Stigmast-4-en-3-one from Euonymus alatus (Thunb.) Siebold. improves diabetic retinopathy and angiogenesis mediated by glucocorticoids receptor.

ETHNOPHARMACOLOGICAL RELEVANCE: Euonymus alatus (Thunb.) Siebold. (EA), a traditional Chinese medicine, is widely used in the treatment of diabetes. Our group has previously found that EA could treat diabetic retinopathy (DR) and stigmast-4-en-3-one (Numbered E6) is the active substance responsible for inhibiting angiogenesis in vitro by EA. However, the effects and mechanisms of E6 in the treatment of DR is still unknown. AIM OF THE STUDY: The aim of this study was to investigate the effects and mechanisms of E6 in EA on DR. Additionally, a comparison was made between the effects of E6 and triamcinolone acetonide (TA), as well as the side effects of E6 and dexamethasone. MATERIALS AND METHODS: Ocular affinity assessment and pharmacokinetic parameter prediction were conducted to evaluate the potential of E6 to treat DR. Retinal endothelial cells were used to investigate the in vitro inhibitory effect of E6 on vascular proliferation. Additionally, chicken embryos, zebrafish, and mice were used to investigate the in vivo anti-vascular proliferation effect of E6. Finally, diabetic mice were used to investigate whether E6 improves diabetic retinopathy and to compare its efficacy with that of TA. We then used network pharmacology to study the targets of E6 and performed molecular docking; followed by immunofluorescence experiments, ELISA, Western blot, and tube formation experiments to further investigate its mechanism. Finally, we compared the side effects of E6 with those of dexamethasone. RESULTS: E6 was found to have an affinity for the eye and to inhibit vascular proliferation both in vivo and in vitro. Moreover, E6 was found to be more efficacious than TA in the treatment of DR. Molecular docking experiments predicted that the glucocorticoid receptor (GR) is a potential target of E6, and immunofluorescence analyses confirmed that E6 upregulated the expression of the GR in the retina of hyperglycemic mice. In addition, western blotting results and tube formation experiments showed that E6 also attenuated angiogenesis by inhibiting the Hippo and VEGF pathways. Finally, by comparing the effects of E6 and dexamethasone on glucose regulation and osteoporosis, E6 was found to have fewer side effects. CONCLUSIONS: E6 is a highly effective drug for the treatment of DR, superior to TA and with fewer side effects than dexamethasone. Its mechanism involves the activation of glucocorticoid receptor and inhibition of Hippo and VEGF pathways to alleviate angiogenesis and inflammation. This study is the first to investigate the role and mechanism of E6 in improving DR. The findings suggest that E6 has unique advantages in the treatment of DR.

Simultaneous determination of five N-alkylamides in the root of Anacyclus pyrethrum by HPLC and profiling of components in its methanolic root extract by UPLC/Q-TOF-MS

ABSTRACT The root of Anacyclus pyrethrum (L.) Lag., Asteraceae, is very widely used for treating various diseases in Traditional Uygur Medicine, particularly in the treatment of vitiligo. However, there have been few studies on the quality standards of A. pyrethrum in China. A. pyrethrum contains abundant N-alkylamides, which are considered to be the principal components. Therefore, based on the previous research in our group, six N-alkylamides were obtained by using column chromatography. We used ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry to determine the mass spectrometry cleavage mechanism of these six monomer components and established the mass spectrometry cleavage law of N-alkylamides. Then, we used the ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry method to rapidly identify and analyze the N-alkylamide components of the A. pyrethrum methanol extract. Finally, twenty N-alkylamides were identified, including eleven N-isobutylamides, two N-methyl isobutylamides, six 4-hydroxyphenylethyl-amide and one 2-phenylethylamide. Five of these compounds were identified as new compounds that have not been reported to date. Two of these compounds were identified for the first time in this herb. Therefore, this work provides an approach for the quality analysis of N-alkylamides in the root of A. pyrethrum. A search of the literature showed that the content determination in the A. pyrethrum quality standard is still a remaining problem. N-alkylamides are the main components of A. pyrethrum. Even though ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry has the advantages of lower time and higher efficiency compared to high-performance liquid chromatography, considering the ease of repeatability and universality of the quality control method, we chose to use high-performance liquid chromatography for content determination. In this experiment, high-performance liquid chromatography was used for the first time to establish a simple, rapid and accurate method for evaluating the N-alkylamide content in A. pyrethrum with five N-alkylamides used as the standards. Finally, this work provides a qualitative and quantitative method for the analysis of N-alkylamides in A. pyrethrum, improving the quality control standards for A. pyrethrum.