In vitro antiviral activity of peptide-rich extracts from seven Nigerian plants against three non-polio enterovirus species C serotypes.

BACKGROUND: As frequent viral outbreaks continue to pose threat to public health, the unavailability of antiviral drugs and challenges associated with vaccine development underscore the need for antiviral drugs discovery in emergent moments (endemic or pandemic). Plants in response to microbial and pest attacks are able to produce defence molecules such as antimicrobial peptides as components of their innate immunity, which can be explored for viral therapeutics. METHODS: In this study, partially purified peptide-rich fraction (P-PPf) were obtained from aqueous extracts of seven plants by reverse-phase solid-phase extraction and cysteine-rich peptides detected by a modified TLC method. The peptide-enriched fractions and the aqueous (crude polar) were screened for antiviral effect against three non-polio enterovirus species C members using cytopathic effect reduction assay. RESULTS: In this study, peptide fraction obtained from Euphorbia hirta leaf showed most potent antiviral effect against Coxsackievirus A13, Coxsackievirus A20, and Enterovirus C99 (EV-C99) with IC50 < 2.0 µg/mL and selective index ≥ 81. EV-C99 was susceptible to all partially purified peptide fractions except Allamanda blanchetii leaf. CONCLUSION: These findings establish the antiviral potentials of plants antimicrobial peptides and provides evidence for the anti-infective use of E. hirta in ethnomedicine. This study provides basis for further scientific investigation geared towards the isolation, characterization and mechanistic pharmacological study of the detected cysteine-rich peptides.

Molecular identification, in vivo and in vitro activities of Calvatia gigantea (macro-fungus) as an antidiabetic agent.

Mushrooms are cherished as sources of food, nutrients and medicine. Inadequate data on the identity and medicinal properties of many wild Nigerian mushrooms has limited their utilization. This work was carried out to identify and authenticate a puffball mushroom using molecular tools and investigate its antidiabetic properties. Taxonomic guides were employed in morphological identifying the mushroom as Lycoperdon umbrinum, methanol extract of fruiting bodies was evaluated for antidiabetic activity using in vitro α-amylase assay and in vivo activity in the alloxan-induced diabetic rat model. The macro fungus was identified using Internal Transcribed Spacers (ITS) sequence analysis after which sequences generated were compared using the basic local alignment search tool (BLAST) at NCBI GenBank. In the acute in vivo test, the 400 mg/kg dose showed the best activity with percentage reduction in blood glucose 29.3%, compared with 5 mg/kg glibenclamide at 15%. The in vitro assay established that the extract possessed potent activity with IC50 of 0.46 µg/mL compared to its DCM, butanol fractions and acarbose (IC50 5.3 µg/mL, 5.6 µg/mL, 45 µg/mL) respectively. BLAST analysis revealed the mushroom (accession number, KRO78278.1) to show 98% identity to Calvatia gigantea. The study established the identity of this mushroom and confirmed its antidiabetic activity.