Anti-Sindbis Activity of Flavanones Hesperetin and Naringenin.

Abstract

Sindbis virus is a positive single stranded RNA virus of the Togaviridae family. Wild type and a neurovirulent strain, NSV, have provided a valuable model system for studying alphavirus induced encephalomyelitis in mice. [1][2][3] In recent years, there has been a growing interest in search for antiviral substances with high efficacy, low toxicity and minor side effects, one approach is the search for viral inhibitors of plant origin. Flavanones, also called citrus flavonoids, possess many biological activities, 4) previous studies have shown its antiviral activity, hesperetin was found to inhibit the replication of herpes simplex virus type 1, poliovirus type 1, parainfluenza virus type 3 and influenza. 5,6) Hesperidin and Naringin had inhibitory activity on rotavirus infection. 7)Here, we report the effects of hesperetin, naringenin and its glycosides on BHK-21 clone 15 cells, as well as their inhibitory effect on the replication of a neuro-adapted strain of Sindbis (NSV). MATERIALS AND METHODS ChemicalsThe four flavanones studied were hesperidin, naringin and its aglycones hesperetin and naringenin, purchased from Sigma Chemical, St. Louis, Mo, U.S.A. A stock solution of each compound was prepared by dissolved in dimethyl sulfoxide (DMSO) and stored at Ϫ20°C.Cells and Virus BHK-21 clone 15 cells were kindly provided by Dr. Guadalupe Guzmán (Virology Department of the Pedro Kourí Institute, Havana, Cuba). The neurovirulent strain (NSV) of Sindbis virus was donated by Dr. Dianne Griffin (Medical School, John Hopkins University, Baltimore, U.S.A.). BHK-21 cells were grown in Eagle's minimal essential medium (MEM) supplemented with 5% inactivated fetal bovine serum (FBS), 2 mM glutamine and 50 mg/ml gentamicine (growth medium). The cells were maintained in a humidified atmosphere containing 5% CO 2 at 37°C. Virus stock NSV was grown in BHK-21 cells with maintenance medium (MEM, 1% FBS, 2 mM glutamine and 50 mg/ml gentamicine) for 24 h. Viral titer was obtained by plaque assay. 8)Cytotoxic Assay The effect of the compounds over cell viability was determined by a modified MTT assay. 9) Briefly, cells were adjusted to 4ϫ10 4 cells/100 ml in growth medium and seeded in a 96-well plate. Cells were stabilized for 24 h and then incubated with twofold serial dilutions of each compound from 25-0.09 mg/ml in maintenance medium. After 24 h 10 ml (10 mg/ml) of MTT were added to each well; it was metabolized for 3 h, and 100 ml of the lysis buffer (20% SDS, 50% N,N-dimethylformamide) was added. Plates were read at 570 nm after 18 h. Antiviral Activity The effect of these compounds over the mammalian cells was assayed in the same conditions as the cytotoxic assay. BHK cells were infected with NSV at a multiplicity of infection (moi) of 0.1 pfu/cell. The infections were carried out in the presence or absence of different concentrations of compound. After 24 h, the viability of the cells was determined by MTT assay as described before. In addition, plaque reduction assay were carried out. 8) Briefly, BHK-21 clone 15 at a final c...

Identification of a Novel Antiviral Inhibitor of the Flavivirus Guanylyltransferase Enzyme

“…Medium samples of 250 l were taken at 4, 12, 24, 36, 48, 72, 96, and 120 h postinfection and stored at Ϫ80°C. Sample virus concentrations were determined by plaque assay on BHK cells as previously described (20). Viral growth curves were generated with Prism (GraphPad Inc., La Jolla, CA).…”

Glucosyl Hesperidin Prevents Influenza A Virus Replication <i>in Vitro</i> by Inhibition of Viral Sialidase

“…10) Its aglycone, hesperetin, has also been reported to possess a wide range of biological properties including antiviral activity. [11][12][13][14][15] Hesperetin has shown anti-influenza virus activity, but hesperidin has very weak or no activity. The use of these flavanoids in the field of medicine and in foods has been limited due to their very low solubility in water (Ͻ0.01%).…”

Antioxidant and antibacterial activity of extracts, fractions and isolated substances from the flowers of Acacia podalyriifolia A. Cunn. ex G. Don

“…Numerous studies describe the pharmacological properties of these compounds. Among the several applications of these flavanones are an antioxidant effect (Acker, 2000), hepatoprotective (Lee et al, 2004;Salgado et al, 2007), anti-inflammatory (Bodet et al, 2008), antiviral (Paredes et al, 2003;Nahmias et al, 2008), antihypertensive (Saponara et al, 2006) and antimutagenic (Choi et al, 1994;Renugadevi, Prabu, 2009) effects. These studies demonstrate the many potential applications of these compounds, with A. podalyriifolia an important source of these substances.…”