Wound healing activity of Delonix elata stem bark extract and its isolated constituent quercetin-3-rhamnopyranosyl-(1-6) glucopyranoside in rats

Delonix elata L.is a Ceasalpinaceae species and is traditionally used in India for treatment of skin diseases,liver diseases and rheumatic problems.However,systematic evaluation of its wound healing activity is lacking.Thus,in the present study,we aimed to assess the wound healing activity of D.elata stem bark extract(DSE) and its isolated constituent quercetin-3-rhamnopyranosyl-(1-6) glucopyranoside(QRPG) in rats.The formulations effects on wound healing were assessed by the wound contraction rate,epithelialization period,tensile strength,content of the hydroxyproline,hexosamine and uronic acid in granulation tissue,histopathological studies and Col 1 α(I) expression level in wound tissue by reverse transcription polymerase chain reaction(RT-PCR) study.The topical application of DSE ointment caused faster epithelialization,significant wound contraction(100%),and better tensile strength(710.5 ± 10.5 g/cm^2),while QRPG showed wound epithelialization with 98.2%contraction,better than that of the control group(78.18%).The biochemical analysis of granulation tissue revealed that DSE and QRPG significantly increased hydroxyproline,hexosamine and uronic acid content.A significant increase in the expression of Col 1 α(I) was observed in the wound tissue of DSE and QRPG treated rats.DSE and QRPG were shown to enhance wound healing by increasing collagen synthesis through upregulation of Col 1 α(I),thus validating ethnomedicinal uses.

Isolation and Confirmation of Quercetin-3-O-Glycosides from Rubber Cassava Leaves

The core of the natural product chemistry laboratory is isolation secondary metabolites. One of the potential secondary metabolites for isolation in the natural product chemistry laboratory is routine (quercetin-3-O-glycosides). Routine (Quercetin-3-O-glycoside) has been isolated from ethanol extract of rubber cassava leaves (Manihot glaziovii MA). Isolation was done by maceration and recrystallization. The isolation method used in this study is complemented by the isolation method published. The isolated (Quercetin-3-O-glycoside) routine using this method obtained a yield of 0.118% of the total dried leaf extract. The routine (Quercetin-3-O-glycoside) was identified using a standard routine. Routine can be further utilized in the world of medicine as an amplifier of capillary structure, reducing the permeability and fragility of blood vessels.

Quercetin-3-O-β-D-glucopyranosyl-(4→1)-α-L-rhamnoside metabolites in the rat using UPLC-Q-TOF/MS

Ultraperformance liquid chromatography/quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF/MS) and the MetabolynxTM software, combined with mass defect filtering, were applied to identity the metabolites of quercetin-3-O-β-D-glucopyranosyl-(4→1)-α-L-rhamnoside(QGR) in rats after intravenous administration. MSE was used for simultaneous acquisition of precursor ion information and fragment ion data at high and low collision energy in one analytical run, which facilitated the rapid structural characterization of eight metabolites in rat plasma, urine and bile. The results indicated that methylation and glucuronidation were the major metabolic pathways of QGR in vivo. The present study provided important information about the metabolism of QGR which will be useful for fully understanding the mechanism of action of this compound. Furthermore, this work demonstrated the potential of the UPLC-Q-TOF/MS approach using Metabolynx for rapid and automated research of the metabolites of natural products.

Rapid determination of quercetin-3'-O-glucoside in rat plasma by high performance liquid chromatography-tandem mass spectrometry

A method for the quantification of quercetin-3’-O-glucoside in rat plasma by high-performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） was developed and validated.Along with internal standard（carbamazepine）,quercetin-3’-O-glucoside was extracted from plasma samples by simple liquid-liquid extraction with ethyl acetate.The mass spectrometry detection was set in multiple reaction monitoring（MRM） mode via positive electrospray ionization（ESI）.The chromatographic run time was 3.5 min per sample.The calibration curves were linear（r^2 = 0.9992） with a lower limit of quantification（LLOQ） of 10.625 ng/mL,and the limit of detection（LOD） was 4.25 ng/mL.The intra-and inter-day precision and accuracy,in terms of relative standard deviation（RSD）,were all lower than 10.44%.The recovery rate of the analyte and internal standard were higher than 66.80%.After intravenous administration of 10 mg/kg quercetin-3’-O-glucoside,the t1/2 and AUC were（0.02±0.01） h and（1.22±0.28）×10^4 μg/L·h.The method is accurate,stable and sensitive,which is suitable for the pharmacokinetic study of quercetin-3’-O-glucoside in rats.

Antiviral activity of quercetin-3-β-O-D-glucoside against Zika virus infection

Dear Editor, The 2015-2016 outbreak of Zika virus （ZIKV） fever, first reported in Brazil during early 2015 （Zanluca et al., 2015）, has infected millions of people and is a global public health concern. ZIKV infections are associated with fetal microcephaly, as well as neurological complications in humans. The virus can be shed in the semen and vaginal secretions of humans, leading to sexual transmission, and unexpectedly ZIKV infections cause severe damage to the male reproductive organs in male mice （Govero et al., 2016; Ma et al., 2016）.

Quercetin-3-O-β-D-glucuronide Inhibits Mitochondria Pathway-mediated Platelet Apoptosis via the Phosphatidylinositol-3-kinase/AKT Pathway in Immunological Bone Marrow Failure

Objective: Quercetin-3-O-β-D-glucuronide(QG) can alleviate immunological bone marrow failure(BMF) by increasing platelet counts. However, the principal mechanism is less known. This study aimed at deciphering the possible underlying mechanism of QG that is indicated in thrombocytopenic purpura. Methods: In vitro and in vivo experiments were carried out for investigating the mechanism behind QG-facilitated inhibition of mitochondrial pathway-mediated excessive apoptosis of platelets through the phosphatidylinositol-3-kinase(PI3K)/AKT pathway. Results: Our results revealed that QG, the main effective ingredient of Herba Sarcandrae, increases the number of platelets and decreases the expression of Bax, Bad, Bid, and caspase-9 in immunological BMF, indicating the inhibition of mitochondrial pathway-mediated apoptosis. Moreover, we found that the protein and m RNA expressions, as well as the phosphorylated levels of PI3K and AKT, were increased significantly by QG, suggesting the activation of the PI3K/AKT pathway. Furthermore, the inhibition of the PI3K/AKT pathway by LY294002 antagonizes the effects of QG on platelet counts and mitochondrial pathway-mediated apoptosis. Conclusion: We demonstrate that QG inhibits the mitochondria pathway-mediated platelet apoptosis via the PI3K/AKT pathway in immunological BMF. This study thus sheds light on exploring the possible regulatory mechanism of traditional Chinese medicine in the treatment of thrombocytopenia induced by BMF.

Application of high-speed counter-current chromatography coupled with high performance liquid chromatography for the separation and purification of Quercetin-3-O-sambubioside from the leaves of Nelumbo nucifera

Quercetin-3-O-sambubioside[Quercetin-3-O-β-D-xylopyranosyl(1→2)-β-D-glucopyranoside]was separated and purified by semi-preparative high-speed counter-current chromatography(HSCCC)with a twophase-solvent system composed of ethyl acetate-nbutanol-water(4∶1∶5,v/v)from the leaves of Nelumbo nucifera(Lotus).A total of 5.0 mg of the targeted compound with a purity of 98.6%as determined by high performance liquid chromatography(HPLC)was obtained from 100 mg of the crude extract cleaned up by AB-8 macroporous resin in a one-step separation.Quercetin-3-O-sambubioside was a novel flavonoid glycoside from the leaves of Nelumbo nucifera,and its chemical structure was identified by means of ESI-MS,1D NMR and 2D NMR.