insulin resistance model developed in hMSC derived adipocytes was used to study the insulin sensitizing property. 8 week HFD fed C57BL6 mice was given 50 mg/Kg of the selected compound and metabolic phenotyping was done to evaluate its anti-diabetic effect. RESULTS: As predicted by in-silico 3D pharmacophore modeling, the compound 10C was found to be the most active and specific ß3-AR agonist with EC50 value of 447 nM. The compound 10C activated ß3AR pathway, induced lipolysis, fatty acid oxidation and increased oxygen consumption rate (OCR) in human adipocytes. Compound 10C induced expression of brown adipocytes specific markers and reverted chronic insulin induced insulin resistance in white adipocytes. The compound 10C also improved insulin sensitivity and glucose tolerance in 8 week HFD fed C57BL6 mice. CONCLUSION: This study enlightens the use of in vitro insulin resistance model close to human physiology to elucidates the insulin sensitizing activity of the compound 10C and edifies the use of ß3AR agonist as therapeutic interventions for insulin resistance and type 2 diabetes.

Aegeline inspired synthesis of novel amino alcohol and thiazolidinedione hybrids with antiadipogenic activity in 3T3-L1 cells.

Excess adiposity is a hallmark of obesity, which is caused due to an imbalance between energy intake and energy consumed. Obesity is often associated with several metabolic disorders like dyslipidemia, cardiovascular diseases and type 2 diabetes. Earlier, our group had reported natural product Aegeline (amino-alcohol) isolated from the plant Aegle marmelos as an anti-diabetic and anti-dyslipidemic compound. With this background, we synthesized a series of novel amino alcohol and thiazolidinedione hybrid molecules and studied their antiadipogenic activity. As a result, we have identified a potent hybrid compound 12c as an inhibitor of adipocyte differentiation. The compound 12c inhibits lipid accumulation and adipogenesis in 3T3-L1 preadipocyte cell line. Exposure of compound 12c blocks mitotic clonal expansion and arrests cells in S-phase of cell cycle. Detailed analysis showed that compound 12c decreases expression of two major transcription factors that are involved in adipocyte differentiation, PPARγ, C/EBPα, and other adipogenesis associated genes like aP2 and FAS. Thus, we concluded that compound 12c shows potential ability to inhibit adipocyte differentiation which can be used therapeutically for the treatment of obesity and its associated metabolic disorders.