Anti-diabetic effects of eight extracts from leaves ofL. speciosausing different manufacturing processes based on the contents of active ellagitannins and inhibitory ellagic acid derivatives.
Morus australis distributed widely in China has high value in food and agriculture. Twelve phenolic compounds were isolated and identified as major constituents of M. australis root from Shaanxi province, China, while the protective effect of M. australis root on liver injury has never been determined in detail. In this study, the hepatoprotective ability of M. australis root was investigated in vivo and in vitro. The ethanol-water extract prepared from M. australis root showed protection on alcohol-induced liver damage in mice by decreasing the levels of serum alanine aminotransferase, aspartate transaminase, triacylglycerol and malondialdehyde, and by increasing glutathione contents. Furthermore, among 12 major constituents of M. australis root, 10 flavonoids (especially 1) showed protection against carbon tetrachloride (CCl4)-intoxicated HepG2 cell lines by decreased lactic dehydrogenase levels. In addition a validated HPLC-DAD method was established for the quantitative analysis of 10 flavonoids in the bioactive extract. Practical applications Our results showed that M. australis root extract significantly alleviated the liver damage in mice. Ten flavonoids from the root of this plant exhibited protection on CCl4-intoxicated HepG2 cell lines. This study suggests that Morus australis root has hepatoprotective potential as a promising supplement for the prevention and treatment of liver diseases.
Fraxinus mandshurica is widely used in folk medicine to treat various diseases and has significant pharmacological effects. To make full use of this resource, its roots were studied. Twelve lignans were first obtained by natural product extraction, selective separation and identification, and were identified and quantified by high performance liquid chromatography-photodiode array (HPLC-DAD). The results of quantitative analysis showed that the highest lignin content in F. mandshurica roots was compound 9 with 102.02 mg/g, while the overall lignin content in Shanxi was low. The results of methodological validation showed that the RSD values of intra-day precision ranged from 0.35-1.38%, while the RSD values of inter-day precision were within 1.97%; the RSD values of reproducibility experiments ranged from 0.35-1. 96%, while the RSD values of stability experiments were less than 2.97%; the spiked recovey of samples were within 102.84%, and the RSD values ranged from 0.39%-1.77%, which fully confirmed the high precision and good reproducibility of the analytical method. In addition, fingerprinting and heatmap were established for 40 batches of samples from 8 origins. Next, multivariate analysis, including principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA), was performed to investigate the differences in lignin content in the roots of F. mandshurica from different origins, and four lignins that could be used to distinguish F. mandshurica from different origins were screened. Finally, 12 lignans were evaluated for enzyme activity inhibition with α-glucosidase, tyrosinase and acetylcholinesterase, and the results showed that all 12 lignans exhibited enzyme activity inhibition to different degrees, which have potential applications in anti-diabetic, whitening and light spot and anti-Alzheimer's disease, and become a new source of natural enzyme activity inhibitors. This study established an identification and evaluation method applicable to plants of different origins, which provides a certain theoretical basis for the comprehensive exploitation of F. mandshurica.
Bee pollen is known as a natural nutrient storehouse and plays a key role in many biological processes. Based on the preliminary separation, identification, and characterization of the main active components of Fagopyrum esculentum Moench. bee pollen (FBP), the protective effects of F. esculentum bee pollen extract (FBPE) on high-fat-diet (HFD) and streptozocin (STZ) induced type II diabetes mellitus (T2DM) was evaluated in this study. The results revealed that FBPE contains 10 active compounds mainly including luteolin (9.46 g/kg), resveratrol (5.25 g/kg), kaemferol (3.67 g/kg), etc. The animal experiment results showed that FBPE could improve HFD-STZ induced T2DM mice. Moreover, the underlying mechanism of the above results could be: (i) FBPE could reduce the inflammation related to phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway, and (ii) the gut microbiota remodeling. The results of correlation analysis showed Candidatus Arthromitus and SMB53 indicated positive correlations to tumor necrosis factor-α (TNF-α); Coprococcus, Ruminocossus, and Odoribacteraceae reported negative correlations to transforming growth factor-β (TGF-β). That FBPE has an outstanding ability to improve T2DM and could be used as a kind of potential functional food for the prevention of T2DM.