The Combination of Dimorphandra gardneriana Galactomannan and Mangiferin Inhibits Herpes Simplex and Poliovirus.

BACKGROUND: Herpes simplex virus (HSV) and poliovirus (PV) are both agents of major concern in the public health system. It has been shown that Dimorphandra gardneriana galactomannans can be used as solubilizer vehicles in the manufacturing of medicine. Mangiferin is the major constituent of Mangifera indica and presents multiple medicinal and biological activities. OBJECTIVE: This study assayed the effect of D. gardneriana galactomannan combined with mangiferin (DgGmM) against HSV-1 and PV-1. METHODS: The DgGmM cytotoxicity was evaluated by the colorimetric MTT method and the antiviral activity by plaque reduction assay, immunofluorescence and polymerase chain reaction (PCR), in HEp-2 cells. RESULTS: The DgGmM showed a 50% cytotoxic concentration (CC50) > 2000 µg/mL. The 50% inhibitory concentrations (IC50) for HSV-1 and PV-1 were, respectively, 287.5 µg/mL and 206.2 µg/mL, with selectivity indexes (SI) > 6.95 for the former and > 9.69 for the latter. The DgGmM time-ofaddition protocol for HSV-1 showed a maximum inhibition at 500 µg/mL, when added concomitantly to infection and at the time 1 h post-infection (pi). While for PV-1, for the same protocol, the greatest inhibition, was also observed concomitantly to infection at 500 µg/mL and at the times 4 h and 8 h pi. The inhibition was also demonstrated by the decrease of fluorescent cells and/or the inhibition of specific viral genome. CONCLUSION: These results suggested that the DgGmM inhibited HSV-1 and PV-1 replication, with low cytotoxicity and high selectivity and, therefore, represents a potential candidate for further studies on the control of herpes and polio infections.

Characterization and antiherpetic activity of native and chemically sulfated polysaccharide from Adenanthera pavonina.

The herpes simplex virus (HSV) is a widespread human pathogen and for many reasons the development of anti-herpetic drugs from natural products has been encouraged. Adenanthera pavonina (Ap) is a medicinal plant widely used in Brazil, among other uses. Herein, a native Ap seed polysaccharide (PLSAp) and its chemically sulfated derivate (SPLSAp) were studied by Fourier transform IR spectra (FT-IR), gel permeation chromatography (GPC) for molar mass determination and their intrinsic viscosity [η]. Biologically, the compounds were evaluated for anti-HSV activity, in HEp2 cell cultures. The cytotoxic concentrations (CC50) and the inhibitory concentrations (IC(50)) of the polysaccharides were determined by the colorimetric assay (dimethyl-thiazolyl-diphenyltetrazolium bromide) and plaque reduction assay (PRA), respectively. The SPLSAp showed a better antiviral activity when compared to the PLSAp with a CC(50) of 500 µg/ml, the IC(50) equal to 15 µg/ml and the selectivity index (SI) of 33.3. The time-of-addition and the time-of-removal assays demonstrated the highest inhibitory activity between 8-16h after the infection. The inhibition of viral DNA and protein syntheses by SPLSAp monitored by PCR and immunofluorescence assay (IFA), respectively, has also demonstrated. These findings demonstrated that the SPLSAp inhibited HSV-1 infection in different steps of the replication and, therefore, represents a valuable compound for preclinical studies in anti-herpetic therapy.

Antiviral Activity of Trichilia catigua Bark Extracts for Herpesvirus and Poliovirus.

Herpesvirus and poliovirus are responsible for important diseases in human and animal. Trichilia catigua a Brazilian native plant known as catiguá has several medicinal properties among them antimicrobial for bacteria and protozoa, however, no antiviral activity has been reported yet. This study evaluated the antiviral activity of the crude extract (CE) and aqueous and ethyl acetate fractions (AF, EAF) obtained from T. catigua in the replication of the Herpes simplex virus (HSV-1), bovine herpesvirus (BoHV-1) and poliovirus (PV-1). The cytotoxicity was analyzed by MTT assay and the antiviral effect was determined by the addition of extracts (0.25 to 100.0 µg/ml), before (-2h and -1h), during (Oh) and after (1h and 2h) the viral infection, by plaque reduction assay, in HEp-2 cell culture. The virucidal activity and inhibition of viral adsorption were also evaluated. In addition, the combination index (CI) with Acyclovir (ACV - reference drug) was determined for HSV-1. CE, AF and EAF showed a low toxicity (CC(50) >400 µg/ml) and low inhibitory concentration (IC50), ranging from 2.44-34.25 µg/ml for herpesvirus and 0.67 to 1.8 µg/ml for PV-1, associated with high selectivity index. The tested compounds showed high virucidal effect and high ability to inhibit viral adsorption, for all virus. The CI demonstrated a synergic effect (CI<1) for AF and EAF comparatively to acyclovir (ACV). Our study demonstrated that the extract and fractions of T. catigua is promising for future antiviral drug design with economically feasible production.

Strains of lentinula edodes suppress growth of phytopathogenic fungi and inhibit Alagoas serotype of vesicular stomatitis virus

Four Lentinula edodes strains (Le10, 46, K2, Assai) were assessed for their antagonistic effect on four filamentous fungus species of agricultural importance (Helminthosporium euphorbiae, Helminthosporium sp, Fusarium solani and Phomopsis sojae) and on Alagoas serotype of Vesicular Stomatitis Virus (VSA). The L. edodes strains studied had variable effects on the filamentous fungi and on VSA. The K2 and Le10 strains were antagonistic on the fungi assessed and the 46 and K2 strains were efficient on the Vesicular Stomatitis Virus. The results widened the list of beneficial effects of L. edodes on the control and prevention of animal pathogenic virus and filamentous fungi.