Search Results (33)

Several natural products have been shown to display antiviral activity against the hepatitis B virus (HBV), among a number of other viruses. In a previous study, the hydro-alcoholic extracts (n = 66) of 31 species from the Venezuelan Amazonian rain forest were tested on the hepatoma cell line HepG2.2.15, which constitutively produces HBV. One of the species that exerted inhibitory activity on HBV replication was Senna silvestris. The aim of this study was the bioassay-guided purification of the ethanol fraction of leaves of S. silvestris, which displayed the most significant inhibitory activity against HBV. After solvent extraction and two rounds of reverse-phase HPLC purification, NMR analysis identified salsolinol as the compound that may exert the desired antiviral activity. The purified compound exerted inhibition of both HBV DNA and core HBV DNA. Pure salsolinol obtained from a commercial source also displayed anti-HBV DNA inhibition, with an approximate MIC value of 12 µM. Although salsolinol is widely used in Chinese traditional medicine to treat congestive heart failure, it has also been associated with Parkinson’s disease. More studies are warranted to analyze the effect of changes in its chemical conformation, searching for potent antiviral, perhaps dual agents against HBV and HIV, with reduced toxicity. Full article

One of the medicinal plants used in Ecuador that has the best prospects for industrialization is guayusa (Ilex guayusa Loes.). This review shows the potential of the species, analyzing the ethnobotanical aspects, ancestral uses, secondary metabolites, and research. The plant has been consumed for thousands of years by the high Amazonian peoples of Ecuador and currently forms part of the gardens of ancestral peoples and mestizo settlers. The most relevant secondary metabolites that have been investigated are xanthine alkaloids, terpenes, and phenolic compounds, while from the pharmacological point of view, the following uses stand out: physical and mental stimulants, analgesic, antioxidant, antimicrobial, anti-inflammatory, anti-diabetic, and phytohormonal. The goal of this review is to make known the benefits of guayusa, with the purpose of representing a resource that will provide benefits to the Amazonian inhabitants in the future. Full article

Background: Paullinia cupana Kunth, popularly known as guarana, a native Amazonian shrub cultivated by the Sateré-Mawé ethnic group, has been used in traditional medicine for various purposes, including stimulant and therapeutic actions, due to its chemical composition, which is rich in bioactive compounds. This study explored the reductive potential of guarana with nanobiotechnology and aimed to synthesize silver nanoparticles (AgNPs) using the aqueous extract of leaves collected during the dry and rainy seasons, assessing their biological and catalytic activities. Methods: The AgNPs were synthesized in a water bath at 70 °C for three hours and then characterized using techniques such as UV-Vis spectroscopy, DLS, zeta potential, MET, NTA, and EDX and had their effects on various biological systems assessed in vitro, as well as in catalytic tests aimed at indicating the probable influence of the time when the plant material was collected on the properties of the nanostructures. Results: The AgNPs had an average diameter between 39.33 and 126.2 nm, spherical morphology, absorption bands between 410 and 450 nm, and high colloidal stability over two years. The biological results showed antibacterial activity against all the species tested, as well as remarkable antioxidant action against DPPH and ABTS free radicals, in the same way as the aqueous leaf extracts of P. cupana, in addition to cytotoxic properties against cancerous (A431 and A549) and non-cancerous (HaCaT and HNTMC) cells. The AgNPs were active against promastigote forms of Leishmania (Leishmania) amazonensis while not affecting the viability of macrophages, and from the LC₅₀ and LC₉₀ values, the AgNPs were more effective than the metal salt solution in controlling Aedes aegypti larvae and pupae. We also reported that the catalytic degradation of the organic dyes methylene blue (MB) and methyl orange (MO) by AgNPs was over 90% after 40 or 14 min, respectively. Conclusions: Thus, our results support the potential of seasonal extracts of guarana leaves to produce AgNPs with diverse application possibilities for the health, industrial, and environmental sectors. Full article

Cecropia sp. (Urticaceae) are commonly used in traditional medicine in South American countries for the treatment of different diseases. To date, the species Cecropia concolor Willd, of Amazonian occurrence, has not been investigated for its pharmacological potential. In this study, we described the chemical profile and the antileishmanial, antioxidant and cytotoxic activities of extracts of the leaves of C. concolor. The ethanolic extract and its partition phases (hexane, ethyl acetate and hydroethanolic) were analyzed for their chemical classes and phenolic content. Antileishmanial activity was assessed against Leishmania (L.) amazonensis. The antioxidant activity was evaluated using the DPPH method and in MRC-5 human fibroblast cells. Toxicity was tested against Artemia salina and in human cells (fibroblasts and cancer lines). The leaves of C. concolor have phenolic substances, such as flavonoids, as well as terpenes, steroids and alkaloids. Chlorogenic acid, caffeic acid, schaftoside and vicenin 2 were identified. The hydroethanolic phase showed a high concentration of phenolic compounds and pronounced antioxidant activity. The antileishmanial activity was observed in the ethanolic extract, with a promising effect of the hexane phase. The C. concolor ethanolic extract and its phases are non-toxic, which makes this species of interest in pharmaceutical and cosmetics applications. Full article

Couroupita guianensis, a medicinal plant autochthonal to South America and South India, is widely used in the ethnomedicine of the indigenous peoples of these regions thanks to its alleged antimicrobial, anti-inflammatory, antioxidant and wound-healing properties. The majority of studies have mainly analyzed organic extracts of the Indian plant’s flowers and leaves, with limited research on its bark decoction, traditionally used in Amazonian shamanic medicine. In this study, we investigated the anticancer effects of the bark decoction and its main fractions obtained through chromatographic separation, as well as the underlying molecular mechanisms in AGS gastric cancer cells. Viability, cell proliferation, cell cycle, apoptosis and protein expression related to these processes were evaluated. Both the bark decoction and fraction III significantly inhibited cell viability, and the cytotoxic effect was linked to cell cycle blockade and the induction of apoptosis also through an engulfment of the autophagic flux. Increased expression or activation of the key proteins (p53, p21, cdk2, Bak, caspases, pAMPK, pAkt, beclin, p62 and LC3BII) involved in these processes was observed. The results obtained confirmed an important anticancer effect of C. guianensis bark decoction, providing scientific validation for its use in traditional medicine and highlighting its potential as a therapeutic agent against gastric cancer. Full article

Radiotherapy is focused on the tumor but also reaches healthy tissues, causing toxicities that are possibly related to genomic factors. In this context, radiogenomics can help reduce the toxicity, increase the effectiveness of radiotherapy, and personalize treatment. It is important to consider the genomic profiles of populations not yet studied in radiogenomics, such as the indigenous Amazonian population. Thus, our objective was to analyze important genes for radiogenomics, such as ATM, TGFB1, RAD51, AREG, XRCC4, CDK1, MEG3, PRKCE, TANC1, and KDR, in indigenous people and draw a radiogenomic profile of this population. The NextSeq 500^® platform was used for sequencing reactions; for differences in the allelic frequency between populations, Fisher’s Exact Test was used. We identified 39 variants, 2 of which were high impact: 1 in KDR (rs41452948) and another in XRCC4 (rs1805377). We found four modifying variants not yet described in the literature in PRKCE. We did not find any variants in TANC1—an important gene for personalized medicine in radiotherapy—that were associated with toxicities in previous cohorts, configuring a protective factor for indigenous people. We identified four SNVs (rs664143, rs1801516, rs1870377, rs1800470) that were associated with toxicity in previous studies. Knowing the radiogenomic profile of indigenous people can help personalize their radiotherapy. Full article

Pigments of fungal origin have aroused increasing interest in the food dye and cosmetic industries since the global demand for natural dyes has grown. Endophytic microorganisms are a source of bioactive compounds, and Amazonian plant species can harbor fungi with a wide range of biotechnological applications. Popularly known in Brazil as crajiru, Fridericia chica is a medicinal plant that produces a red pigment. In this study, a total of 121 fungi were isolated in potato dextrose agar from three plants. We identified nine pigment-producing endophytic fungi isolated from branches and leaves of F. chica. The isolates that showed pigment production in solid media were molecularly identified via multilocus analysis as Aspergillus welwitschiae, A. sydowii, Curvularia sp., Diaporthe cerradensis (two strains), Hypoxylon investiens, Neoscytalidium sp. (two strains) and Penicillium rubens. These isolates were subjected to submerged fermentation in two culture media to obtain metabolic extracts. The extracts obtained were analyzed in terms of their absorbance between 400 and 700 nm. The pigmented extract produced by H. investiens in medium containing yeast extract showed maximum absorbance in the red absorption range (UA₇₀₀ = 0.550) and significant antioxidant and antimicrobial activity. This isolate can thus be considered a new source of extracellular pigment. Full article

In the Ecuadorian Amazon region, there are various types of edible fruits that have distinct qualities and benefits. Understanding the uses, properties, and functions of these fruits is important for researching products that are only available in local markets. This review aims to gather and summarize the existing scientific literature on the ethnobotany, physicochemical composition, and bioactive compounds of these native fruits to highlight the potential of the region’s underutilized biodiversity. A systematic review was carried out following the PRISMA methodology, utilizing databases such as Web of Science, Scopus, Pubmed, Redalyc, and SciELO up to August 2023. The research identified 55 edible fruits from the Ecuadorian Amazon and reported their ethnobotanical information. The most common uses were fresh fruit consumption, preparation of typical food, and medicine. Additionally, nine native edible fruits were described for their physicochemical characteristics and bioactive components: Aphandra natalia (Balslev and Henderson) Barfod; Eugenia stipitate McVaugh; Gustavia macarenensis Philipson; Mauritia flexuosa L.f; Myrciaria dubia (Kunth) McVaugh; Oenocarpus bataua Mart; Plukenetia volubilis L.; Pouteria caimito (Ruiz and Pav.) Radlk.; and Solanum quitoense Lam. The analyzed Amazonian fruits contained bioactive compounds such as total polyphenols, flavonoids, carotenoids, and anthocyanins. This information highlights their potential as functional foods and the need for further research on underutilized crops. Full article

There are several Amazonian plant species with potential pharmacological validation for the treatment of acute kidney injury, a condition in which the kidneys are unable to adequately filter the blood, resulting in the accumulation of toxins and waste in the body. Scientific production on plant compounds capable of preventing or attenuating acute kidney injury—caused by several factors, including ischemia, toxins, and inflammation—has shown promising results in animal models of acute kidney injury and some preliminary studies in humans. Despite the popular use of Amazonian plant species for kidney disorders, further pharmacological studies are needed to identify active compounds and subsequently conduct more complex preclinical trials. This article is a brief review of phytocompounds with potential nephroprotective effects against acute kidney injury (AKI). The classes of Amazonian plant compounds with significant biological activity most evident in the consulted literature were alkaloids, flavonoids, tannins, steroids, and terpenoids. An expressive phytochemical and pharmacological relevance of the studied species was identified, although with insufficiently explored potential, mainly in the face of AKI, a clinical condition with high morbidity and mortality. Full article

The endophytic fungal community of the Amazonian medicinal plant Arrabidaea chica (Bignoniaceae) was evaluated based on the hypothesis that microbial communities associated with plant species in the Amazon region may produce metabolites with interesting bioactive properties. Therefore, the antimicrobial and antioxidant activities of the fungal extracts were investigated. A total of 107 endophytic fungi were grown in liquid medium and the metabolites were extracted with ethyl acetate. In the screening of fungal extracts for antimicrobial activity, the fungus identified as Botryosphaeria mamane CF2-13 was the most promising, with activity against E. coli, S. epidermidis, P. mirabilis, B. subtilis, S. marcescens, K. pneumoniae, S. enterica, A. brasiliensis, C. albicans, C. tropicalis and, especially, against S. aureus and C. parapsilosis (MIC = 0.312 mg/mL). Screening for antioxidant potential using the DPPH elimination assay showed that the Colletotrichum sp. CG1-7 endophyte extract exhibited potential activity with an EC₅₀ of 11 µg/mL, which is equivalent to quercetin (8 µg/mL). The FRAP method confirmed the antioxidant potential of the fungal extracts. The presence of phenolic compounds and flavonoids in the active extracts was confirmed using TLC. These results indicate that two of the fungi isolated from A. chica exhibit significant antimicrobial and antioxidant potential. Full article

Ayahuasca is an Amazonian psychoactive plant medicine being explored for its potential therapeutic uses in Western contexts. Preliminary studies link ayahuasca use with improvements across a range of mental health indicators, but studies have not yet explored qualitative aspects of the post-treatment process known in the psychedelic literature as “integration”. This includes how participants make sense of their ayahuasca experiences and minimise harm/maximise benefits after ayahuasca use. A global online survey, conducted between 2017 and 2019, collected responses from 1630 ayahuasca drinkers (50.4% male, mean age = 43 years) to an open-ended question about their integration experiences after consuming ayahuasca. Inductive codebook thematic analysis was used to identify themes in participants’ integration experiences. Participants described integration experiences in three main ways. First, was an overall appraisal of the integration experience (e.g., as easy, challenging, or long-term/ongoing). Second, was describing beneficial tools which facilitated integration (e.g., connecting with a like-minded community and ongoing practice of yoga, meditation, journaling, etc.). Third, was describing integration challenges (e.g., feeling disconnected, going back to “old life” with new understandings, etc.). These findings suggest that integrating ayahuasca experiences can be challenging and take considerable time, though working through integration challenges may facilitate positive growth. Findings also challenge the role of individual psychotherapy as the primary integration tool in Western psychedelic therapy, suggesting that communal and somatic elements may also be useful. An expanded definition of psychedelic integration is proposed which includes working with integration challenges and adjusting to life changes. Full article

Background: Ayahuasca is a serotoninergic hallucinogen that plays a central role in the Amazonian traditional medicine. Its psychoactive effects are associated with the presence of N,N-dimethyltryptamine (DMT), and monoamine oxidase inhibitors (MAO-A). Advances in neuroimaging investigations have provided insight into ayahuasca’s neurobiological mechanisms of action. Methods: Selecting only studies with neuroimaging results related to human ayahuasca consumption, we included six articles from a previous systematic review of serotoninergic hallucinogen neuroimaging studies up to 2016. Furthermore, we updated the data with a new systematic search from 2016 to 2022. We searched the PubMed, SciELO, and LILACS databases using the search terms “(ayahuasca OR DMT) AND (MRI OR fMRI OR PET OR SPECT OR imaging OR neuroimaging)”. Results: Our updated search provided five new articles for a total of 11 included in this review. The results on the Default Mode Network (DMN) are evident and may indicate a path to short term neuromodulation. Acutely, local neural networks appeared to become expanded, while overall brain connectivity declined. On chronic consumers, anatomical changes were reported, most notably related to cingulate cortex. Conclusion: Ayahuasca seems to change acute brain connectivity similarly to other psychedelics. The results are preliminary and further studies are warranted. Full article

The Colombian program to end trachoma implements the component F of the SAFE strategy in the Vaupés department of the Amazon rainforest. Cultural, linguistic, and geographical barriers and the coexistence of an ancestral medical system demand the technical and sociocultural adaptation of this component. A cross-sectional survey combined with focus-group discussions to understand the knowledge, attitudes, and practices of the indigenous population related to trachoma was conducted in 2015. Of the 357 heads of households that participated, 45.1% associated trachoma with a lack of hygiene, and 94.7% associated the concept of hygiene with taking one or more body baths per day, using commercial or handcrafted soap. In total, 93% reported cleaning their children’s faces and eyes more often when they have conjunctivitis, but 66.1% also did this with clothes or towels in use, and 52.7% of people shared towels; in total, 32.8% indicated that they would use ancestral medicine to prevent and treat trachoma. The SAFE strategy in Vaupés requires an intercultural approach to facilitate stakeholder support and participation to promote general and facial hygiene, washing clothes with soap, and not sharing towels and clothes to dry and clean children’s faces for effective and sustainable elimination of trachoma as a public health problem. This qualitative assessment facilitated an intercultural approach locally and in other Amazonian locations. Full article

The Amazonian region of Ecuador has an extremely rich vegetal biodiversity, and its inhabitants have proven to have a millennial ancestral knowledge of the therapeutic and medicinal use of these resources. This work aimed to evaluate the chemical composition and biological activity of the essential oil obtained from the medicinal plant Clinopodium brownei (Sw.) Kuntze, which is widely spread in tropical and subtropical America. This species is traditionally used for treating respiratory and digestive diseases and is also known for its analgesic properties. Most of the molecules detected on a non-polar column were ethyl cinnamate 21.4%, pulegone 20.76%, methyl cinnamate 16.68%, caryophyllene 8.17%, β-selinene 7.92% and menthone 7.51%, while those detected on a polar column were: pulegone 29.90%, ethyl cinnamate 18.75%, methyl cinnamate 13.82%, caryophyllene 10.0% and menthone 8.04%. The antioxidant activity by the assays, DPPH (2.2-diphenyl-1-picrylhydrazyl) and ABTS (2.2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)), shows the following values of 50% inhibition of oxidation, IC50 DPPH 1.77 mg/mL, IC50 ABTS 0.06 mg/mL, which, compared to the essential oil of Thymus vulgaris (natural positive control), turn out to be less active. Bioautography indicates that the molecules responsible for the antioxidant activity are derived from cinnamic acid: ethyl cinnamate and methyl cinnamate, and caryophyllene. The antimicrobial activity on the nine microorganisms evaluated shows bacterial growth inhibitory concentrations ranging from 13.6 mg/mL for Staphylococcus epidermidis ATCC 14990 to 3.1 mg/mL for Candida albicans ATCC 10231; the results are lower than those of the positive control. Bioautography assigns antimicrobial activity to caryophyllene. The results indicate a very interesting activity of the essential oil and several of its molecules, validating the traditional use and the importance of this medicinal plant from Ecuador. Full article

Harmful usage of tobacco is a global public health problem associated with adverse health effects and addiction. Yet, in the Peruvian Amazon, the native region of Nicotiana rustica L., this plant is used in remarkably different manners: it is considered a potent medicinal plant, applied in liquid form for oral ingestion to treat mental health problems, a common and ancient healing practice in this region. Using a transdisciplinary field research approach with mixed ethnopsychological methods, this work aimed to report for the first time a case study in this context. The intervention took place in the Peruvian Amazon (Loreto) and involved ritual tobacco ingestion in a weeklong retreat-like frame, administered by a specialized traditional Amazonian healer. The patient was a 37-year-old woman with diagnosed mood, anxiety, and attention deficit disorders, as well as a chronic somatic condition. We applied qualitative experience-sampling during and quantitative symptom assessments pre- and post-treatment. Our findings offer a detailed description of the experiential therapeutic process during the treatment week and suggest clinically relevant improvements in patient well-being. This work is significant in view of the globally prevalent harmful uses of tobacco and the current scientific trend of revisiting herbal psychoactives (e.g., cannabis, psilocybin) for their therapeutic potentials. Full article