Diospyros anisandra phytochemical analysis and anti-hemagglutinin-neuraminidase activity on influenza AH1N1pdm09 virus

The Genus Diospyros: A Review of Novel Insights into the Biological Activity and Species of Mozambican Flora

Species of the Diospyros L. genus (Ebenaceae family) have been largely used in traditional medicine for the treatment of several diseases, especially infectious ones. To date, active major compounds such as naphthoquinones, triterpenoids, and tannins have been isolated and pharmacologically validated from Diospyros species. The present study summarizes the information available in the literature on the species described in the Flora of Mozambique. To do so, scientific databases (e.g., PubMed, Scopus, Web of Science, and Google Scholar) were searched using various keywords and Boolean connectors to gather and summarize the information. Of the 31 native and naturalized species in the Flora of Mozambique, 17 are used in different regions of Africa and were described for their traditional uses. They were reported to treat more than 20 diseases, mostly infectious, in the gastrointestinal and oral cavity compartments. This work provides an overview of the therapeutical potential of Diospyros species and explores novel insights on the antimicrobial potential of extracts and/or isolated compounds of these Mozambican species.

In Vitro Anti-Influenza Virus Activity of Non-Polar Primula veris subsp. veris Extract

Medicinal plants have long been recognized as a tremendous source of candidate compounds for the development of pharmaceuticals, including anti-viral agents. Herein, we report the identification of anti-influenza virus activity in non-polar Primula veris L. subsp. veris extracts. We show that P. veris subsp. veris flower extracts, obtained using supercritical fluid or ultrasound-based extraction, possess virucidal/virus inactivation properties and confer prophylactic and therapeutic effects against influenza virus-induced cytolysis in vitro. By GC-MS and UPLC-HRMS analysis of non-polar P. veris subsp. veris extracts we identified terpenes, flavones, tocopherols, and other classes of phytochemicals with known or putative anti-influenza properties. In silico prediction of cellular functions and molecular pathways affected by these phytochemicals suggests putative effects on signal transduction, inflammasome, and cell death pathways that are relevant to influenza virus pathogenesis. Combining P. veris subsp. veris with extracts of medicinal plants with proven anti-influenza activity such as Echinacea purpurea (L.) Moench and Cistus creticus L. subsp. creticus achieves an impressive protective effect against infection by influenza virus H1N1 in vitro and reduced progeny virus production by infected cells. Collectively, these findings uncover a previously uncharted biological property of non-polar P. veris flower extracts that warrants further studies to assess clinical efficacy.

Bioassay-Guided Fractionation of Erythrostemon yucatanensis (Greenm.) Gagnon & GP Lewis Components with Anti-hemagglutinin Binding Activity against Influenza A/H1N1 Virus

Erythrostemon yucatanensis (Greenm.) Gagnon & GP Lewis is a legume tree native to and widely distributed in southeast Mexico, where its branches are used in traditional medicine. An in vitro evaluation of the antiviral activity of extracts and fractions from the leaves, stem bark and roots against two strains of the AH1N1 influenza virus was performed, leading to the identification of bioactive compounds in this medicinal plant. In a cytopathic effect reduction assay, the fractions from the leaves and stem bark were the active elements at the co-treatment level. These were further fractionated based on their hemagglutination inhibition activity. The analysis of spectroscopy data identified a combination of phytosterols (β-sitosterol, stigmasterol and campesterol) in the stem bark active fraction as the main anti-hemagglutinin binding components, while 5-hydroxy-2(2-hydroxy-3,4,5-trimethoxyphenyl)-7-metoxi-4H(chromen-4-ona), which was isolated from the leaf extracts, showed a weak inhibition of viral hemagglutinin. Time of addition experiments demonstrated that the mixture of sterols had a direct effect on viral particle infectivity at the co-treatment level (IC50 = 3.125 µg/mL). This effect was also observed in the virus plaque formation inhibition assay, where the mixture showed 90% inhibition in the first 20 min of co-treatment at the same concentration. Additionally, it was found using qRT-PCR that the NP copy number was reduced by 92.85% after 60 min of co-treatment. These results are the first report of components with anti-hemagglutinin binding activity in the genus Erythrostemon sp.