ABSTRACT
Herpes simplex virus type 1 (HSV-1) is a ubiquitous and widespread human pathogen, which gives rise to a range of diseases, including cold sores, corneal blindness, and encephalitis. Currently, the use of nucleoside analogs, such as acyclovir and penciclovir, in treating HSV-1 infection often presents limitation due to their side effects and low efficacy for drug-resistance strains. Therefore, new anti-herpetic drugs and strategies should be urgently developed. Here, we reported that baicalein, a naturally derived compound widely used in Asian countries, strongly inhibited HSV-1 replication in several models. Baicalein was effective against the replication of both HSV-1/F and HSV-1/Blue (an acyclovir-resistant strain)
ABSTRACT
Aims@#Phytochemical analysis showed Orthosiphon stamineus (OS) possessed bioactive compounds with antiviral properties against Herpes Simplex Virus Type 1 (HSV-1). However, there isn’t any study reported so far on OS virucidal properties towards HSV-1. Thus, this study aims to investigate virucidal mechanism of OS aqueous extract that possibly acts as a potent entry inhibitor against HSV-1 infection. @*Methodology and results@#Virucidal attachment and penetration assays were done via plaque assay to investigate the virucidal anti-HSV-1 mechanism of OS. The aqueous extract of OS leaves (OSA) was found to reduce HSV-1 plaques in virucidal assays. Inhibitory effect by OSA was observed as early as 30 min after exposing OSA to HSV-1 in a concentration-dependent manner suggesting a direct anti-HSV-1 property of OSA. Further investigation of the stages in which OSA inhibits HSV-1 shows virions treated with OSA failed to attach onto the host cell which implicated a role of OSA in blocking HSV-1 attachment to its host. OSA was also found to reduce HSV-1 plaques in penetration assay. Further evaluation using transmission electron microscopy (TEM) on OSA treated virion showed defective HSV-1 virion without envelope and the remaining capsid was altered. @*Conclusion, significance and impact of study@#These findings concluded that Orthosiphon stamineus leaves extract have virucidal activity by disintegrating HSV-1 virion structure and interfering with the attachment and penetration of the virus into the host cell. Thus, through the new mechanism against HSV-1, OS has the potential to be further developed as an anti-HSV-1 agent.
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Aims: The present study is aimed at determining the antiviral activity of Eleusine indica whole plant methanol extract. Methodology and results: Whole dried plants were extracted with methanol and the solvent was evaporated using a rotary evaporator. The crude methanol extract was previously shown to have antiviral activity towards herpes simplex virus type 1 (HSV-1) with selective index (SI = CC50 / EC50) of 12.2. The extract was further studied for the possible mode of action including pretreatment, attachment, penetration or virucidal activity. The observations suggested that E. indica crude methanol extract protects cells from HSV-1 infection, inhibits virus from docking to the surface of the cells and penetrating into the cells, as well as modifying virus through the virucidal effect. Conclusion, significance and impact of study: Methanol extract of E. indica is safe with antiviral potential as a prophylactic agent, inhibits viral attachment, penetration and virucidal effect.
Subject(s)
Herpesvirus 1, HumanABSTRACT
This study deals with the evaluation of in vitro cytotoxicity of the methanol 80% extract of Ficus vasta aerial parts in Vero cells, anti-HSV-1 and antibacterial activities and the determination of the phytochemical content of the F. vasta methanol extract. The extract was tested for its cytotoxicity in Vero cells and for anti-HSV-1 and against bacterial strains as S. aureus, S. epidermidis, E. coli and P. aeruginosa and also phytochemical constituents were detected. The results showed that this extract presented a CC50 value of 389 μg/mL, an intermediate value taking into account other researchers reported for some Moraceae species. Regarding the other biological activities, antiviral effect was not demonstrated by a HSV-1 challenge dilution of 100x tissue culture infective dose 50% (TCID50) and also by the disk-diffusion method at the higher non-toxic concentration of the extract (119 μg/mL). Phytochemical analysis of the methanol extract proved the presence of carbohydrates, tannins, flavonoids, coumarins, alkaloids and triterpenes. Chromatographic separation of the methanol extract resulted in the isolation and identification of β-sitosterol, stigmasterol, lupeol, ursolic acid, naringenin, luteolin, quercetin, vitexin, quercetin 3-O-β-glucoside and rutin. The results indicated that F. vasta aerial parts methanol extract is potential candidate for experiments of biological activity screening that are not anti-HSV-1 or antibacterial against the strains evaluated in this study, to be carried on in the future.
ABSTRACT
This study deals with the evaluation of in vitro cytotoxicity of the methanol 80% extract of Ficus vasta aerial parts in Vero cells, anti-HSV-1 and antibacterial activities and the determination of the phytochemical content of the F. vasta methanol extract. The extract was tested for its cytotoxicity in Vero cells and for anti-HSV-1 and against bacterial strains as S. aureus, S. epidermidis, E. coli and P. aeruginosa and also phytochemical constituents were detected. The results showed that this extract presented a CC50 value of 389 μg/mL, an intermediate value taking into account other researchers reported for some Moraceae species. Regarding the other biological activities, antiviral effect was not demonstrated by a HSV-1 challenge dilution of 100x tissue culture infective dose 50% (TCID50) and also by the disk-diffusion method at the higher non-toxic concentration of the extract (119 μg/mL). Phytochemical analysis of the methanol extract proved the presence of carbohydrates, tannins, flavonoids, coumarins, alkaloids and triterpenes. Chromatographic separation of the methanol extract resulted in the isolation and identification of β-sitosterol, stigmasterol, lupeol, ursolic acid, naringenin, luteolin, quercetin, vitexin, quercetin 3-O-β-glucoside and rutin. The results indicated that F. vasta aerial parts methanol extract is potential candidate for experiments of biological activity screening that are not anti-HSV-1 or antibacterial against the strains evaluated in this study, to be carried on in the future.
ABSTRACT
Nucleoside analogues have been the mainstay of clinical treatment of herpes simplex virus 1 (HSV-1) infections since their development. However, the emergence of drug resistant strains has underlined the urgency of the discovery of novel anti-HSV-1 drugs. Natural products, which provided many novel drug leads, are known to be an important source of anti-HSV-1 agents. Herein, we present an overview of natural products with anti-HSV-1 activities isolated from a variety of plants reported in recent years. Several different compounds, mainly belonging to the three groups of polysaccharides, polyphenols and terpenes, showed antiviral effects against HSV-1, indicating their potential to be promising anti-HSV-1 agents.