Medicinal plants: Treasure for antiviral drug discovery

Abstract

The pandemic of viral diseases like novel coronavirus (2019‐nCoV) prompted the scientific world to examine antiviral bioactive compounds rather than nucleic acid analogous, protease inhibitors, or other toxic synthetic molecules. The emerging viral infections significantly associated with 2019‐nCoV have challenged humanity's survival. Further, there is a constant emergence of new resistant viral strains that demand novel antiviral agents with fewer side effects and cell toxicity. Despite significant progress made in immunization and regenerative medicine, numerous viruses still lack prophylactic vaccines and specific antiviral treatments that are so often influenced by the generation of viral escape mutants. Of importance, medicinal herbs offer a wide variety of therapeutic antiviral chemotypes that can inhibit viral replication by preventing viral adsorption, adhering to cell receptors, inhibiting virus penetration in the host cell, and competing for pathways of activation of intracellular signals. The present review will comprehensively summarize the promising antiviral activities of medicinal plants and their bioactive molecules. Furthermore, it will elucidate their mechanism of action and possible implications in the treatment/prevention of viral diseases even when their mechanism of action is not fully understood, which could serve as the base for the future development of novel or complementary antiviral treatments.

Anti-dengue activity of super critical extract and isolated oleanolic acid of Leucas cephalotes using in vitro and in silico approach

“…Like oleanolic acid, the other phytochemicals such as quercetin, sulfated galactomannans, 7-O-methyl-glabranine, flavonoids, glabranine, eugenol, ursolic acid, azadirachtin, D-galactose, carrageenan, chalcone 4- hydroxypanduratin A and panduratin isolated from different plants have been reported for anti-dengue virucidal activity [ 22 , 30 ]. Some already reported compounds possess anti-dengue activities are given in Table 3 [ 38 – 41 ]. The oleanolic acid isolated in the present study revealed the 99.17% activity against dengue-2 virus while the SFE extract revealed the 100% anti-dengue activity.…”

Plant-Derived Antimicrobial Peptides as Potential Antiviral Agents in Systemic Viral Infections

“…Results showed that meliacine increased host survival, and reduced by 90% the severity of clinical symptoms and the presence of viral particles in vaginal fluids. It is noteworthy that the composition of this fluid was different from the one of untreated mice, as it presented increasing amounts of IFN-gamma (2550 ± 63 pg/mL) and TNF-alpha (from 7 ± 0.9 ng/mL to 12.15 ± 0.92 ng/mL), cytokines implicated in inflammation [ 47 , 48 ]. This ability to increase cytokine production has been confirmed by another study using 56 µg/mL of meliacine applied in lipopolysaccharide-producing Escherichia coli bacterial infection [ 47 , 48 ].…”

“…Cyclotides target HIV through interactions with the viral envelope and more specifically by disrupting the viral lipid envelope. This leads to the formation of pores, the leakage of components and the destruction of viral particles before their entry into host cells: cyclotides could prevent fusion between HIV and host cells ( Figure 1 ) [ 47 , 51 , 79 ].…”

A Review: Positive Outcome of Resveratrol Dry Suspension in Piglets against Rotavirus Infection

“…The diarrhea index calculated after the resveratrol dry suspension applied to the groups of the piglets, which infected with the Rotavirus [35]. The diarrhea index formula given below of the four groups are given: Resveratrol have many antiviral properties and used against the Rotavirus diarrhea and enterovirus [39], which cause the inflammation of the hearts of mice, which reduced the hearts ability to pump he blood normally and blocked the replication of enterovirus [40]. Therefore, we use he resveratrol against the Rotavirus, which is harmful for the piglets [41], which cause diarrhea and gastroenteritis in piglets and we know that resveratrol dry suspension could regulate the immune response and inhibit the diarrhea and other viral infection [42].…”