Bioassay-guided isolation of Poliovirus-inhibiting constituents from Zephyranthes candida.

Abstract

CONTEXT:

Plants of the Zephyranthes genus are globally used in folk medicine. In a previous study, Zephyranthes candida Linn. (Amaryllidaceae) was identified as having antiviral properties; this led to anti-poliovirus assay-guided isolation of compounds from crude methanol extract of the plant.

OBJECTIVE:

Isolation of anti-poliovirus constituents from Z. candida.

MATERIAL AND METHODS:

Active chloroform fraction from crude methanol extract of Z. candida (whole plant) was subjected to bioassay-guided fractionation; repeated column and preparative thin layer chromatography led to isolation of active compounds. Chemical structures were identified using spectroscopic techniques. Using serial two-fold dilution of maximum non-toxic concentration (MNTC) of each compound (0.0625-1 µg/mL for lycorine and 0.625-10 µg/mL for trisphaeridine and 7-hydroxy-3',4'-methylenedioxyflavan), the ability of extracts to inhibit viral-induced cell death in tissue culture was evaluated 72 h post-infection by the colorimetric method using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) dye. Regression analysis was used to determine 50% inhibitory concentration (IC50) and 50% cytotoxicity concentration (CC50), from which selective index (SI) was calculated.

RESULTS:

From the chloroform fraction, three compounds were isolated and identified, namely lycorine (1), trisphaeridine (2), and 7-hydroxy-3',4'-methylenedioxyflavan (3) as the anti-polioviral components. Lycorine was the most active, with an IC50 value of 0.058 µg/mL followed by trisphaeridine (2) with an IC50 of 0.1427 µg/mL, and 7-hydroxy-3',4'-methylenedioxyflavan (3) with an IC50 of 0.2384 µg/mL.

DISCUSSIONS AND CONCLUSIONS:

The antipoliovirus activity of trisphaeridine (2) and 7-hydroxy-3',4'-methylenedioxyflavan (3) is established in this report; these compounds are of moderate toxicity and have very good SI. They could be a potential template for the development of a new antiviral agent.

• Authors: Ogbole Omonike Oluyemisi, Ajaiyeoba Edith Oriabure, Adeniji J Adekunle, Kamdem Soup T Ramsay, Sajan Shyyaula, Muhammad Iqbal Choudhary
• Journal: Pharmaceutical biology (Pharm Biol) Vol. 53 Issue 6 Pg. 882-7 (Jun 2015) ISSN: 1744-5116 [Electronic] England
• PMID: 25431196 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Alkaloids
• Amaryllidaceae Alkaloids
• Antiviral Agents
• Dioxoles
• Phenanthridines
• Plant Extracts
• trispheridine
• lycorine

Topics

• Alkaloids (isolation & purification, pharmacology)
• Amaryllidaceae Alkaloids (chemistry, isolation & purification, pharmacology)
• Antiviral Agents (pharmacology)
• Cell Line
• Cell Survival (drug effects)
• Cytopathogenic Effect, Viral (drug effects)
• Dioxoles (chemistry, isolation & purification, pharmacology)
• Humans
• Inhibitory Concentration 50
• Liliaceae (chemistry)
• Phenanthridines (chemistry, isolation & purification, pharmacology)
• Plant Extracts (chemistry, pharmacology)
• Poliovirus (drug effects)