Unravelling effects of phytochemicals from buckwheat on cholesterol metabolism and lipid accumulation in HepG2 cells and its validation through gene expression analysis.

BACKGROUND: The objective of this research was to elucidate the hypocholesterolemic effects of a bioactive compound extracted from buckwheat, and to delineate its influence on the regulatory mechanisms of cholesterol metabolism. The compound under investigation was identified as quercetin. MATERIAL AND RESULTS: In vitro experiments conducted on HepG2 cells treated with quercetin revealed a significant reduction in intracellular cholesterol accumulation. This phenomenon was rigorously quantified by assessing the transcriptional activity of key genes involved in the biosynthesis and metabolism of cholesterol. A statistically significant reduction in the expression of HMG-CoA reductase (HMGCR) was observed, indicating a decrease in endogenous cholesterol synthesis. Conversely, an upregulation in the expression of cholesterol 7 alpha-hydroxylase (CYP7A1) was also observed, suggesting an enhanced catabolism of cholesterol to bile acids. Furthermore, the study explored the combinatory effects of quercetin and simvastatin, a clinically utilized statin, revealing a synergistic action in modulating cholesterol levels at various dosages. CONCLUSIONS: The findings from this research provide a comprehensive insight into the mechanistic pathways through which quercetin, a phytochemical derived from buckwheat, exerts its hypocholesterolemic effects. Additionally, the observed synergistic interaction between quercetin and simvastatin opens up new avenues for the development of combined therapeutic strategies to manage hyperlipidemia.

Synthesis, antioxidant, antiproliferative activity, molecular docking and DFT studies of novel isoxazole derivatives of diosgenin, a steroidal sapogenin from Dioscorea deltoidea.

Diosgenin [25R-spirost-5-en-3ß-ol], isolated from Dioscorea deltoidea was used as a starting material for synthesizing its various isoxazole derivatives. A library of fifteen isoxazole analogues (DG1-DG15) were synthesised via modification at the C-3 hydroxyl group. The resulting analogues were fully characterized by spectral techniques and evaluated for their antioxidant and anticancer activity against four breast cancer cell lines; MDA-MB-231, MDA-MB-468, MCF-7, and 4 T1, using MTT assay. Molecular docking studies were carried out for all analogues with EGFR protein (PDB id: 6LUD) to check their activity by inhibiting EGFR protein, which is an effective strategy for cancer cell death. Furthermore, DFT studies were carried out for four analogues. Among all analogues, compound DG6 and DG9 showed the highest scavenging activity and compound DG9 exhibited a maximum cytotoxic effect on the MDA-MB-468 and MCF-7 cell lines with an IC50 value of 6.25 µg/mL and 6.81 µg/mL, while compound DG5 was the least potent (IC50 25.89 µg/mL). Molecular docking results revealed that DG8 and DG9 afforded the highest binding energy of -14.33 and - 14.71 kcal/mol, respectively for the target EGFR protein. These results demonstrate the potential of diosgenin analogues as drug candidates for breast cancer therapy. Furthermore, DFT studies revealed that the molecules are more polarizable and have smaller energy gap between their HOMO and LUMO orbitals, the smallest being of DG9 (3.221 eV) and hence are more reactive.