In-Vitro Antiviral Activities of Extracts of Plants of The Brazilian Cerrado against the Avian Metapneumovirus (aMPV)

How does a Saccharomyces cerevisiae extract influence the components of isolated rotavirus particles from stool samples collected in a clinical setting from children?

Human Rotavirus (HRV) is the causative pathogen of severe acute enteric infections that cause mortality among children worldwide. This study focuses on developing a new and effective treatment for rotavirus infection using an extract from Saccharomyces cerevisiae, aiming to make this treatment easily accessible to everyone. 15 antigens and 26 antibodies were detected in serum and stool using ELISA. The titers of HRVq1, HRVq2, HRVC1, and HRVC2 on Vero cells were determined to be 1.2x106, 3.0x106, 4.2x106, and 7.5x105 (Plaque forming unit, PFU/ml) four days after infection, respectively. The HRVq1 isolate induced cytopathic effects, i.e., forming multinucleated, rounded, enlarged, and expanding gigantic cells. RT-PCR identified this isolate, and the accession number 2691714 was assigned to GeneBank. The molecular docking analysis revealed that nonstructural proteins (NSPs) NSP1, NSP2, NSP3, NSP4, NSP5, and NSP6 exhibited significant binding with RNA. NSP2 demonstrated the highest binding affinity and the lowest binding energy (-8.9 kcal/mol). This affinity was maintained via hydrophobic interactions and hydrogen bonds spanning in length from 1.12 Å to 3.11 Å. The ADMET and bioactivity predictions indicated that the yeast extract possessed ideal solubility, was nontoxic, and did not cause cancer. The inhibitory constant values predicted for the S. cerevisiae extract in the presence of HRV vital proteins varied from 5.32 to 7.45 mM, indicating its potential as a viable drug candidate. Saccharomyces cerevisiae extract could be utilized as a dietary supplement to combat HRV as an alternative dietary supplement.

Metabolic profiling of milk thistle different organs using UPLC-TQD-MS/MS coupled to multivariate analysis in relation to their selective antiviral potential

INTRODUCTION

Silybum marianum commonly known as milk thistle is one of the most imperative medicinal plants due to its remarkable pharmacological activities. Lately, the antiviral activities of S. marianum extract have been studied and it showed effectiveness against many viruses.

OBJECTIVE

Although most previous studies were concerned mainly with silymarin content of the fruit, the present study provides comprehensive comparative evaluation of S. marianum different organs' chemical profiles using UPLC-MS/MS coupled to chemometrics to unravel potentially selective antiviral compounds against human coronavirus (HCoV-229E).

METHODOLOGY

UPLC-ESI-TQD-MS/MS analysis was utilized to establish metabolic fingerprints for S. marianum organs namely fruits, roots, stems and seeds. Multivariate analysis, using OPLS-DA and HCA-heat map was applied to explore the main discriminatory phytoconstituents between organs. Selective virucidal activity of organs extracts against coronavirus (HCoV-229E) was evaluated for the first time using cytopathic effect (CPE) inhibition assay. Correlation coefficient analysis was implemented for detection of potential constituents having virucidal activity.

RESULTS

UPLC-MS/MS analysis resulted in 87 identified metabolites belonging to different classes. OPLS-DA revealed in-between class discrimination between milk thistle organs proving their significantly different metabolic profiles. The results of CPE assay showed that all tested organ samples exhibited dose dependent inhibitory activity in nanomolar range. Correlation analysis disclosed that caffeic acid-O-hexoside, gadoleic and linolenic acids were the most potentially selective antiviral phytoconstituents.

CONCLUSION

This study valorizes the importance of different S. marianum organs as wealthy sources of selective and effective antiviral candidates. This approach can be extended to unravel potentially active constituents from complex plant matrices.

Antiviral activity of silver nanoparticles against the influenza A virus

Viral infections occupy an essential place in modern medicine, particularly a large group of diseases caused by the influenza viruses. They are rapidly transmitted and mutate quickly, which can lead to significant socio-economic consequences. Silver nanoparticles (AgNPs) are considered to be an effective antimicrobial agent. This study shows that they have strong antiviral properties against the influenza A virus infection. Their absence of cytotoxicity at inhibitory concentrations demonstrates that they could be an effective antiviral agent against this virus. As AgNPs inhibit the influenza A virus replication and spread, they could also be successfully used as a post-infection virostatic agent.

Ammi-visnaga extract; a novel phyto-antiviral agent against bovine rotavirus

The spread of bovine rotavirus has a great impact on animal productivity, milk products, and human public health. Thus, this study aimed to develop a novel, effective and accessible Phyto-antiviral treatment made from methanolic Ammi-visnaga seed extract against rotavirus infection. Rotaviruses were isolated from raw milk and cottage cheese samples randomly collected from Cairo and Qalubia governorates. They were all identified serologically, however, only three of them were both biologically and molecularly confirmed. The methanolic extract derived from Khella seeds (MKSE) was chemically analyzed with mass chromatography. The cellular toxicity of MKSE was tested on Caco-2 cells and its antiviral activity against one of the isolated bovine rotaviruses (BRVM1) was tested by both the cytopathic inhibition assay and the plaque reduction assay. Our results showed that 17.3% of the total collected 150 dairy samples were bovine rotavirus antigen positive. Three representatives of them were phylogenetically identified to be included in group A based on a 379 bp coat protein gene. Visnagin, Benzopyran, Khellin, and Benzenepropanoic acid were the major active components found in the MKSE. The maximum non-toxic concentration of MKSE was 5 µg/mL and the CC50 value was 417 µg/mL. The MKSE exhibited in-vitro antiviral activity against BRVM1 indicated by inhibition of the viral cytopathic effect (SI = 204.5, IP = 98%), causing a 1.5 log decrease in BVRM1 TCID50 and reducing the viral plaques count by the percentage of 93.14% at MNTC (5 ug/ml). In conclusion, our study showed that bovine rotavirus represents a severe health problem that needs attention in Egypt, and it supports using MKSE as a potential natural anti-rotavirus agent.

Anti-Mayaro virus activity of a hydroethanolic extract from Fridericia chica (Bonpl.) L. G. Lohmann leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Mayaro fever is a neglected tropical disease. The region of the most significant circulation of the Mayaro virus (MAYV) is the Amazon rainforest, situated in remote areas that are difficult to access and where medicine is scarce. Thus, the regional population uses plants as an alternative for the treatment of various diseases. Fridericia chica is an endemic plant of tropical regions used in traditional medicine to treat fever, malaise, inflammation, and infectious diseases such as hepatitis B. However, its antiviral activity is poorly understood.

AIM OF THE STUDY

This study aimed to investigate the anti-MAYV activity of the hydroethanolic extract of the leaves of Fridericia chica (HEFc) in mammalian cells and its possible mechanism of action.

MATERIALS AND METHODS

The antiviral activity of HEFc was studied using Vero cell lines against MAYV. The cytotoxicity and antiviral activity of the extract were evaluated by the 3-(4, 5- dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. The overall antiviral activity was confirmed by the plaque forming units (PFU) method. Then, the effects of HEFc on MAYV multiplication kinetics, virus adsorption, penetration, and post-penetration, and its virucidal activity were determined in Vero cells using standard experimental procedures.

RESULTS

HEFc exerted a effect against viral infection in Vero cells at a non-cytotoxic concentration, and no virion was detected in the supernatant in a dose-dependent and selective manner. HEFc inhibited MAYV in the early and late stages of the viral multiplication cycle. The extract showed significant virucidal activity at low concentrations and did not affect adsorption or viral internalization stages. In addition, HEFc reduced virions at all post-infection times investigated.

CONCLUSIONS

HEFc has good antiviral activity against MAYV, acting directly on the viral particles. This plant extract possesses an excellent and promising potential for developing effective herbal antiviral drugs.

Therapeutic Potential of Leaves from Fridericia chica (Bonpl.) L. G. Lohmann: Botanical Aspects, Phytochemical and Biological, Anti-Inflammatory, Antioxidant and Healing Action

Plants of the species Fridericia chica (Bonpl.) L. G. Lohmann (Bignoniaceae), which are widely distributed in Brazil and named crajiru in the state of Amazonas, are known in folk medicine as a traditional medicine in the form of a tea for the treatment of intestinal colic, diarrhea, and anemia, among other diseases. The chemical analysis of extracts of the leaves has identified phenolic compounds, a class of secondary metabolites that provide defense for plants and benefits to the health of humans. Several studies have shown the therapeutic efficacy of F. chica extracts, with antitumor, antiviral, wound healing, anti-inflammatory, and antioxidant activities being among the therapeutic applications already proven. The healing action of F. chica leaf extract has been demonstrated in several experimental models, and shows the ability to favor the proliferation of fibroblasts, which is essential for tissue repair. The anti-inflammatory activity of F. chica has been clearly demonstrated by several authors, who suggest that it is related to the presence of 3-deoxyanthocyanidins, which is capable of inhibiting pro-inflammatory pathways such as the kappa B (NF-kB) nuclear transcription factor pathway. Another important effect attributed to this species is the antioxidant effect, attributed to phenolic compounds interrupting chain reactions caused by free radicals and donating hydrogen atoms or electrons. In conclusion, the species Fridericia chica has great therapeutic potential, which is detailed in this paper with the objective of encouraging new research and promoting the sum of efforts for the inclusion of herbal medicines in health systems around the world.

Nanocomposites Based on Cerium, Lanthanum, and Titanium Oxides Doped with Silver for Biomedical Application

Nanosized composites CeO2–Ag, La2O3–Ag, and TiO2–Ag are a class of nanomaterials suitable for photocatalysis, optical devices, and photoelectrochemical elements. Further, nanocomposites with several wt.% of silver can be used as creating materials for pathogenic virus inactivation with pandemic-neutralizing potential. Thus, CeO2–Ag, La2O3–Ag, and TiO2–Ag nanocomposites are prospective materials due to their optical and biological activity. In the present work, CeO2–Ag, La2O3–Ag, and TiO2–Ag nanocomposites were synthesized by the co-precipitation method. The morphological and optical properties and the structure of the prepared nanocomposites were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) with EDX, and nitrogen adsorption-desorption based on BET, Raman spectroscopy, and photoluminescence (PL). Both oxide matrixes corresponded to the cubic crystal lattice with the inclusion of argentum into the crystal lattice of oxides at relative low c(Ag) and reduction of silver on particle surface at 5 wt.% Ag and greater. The CeO2, TiO2, and La2O3 with a concentration of 4 wt.% Ag inhibited the growth processes of prokaryotic cells of E. coli, Bacillus sp., and S. aureus compared to pure oxides. Influenza A virus and herpes completely suppressed reproduction by nanocomposites of CeO2–Ag (2, 5 wt.%) and La2O3–Ag (2, 5 wt.%) action.

Structure-Morphology-Antimicrobial and Antiviral Activity Relationship in Silver-Containing Nanocomposites Based on Polylactide

Green synthesis of silver-containing nanocomposites based on polylactide (PLA) was carried out in two ways. With the use of green tea extract, Ag⁺ ions were reduced to silver nanoparticles with their subsequent introduction into the PLA (mechanical method) and Ag⁺ ions were reduced in the polymer matrix of PLA-AgPalmitate (PLA-AgPalm) (in situ method). Structure, morphology and thermophysical properties of nanocomposites PLA-Ag were studied by FTIR spectroscopy, wide-angle X-ray scattering (WAXS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) methods. The antimicrobial, antiviral, and cytotoxic properties were studied as well. It was found that the mechanical method provides the average size of silver nanoparticles in the PLA of about 16 nm, while in the formation of samples by the in situ method their average size was 3.7 nm. The strong influence of smaller silver nanoparticles (3.7 nm) on the properties of nanocomposites was revealed, as with increasing nanosilver concentration the heat resistance and glass transition temperature of the samples decreases, while the influence of larger particles (16 nm) on these parameters was not detected. It was shown that silver-containing nanocomposites formed in situ demonstrate antimicrobial activity against gram-positive bacterium S. aureus, gram-negative bacteria E. coli, P. aeruginosa, and the fungal pathogen of C. albicans, and the activity of the samples increases with increasing nanoparticle concentration. Silver-containing nanocomposites formed by the mechanical method have not shown antimicrobial activity. The relative antiviral activity of nanocomposites obtained by two methods against influenza A virus, and adenovirus serotype 2 was also revealed. The obtained nanocomposites were not-cytotoxic, and they did not inhibit the viability of MDCK or Hep-2 cell cultures.

Preparation, Characterization, and Antimicrobial and Antiviral Properties of Silver-Containing Nanocomposites Based on Polylactic Acid-Chitosan

Antimicrobial and antiviral nanocomposites based on polylactic acid (PLA) and chitosan were synthesized by a thermochemical reduction method of Ag⁺ ions in the PLA-Ag⁺-chitosan polymer films. Features of the structural, morphological, thermophysical, antimicrobial, antiviral, and cytotoxic properties of PLA-Ag-chitosan nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and antiviral, antimicrobial, and cytotoxic studies. The effects of temperature and the duration of reduction of Ag⁺ ions on the structure of PLA-Ag-chitosan nanocomposites were established. During the thermochemical reduction (T = 160 °C, t = 5 min) of silver palmitate ions in PLA-Ag⁺-chitosan polymer films, Ag nanoparticles with an average size of 4.2 nm were formed. PLA-Ag-chitosan polymer nanocomposites have strong antimicrobial activity against S. aureus and E. coli strains. In particular, for PLA-chitosan samples containing 4% Ag, the diameters of the S. aureus and E. coli growth inhibition zones were 25.8 and 25.0 mm, respectively. The antiviral activity of the nanocomposites against influenza A virus, herpes simplex virus type 1, and adenovirus serotype 2 was also revealed. The PLA-4%Ag-chitosan nanocomposites completely inhibited the cytopathic effect (CPE) of herpes virus type 1 by 5.12 log₁₀TCID₅₀/mL (high antiviral activity) and the development of the CPE of influenza virus and adenovirus by 0.60 and 1.07 log₁₀TCID₅₀/mL (relative antiviral activity). The obtained nanocomposites were not cytotoxic; they did not inhibit the viability of MDCK, BHK-21, and Hep-2 cell cultures.

Toxic Potential of Cerrado Plants on Different Organisms

Cerrado has many compounds that have been used as biopesticides, herbicides, medicines, and others due to their highly toxic potential. Thus, this review aims to present information about the toxicity of Cerrado plants. For this purpose, a review was performed using PubMed, Science Direct, and Web Of Science databases. After applying exclusion criteria, 187 articles published in the last 20 years were selected and analyzed. Detailed information about the extract preparation, part of the plant used, dose/concentration tested, model system, and employed assay was provided for different toxic activities described in the literature, namely cytotoxic, genotoxic, mutagenic, antibacterial, antifungal, antiviral, insecticidal, antiparasitic, and molluscicidal activities. In addition, the steps to execute research on plant toxicity and the more common methods employed were discussed. This review synthesized and organized the available research on the toxic effects of Cerrado plants, which could contribute to the future design of new environmentally safe products.

Nano Zinc Oxide Green-Synthesized from Plumbago auriculata Lam. Alcoholic Extract

Zinc oxide nanoparticles (ZnO NPs) were synthesized by using an alcoholic extract of the flowering aerial parts of Plumbago auriculata Lam. Dynamic Light Scattering (DLS) revealed that the average size of synthesized ZnO NPs was 10.58 ± 3.350 nm and the zeta potential was -19.6 mV. Transmission electron microscopy (TEM) revealed that the particle size was in the range from 5.08 to 6.56 nm. X-ray diffraction (XRD) analysis verified the existence of pure hexagonal shaped crystals of ZnO nanoparticles with an average size of 35.34 nm in the sample, which is similar to the particle size analysis acquired by scanning electron microscopy (SEM) (38.29 ± 6.88 nm). HPLC analysis of the phenolic ingredients present in the plant extract showed that gallic acid, chlorogenic acid, and catechin were found as major compounds at concentrations of 1720.26, 1600.42, and 840.20 µg/g, respectively. Furthermore, the inhibitory effects of ZnO NPs and the plant extract against avian metapneumovirus (aMPV) subtype B were also investigated. This assessment revealed that the uncalcinated form of Nano-ZnO mediated by P. auriculata Lam. extract possessed a significant antiviral activity with 50% cytotoxic concentration (CC₅₀) and 50% inhibition concentration (IC₅₀) of 52.48 ± 1.57 and 42.67 ± 4.08 µg/mL, respectively, while the inhibition percentage (IP) was 99% and the selectivity index (SI) was 1.23.

In Vitro Antiviral Activity of α-Mangostin against Dengue Virus Serotype-2 (DENV-2)

Dengue virus (DENV), a member of the family Flaviviridae, is a threat for global health as it infects more than 100 million people yearly. Approved antiviral therapies or vaccines for the treatment or prevention of DENV infections are not available. In the present study, natural compounds were screened for their antiviral activity against DENV by in vitro cell line-based assay. α-Mangostin, a xanthanoid, was observed to exert antiviral activity against DENV-2 under pre-, co- and post-treatment testing conditions. The antiviral activity was determined by foci forming unit (FFU) assay, quantitative RT-PCR and cell-based immunofluorescence assay (IFA). A complete inhibition of DENV-2 was observed at 8 µM under the co-treatment condition. The possible inhibitory mechanism of α-Mangostin was also determined by docking studies. The molecular docking experiments indicate that α-Mangostin can interact with multiple DENV protein targets such as the NS5 methyltransferase, NS2B-NS3 protease and the glycoprotein E. The in vitro and in silico findings suggest that α-Mangostin possesses the ability to suppress DENV-2 production at different stages of its replication cycle and might act as a prophylactic/therapeutic agent against DENV-2.

COVID-19 Prophylaxis Efforts Based on Natural Antiviral Plant Extracts and Their Compounds

During the time of the novel coronavirus disease 2019 (COVID-19) pandemic, it has been crucial to search for novel antiviral drugs from plants and well as other natural sources as alternatives for prophylaxis. This work reviews the antiviral potential of plant extracts, and the results of previous research for the treatment and prophylaxis of coronavirus disease and previous kinds of representative coronaviruses group. Detailed descriptions of medicinal herbs and crops based on their origin native area, plant parts used, and their antiviral potentials have been conducted. The possible role of plant-derived natural antiviral compounds for the development of plant-based drugs against coronavirus has been described. To identify useful scientific trends, VOSviewer visualization of presented scientific data analysis was used.

In vitro screening antiviral activity of Thai medicinal plants against porcine reproductive and respiratory syndrome virus

BACKGROUND

Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) results in economic losses in the swine industry globally. Several studies have investigated the use of plant extracts in the prevention and control of PRRS outbreaks. Thai medicinal plants may be useful for treating PRRSV infection in pigs. Therefore, we investigated the in vitro anti-PRRSV and antioxidant properties of seven Thai medicinal plants: Caesalpinia sappan Linn., Garcinia mangostana Linn., Houttuynia cordata, Perilla frutescens, Clinacanthus nutans, Phyllanthus emblica, and Tiliacora triandra.

RESULTS

Using antiviral screening, we observed that T. triandra extract strongly inhibited PRRSV infectivity in MARC-145 cells [virus titer 3.5 median tissue culture infective dose (TCID₅₀)/ml (log10)] at 24 h post-infection, whereas C. sappan extract strongly inhibited PRRSV replication [virus titer 2.5 TCID₅₀/ml (log10)] at 72 h post-infection. C. sappan extract had the highest total phenolic content [220.52 mM gallic acid equivalent/g] and lowest half-maximal inhibitory concentration [1.17 mg/ml in 2,2-diphenyl-1-picrylhydrazyl and 2.58 mg/ml in 2,2-azino-bis (3-ethylbenzothiazo-line-6-sulfonic acid) diammonium salt].

CONCLUSION

T. triandra extract could inhibit PRRSV infectivity, whereas C. sappan extract was the most effective in inhibiting PRRSV replication in MARC-145 cells. This study elucidates the antiviral activities of Thai medicinal plant extracts in vivo. The results promise that Thai medicinal plant extracts, particularly T. triandra and C. sappan extracts, can be developed into pharmaceutical drugs for the prevention of PRRS in pigs.

Antiviral Activity of Exopolysaccharides Produced by Lactic Acid Bacteria of the Genera Pediococcus, Leuconostoc and Lactobacillus against Human Adenovirus Type 5

Background and objectives: The use of antagonistic probiotic microorganisms and their byproducts represents a promising approach for the treatment of viral diseases. In the current work, the effect of exopolysaccharides (EPSs) produced by lactic acid bacteria from different genera on the structural and functional characteristics of cells and the development of adenoviral infection in vitro was studied. Materials and Methods: Cytotoxicity of six EPSs of lactic acid bacteria of the genera Lactobacillus, Leuconostoc and Pediococcus was determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The influence of the EPSs on the infectivity of human adenovirus type 5 (HAdV-5) and on the cell cycle under a condition of adenovirus infection was studied using plaque reduction assay and flow cytometric analysis, respectively. Results: It was shown that exopolysaccharides were non-toxic to Madin-Darby bovine kidney cells (MDBK) as they reduced their viability by 3-17%. A change in the distribution of the cell cycle phases in the non-infected cell population treated with EPSs was observed. The analysis demonstrated an increase in the number of cells in the S phase by 47% when using EPSs 15a and a decrease in the number of cells in the G1 phase by 20-27% when treated with the EPSs 15a, 33a, and 19s. The use of EPSs did not led to the normalization of the life cycle of HAdV-5 infected cells to the level of non-infected cells. The EPSs showed low virucidal activity and reduced the HAdV-5 infectivity to 85%. Among the studied exopolysaccharides, anti-adenovirus activity was found for EPS 26a that is produced by Lactobacillus spp. strain. The treatment of cells with the EPS following virus adsorption completely (100%) suppressed the formation and release of HAdV-5 infectious. Conclusions: EPS 26a possessed distinct anti-HAdV-5 activity and the obtained data demonstrate the potential of using exopolysaccharides as anti-adenoviral agents.

The Antiviral Effect of Indonesian Medicinal Plant Extracts Against Dengue Virus In Vitro and In Silico

Dengue infections are still a worldwide burden, especially in Indonesia. There is no specific medication against the dengue virus. Recently, many types of research have been conducted to discover a new drug for dengue virus using natural resource extracts. Indonesia, as a tropical country, has a wide biodiversity. There are several medicinal plants in Indonesia that are believed to possess anti-dengue activity, such as Myristica fatua, Cymbopogon citratus, and Acorus calamus plants. We conducted an in vitro laboratory experiment of several extracts from Indonesian herbs combined with in silico analysis. The extracts were evaluated for safety and antiviral activity in Huh7it-1 cell lines, using a single dose of 20 µg/mL and dose-dependent (5, 10, 20, 40, 80 and 160 µg/mL) of plant extracts against dengue virus serotype 2 (DENV-2) NGC strain. The DMSO 0.1% was used as a negative control. The cytotoxic aspect was assessed by counting the cell viability, while the antiviral activity was calculated by counting the average inhibition. The selectivity index (SI) of plant extracts were performed from a ratio of CC₅₀/EC₅₀ value. In silico analysis was conducted to determine the free energy of binding between NS5 of dengue virus with bioactive compounds contained in Myristica fatua, Cymbopogon citratus and Acorus calamus extract plants. We determined that all extracts were not toxic against Huh7it-1 cell lines. The methanolic extracts of A. calamus, C. citratus, and M. fatua showed inhibition of DENV-2 at a dose of 20 µg/mL to 96.5%, 98.9%, and 122.7%, respectively. The dose-dependent effects showed that M. fatua has the best inhibition activity towards DENV-2. Molecular docking result showed that artesunic acid within M. fatua has the best free energy of binding (-7.2 kcal/mol), followed by homoegonol (-7.1 kcal/mol) which was slightly different from artesunic acid among others. The methanolic extracts of A. calamus, C. citratus, and M. fatua showed prospective anti-dengue activities both in vitro and in silico. Future research should be conducted to find the pure extracts of all useful herbs as a new candidate of antiviral drug.

Aspidosperma species: A review of their chemistry and biological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Species of Aspidosperma are known popularly as "peroba, guatambu, carapanaúba, pau-pereiro" and "quina". The genus can be found in the Americas, mainly between Mexico and Argentina. Many species of Aspidosperma are used by the population in treating cardiovascular diseases, malaria, fever, diabetes and rheumatism. The phytochemical aspects of the species of the genus Aspidosperma have been studied extensively. The monoterpene indole alkaloids are the main secondary metabolites in Aspidosperma species, and about 250 of them have been isolated showing a considerable structural diversity. Several of them have showed some important pharmacological activities. Aspidosperma subincanum Mart. and Aspidosperma tomentosum Mart. (Apocynaceae) are Brazilian species widely used by the population to treat diabetes mellitus, hypercholesterolemia. The pharmacological activities of both species have been investigated and the biological properties described can be related to their isolated indole alkaloids. However, more pharmacological studies are needed in order to justify the use of these species in folk medicine. In this review, we present reports mainly focused on chemical and biological studies and their relationship with the ethnopharmacological use of both Aspidosperma species.

AIM OF THE STUDY

The aim of this review is to present their ethnopharmacological use as correlated to their biological activities as described for the extracts and isolated compounds from Aspidosperma subincanum Mart. and Aspidosperma tomentosum Mart. In addition, some aspects related to the biosynthetic pathways are discussed, also NMR assignments and some synthesis information about indole alkaloids from both Aspidosperma species are included.

MATERIAL AND METHODS

The bibliographic search was made in theses and dissertations using some databases such as NDLTD (Networked Digital Library of Theses and Dissertations), OATD (Open Access Theses and Dissertations) and Google Scholar. More data were gathered from books, Brazilian journals and articles available on electronic databases such as, Google Scholar, PubChem, Scifinder, Web of Science, SciELO, PubMed and Science Direct. Additionally, the Google Patents and Espacenet Patent Search (EPO) were also consulted. The keywords Aspidosperma, A. subincanum, A. tomentosum, indole alkaloids were used in the research. The languages were restricted to Portuguese, English and Spanish and references were selected according to their relevance.

RESULTS

A. subincanum Mart. and A. tomentosum Mart. (Apocynaceae) are Brazilian species widely used by the population to treat a few diseases. Extracts and isolated compounds of both species have shown antitumor and antimalarial activities. The antitumor activity of isolated compounds has been extensively studied. However, the antiplasmodial activity needs to be investigated further as well as the anti-inflammatory, anti-hyperlipidemic and anorexigenic activities. From A. subincanum twenty-one indole alkaloids were isolated and some of them have been extensively studied. From the leaves and bark of A. tomentosum four alkaloids and one flavonoid were isolated. Furthermore, CG-MS analysis of seeds, branches, leaves and arils identified nine indole alkaloids. Stemmadenine has been proposed as a precursor of indole alkaloids obtained from some species of Aspidosperma. Many of the biosynthetic steps have been characterized at the enzymatic level and appropriate genes have been identified, however, other steps have yet to be investigated and they are still controversial. Some isolated alkaloids from A. subincanum and A. tomentosum were identified only by mass spectrometry. In many cases, their NMR data was either not available or was incomplete. The described meta-analysis of the available NMR data revealed that the chemical shifts belonging to the indole ring might be used to characterize this class of alkaloids within complex matrices such as plant extracts. The biological activities and the structural complexity of these compounds have stimulated the interest of many groups into their synthesis. In this review, some information about the synthesis of indole alkaloids and their derivatives was presented.

CONCLUSIONS

A. subincanum and A. tomentosum are used by the population of Brazil to treat many diseases. A few biological activities described for the extracts and isolated compounds of both species are in agreement with the ethnopharmacological use for others species of Aspidosperma, such as, antimalarial, the treatment of diabetes and other illnesses. These species are sources of leading compounds which can be used for developing new drugs. In addition, other biological activities reported and suggested by ethnopharmacological data have yet to be investigated and could be an interesting area in the search for new bioactive compounds.

Anti-Adenoviral Activity of 2-(3-Chlorotetrahydrofuran-2-yl)-4-Tosyl-5-(Perfluoropropyl)-1,2,3-Triazole

Background and objectives: A considerable increase in the levels of adenoviral diseases among both adults and children necessitate the development of effective methods for its prevention and treatment. The synthesis of the new fluorinated 1,2,3-triazoles, and the study of the mechanisms of their action, are promising for the development of efficient antiviral drugs of our time. Materials and Methods: Antiviral activity and cell cytotoxic effect of 2-(3-chlorotetrahydrofuran-2-yl)-4-tosyl-5-(perfluoropropyl)-1,2,3-triazole (G29) were determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The influence of the compound on the infectivity of human adenovirus type 5 (HAdV-5) was carried out via the cytomorphology method. The influence of the compound on the cell cycle under a condition of adenovirus infection was studied using flow cytometric analysis of propidium iodide-stained cells. Results: It was found that G29 suppressed HAdV-5 reproduction by 50% in concentrations of 37 μg/mL. Furthermore, the compound reduced the titer of virus obtained de novo, and inhibited HAdV-5 inclusion bodies formation by 84–90%. The use of fluorinated compounds under the conditions of adenovirus infection decreased the number of apoptotic cells by 11% and the number of cells in S phase by 21–42% compared to the profile of infected cells. Conclusions: The fluorinated compound G29 showed moderate activity against HAdV-5 based on several mechanisms. It led to the normalization of the life cycle of cells infected with adenovirus to the level of non-infected cells and caused the obstruction of HAdV-5 reproduction, inducing the formation of non-infectious virus progeny.