Research progress on rutin derivatives / 中国中药杂志

Compounds derived from natural products present satisfactory efficacy in disease prevention and treatment. The use of chemical substances in plants to promote healthhas increasingly attracted people's attention. Rutin, a typical flavonoid, is mainly found in various vegetables, fruits and Chinese herbal medicines. As a natural antioxidant, it features many pharmacological activities, such as anti-inflammation, anti-virus, anti-tumor, and prevention and treatment of cardiovascular and cerebrovascular diseases. However, the low bioavailability and poor water solubility limit its clinical application. In view of this, its structure is optimized and modified to afford rutin derivatives with good solubility, high bioavailability, stable metabolism and small toxic side effects. So far, a large number of rutin ethers, esters, and complexes have been synthesized and undergone activity testing. This paper reviews the structural modification of rutin in recent years, and the obtained derivatives have excellent properties and significant biological activity.

Research progress on therapeutic potential of quercetin / 中国中药杂志

Quercetin is a naturally occurring phytochemical with good bioactivity, which mainly exists in the form of glycoside in vegetables, fruits, tea, and wine and exhibits beneficial health effects. Quercetin is a dietary polyphenol that exerts the protective effects through diet or use as a food supplement. Compared with chemical agents, quercetin is widely available and safe. Quercetin has been extensively studied for its anti-diabetic, anti-hypertensive, anti-Alzheimer's disease, anti-arthritic, anti-influenza virus, anti-microbial infection, anti-aging, autophagy-regulating, and cardiovascular protective effects. Studies on its activities against different can-cer cell lines have also been reported recently. However, the poor water solubility, rapid in vivo metabolism, and short half-life of quercetin have led to its low bioavailability, thus limiting its application in the field of medicine. Quercetin nanoparticles and nanoparticle drug delivery system have been effectively utilized for enhancing its bioavailability. This paper reviewed the therapeutic potential of quercetin from both preclinical and clinical aspects and proposed solutions to improve its bioavailability, so as to provide a reference for the therapeutic application of natural compounds in the field of medicine.

Research progress on antitumor activity of quercetin derivatives / 中国中药杂志

Quercetin is a kind of typical flavonoid, mainly found in various vegetables, fruits and Chinese herbs that are consumed daily, with the functions of anti-oxidation, anti-tumor, prevention and treatment of cardiovascular and cerebrovascular diseases. Quercetin is a natural compound with defined anti-tumor activity. Due to its low bioavailability and poor water solubility, quercetin has limitations in clinical application. The quercetin derivatives with good solubility, high bioavailability, metabolic stability, and low toxicity have been obtained through modification of quercetin structure. In recent years, a large number of quercetin ethers, esters, complexes, C-4 carbonyloxy substituted derivatives, A,B-ring modified compounds and other derivatives have been synthesized and tested for in vitro anticancer activity. The quercetin derivatives with anti-tumor activity synthesized in the last 5 years were reviewed in this paper.

Study on synthesis and biological activities of quercetin-3-O-amide derivatives / 中草药

Objective: To design and synthesize quercetin amide derivatives and study the antitumor activity of these compounds in vitro. Methods: The cheap rutin was used as the raw material, the benzyl group was selectively protected, the Williamson was converted into ether, and then the target product was obtained by the hydrogenation debenzylation of Pd/C catalyst. The antioxidant activity of the target compound was investigated by the DPPH method. The inhibitory effects of the target compounds on the proliferation of human esophageal squamous cell carcinoma cell EC109, human esophageal squamous cell carcinoma cell EC9706, human gastric cancer cell SGC7901, and mouse melanoma cells B16-F10 were investigated by MTT method. Results: The structures of the 15 quercetin amide derivatives were confirmed by 1H-NMR, 13C-NMR, and ESI-MS. The antioxidant results showed that the SC50 of most target compounds was smaller than or equivalent to quercetin, which suggests that 3-OH is not an essential group for the antioxidant activity of quercetin. The results of anti-tumor experiments showed that after the structural modification of quercetin by chemical methods, its anti-tumor activity was significantly enhanced in vitro. Among them, the inhibitory effect of compound 7-6 on EC109 (IC50 = 10.25 μmol/L) is significantly better than that of the parent drugs quercetin (IC50 = 31.884 μmol/L) and 5-FU (IC50 = 41.738 μmol/L). Potential new antitumor candidate compounds. Conclusion: The 15 quercetin-3-O-amide derivatives are all new compounds. Among them, compounds 7-6 have good antitumor activity and deserve further study.

Effects of morinda officinalis oligosaccharide on the proliferation, differentiation and paracrine of vascular endothelial progenitor cells / 中国组织工程研究

BACKGROUND: Morinda officinalis oligosaccharide is the main active ingredient of morinda officinalis extract,which can promote the angiogenesis of ischemic tissue, but the mechanism is unknown. At present, there are two ways for endothelial repair:vascular endothelial cell division or differentiation from vascular endothelial progenitor cells in the peripheral blood. Here, we attempted to explain the pro-angiogenesis mechanism of morinda officinalis oligosaccharide by exploring whether there is a correlation between morinda officinalis oligosaccharide and the biological function of vascular endothelial progenitor cells, thereby providing experimental reference for new drug development. OBJECTIVE: To observe the effect of morindae officinalis oligosaccharide on the proliferation, differentiation and paracrine of vascular endothelial progenitor cells. METHODS: Vascular endothelial progenitor cells were isolated from healthy human peripheral blood, and divided into two groups: control group (without morindae officinalis oligosaccharide) and experimental group (with 0.15 g/L morindae officinalis oligosaccharide), followed by 48 hours of in vitro culture.The proliferation of vascular endothelial progenitor cells was tested by fluorescent staining;the ratio of vascular endothelial progenitor cells expressing CD31 was detected by flow cytometry; and the levels of vascular endothelial growth factor, stromal cell-derived factor 1 and interleukin 8 were analyzed by enzyme-linked immunosorbent method. RESULTS AND CONCLUSION: The percentage of vascular endothelial cells expressing CD34, CD133 or VEGFR- 2 was (84.72±4.34)%. After 48 hours of culture by 0.15 g/L morindae officinalis oligosaccharide, the proliferation rate and the positive expression of CD31 in the experimental group were significantly higher than those in the control group (P < 0.05). The levels of vascular endothelial growth factor, stromal cell-derived factor 1 and interleukin 8 in the experimental group were also higher than those in the control group (P < 0.05). To conclude, morindae officinalis oligosaccharide can promote the proliferation and differentiation of vascular endothelial progenitor cells, and meanwhile, it can stimulate the release of vascular endothelial growth factor, stromal cell-derived factor 1 and interleukin 8 from vascular endothelial progenitor cells through the paracrine pathway. Consequently, it is a potential drug for myocardial ischemic diseases.