Quercetin and quercetin 3-O-glycosides from Bauhinia longifolia (Bong.) Steud. show anti-Mayaro virus activity

Abstract

BackgroundThe arthropod-borne Mayaro virus (MAYV) causes ‘Mayaro fever’, a disease of medical significance, primarily affecting individuals in permanent contact with forested areas in tropical South America. Recently, MAYV has attracted attention due to its likely urbanization. Currently, there are no licensed drugs against most mosquito-transmitted viruses. Here, we investigated the in vitro anti-MAYV activity of the flavonoids quercetin and its derivatives from the Brazilian shrub Bauhinia longifolia (Bong.) Steud.MethodsFlavonoids were purified by chromatographic fractionation from leaf extracts of B. longifolia and chemically identified as quercetin and quercetin glycosides using spectroscopic techniques. Cytotoxicity of purified flavonoids and of EtOAc- and n-BuOH-containing flavonoid mixtures was measured by the dye-uptake assay while their antiviral activity was evaluated by a virus yield inhibition assay.ResultsThe following flavonoids were purified from B. longifolia leaves: non-glycosylated quercetin and its glycosides guaijaverin, quercitrin, isoquercitrin, and hyperin. EtOAc and n-BuOH fractions containing these flavonoids demonstrated the highest antiviral activity of all tested substances, while quercetin had the highest antiviral activity amongst purified flavonoids. Quercetin, EtOAc, or n-BuOH fractions inhibited MAYV production by more than 90% at 25 μg/mL, displaying a stronger antiviral effect than the licensed antiviral ribavirin. A mixture of the isomers isoquercitrin and hyperin had a modest antiviral effect (IC90 = 104.9), while guaijaverin and quercitrin did not show significant antiviral activity.ConclusionsB. longifolia is a good source of flavonoids with anti-Mayaro virus activity. This is the first report of the activity of quercetin and its derivatives against an alphavirus.

Prophylactic Efficacy of Quercetin 3-β- O - d -Glucoside against Ebola Virus Infection

“…quercetin (18), fisetin (18), isorhamnetin (25), and kaempferol (25). Similarly, quercetin 3-O-glycosides protect against Mayaro virus (19), and quercetin protects against both Mayaro virus (19) and herpes simplex virus 1 (HSV-1) (11). The present study is the first to demonstrate that Ebola virus is also strongly inhibited by a quercetin derivative.…”

“…Quercetin 3-␤-O-D-glucoside (Q3G), for example, is a natural derivative of quercetin that contains a glucoside molecule, and this has been shown to enhance the solubility and bioavailability of the compound when ingested (16). Although much research on quercetin and its derivatives has focused on their properties as potential therapeutic agents against cancer and inflammatory diseases and their anti-metabolic disease effects (17), recent studies have also demonstrated antiviral activity against a wide variety of viruses, including influenza virus, Chikungunya virus, Epstein-Barr virus, hepatitis C virus, and Mayaro virus (18)(19)(20)(21)(22). While a detailed mechanism of action remains undefined, it has been proposed that quercetin and its derivatives affect a step in the viral entry process.…”

“…(Fig. 1A) is a glucosylated form of quercetin, a flavonoid compound that has been shown to exhibit antiviral activity against several RNA viruses (18)(19)(20). In order to test the antiviral activity of our compound against ebolavirus, we first calculated the EC 50 and EC 90 values using Vero E6 epithelial cells.…”

Isoquercitrin Inhibits Hydrogen Peroxide-Induced Apoptosis of EA.hy926 Cells via the PI3K/Akt/GSK3β Signaling Pathway

“…In recent studies, isoquercitrin has been reported to possess anti-Mayaro virus, anti-inflammatory, anti-oxidative, anti-allergic, anti-hypertensive, anti-hyperglycemic, and saluretic/diuretic effects [15][16][17][18][19][20][21][22][23]. Although the antioxidative and neuroprotective effects of isoquercitrin have been established, whether isoquercitrin could exert an anti-apoptotic effect on endothelial cells is not clear.…”

“…Isoquercitrin, also known as quercetin-3-glucoside, is a glucose-bound derivative of quercetin that is commonly found in medicinal herbs, fruits, vegetables, and plant-derived foods and beverages [10][11][12][13][14]. In recent studies, isoquercitrin has been reported to possess anti-Mayaro virus, anti-inflammatory, anti-oxidative, anti-allergic, anti-hypertensive, anti-hyperglycemic, and saluretic/diuretic effects [15][16][17][18][19][20][21][22][23]. Although the antioxidative and neuroprotective effects of isoquercitrin have been established, whether isoquercitrin could exert an anti-apoptotic effect on endothelial cells is not clear.…”