METHODS: Aqueous extract of S. baicalensis was prepared by microwave energy steam evaporation method (MEGHE™), and the anti-dengue virus replication activity was evaluated using the foci forming unit reduction assay (FFURA) in Vero cells. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was used to determine the actual dengue virus RNA copy number. The presence of baicalein, a flavonoid known to inhibit dengue virus replication was determined by mass spectrometry.
RESULTS: The IC(50) values for the S. baicalensis extract on Vero cells following DENV adsorption ranged from 86.59 to 95.19 μg/mL for the different DENV serotypes. The IC(50) values decreased to 56.02 to 77.41 μg/mL when cells were treated with the extract at the time of virus adsorption for the different DENV serotypes. The extract showed potent direct virucidal activity against extracellular infectious virus particles with IC(50) that ranged from 74.33 to 95.83 μg/mL for all DENV serotypes. Weak prophylactic effects with IC(50) values that ranged from 269.9 to 369.8 μg/mL were noticed when the cells were pre-treated 2 hours prior to virus inoculation. The concentration of baicalein in the S. baicalensis extract was ~1% (1.03 μg/gm dried extract).
CONCLUSIONS: Our study demonstrates the in vitro anti-dengue virus replication property of S. baicalensis against all the four DENV serotypes investigated. The extract reduced DENV infectivity and replication in Vero cells. The extract was rich in baicalein, and could be considered for potential development of anti-DENV therapeutics.
AIMS: To provide an up-to-date, authoritative review with respect to the traditional uses, chemical composition, in vitro and in vivo pharmacological properties, and toxicological estimations accomplished either utilizing the crude extracts or, wherever applicable, the bioactive compounds isolated from B. glabra. Besides, a critical evaluation of the published literature has been undertaken with regards to the current biochemical and toxicological data.
MATERIALS AND METHODS: Key databases per se, Ovid, Pubmed, Science Direct, Scopus, and Google scholar amongst others were probed for a systematic search using keywords to retrieve relevant publications on this plant. A total of 52 articles were included for the review depending on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
RESULTS: The studies conducted on either crude extracts, solvent fractions or isolated pure compounds from B. glabra had reported a varied range of biological effects comprising antibacterial, antifungal, antidiabetic, cytotoxic, analgesic, antipyretic, anti-inflammatory, and antioxidant activities. Phytochemical analysis of different parts of B. glabra unveiled 105 phytochemicals, belonging to phenolic, flavonoid, betacyanin, terpenoid, glycoside and essential oils classes of secondary metabolites.
CONCLUSION: Most of the pharmacological activities of crude extracts from this plant have been reported. A very few studies have reported the isolation of compounds responsible for observed biological potential of this plant. Moreover, the toxicity studies of this plant still need to be explored comprehensively to ensure its safety parameters. Additional investigations are recommended to transmute the ethnopharmacological claims of this plant species in folklore medicines into scientific rationale-based information.