Osmanthus fragrans has a long history of cultivation in Asia and is widely used in food production for its unique aroma, which has important cultural and economic values. It is rich in flavonoids with diverse pharmacological properties, such as antioxidant, anti-tumor, and anti-lipid activities. However, little is known regarding the effects of Osmanthus fragrans flavonoid extract (OFFE) on adipogenesis and pre-adipocyte transdifferentiation. Herein, this research aimed to investigate the effect of OFFE on the differentiation, adipogenesis, and beiging of 3T3-L1 adipocytes and to elucidate the underlying mechanism. Results showed that OFFE inhibited adipogenesis, reduced intracellular reactive oxygen species levels in mature adipocytes, and promoted mitochondrial biogenesis as well as beiging/browning in 3T3-L1 adipocytes. This effect was accompanied by increased mRNA and protein levels of the brown adipose-specific marker gene Pgc-1a, and the upregulation of the expression of UCP1, Cox7A1, and Cox8B. Moreover, the research observed a dose-dependent reduction in the mRNA expression of adipogenic genes (C/EBPα, GLUT-4, SREBP-1C, and FASN) with increasing concentrations of OFFE. Additionally, OFFE activated the AMPK signaling pathway to inhibit adipogenesis. These findings elucidate that OFFE has an inhibitory effect on adipogenesis and promotes browning in 3T3-L1 adipocytes, which lays the foundation for further investigation of the lipid-lowering mechanism of OFFE in vivo in the future.
Rhizospheric fungi of medicinal plants are important sources for discovering novel and valuable secondary metabolites with potential pharmaceutical applications. In our research, five new dichlororesorcinols (1–5) and five known metabolites (6–10) were separated from the secondary metabolites of Chaetomium sp. SYP-F6997, which was isolated from the rhizospheric soil of Panax notoginseng. The identification of these compounds was confirmed using various spectroscopic techniques including ESI-MS, UV, IR, NMR and ECD analyses. These findings highlight the potential of rhizospheric fungi as a rich source of novel bioactive compounds. In addition, chiral HPLC was used to successfully separate the enantiomers compound 4 and compound 5, and TDDFT-ECD/optical rotation calculations were used to test their absolute configurations. This is the first report of compounds 1–10 from the genus Chaetomium, and the first report of compounds 1–5 and 7 from the family Chaetomiaceae. We proposed plausible biosynthetic pathways for dichlororesorcinols 1–6 based on their analogous carbon skeleton. These findings provide insights into the biosynthesis of these compounds and expand our understanding of the secondary metabolites produced by Chaetomium sp. SYP-F6997. To evaluate their potential as therapeutic agents, we investigated the cytotoxic activity of all the isolated metabolites against cell lines H9, HL-60, K562, THP-1 and CEM using the MTT method. The new compounds 1 and 2 exhibited significant cytotoxic activities against H9 and CEM, with IC50 values lower than 10 µM. To further explore the potential mechanisms of action, we performed molecular docking studies to investigate the interactions between compounds 1 and 2 with the potential target ERK2. Our results demonstrate that the compounds exhibited strong binding abilities and formed H-bond interactions with ERK2, providing support for their potent antitumor activities and promising potential as lead molecules for the development of antitumor therapeutics.
Low extraction efficiency limits the availability and application of aescins, which exhibit various pharmacological activities. Here, we optimized parameters for ultrasound-assisted extraction of aescins from Aesculus chinensis seeds using deep eutectic solvent (DES)-water mixtures. Seven DES formulations were screened, and one providing the highest yield was selected for optimizing the molar ratio. The effects of four parameters were investigated using single-factor experiments combined with response surface methodology. The optimal extraction conditions were as follows: DES, a 1:1 mixture of 1,3-butanediol and lactic acid, with 42.5% water, used at a liquid-solid ratio of 25 mL/g; ultrasonic frequency, 40 kHz; extraction temperature, 70 °C; and extraction time, 27.5 min. The extraction yield under these conditions was significantly higher than that obtained via traditional methods. Aescin was purified from the DES extract using macroporous resin. AB-8 resin was most efficient in adsorbing aescin in static adsorption tests. Based on dynamic adsorption experiments, optimal separation, with a 100% recovery rate, was achieved by passing four bed volume (BV) of extract through AB-8 column, removing impurities with two BV of deionized water and four BV of 30% ethanol, and eluting with four BV of 60% ethanol at 5–10 mL/min. This green method should be suitable for large-scale applications.