In vitro evaluation of the antiviral properties of Shilajit and investigation of its mechanisms of action

4-(3-Phenylsulfonylindol-2-yl)-1-(pyridin-2-yl)piperazinyl-methanones as Potent Inhibitors of both SARS-CoV-2 and HCoV-OC43 Viruses

SARS-CoV-2 and HCoV-OC43 belong to the same β genus of the Coronaviridae family. SARS-CoV-2 was responsible for the recent COVID-19 pandemic, and HCoV-OC43 is the etiological agent of mild upper respiratory tract infections. SARS-COV-2 and HCoV-OC43 co-infections were found in children with respiratory symptoms during the COVID-19 pandemic. The two β-coronaviruses share a high degree of homology between the 3CLpro active sites, so much so that the safer HCoV-OC43 has been suggested as a tool for the identification of new anti-SARS-COV-2 agents. Compounds 5 and 24 inhibited effectively both Wuhan and British SARS-CoV-2 patient isolates in Vero E6 cells and the HCoV-OC43 in MRC-5 cells at low micromolar concentrations. The inhibition was apparently exerted via targeting the 3CLpro active sites of both viruses. Compounds 5 and 24 at 100 μM inhibited the SARS-CoV-2 3CLpro activity of 61.78 and 67.30%, respectively. These findings highlight 5 and 24 as lead compounds of a novel class of antiviral agents with the potential to treat SARS-COV-2 and HCoV-OC43 infections.

Polyoxometalate exerts broad-spectrum activity against human respiratory viruses hampering viral entry

Human respiratory viruses have an enormous impact on national health systems, societies, and economy due to the rapid airborne transmission and epidemic spread of such pathogens, while effective specific antiviral drugs to counteract infections are still lacking. Here, we identified two Keggin-type polyoxometalates (POMs), [TiW11CoO40]8- (TiW11Co) and [Ti2PW10O40]7- (Ti2PW10), endowed with broad-spectrum activity against enveloped and non-enveloped human respiratory viruses, i.e., coronavirus (HCoV-OC43), rhinovirus (HRV-A1), respiratory syncytial virus (RSV-A2), and adenovirus (AdV-5). Ti2PW10 showed highly favorable selectivity indexes against all tested viruses (SIs >700), and its antiviral potential was further investigated against human coronaviruses and rhinoviruses. This POM was found to inhibit replication of multiple HCoV and HRV strains, in different cell systems. Ti2PW10 did not affect virus binding or intracellular viral replication, but selectively inhibited the viral entry. Serial passaging of virus in presence of the POM revealed a high barrier to development of Ti2PW10-resistant variants of HRV-A1 or HCoV-OC43. Moreover, Ti2PW10 was able to inhibit HRV-A1 production in a 3D model of the human nasal epithelium and, importantly, the antiviral treatment did not determine cytotoxicity or tissue damage. A mucoadhesive thermosensitive in situ hydrogel formulation for nasal delivery was also developed for Ti2PW10. Overall, good biocompatibility on cell lines and human nasal epithelia, broad-spectrum activity, and absence of antiviral resistance development reveal the potential of Ti2PW10 as an antiviral candidate for the development of a treatment of acute respiratory viral diseases, warranting further studies to identify the specific target/s of the polyanion and assess its clinical potential.

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

Preparation, characterization, bacteriostatic efficacy, and mechanism of zinc/selenium-loaded sodium humate

In recent years, metal-based complexes including selenium (Se) and zinc (Zn)-containing compounds have been widely explored for their therapeutic properties due to their roles in biological processes and modulation of diverse molecular targets. Humic acid, as a metal complexing agent, is also widely used in biomedical field. In this work, three kinds of modified sodium humate (HNa), including Zn-HNA, Se-HNa, and Zn/Se-HNa, were prepared by ion exchange reaction method. The modified HNa was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and elemental mapping. The bacteriostatic activity and mechanism of modified HNa against gram-positive and gram-negative bacteria were investigated by testing bacterial inhibition zone, minimum inhibitory concentration, and capacity to destroy integrity of the bacterial membrane, promoting ROS generation level and prevention of biofilms. FTIR results showed that HNa could combine with zinc ions and selenite ions. The main XRD peaks did not change significantly. In the modified HNa, the particle shape was irregular. Compared to HNa, Zn-HNA, and Se-HNa, Zn/Se-HNa showed the strongest bacteriostatic activity. Zn/Se-HNa exhibited high bacteriostatic activity against gram-negative bacteria (Escherichia coli, Salmonella typhimurium, Klebsiella pneumoniae) and gram-positive bacteria (Staphylococcus aureus), but showed weak antibacterial activity against another gram-positive bacteria, Bacillus subtilis. The bacteriostasis was achieved by altering the permeability of bacterial cell membranes, generating ROS, and preventing the formation of biofilms. In conclusion, Zn/Se-HNa has high bacteriostatic activity, making it a suitable alternative to antibiotics in fields like the treatment of trauma infections and animal husbandry. KEY POINTS: • Preparate and characterize zinc- and selenium-loaded sodium humate (Zn/Se-HNa). • The combination of Zn and Se enhanced the bacteriostatic activity of HNa. • Zn/Se-HNa alters the permeability of bacterial cell membranes and promotes generation of ROS.

Enhanced Anti-Herpetic Activity of Valacyclovir Loaded in Sulfobutyl-ether-β-cyclodextrin-decorated Chitosan Nanodroplets

Valacyclovir (VACV) was developed as a prodrug of the most common anti-herpetic drug Acyclovir (ACV), aiming to enhance its bioavailability. Nevertheless, prolonged VACV oral treatment may lead to the development of important side effects. Nanotechnology-based formulations for vaginal administration represent a promising approach to increase the concentration of the drug at the site of infection, limiting systemic drug exposure and reducing systemic toxicity. In this study, VACV-loaded nanodroplet (ND) formulations, optimized for vaginal delivery, were designed. Cell-based assays were then carried out to evaluate the antiviral activity of VACV loaded in the ND system. The chitosan-shelled ND exhibited an average diameter of about 400 nm and a VACV encapsulation efficiency of approximately 91% and was characterized by a prolonged and sustained release of VACV. Moreover, a modification of chitosan shell with an anionic cyclodextrin, sulfobutyl ether β-cyclodextrin (SBEβCD), as a physical cross-linker, increased the stability and mucoadhesion capability of the nanosystem. Biological experiments showed that SBEβCD-chitosan NDs enhanced VACV antiviral activity against the herpes simplex viruses type 1 and 2, most likely due to the long-term controlled release of VACV loaded in the ND and an improved delivery of the drug in sub-cellular compartments.

Impact of time-temperature combinations on the anti-Cytomegalovirus activity and biological components of human milk

BACKGROUND

There is extensive evidence that Holder pasteurization (HoP) (30 min at 62.5 °C) has harmful effects on the bioactivities of human milk (HM). We previously demonstrated that lowering HoP temperature is sufficient to inactivate Cytomegalovirus (HCMV). Here, we analyzed the effect of lowering time/temperature on the antiviral activity against HCMV and IgA levels of HM.

METHODS

Eighty HM samples from five mothers were pasteurized in a range of temperature (62.5-56 °C) and time (40-10 min) in a conventional setting of Human Milk Bank. Unpasteurized HM from each mother was used as control. The samples were assayed against HCMV-AD169 strain in cell cultures and IgA levels were determined by ELISA.

RESULTS

All HM samples exhibited anti-HCMV activity, to a different extent. An improvement of antiviral activity was observed in samples treated at 60, 58 and 56 °C compared to those at 62.5 °C, with ID50 values near those of unpasteurized milk. Similarly, better retention in IgA levels was observed by reducing the temperature of treatment.

CONCLUSIONS

We demonstrated that a 2.5 °C reduction of heat treatment significantly preserved the IgA content and fully restored the anti-HCMV activity of HM, supporting this variant of HoP as a valid alternative to preserve HM bioactivities.

IMPACT

This work questions the standard HoP and opens the debate on whether the pasteurization temperature commonly used in Human Milk Banks should be lowered to better preserve the biological components of the milk. A reduction of HoP temperature at 60 °C determined a significant preservation of anti-HCMV activity and IgA content of donor HM, compared to standard HoP. This alternative HoP is highly feasible compared to other substitute pasteurization techniques, since it would employ the same pasteurizer equipment found in most Human Milk Banks.

The Role of Intracellular Signaling Molecules in Macrophage Activation by Peat Humic Acids

Humic acids isolated by sodium pyrophosphate extraction from various types of peat activate macrophages in the classical proinflammatory pathway and stimulate nitric oxide production by these cells. This effect is mediated by activation of intracellular signaling pathways involving MAPK p38, PI3K, MEK 1/2 kinase, cAMP, and NF-κB via TLR-2 and TLR-4 receptors.

Clinical review of humic acid as an antiviral: Leadup to translational applications in clinical humeomics

This clinical review presents what is known about the antiviral features of humic substances (HS) to the benefit of the clinical healthcare provider using available data in humeomics, the study of the soil humeome. It provides the reader with a working framework of historical studies and includes clinically relevant data with the goal of providing a broad appreciation of the antiviral potential of humic substances while also preparing for a translational leap into the clinical application of humic acid.

Influence of Humic Acids Isolated from Raised Bog Sphagnum Peat on Development of Th1/Th2 Immune Response

The course administration of humic acids isolated with sodium pyrophosphate from raised bog sphagnum peat reduces the parameters of a Th1-type immune response in C57BL/6 mice, the severity of an anaphylactic shock in outbred CD1 mice, and degranulation of mast cells after their immunization with ovalbumin. The addition of humic acids increases the stimulated production of IL-4, IL-10 and reduces the production of IL-2, IFNγ by peripheral blood mononuclear cells of healthy donors.

Antiviral and Virucidal Properties of Essential Oils and Isolated Compounds - A Scientific Approach

Essential oils and isolated essential oil compounds are known to exert various pharmacological effects, such as antibacterial, antifungal, antiviral, anti-inflammatory, anti-immunomodulatory, antioxidant, and wound healing effects. Based on selected articles, this review deals with the potential antiviral and virucidal activities of essential oils and essential oil compounds together with their mechanism of action as well as in silico studies involving viral and host cell-specific target molecules that are indispensable for virus cell adsorption, penetration, and replication. The reported in vitro and in vivo studies highlight the baseline data about the latest findings of essential oils and essential oil compounds antiviral and virucidal effects on enveloped and non-enveloped viruses, taking into account available biochemical and molecular biological tests. The results of many in vitro studies revealed that several essential oils and essential oil compounds from different medicinal and aromatic plants are potent antiviral and virucidal agents that inhibit viral progeny by blocking different steps of the viral infection/replication cycle of DNA and RNA viruses in various host cell lines. Studies in mice infected with viruses causing respiratory diseases showed that different essential oils and essential oil compounds were able to prolong the life of infected animals, reduce virus titers in brain and lung tissues, and significantly inhibit the synthesis of proinflammatory cytokines and chemokines. In addition, some in vitro studies on hydrophilic nano-delivery systems encapsulating essential oils/essential oil compounds exhibited a promising way to improve the chemical stability and enhance the water solubility, bioavailabilty, and antiviral efficacy of essential oils and essential oil compounds.

Mummy Induces Apoptosis Through Inhibiting of Epithelial-Mesenchymal Transition (EMT) in Human Breast Cancer Cells

Background:

Mummy (Iranian pure shilajit) is a remedy with possessing anti-inflammatory, antioxidant and anticancer activities. This study aimed to examine mummy effects on epithelial-mesenchymal transition (EMT) and invasiveness of MCF-7 and MDA-MB-231 breast cancer (BC) cell lines with underlying its mechanism.

Materials and Methods:

The dose-dependent inhibitory effect of the mummy on cell proliferation in vitro was determined using the MTT assay. Flow cytometry and 4’,6-diamidino-2-phenylindole dihydrochloride staining were respectively used for quantitative and qualitative analysis of cellular apoptosis, and gene expression analysis was conducted using real-time PCR.

Results:

MDA-MB-231 showed more sensitivity than the MCF-7 cell line to the anticancer activity of mummy, while mummy did not exhibit significant cell cytotoxicity against human normal cells (MCF-10A). The gene expression profile demonstrated a significant decrease in TGF-β1, TGF-βR1, TWIST1, NOTCH1, CTNNB1, SRC along with an increase in E-cadherin mRNA levels in mummy treated cells compared to the untreated control group (P≤0.05).

Conclusion:

Mummy triggers inhibition of EMT and metastasis in breast cancer cells mainly through the downregulation of TGFβ1 activity, and more studies required to find its specific anticancer activity with details.

Antiviral activity of natural humic substances and shilajit materials against HIV-1: Relation to structure

Natural products, such as humic substances (HS) and shilajit, are known to possess antiviral activity. Humic-like components are often called as carriers of biological activity of shilajit. The goal of this study was to evaluate anti-HIV activity of well characterized HS isolated from coal, peat, and peloids, and compare it to that of water-soluble organic matter (OM) isolated from different samples of Shilajit. The set of humic materials included 16 samples of different fractional composition: humic acid (HA), hymatomelanic acid (HMA), fulvic acid (FA). The set of shilajit OM included 19 samples of different geographic origin and level of alteration. The HIV-1 p24 antigen assay and cell viability test were used for assessment of antiviral activity. The HIV-1 Bru strain was used to infect CEM-SS cells. The obtained EC50 values varied from 0.37 to 1.4 mg L^-1 for the humic materials, and from 14 to 142 mg L^-1 for the shilajit OM. Hence, all humic materials used in this study outcompeted largely the shilajit materials with respect to anti-HIV activity: For the humic materials, the structure-activity relationships revealed strong correlation between the EC50 values and the content of aromatic carbon indicating the most important role of aromatic structures. For shilajit OM, the reverse relationship was obtained indicating the different mechanism of shilajit activity. The FTICRMS molecular assignments were used for ChEMBL data mining in search of the active humic molecules. As potential carriers of antiviral activity were identified aromatic structures with alkyl substituents, terpenoids, N-containing analogs of typical flavonoids, and aza-podophyllotoxins. The conclusion was made that the typical humic materials and Shilajit differ greatly in molecular composition, and the humic materials have substantial preferences as a natural source of antiviral agents as compared to shilajit.

Human Colostrum and Derived Extracellular Vesicles Prevent Infection by Human Rotavirus and Respiratory Syncytial Virus in Vitro

BACKGROUND

It is known that breastfeeding protects the infant from enteric and respiratory infections; however, the antiviral properties of human milk against enteric and respiratory viruses are largely unexplored.

RESEARCH AIMS

To explore the antiviral activity of human preterm colostrum against rotavirus and respiratory syncytial virus and to assess whether the derived extracellular vesicle contribute to this activity.

METHODS

We used a cross-sectional, prospective two-group non-experimental design. Colostra were collected from mothers of preterm newborns (N = 10) and extracellular vesicles were purified and characterized. The antiviral activity of colostra and derived extracellular vesicles were tested in vitro against rotavirus and respiratory syncytial virus and the step of viral replication inhibited by extracellular vesicles was investigated.

RESULTS

Each sample of colostrum and colostrum-derived extracellular vesicles had significant antiviral activity with a wide interpersonal variability. Mechanism of action studies demonstrated that extracellular vesicles acted by interfering with the early steps of the viral replicative cycle.

CONCLUSION

We demonstrated the intrinsic antiviral activity of human colostrum against rotavirus and respiratory syncytial virus and we showed that extracellular vesicles substantially contribute to the overall protective effect. Our results contribute to unravelling novel mechanisms underlying the functional role of human milk as a protective and therapeutic agent in preterm infants.

Review on Extraction of Phenolic Compounds from Natural Sources Using Green Deep Eutectic Solvents

For more sustainable and environmentally friendly scientific research, it is essential to apply green chemistry principles in all areas of science. A possible area in which green chemistry principles can significantly influence the productivity and the quality of the outcome is extraction of natural products. The conventional toxic solvents can be replaced by environmentally friendly solvents known as deep eutectic solvents, which fortunately, due to their unique properties, can significantly improve extraction efficiency. In this literature review, the extraction of a specific class of natural products, phenolic compounds, using different types of green deep eutectic solvents has been reviewed. Within this review, the composition of those solvents used to extract different types of phenolic compounds has been discussed. In addition, the factors affecting their extraction, extracting solvent component structure, molar ratio of extracting solvent components, extraction temperature, solid to extraction solvent ratio, and water content, have been evaluated.

Analysis of Thermal Sensitivity of Human Cytomegalovirus Assayed in the Conventional Conditions of a Human Milk Bank

One of the main concerns in human milk banks (HMB) is the transmission of human cytomegalovirus (HCMV) that could be present in the milk of infected women. There are consistent data showing that this virus is destroyed by Holder pasteurization (62.5°C for 30 min), but there is a lack of information about the response of the virus to the treatment at lower temperatures in strict HMB conditions. In order to analyze the effectiveness of different temperatures of pasteurization to eliminate HCMV in human milk, a preliminary assay was performed incubating HCMV-spiked raw milk samples from donor mothers at tested temperatures in a PCR thermocycler and the viral infectivity was assayed on cell cultures. No signs of viral replication were observed after treatments at temperatures equal or >53°C for 30, 20, and 10 min, 58°C for 5 min, 59°C for 2 min, and 60°C for 1 min. These data were confirmed in a pasteurizer-like model introducing HCMV-spiked milk in disposable baby bottles. No viral infectivity was detected on cell cultures after heating treatment of milk for 30 min at temperatures from 56 to 60°C. Thus, our results show that by using conventional pasteurization conditions, temperatures in the range of 56-60°C are enough to inactivate HCMV. Consequently, we consider that, in order to provide a higher quality product, the current recommendation to pasteurize both mother's own milk and donated milk at 62.5°C must be re-evaluated.

Extracellular Vesicles in Human Preterm Colostrum Inhibit Infection by Human Cytomegalovirus In Vitro

Breast milk is a complex biofluid that nourishes infants, supports their growth and protects them from diseases. However, at the same time, breastfeeding is a transmission route for human cytomegalovirus (HCMV), with preterm infants being at a great risk of congenital disease. The discrepancy between high HCMV transmission rates and the few reported cases of infants with severe clinical illness is likely due to the protective effect of breast milk. The aim of this study was to investigate the anti-HCMV activity of human preterm colostrum and clarify the role of colostrum-derived extracellular vesicles (EVs). Preterm colostrum samples were collected and the EVs were purified and characterized. The in vitro anti-HCMV activity of both colostrum and EVs was tested against HCMV, and the viral replication step inhibited by colostrum-purified EVs was examined. We investigated the putative role EV surface proteins play in impairing HCMV infection using shaving experiments and proteomic analysis. The obtained results confirmed the antiviral action of colostrum against HCMV and demonstrated a remarkable antiviral activity of colostrum-derived EVs. Furthermore, we demonstrated that EVs impair the attachment of HCMV to cells, with EV surface proteins playing a role in mediating this action. These findings contribute to clarifying the mechanisms that underlie the protective role of human colostrum against HCMV infection.

Effects of Humic Acids, Isolated from High-Moor Pine-Peat Moss-Cotton Grass Peat on the Production of Cytokines by Mouse and Human Immunocompetent Cells and on Humoral Immune Response

A course of treatment with humic acids extracted with sodium pyrophosphate from high-moor pine-peat moss-cotton grass peat improves humoral immune response of C57BL/6 mice, stimulates the production of TNFα, IL-1β, and IL-12 by the animal peritoneal macrophages and the production of IFNγ and TNFα by donor peripheral blood mononuclears, causing no changes in the production of IL-10 in vitro.

Coumarin: An emerging antiviral agent

Viral infections are responsible for many illnesses, and recent outbreaks have raised public health concerns. Despite the availability of many antiviral drugs, they are often unsuccessful due to the generation of viral mutants and less effective against their target virus. Identifying novel antiviral drugs is therefore of critical importance and natural products are an excellent source for such discoveries. Coumarin is one such natural compound that is a potential drug candidate owing to its properties of stability, solubility, and low toxicity. There are numerous evidences showing its inhibitory role against infection of various viruses such as HIV, Influenza, Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16). The mechanisms involve either inhibition of proteins essential for viral entry, replication and infection or regulation of cellular pathways such as Akt-Mtor (mammalian target of rapamycin), NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells), and anti-oxidative pathway including NrF-2 (The nuclear factor erythroid 2 (NFE2)-related factor 2). This review summarizes the present state of understanding with a focus on coumarin's antiviral effect and their possible molecular mechanisms against Influenza virus, HIV, Hepatitis virus, Dengue virus and Chikungunya virus.

Shilajit (Mumie): Current Status of Biochemical, Therapeutic and Clinical Advances

Methods:

Scientific literature and ethnopharmacological information were compiled from the published peer-reviewed articles, unpublished materials, thesis, books, patent databases, clinical trial registries and from the websites of research councils of traditional medicine. The scientific databases, thesis repositories and books databases were searched with keywords Shilajit, mumie, mumijo, salajeet, asphaltum, fulvic acid, dibenzo-alpha-pyrones etc.

Results:

Scientifically validated research and ancient texts suggest multifaceted benefits of Shilajit. It is endowed with anti-stress, memory and energy enhancing, antioxidant, anti-inflammatory, antidiabetic, spermatogenic, neuroprotective, antiulcer and wound healing activities. These pharmacological effects are mainly attributed to the presence of humic acid, fulvic acid, dibenzo-α-pyrones, dibenzo- α-pyrones chromoproteins and trace elements.

Conclusion:

This review summarizes the traditional importance of Shilajit for the treatment and prevention of several acute and chronic diseases and health ailments. Despite numerous health claims, there are still major gaps in our understanding of its mechanism of action, variability in efficacy and toxicity profile. Therefore, a coordinated interdisciplinary approach is needed to establish the underlying mechanisms of action, comprehensive toxicological profile, pharmacokinetics parameters and effects on different organ systems. Regulatory and governmental impetus to basic and clinical research, safety testing and formulations quality control is warranted.

Anti-Cytomegalovirus Activity in Human Milk and Colostrum From Mothers of Preterm Infants

OBJECTIVES

This study aimed to investigate the anti-human cytomegalovirus (CMV) activity of milk from seropositive and seronegative mothers of preterm infants and to analyze its changes throughout the different stages of lactation and after Holder pasteurization, a procedure adopted by donor human milk banks.

METHODS

Eighteen mothers of preterm infants were enrolled in the study. Colostrum, transitional milk, and mature milk samples were collected and tested for anti-CMV activity. Depletion of immunoglobulins A from milk samples was carried out by jacalin resin. Pools of milk samples were pasteurized according to Holder technique.

RESULTS

All samples were endowed with anti-CMV activity, although to a different extent. In CMV IgG-positive mothers, colostra were significantly more active than the transitional milk and mature milk samples. Moreover, they were more potent than colostra from seronegative mothers. Immunoglobulins A depletion in colostra from IgG-positive mothers resulted in a partial loss of anti-CMV activity. Holder pasteurization significantly reduced the antiviral activity.

CONCLUSIONS

Human milk is endowed with anti-CMV activity and its potency may vary depending on the stage of lactation and the serological status of the mother. This biological property could partially neutralize CMV particles excreted in the milk of CMV IgG-positive mothers thus reducing the risk of transmitting infectious viruses to the infant.

Synthesis and evaluation of steroidal thiazoline conjugates as potential antiviral agents

Aim: Many heterocyclic compounds derived from natural steroids exhibited broad activities, so this work focused on the investigations on a series of steroidal thiazoline conjugates as antiviral agents. Materials & methods: A series of steroid derivatives containing thiazoline heterocycles were designed and synthesized via a convenient condensation procedure. The compounds were screened for their potential antivirus activities against Enterovirus 71 (EV71) and Coxsackie Virus Type B (CVB3). Results and Conclusion: The in vitro bioassay indicated that compounds 5b, 5g and 5i exhibited excellent antiviral effects on EV71, and compounds 5b, 5e, 6c and 6g presented better antiviral activities against CVB3 compared with the controls ribavirin or pirodavir. These results indicate that these steroidal thiazoline conjugates might be feasible therapeutic candidates against EV71 infection, which might also be considered as promising compounds for optimization of potential antivirus agents.

Humic acid inhibits HBV-induced autophagosome formation and induces apoptosis in HBV-transfected Hep G2 cells

Hepatitis B Virus (HBV) utilizes several mechanisms to survive in the host cells and one of the main pathways being autophagosome formation. Humic acid (HA), one of the major components of Mineral pitch, is an Ayurvedic medicinal food, commonly used by the people of the Himalayan regions of Nepal and India for various body ailments. We hypothesized that HA could induce cell death and inhibit HBV-induced autophagy in hepatic cells. Incubation of Hep G2.2.1.5 cells (HepG2 cells stably expressing HBV) with HA (100 μM) inhibited both cell proliferation and autophagosome formation significantly, while apoptosis induction was enhanced. Western blot results showed that HA incubation resulted in decreased levels of beclin-1, SIRT-1 and c-myc, while caspase-3 and β-catenin expression were up-regulated. Western blot results showed that HA significantly inhibited the expression of HBx (3-fold with 50 μM and 5-fold with 100 μM) compared to control cells. When HA was incubated with HBx-transfected Hep G2 cells, HBx-induced autophagosome formation and beclin-1 levels were decreased. These data showed that HA induced apoptosis and inhibited HBV-induced autophagosome formation and proliferation in hepatoma cells.

Effects of Humic Acids Isolated from Peat of Various Origin on in Vitro Production of Nitric Oxide: a Screening Study

A screening study of biological activity of native humic acids isolated from peat was performed; several physical and chemical parameters of their structures were studied by UV- and infrared spectroscopy. Spectroscopy yielded similar shape of light absorption curves of humic acids of different origin, which can reflect similarity of general structural principles of these substances. Alkaline humic acids have more developed system of polyconjugation, while molecular structures of pyrophosphate humic acids were characterized by higher aromaticity and condensation indexes. Biological activity of the studied humic acids was assessed by NO-stimulating capacity during their culturing with murine peritoneal macrophages in a wide concentration range. It was shown that due to dose-dependent enhancement of NO production humic acids can change the functional state of macrophages towards development of pro-inflammatory properties. These changes were associated with high activity of humic acids isolated by pyrophosphate extraction, which allows considering effects of isolation method on biological activity.

Ficus religiosa L. bark extracts inhibit infection by herpes simplex virus type 2 in vitro

Ficus religiosa extracts have been used in traditional Indian medicine to treat sexually transmitted infections such as gonorrhea and genital ulcers. The aim of this study was to investigate the antiviral activity of F. religiosa extracts against herpes simplex virus type 2 (HSV-2), the main causative agent of genital ulcers and sores. Water and chloroform bark extracts were the most active against HSV-2, and also against an acyclovir-resistant strain. We demonstrate that the water extract has a direct virus-inactivating activity. By contrast, the chloroform extract inhibits viral attachment and entry and limits the production of viral progeny.

Mineral pitch induces apoptosis and inhibits proliferation via modulating reactive oxygen species in hepatic cancer cells

Background

Mineral Pitch (MP) is a dark brown coloured humic matter originating from high altitude rocks. It is an Ayurvedic medicinal food, commonly used by the people of the Himalayan regions of Nepal and India for various body ailments.

Methods

The Huh-7 cells were treated with different concentrations of MP for 24 h, and both apoptosis and proliferation was determined by the TUNEL and MTT assays respectively. The formation of ROS and nitric oxide was analysed by DCFH-DA and Griess reagent respectively. The expression of miRNA-21 and miRNA-22 were checked by the real time PCR. Effect of miRNA-22 on proliferation and c-myc was studied by over-expressing miRNA-22 premiRs in Huh-7 cells.

Results

We found that MP enhanced anti-cancer effects by inducing apoptosis and inhibiting proliferation. MP induced both ROS and NO, upon neutralizing them, there was a partial recovery of apoptosis and proliferation. MP also induced miRNA-22 expression, while miRNA-21 expression was inhibited. Over-expression of miRNA-22 resulted in a significant inhibition of proliferation. miRNA-22 directly targeted c-myc gene, thereby inhibited proliferation. These results clearly show that MP induces its anti-cancer activity by more than one pathway.

Conclusion

The data clearly indicate that MP induced apoptosis via the production of ROS, and inhibited proliferation by inducing miRNA-22 and inhibiting miRNA-21 in Huh-7 cells.

Ficus religiosa L. bark extracts inhibit human rhinovirus and respiratory syncytial virus infection in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Ficus religiosa L. is one of the most relevant members of the family of Moraceae. It is the most sacred tree of South Asia, and it is used in traditional Ayurvedic and Unani medicine to cure respiratory disorders like cough, wheezing and asthma. Some studies were performed to investigate the anti-asthmatic potential of F. religiosa bark, leaves and fruit extracts but none of them tested their antiviral activity against viruses responsible for the exacerbation of wheezing and asthma.

AIM OF THE STUDY

The present study was undertaken to investigate the antiviral activity of F. religiosa L. extracts against respiratory viruses such as human respiratory syncytial virus (RSV) and human rhinovirus (HRV).

MATERIALS AND METHODS

The antiviral activity of F. religiosa L. was tested in vitro by plaque reduction and virus yield assays and the major mechanism of action was investigated by virus inactivation and time-of-addition assays.

RESULTS

F. religiosa L. methanol bark extract was the most active against HRV with an EC50 of 5.52 µg/mL. This extract likely inhibited late steps of replicative cycle. Water bark extract was the most active against RSV with an EC50 between 2.23 and 4.37 µg/mL. Partial virus inactivation and interference with virus attachment were both found to contribute to the anti-RSV activity. Replication of both viruses was inhibited in viral yield reduction assays.

CONCLUSIONS

The results of the present study demonstrate that F. religiosa L. is endowed with antiviral activity against RSV and HRV in vitro. Further work remains to be done to identify the active components and to assess the therapeutic potential in vivo.