Search

Background: In early 2020, COVID-19 pandemic has mobilized researchers in finding new remedies including repurposing of medicinal plant products focusing on direct-acting antiviral and host-directed therapies. In this study, we performed an in vitro investigation on the standardized Marantodes pumilum extract (SKF7®) focusing on anti-SARS-CoV-2 and anti-inflammatory activities. Methods: Anti-SARS-CoV-2 potential of the SKF7® was evaluated in SARS-CoV-2-infected Vero E6 cells and SARS-CoV-2-infected A549 cells by cytopathic effect-based assay and RT-qPCR, respectively. Target based assays were performed on the SKF7® against the S1-ACE2 interaction and 3CL protease activities. Anti-inflammatory activity of the SKF7® was evaluated by nitric oxide inhibitory and TLR2/TLR4 receptor blocker assays. Results: The SKF7® inhibited wild-type Wuhan (EC50 of 21.99 µg/mL) and omicron (EC50 of 16.29 µg/mL) SARS-CoV-2 infections in Vero-E6 cells. The SKF7® also inhibited the wild-type SARS-CoV-2 infection in A549 cells (EC50 value of 6.31 µg/mL). The SKF7® prominently inhibited 3CL protease activity. The SKF7® inhibited the LPS induced-TLR4 response with the EC50 of 16.19 µg/mL. Conclusions: In conclusion, our in vitro study highlighted anti-SARS-CoV-2 and anti-inflammatory potentials of the SKF7®. Future pre-clinical in vivo studies focusing on antiviral and immunomodulatory potentials of the SKF7® in affecting the COVID-19 pathogenesis are warranted. [ABSTRACT FROM AUTHOR]

Due to dengue fever's swift global expansion and the lack of effective antiviral remedies, it is crucial to discover and develop new antiviral drugs. The study aimed to assess the antiviral potential of the extract and fractions from the leaves of Goniothalamus lanceolatus Miq. (Annonaceae). New Guinea C strain DENV-2, at a multiplicity of infection of 0.4, was used to infect Vero cells. The assessment of antiviral effectiveness was conducted through the plaque reduction assay. Deep metabolome analysis of the active fraction identified nine styryllactones based on reference standards and eighteen styryllactones were further annotated through a molecular database search. One new 2 H -tetrahydropyran derivative, 3- epi -goniothalesdiol A (19), together with seven known styryllactones (8 , 11 , 14 , 16 , 17 , 18 , and 22) were isolated from the leaves of G. lanceolatus. The active bis-styryllactone goniolanceolatin A (22) with the highest selectivity index (SI) underwent further evaluation using quantitative reverse transcription qRT-PCR to determine the viral RNA level. The qRT-PCR data showed that the IC 50 value for the active compound was 5.07 µg/mL, and its corresponding SI value was 5.30. Following comprehensive docking studies, the bis-styryllactone derivative 22 showed potential binding interactions with crucial amino acids of the Envelope (E) of DENV proteins comparable to those of ribavirin. [Display omitted] • In vitro evaluation of Goniothalamus lanceolatus leaf dichloromethane (GLLD) extract showed the strongest anti-dengue activity. • One new 2H-tetrahydropyran derivative was successfully isolated from the leaves of G. lanceolatus during a bioactivity-directed. • In vitro and in silico evaluation of bis-styryl lactone isolated from the most active fraction of leaves of G. lanceolatus showed the most potential anti-dengue activity. [ABSTRACT FROM AUTHOR]

Since the COVID-19 pandemic in 2020, many reports have highlighted several potential anti-SARS-CoV-2 drug candidates, including phenolic compounds. Therefore, this study aimed to evaluate the anti-SARS-CoV-2 activity of nine common phenolic compounds found in plants using the in vitro cellular infection model. The anti-SARS-CoV-2 activity of curcumin, quercetin, gallic acid, catechin, rutin, kaempferol, naringenin, coumaric acid and caffeic acid were evaluated on SARS-CoV-2-infected Vero E6 cells by using a cytopathic effect (CPE)-based assay. The anti-SARS-CoV-2 activity in human lung cells, A549 expressing human ACE2 and TMPRSS2, was evaluated by the RT-qPCR technique. S1-ACE2 interaction and 3CL protease activity assays were also performed for the potent compound. Of the nine phenolic compounds, only curcumin inhibited the SARS-CoV-2 induced CPE activity (EC50 of 13.63 µM) in Vero E6 cells, but with a low selective index (SI) value. Interestingly, curcumin exhibited potent anti-SARS-CoV-2 activity in A549 cells with an EC50 of 4.57 µM and an SI value of 7.96. S1-ACE2 interaction and 3CL protease inhibitory activities of curcumin were also observed. In conclusion, curcumin showed a moderate in vitro anti-SARS-CoV- 2 activity. The true potential of curcumin as an anti-SARS-CoV-2 candidate could be further evaluated in a COVID-19 animal model. [ABSTRACT FROM AUTHOR]

Background: Carica papaya leaves have been used for traditional treatment of dengue fever and have been reported to exhibit an immunomodulatory activity by affecting the level of cytokine production in vitro and in vivo. Due to the lack of adequate in vivo evidence in dengue disease model, the present study was initiated to screen and identify the cytokines affected by freeze-dried C. papaya leaf juice (FCPLJ) treatment in AG129 mice infected with DEN-2 dengue virus. Methods: The AG129 mice were fed orally with FCPLJ for 3 consecutive days after 24 h of dengue virus inoculation. Plasma cytokines were screened by using ProcartaPlex immunoassay. The gene expression in the liver was analyzed by using RT2 Profiler PCR Array. Results: The results showed that FCPLJ treatment has increased the plasma CCL2/MCP-1 level during peak of viremia. Gene expression study has identified 8 inflammatory cytokine genes which were downregulated in the liver of infected AG129 mice treated with FCPLJ. The downregulated inflammatory cytokine genes were CCL6/MRP-1, CCL8/MCP-2, CCL12/MCP-5, CCL17/TARC, IL1R1, IL1RN/IL1Ra, NAMPT/PBEF1 and PF4/CXCL4. Conclusion: The findings indicated the possible immunomodulatory role of FCPLJ during dengue virus infection in AG129 mice. [ABSTRACT FROM AUTHOR]

The role of Carica papaya L. leaf juice in immune dysregulation caused by dengue virus infection remains unclear. This study aimed to investigate the immunomodulatory activities of the freeze-dried C. papaya leaf juice (FCPLJ) on AG129 mice infected with a clinical DENV-2 (DMOF015) isolate. The infected AG129 mice were orally treated with 500 and 1000 mg/kg/day of FCPLJ, for three days. Platelet, leukocyte, lymphocyte and neutrophil counts were microscopically determined. The level of plasma proinflammatory cytokines was measured by multiplex immunoassay. The levels of intracellular cytokines and viral RNA were determined by RT-qPCR technique. The results showed that the FCPLJ treatment increased the total white blood cell and neutrophil counts in the infected mice. The FCPLJ treatment decreased the level of GM-CSF, GRO-alpha, IL-1 beta, IL-6, MCP-1 and MIP-1 beta in the plasma of the infected mice. The intracellular IL-6 and viral RNA levels in the liver of infected mice were decreased by the FCPLJ treatment. In conclusion, this study supports the potential immunomodulatory role of the FCPLJ in a non-lethal, symptomatic dengue mouse model. Further studies on the action mechanism of the C. papaya leaf juice and its possible use as adjunctive dengue immunotherapy are warranted. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to profile and identify the endothelial cell biology related genes that are affected by dengue virus infection in the liver tissue of AG129 mice, with and without Carica papaya leaf juice treatment. Results: The dengue fever mouse model was established by intraperitoneal inoculation of dengue virus, New Guinea C strain at 2 × 106 PFU. Daily oral administration of 1000 mg/kg freeze-dried C. papaya leaf juice (FCPLJ) was done starting from day 1 to day 3 post infection. The RNA was extracted from liver tissues harvested on day 4 post infection. The expression levels of 84 genes related to mouse endothelial cell biology were determined by qRT-PCR technique. Dengue virus infection upregulated 15 genes and downregulated two genes in the liver of AG129 mice. The FCPLJ treatment upregulated monocyte chemoattractant protein 1 and downregulated intercellular adhesion molecule 1, integrin beta 3 and fibronectin 1 genes during dengue virus infection. The data showed the potential effect of FCPLJ treatment on the expression profile of endothelial cell biology related genes in the liver of dengue virus infected-AG129 mice. Further proteomic studies are needed to determine the functional roles of the genes affected by FCPLJ treatment. [ABSTRACT FROM AUTHOR]

Eurycoma longifolia is one of the commonly consumed herbal preparations and its major chemical compound, eurycomanone, has been described to have antimalarial, antipyretic, aphrodisiac, and cytotoxic activities. Today, the consumption of E. longifolia is popular through the incorporation of its extract in food items, most frequently in drinks such as tea and coffee. In the current study, the characterisation of the physicochemical and pharmacokinetic (PK) attributes of eurycomanone were conducted via a series of in vitro and in vivo studies in rats and mice. The solubility and chemical stability of eurycomanone under the conditions of the gastrointestinal tract environment were determined. The permeability of eurycomanone was investigated by determining its distribution coefficient in aqueous and organic environments and its permeability using the parallel artificial membrane permeability assay system and Caco-2 cultured cells. Eurycomanone's stability in plasma and its protein-binding ability were measured by using an equilibrium dialysis method. Its stability in liver microsomes across species (mice, rat, dog, monkey, and human) and rat liver hepatocytes was also investigated. Along with the PK evaluations of eurycomanone in mice and rats, the PK parameters for the Malaysian Standard (MS: 2409:201) standardised water extract of E. longifolia were also evaluated in rats. Both rodent models showed that eurycomanone in both the compound form and extract form had a half-life of 0.30 h. The differences in the bioavailability of eurycomanone in the compound form between the rats (11.8%) and mice (54.9%) suggests that the PK parameters cannot be directly extrapolated to humans. The results also suggest that eurycomanone is not readily absorbed across biological membranes. However, once absorbed, the compound is not easily metabolised (is stable), hence retaining its bioactive properties, which may be responsible for the various reported biological activities. [ABSTRACT FROM AUTHOR]