Antimicrobial activity of plants used as medicinals on an indigenous reserve in Rio das Cobras, Paraná, Brazil

Health from Brazilian Amazon food wastes: Bioactive compounds, antioxidants, antimicrobials, and potentials against cancer and oral diseases

Brazilian Amazon contains over 30,000 plant species and foods rich in bioactive compounds such as terpenes, phenolic acids, alkaloids, and flavonoids, of potential health benefits (antioxidant, antimicrobial, antiparasitic, anticancer, gastroprotection, prebiotic effects, among others). The existence of residues from non-edible parts of plants (leaves, roots, stems, branches, barks) or fruit wastes (peel, bagasse, seeds) in the agri-food industry and its supply chain is an important challenge in food loss and waste management. In this critical review several Amazon species, focusing on extracts/essential oils from nonedible parts or wastes, were analyzed in terms of phytochemicals, biological activity, and underlying mechanisms. We hope this review emphasizes the importance of Amazon's sustainability initiatives on population health due to the potential shown against cancer, infectious diseases, and prevention of oral diseases. It is urgent to think about the conversion of amazon food wastes and co-products into high-added-value raw materials to develop novel drugs, food packaging systems, or nutraceutical foods.

Essential Oils of Aromatic Plant Species from the Atlantic Rainforest Exhibit Extensive Chemical Diversity and Antimicrobial Activity

Microbial resistance, caused by the overuse or inadequate application of antibiotics, is a worldwide crisis, increasing the risk of treatment failure and healthcare costs. Plant essential oils (EOs) consist of hydrophobic metabolites with antimicrobial activity. The antimicrobial potential of the chemical diversity of plants from the Atlantic Rainforest remains scarcely characterized. In the current work, we determined the metabolite profile of the EOs from aromatic plants from nine locations and accessed their antimicrobial and biocidal activity by agar diffusion assays, minimum inhibitory concentration, time-kill and cell-component leakage assays. The pharmacokinetic properties of the EO compounds were investigated by in silico tools. More than a hundred metabolites were identified, mainly consisting of sesqui and monoterpenes. Individual plants and botanical families exhibited extensive chemical variations in their EO composition. Probabilistic models demonstrated that qualitative and quantitative differences contribute to chemical diversity, depending on the botanical family. The EOs exhibited antimicrobial biocidal activity against pathogenic bacteria, fungi and multiple predicted pharmacological targets. Our results demonstrate the antimicrobial potential of EOs from rainforest plants, indicate novel macromolecular targets, and contribute to highlighting the chemical diversity of native species.

Screening of medicinal plants from El Salvador for anti-viral activity against Herpes simplex 1

Herpes simplex virus 1 is one of the most prevalent pathogens worldwide. Resistant strains to current anti-viral treatment have been reported, requiring the search for novel anti-virals. Using a qPCR method to assess anti-herpetic activity from natural products, we analyzed 72 plant extracts from El Salvador and identified eighteen methanolic extracts with anti-viral activity of ≥ 75%. Anti-herpetic activity has not been previously reported in fourteen of the plants (Euphorbia lancifolia, Piper tuberculatum, Cordia alliodora, Tecoma stans, Taraxacum officinale, Hamelia patens, Witheringia solanacea, Emilia fosbergii, Gnaphalium viscosum, Citrus aurantium, Ambrosia peruviana, Carica papaya, Solanum hazenii and Melothria pendula). Four extracts were from species with previously reported anti-herpetic activity (Plantago major, Psidium guajava, Sida acuta and Bursera simaruba). These extracts effective anti-viral concentrations (EC₅₀) were between 203 and 6.31 µg/mL, while the selectivity indexes (SI) were between 55.91 and 2.57. Euphorbia lancifolia showed the most effective anti-viral activity (EC₅₀ = 6.31 µg/mL, SI = 51.82).

Antiviral Plants from Marajó Island, Brazilian Amazon: A Narrative Review

Diseases caused by viruses are a global threat, resulting in serious medical and social problems for humanity. They are the main contributors to many minor and major outbreaks, epidemics, and pandemics worldwide. Over the years, medicinal plants have been used as a complementary treatment in a range of diseases. In this sense, this review addresses promising antiviral plants from Marajó island, a part of the Amazon region, which is known to present a very wide biodiversity of medicinal plants. The present review has been limited to articles and abstracts available in Scopus, Web of Science, Science Direct, Scielo, PubMed, and Google Scholar, as well as the patent offices in Brazil (INPI), United States (USPTO), Europe (EPO) and World Intellectual Property Organization (WIPO). As a result, some plants from Marajó island were reported to have actions against HIV-1,2, HSV-1,2, SARS-CoV-2, HAV and HBV, Poliovirus, and influenza. Our major conclusion is that plants of the Marajó region show promising perspectives regarding pharmacological potential in combatting future viral diseases.

In vitro activity of Schinus terebinthifolius extract and fractions against Sporothrix brasiliensis

BACKGROUND

Sporothrix brasiliensis is the causative agent of zoonotic cases of sporotrichosis in Brazil and is associated with atypical and severe presentations in cats, dogs, and humans. Sporotrichosis treatment is usually time- and cost-consuming, sometimes with poor response and host toxicity. Schinus terebinthifolius has proven efficacy against bacteria and fungi of clinical interest.

OBJECTIVE

To determine the in vitro activity of S. terebinthifolius against S. brasiliensis.

METHODS

Five S. brasiliensis isolates and three reference strains were subjected to a hydroethanol extract derived from the leaves of S. terebinthifolius and its fractions. The minimal inhibitory concentration (MIC) was determined using the broth microdilution method according to the M38-A2 CLSI guidelines. Also, the fungicidal/fungistatic activity of the extract and fractions was studied.

FINDINGS

The crude extract of S. terebinthifolius inhibited the growth of S. brasiliensis (MIC: 0.5-1.0 µg/mL), while the partitioned extracts dichloromethane, ethyl acetate, and butanol demonstrated growth inhibition at 8 µg/mL due to a fungistatic activity.

MAIN CONCLUSIONS

Due to its in vitro efficacy against S. brasiliensis and its known pharmacological safety, S. terebinthifolius is a candidate to be tested using in vivo models of sporotrichosis.

Multiresistant bacteria isolated from domestic and wild animals with skin lesions were susceptible to native plants from Southern Brazil

We evaluated the chemical composition, toxicity, and antibacterial activity of Schinus terebinthifolia (SCH), Eugenia uniflora (EUG), Persicaria hydropiperoides (PER), Equisetum hyemale (EQU), Solidago chilensis (SOL), and Baccharis trimera (BRA). These plants were tested (7.5-0.01 mg/mL) against Gram-positive (G+; n = 32) and Gram-negative (G-; n = 26) isolates from animals (M07-A9, CLSI). Antibiogram (disk diffusion), chromatographic analysis (UPLC), and toxicity assay (HET-CAM) were also performed. A high incidence of resistance was noted, in which 18.4% (07/38) of G+ (Staphylococcus intermedius/Enterococcus faecium) and 17.7% (06/34) of G- (Pseudomonas aeruginosa/Escherichia coli/Proteus mirabilis) were multidrug-resistant. All bacteria were sensitive (MIC₅₀) to SCH (both 3.75 mg/mL), EUG (3.75 mg/mL and 7.5 mg/mL, respectively) and PER (both 7.5 mg/mL). SCH/EUG/PER highlighted as antibacterial, probably due to the major compounds (ethyl gallate, quinic acid, quercetin). These extracts showed normal embryonic development (SCH/EUG: 7.5-0.94 mg/mL). These findings highlighted the promising use of native plants for therapeutic purposes.

Review of Whole Plant Extracts With Activity Against Herpes Simplex Viruses In Vitro and In Vivo

Herpes simplex viruses, HSV-1 and HSV-2, are highly contagious and cause lifelong, latent infections with recurrent outbreaks of oral and/or genital lesions. No cure exists for HSV-1 or HSV-2 infections, but antiviral medications are commonly used to prevent and treat outbreaks. Resistance to antivirals has begun to emerge, placing an importance on finding new and effective therapies for prophylaxis and treatment of HSV outbreaks. Botanicals may be effective HSV therapies as the constituents they contain act through a variety of mechanisms, potentially making the development of antiviral resistance more challenging. A wide variety of plants from different regions in the world have been studied for antiviral activity against HSV-1 and/or HSV-2 and showed efficacy of varying degrees. The purpose of this review is to summarize research conducted on whole plant extracts against HSV-1 and/or HSV-2 in vitro and in vivo. The majority of the research reviewed was conducted in vitro using animal cell lines, and some studies used an animal model design. Also summarized are a limited number of human trials conducted using botanical therapies on HSV lesions.

The use of plant extracts and their phytochemicals for control of toxigenic fungi and mycotoxins

Mycotoxins present a great concern to food safety and security due to their adverse health and socio-economic impacts. The necessity to formulate novel strategies that can mitigate the economic and health effects associated with mycotoxin contamination of food and feed commodities without any impact on public health, quality and nutritional value of food and feed, economy and trade industry become imperative. Various strategies have been adopted to mitigate mycotoxin contamination but often fall short of the required efficacy. One of the promising approaches is the use of bioactive plant components/metabolites synergistically with mycotoxin-absorbing components in order to limit exposure to these toxins and associated negative health effects. In particular, is the fabrication of β-cyclodextrin-based nanosponges encapsulated with bioactive compounds of plant origin to inhibit toxigenic fungi and decontaminate mycotoxins in food and feed without leaving any health and environmental hazard to the consumers. The present paper reviews the use of botanicals extracts and their phytochemicals coupled with β-cyclodextrin-based nanosponge technology to inhibit toxigenic fungal invasion and detoxify mycotoxins.

Photodamage on Staphylococcus aureus by natural extract from Tetragonia tetragonoides (Pall.) Kuntze: Clean method of extraction, characterization and photophysical studies

Photodynamic therapy (PDT) is a clinical modality that allows the destruction of tumor cells and microorganisms by reactive oxygen species, formed by the combination of photosensitizer (PS), molecular oxygen and adequate wavelength light. This research, through a clean methodology that involves pressurized liquids extraction (PLE), obtained a highly antimicrobial extract of Tetragonia tetragonoides, which rich in chlorophylls as photosensitizers. The Chlorophylls-based extract (Cbe-PLE) presented pharmacological safety, through the maintenance of cellular viability. In addition, Cbe-PLE showed great efficacy against Staphylococcus aureus, with severe dose-dependent damage to the cell wall of the pathogen. The obtained product has a high potential for the development of photostimulated phytotherapic formulations for clinical applications in localized infections, as a complementary therapeutic alternative to antibiotics.

Ethnopharmacology Study of Plants from Atlantic Forest with Leishmanicidal Activity

Leishmaniasis is an infectious disease caused by a protozoan belonging to Leishmania genus. Different clinical outcomes can be observed depending on the parasite species and patient's health condition. The outcomes can range from single cutaneous lesions to lethal visceral form. The treatment of all forms of leishmaniasis is based on pentavalent antimonials, and, in some cases, the second-line drug, amphotericin B, is used. Beside the toxicity of both classes of drugs, in some areas of the world, parasites are resistant to antimonial. These detrimental features make fundamental the discovery and characterization of new drugs or plant extracts with leishmanicidal effects. Brazil is a well-known country for its biodiversity. Additionally, the common knowledge inherited for generations in small villages makes Brazil a source of new information and resources for the discovery and development of new drugs. Based on ethnopharmacology, elderlies were interviewed about plants they commonly used for skin diseases and infections. Five native plants from Atlantic forest were indicated; EtOH and n-hexane extracts were prepared with the vegetative organs of the plants and assayed against promastigote and amastigote forms of L. (L.) amazonensis. The major molecules of each extract were detected using qualitative nuclear magnetic resonance. Among all tested extracts, the n-hexane extract from the leave of Eugenia uniflora (Myrtaceae), enriched in myricitrin and quercitrin flavonoids, was the most effective against L. (L.) amazonensis amastigotes. This data supports the ethnopharmacology approach as a successful tool for the discovery of new drugs with leishmanicidal effects.

Traditional uses, phytochemistry and pharmacology of the medicinal species of the genus Cordia (Boraginaceae)

OBJECTIVES

Cordia (family Boraginaceae) is a genus of deciduous flowering trees or shrubs comprising more than 300 species distributed widely in the tropical regions. The aim of this review was to provide exhaustive scientific information on traditional uses, phytochemistry and pharmacological activities of the 36 important species with medicinal value from the genus Cordia, to divulge prospects for further research on its therapeutic potential.

KEY FINDINGS

Leaves, fruit, bark and seed of a majority of the species were found to possess abundant ethnomedicinal value, but leaves were found to be used most frequently to treat many ailments such as respiratory disorders, stomach pain, wound, inflammation, myalgia, cough, dysentery and diarrhoea. The phytochemical investigation of 36 species resulted in isolation of 293 chemical constituents from various chemical classes. The crude extracts, fractions, essential oils and pure compounds isolated from various Cordia species were reported to have a varied range of pharmacological activities.

SUMMARY

Many of the traditional uses of the genus Cordia were supported by the results obtained from pharmacological studies performed using various extracts or pure compounds. More attention should be given to the biological evaluation using pure phytochemicals and to identify the mechanism of actions and exploring this genus for new drug discovery.

Virulence Inhibitors from Brazilian Peppertree Block Quorum Sensing and Abate Dermonecrosis in Skin Infection Models

Widespread antibiotic resistance is on the rise and current therapies are becoming increasingly limited in both scope and efficacy. Methicillin-resistant Staphylococcus aureus (MRSA) represents a major contributor to this trend. Quorum sensing controlled virulence factors include secreted toxins responsible for extensive damage to host tissues and evasion of the immune system response; they are major contributors to morbidity and mortality. Investigation of botanical folk medicines for wounds and infections led us to study Schinus terebinthifolia (Brazilian Peppertree) as a potential source of virulence inhibitors. Here, we report the inhibitory activity of a flavone rich extract "430D-F5" against all S. aureus accessory gene regulator (agr) alleles in the absence of growth inhibition. Evidence for this activity is supported by its agr-quenching activity (IC50 2-32 μg mL-1) in transcriptional reporters, direct protein outputs (α-hemolysin and δ-toxin), and an in vivo skin challenge model. Importantly, 430D-F5 was well tolerated by human keratinocytes in cell culture and mouse skin in vivo; it also demonstrated significant reduction in dermonecrosis following skin challenge with a virulent strain of MRSA. This study provides an explanation for the anti-infective activity of peppertree remedies and yields insight into the potential utility of non-biocide virulence inhibitors in treating skin infections.

Campomanesia adamantium Peel Extract in Antidiarrheal Activity: The Ability of Inhibition of Heat-Stable Enterotoxin by Polyphenols

Campomanesia adamantium (Myrtaceae) is a medicinal plant distributed in Brazilian Cerrado. Different parts of this plant are used in popular medicine for treatment of several diseases like fever, diarrhea, hypercholesterolemia and rheumatism. The aim of this work was to evaluate the inhibition of heat-stable enterotoxin type A (STa) by gallic acid present in the peel of C. adamantium fruit and assays to assess the antidiarrheal activity, anti-inflammatory and cytotoxic properties of peel extract using the T84 cell line model. The possible inhibition exerted by the gallic acid of the peel extract on the STa peptide was inferred by molecular dynamics simulations. The antidiarrheal effects were investigated measuring cGMP accumulation in cells after stimulation by STa toxin and antibacterial activity was assessed. The anti-inflammatory activity was assessed by inhibition of COX-1 and COX-2. MTT and LDH assays were used to evaluate any possible cytotoxic action while the CyQUANT test was used to investigate the effect on cell proliferation. A representation showing how the possible interactions between STa and the gallic acid of the extract might reduce the action of the enterotoxin is presented. C. adamantium peel extract significantly decreased the levels of cGMP in T84 cells. However, no effect on the species of microorganisms was observed. The extract also inhibited COX-1 (IC₅₀ 255.70 ± 0.04 ng/mL) and COX-2 (IC₅₀ 569.50 ± 0.11 ng/mL) enzymes. Cytotoxicity assay have shown significant changes in cells treated with the extract, which inhibited the cell proliferation until 72 hours of treatment. Direct interactions of phenolic compounds present in the extract with the STa toxin may limit its activity. Curative effect in the diarrhea treatment and its anti-inflammatory action is based on the pharmacological properties, mechanism of action of the C. adamantium peel extract, and no toxic effects of the peel extract presented on this work.

Inhibitory effects of Zanthoxylum rhoifolium Lam. (Rutaceae) against the infection and infectivity of macrophages by Leishmania amazonensis

ABSTRACT Zanthoxylum rhoifolium Lam. (Rutaceae) has been traditionally used in the treatment of microbial infections and parasitic diseases. In the present study, the antileishmanial effect induced by the ethanol extract of stem barks from Z. rhoifolium (ZR-EEtOH) and its n-hexane fraction (ZR-FHEX) on infection and infectivity of murine macrophages by promastigote forms of Leishmania amazonensis were investigated. In different set of experiments, macrophages or promastigotes were pretreated with ZR-EEtOH or ZR-FHEX at non-lethal concentrations for 24 hours, and then macrophages were submitted to infection by promastigotes. Moreover, their effects on activation of macrophages, as well as on the DNA content, size and number of promastigotes by flow cytometry were also evaluated. The infection rate and the number of internalized amastigote forms were markedly decreased after pretreatment of macrophages or promastigotes when compared with non-treated cells. The increase in phagocytic capability and nitrite content was also observed. Furthermore, the decrease of DNA content, size and number of promastigotes was also observed. In conclusion, ZR-EEtOH and ZR-FHEX promoted a markedly significant antileishmanial effect and reduction of infection of macrophages, probably underlying defense mechanisms activation in macrophages. These findings reinforce the potential application of Z. rhoifolium in the treatment of leishmaniasis.

In vitro Cytotoxicity and Anti-herpes Simplex Virus Type 1 Activity of Hydroethanolic Extract, Fractions, and Isolated Compounds from Stem Bark of Schinus terebinthifolius Raddi

Background:

Herpes simplex virus type 1 (HSV-1) is associated with orofacial infections and is transmitted by direct contact with infected secretions. Several efforts have been expended in the search for drugs to the treatment for herpes. Schinus terebinthifolius is used in several illnesses and among them, for the topical treatment of skin wounds, especially wounds of mucous membranes, whether infected or not.

Objective:

To evaluate the cytotoxicity and anti-HSV-1 activity of the crude hydroethanolic extract (CHE) from the stem bark of S. terebinthifolius, as well as its fractions and isolated compounds.

Materials and Methods:

The CHE was subjected to bioguided fractionation. The anti-HSV-1 activity and the cytotoxicity of the CHE, its fractions, and isolated compounds were evaluated in vitro by SRB method. A preliminar investigation of the action of CHE in the virus–host interaction was conducted by the same assay.

Results:

CHE presented flavan-3-ols and showed anti-HSV-1 activity, better than its fractions and isolated compounds. The class of substances found in CHE can bind to proteins to form unstable complexes and enveloped viruses, as HSV-1 may be vulnerable to this action. Our results suggest that the CHE interfered with virion envelope structures, masking viral receptors that are necessary for adsorption or entry into host cells.

Conclusion:

The plant investigated exhibited potential for future development treatment against HSV-1, but further tests are necessary, especially to elucidate the mechanism of action of CHE, as well as preclinical and clinical studies to confirm its safety and efficacy.

SUMMARY

Crude hydroethanolic extract (CHE) presents promising activity against herpes simplex virus type 1 (HSV 1), with selectivity index (SI) = 22.50

CHE has flavan-3-ols in its composition, such as catechin and gallocatechin

The fractions and isolated compounds obtained from CHE by bioguided fractionation are less active than the CHE against HSV-1

CHE interferes with viral entry process in the host cell and acts directly on the viral particle.

Abbreviations used: HSV: Herpes simplex virus, CHE: Crude hydroethanolic extract, WF: Water fraction, AF: Ethyl-acetate fraction, MPLC: Medium-performance liquid chromatography, TLC: Thin-layer chromatography, NMR: Nuclear magnetic resonance, ESI-MS: Electrospray ionization mass spectrometry, SRB: Sulforhodamine B, CPE: Cytopathic effect, CC50: 50% cytotoxic concentration, EC50: 50% effective concentration, PBS: Phosphate-buffered saline.

In vitro antibacterial activity of selected medicinal plants traditionally used in Vietnam against human pathogenic bacteria

BACKGROUND

Medicinal plants are widely used for the treatment of different infectious diseases. Infectious diseases caused by bacteria have a large impact on public health. This study aimed to determine the in vitro antibacterial activity of the medicinal plants traditionally used in Vietnam against the bacterial strains associated with infectious diseases.

METHODS

Methanol extracts of twelve Vietnamese medicinal plants were tested for their antibacterial activity against five bacterial species including Gram-positive bacteria (Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) using the broth microdilution method.

RESULTS

All the plant extracts showed antibacterial activity, especially against Gram-positive bacteria (Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus). Baeckea frutescens extract revealed a potent activity against the Gram-positive bacteria with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 62.5 μg/ml. High activity against all the three Gram-positive bacteria was also observed for the extracts of Cratoxylum formosum ssp. pruniflorum, Pogostemon cablin, and Pedilanthus tithymaloides with MICs of 125, 125 and 250 μg/ml and MBCs of 125-250, 125-250 and 250-500 μg/ml, respectively. The extracts of C. formosum ssp. pruniflorum and P. tithymaloides showed a broad-spectrum antibacterial activity against all the bacteria tested with the MICs of 125-2,000 μg/ml.

CONCLUSION

This study indicates clear evidence supporting the traditional use of the plants in treating infectious diseases related to bacteria. In particular, these plant species showed moderate to high antibacterial activity against the Gram-positive bacteria tested.

Antiparasitic activity of natural and semi-synthetic tirucallane triterpenoids from Schinus terebinthifolius (Anacardiaceae): structure/activity relationships

Leishmaniasis and Chagas are diseases caused by parasitic protozoans that affect the poorest population in the World, causing a high mortality and morbidity. As a result of highly toxic and long-term treatments, the discovery of novel, safe and more efficacious drugs is essential. In this work, the in vitro antiparasitic activity and mammalian cytotoxicity of three natural tirucallane triterpenoids, isolated from leaves of Schinus terebinthifolius (Anacardiaceae), and nine semi-synthetic derivatives were investigated against Leishmania (L.) infantum and Trypanosoma cruzi. Trypomastigotes of T. cruzi were the most susceptible parasites and seven compounds demonstrated a trypanocidal activity with IC₅₀ values in the range between 15 and 58 µg/mL. Four compounds demonstrated selectivity towards the intracellular amastigotes of Leishmania, with IC₅₀ values in the range between 28 and 97 µg/mL. The complete characterization of triterpenoids was afforded after thorough analysis of nuclear magnetic resonance (NMR) data as well as electrospray ionization mass spectrometry (ESI-MS). Additionally, structure-activity relationships were performed using Decision Trees.