Herbal Therapeutics for Alzheimer's Disease: Ancient Indian Medicine System from the Modern Viewpoint.

Alzheimer's is a chronic neurodegenerative disease where amyloid-beta (Aß) plaques and neurofibrillary tangles are formed inside the brain. It is also characterized by progressive memory loss, depression, neuroinflammation, and derangement of other neurotransmitters. Due to its complex etiopathology, current drugs have failed to completely cure the disease. Natural compounds have been investigated as an alternative therapy for their ability to treat Alzheimer's disease (AD). Traditional herbs and formulations which are used in the Indian ayurvedic system are rich sources of antioxidant, anti-amyloidogenic, neuroprotective, and anti-inflammatory compounds. They promote quality of life by improving cognitive memory and rejuvenating brain functioning through neurogenesis. A rich knowledge base of traditional herbal plants (Turmeric, Gingko, Ashwagandha, Shankhpushpi, Giloy, Gotu kola, Garlic, Tulsi, Ginger, and Cinnamon) combined with modern science could suggest new functional leads for Alzheimer's drug discovery. In this article Ayurveda, the ancient Indian herbal medicine system based on multiple clinical and experimental, evidence have been reviewed for treating AD and improving brain functioning. This article presents a modern perspective on the herbs available in the ancient Indian medicine system as well as their possible mechanisms of action for AD treatment. The main objective of this research is to provide a systematic review of herbal drugs that are easily accessible and effective for the treatment of AD.

Review on Compounds Isolated from Eriocaulaceae Family and Evaluation of Biological Activities by Machine Learning.

Eriocaulaceae is a pantropical family whose main center of biodiversity is in Brazil. In general, the family has about 1200 species, in which phytochemical and biological studies have shown a variety of structures and activities. The aim of this research is to compile the compounds isolated in the Eriocaulaceae family and carry out a computational study on their biological targets. The bibliographic research was carried out on six databases. Tables were built and organized according to the chemical class. In addition, a summary of the methods of isolating the compounds was also made. In the computational study were used ChEMBL platform, DRAGON 7.0, and the KNIME 4.4.0 software. Two hundred and twenty-two different compounds have been isolated in sixty-eight species, divided mainly into flavonoids and naphthopyranones, and minor compounds. The ligand-based virtual screening found promising molecules and molecules with multitarget potential, such as xanthones 194, 196, 200 and saponin 202, with xanthone 194 as the most promising. Several compounds with biological activities were isolated in the family, but the chemical profiles of many species are still unknown. The selected structures are a starting point for further studies to develop new antiparasitic and antiviral compounds based on natural products.

Machine Learning Analysis of Essential Oils from Cuban Plants: Potential Activity against Protozoa Parasites.

Essential oils (EOs) are a mixture of chemical compounds with a long history of use in food, cosmetics, perfumes, agricultural and pharmaceuticals industries. The main object of this study was to find chemical patterns between 45 EOs and antiprotozoal activity (antiplasmodial, antileishmanial and antitrypanosomal), using different machine learning algorithms. In the analyses, 45 samples of EOs were included, using unsupervised Self-Organizing Maps (SOM) and supervised Random Forest (RF) methodologies. In the generated map, the hit rate was higher than 70% and the results demonstrate that it is possible find chemical patterns using a supervised and unsupervised machine learning approach. A total of 20 compounds were identified (19 are terpenes and one sulfur-containing compound), which was compared with literature reports. These models can be used to investigate and screen for bioactivity of EOs that have antiprotozoal activity more effectively and with less time and financial cost.

Limonene, a citrus monoterpene, non-complexed and complexed with hydroxypropyl-ß-cyclodextrin attenuates acute and chronic orofacial nociception in rodents: Evidence for involvement of the PKA and PKC pathway.

BACKGROUND: Chronic orofacial pain is a serious public health problem with a prevalence of 7-11% in the population. This disorder has different etiologies and characteristics that make pharmacological treatment difficult. Natural products have been shown to be a promising source of treatments for the management of chronic pain, as an example the terpenes. PURPOSE: The aim of this study was to evaluate the anti-nociceptive and anti-inflammatory effects of one of these terpenes, d-limonene (LIM - a common monoterpene found in citrus fruits) alone and complexed with hydroxypropyl-ß-cyclodextrin (LIM/HPßCD) in preclinical animal models. METHODS: Orofacial pain was induced by the administration of hypertonic saline on the corneal surface, the injection of formalin into the temporomandibular joint (TMJ), or chronic constriction injury of the infraorbital nerve (CCI-IoN). The study used male Wistar rats and Swiss mice treated with LIM (50 mg/kg), LIM/HPßCD (50 mg/kg), vehicle (control), gabapentin or morphine, and eyes wiping (induced by hypertonic saline), face rubbing (formalin-induced in TMJ) or mechanical hyperalgesia (provoked by CCI-IoN) were assessed. Additionally, ELISA was used to measure TNF-α, and western blot analysis to assess levels of PKAcα, NFκB, p38MAPK and phosphorylated PKC substrates. Serum levels of aspartate aminotransferase (AST) and alanine transferase (ALT) were also evaluated. RESULTS: LIM and LIM/HPßCD significantly reduced (p < 0.001) corneal nociception and formalin-induced TMJ nociception. In addition, both substances attenuated (p < 0.001) mechanical hyperalgesia in the CCI-IoN model. The antinociceptive effect induced by LIM and HPßCD/LIM was associated with decreased TNF-α levels, downregulation of the NFκB and p38MAPK signalling pathways and reduced PKC substrate phosphorylation and PKA immunocontent. Moreover, the results demonstrated that complexation with HPßCD was able to decrease the therapeutic dose of LIM. CONCLUSION: LIM was found to be a promising molecule for the treatment of orofacial pain due to its capacity to modulate some important mediators essential to the establishment of pain, and HPßCD can be a key tool to improve the profile of LIM.

In Silico Studies of Lamiaceae Diterpenes with Bioinsecticide Potential against Aphis gossypii and Drosophila melanogaster.

BACKGROUND: The growing demand for agricultural products has led to the misuse/overuse of insecticides; resulting in the use of higher concentrations and the need for ever more toxic products. Ecologically, bioinsecticides are considered better and safer than synthetic insecticides; they must be toxic to the target organism, yet with low or no toxicity to non-target organisms. Many plant extracts have seen their high insecticide potential confirmed under laboratory conditions, and in the search for plant compounds with bioinsecticidal activity, the Lamiaceae family has yielded satisfactory results. OBJECTIVE: The aim of our study was to develop computer-assisted predictions for compounds with known insecticidal activity against Aphis gossypii and Drosophila melanogaster. RESULTS AND CONCLUSION: Structure analysis revealed ent-kaurane, kaurene, and clerodane diterpenes as the most active, showing excellent results. We also found that the interactions formed by these compounds were more stable, or presented similar stability to the commercialized insecticides tested. Overall, we concluded that the compounds bistenuifolin L (1836) and bistenuifolin K (1931), were potentially active against A. gossypii enzymes; and salvisplendin C (1086) and salvixalapadiene (1195), are potentially active against D. melanogaster. We observed and highlight that the diterpenes bistenuifolin L (1836), bistenuifolin K (1931), salvisplendin C (1086), and salvixalapadiene (1195), present a high probability of activity and low toxicity against the species studied.

Natural Products as Potential Agents against SARS-CoV and SARSCoV- 2.

BACKGROUND: Natural products are useful agents for the discovery of new lead- compounds and effective drugs to combat coronaviruses (CoV). OBJECTIVE: The present work provides an overview of natural substances, plant extracts, and essential oils as potential anti-SARS-CoV agents. In addition, this work evaluates their drug-like properties which are essential in the selection of compounds in order to accelerate the drug development process. METHODS: The search was carried out using PubMed, ScienceDirect and SciFinder. Articles addressing plant-based natural products as potential SARS-CoV or SARS-CoV-2 agents within the last seventeen years were analyzed and selected. The descriptors for Chemometrics analysis were obtained in alvaDesc and the principal component analysis (PCA) was carried out in SIMCA version 13.0. RESULTS: Based on in vitro assays and computational analyses, this review covers twentynine medicinal plant species and more than 300 isolated substances as potential anti-coronavirus agents. Among them, flavonoids and terpenes are the most promising compound classes. In silico analyses of drug-like properties corroborate these findings and indicate promising candidates for in vitro and in vivo studies to validate their activity. CONCLUSION: This paper highlights the role of ethnopharmacology in drug discovery and suggests the use of integrative (in silico/ in vitro) and chemocentric approaches to strengthen current studies and guide future research in the field of antiviral agents.

Virtual Screening of Natural Products Database.

Constant research on natural products has generated, over time, a large number of compounds with the potential to be evaluated in several biological tests and subsequently have been cataloged in databases that allow other researchers to perform virtual screenings of activity in various biological systems. This considerably reduces the time for the development of new drugs. This review describes the main databases of natural products available for searching bioactive compounds. It also describes the main features of virtual screening strategies for the identification of molecules with the potential to be used as new drugs. In addition, a search was made in the Web of Science database, using the search term "Virtual screening of natural products databases" from 2003 to 2018. The search criterion resulted in 230 articles, which had their abstracts evaluated with pertinence to the criteria required for this work, which are: a) be a research article; b) performing a virtual screening on databases of natural products or containing natural products; and c) works that identified drug candidate molecules. Based on these criteria, the bibliographic review on the topic was excluded. After this analysis, 104 works were selected for this review. We selected relevant papers describing the potential drug candidates that were distributed in 15 classes, of which the anticancer, antibacterial and anti-inflammatory hits were the most abundant. The works showing efforts to search for new molecules against various other diseases in distinct biological systems were also described. In this way, this work shows an overview of several methodologies and we hope they can help and inspire the development of new research to improve people's quality of life.

Virtual screening and assessment of anticancer potential of selenium-based compounds against HL-60 and MCF7 cells.

Aim: Selenium-based compounds have antitumor potential. We used a ligand-based virtual screening analysis to identify selenoglycolicamides with potential antitumor activity. Results & Conclusion: Compounds 3, 6, 7 and 8 were selected for in vitro cytotoxicity tests against various cell lines, according to spectrophotometry results. Compound 3 presented the best cytotoxicity results against a promyelocytic leukemia line (HL-60) and was able to induce cell death at a frequency similar to that observed for doxorubicin. The docking study showed that compound 3 has good interaction energies with the targets caspase-3, 7 and 8, which are components of the apoptotic pathway. These results suggested that selenium has significant pharmacological potential for the selective targeting of tumor cells, inducing molecular and cellular events that culminate in tumor cell death.

Identification of New Targets and the Virtual Screening of Lignans against Alzheimer's Disease.

Alzheimer's disease (AD) is characterized by the progressive disturbance in cognition and affects approximately 36 million people, worldwide. However, the drugs used to treat this disease are only moderately effective and do not alter the course of the neurodegenerative process. This is because the pathogenesis of AD is mainly associated with oxidative stress, and current drugs only target two enzymes involved in neurotransmission. Therefore, the present study sought to identify potential multitarget compounds for enzymes that are directly or indirectly involved in the oxidative pathway, with minimal side effects, for AD treatment. A set of 159 lignans were submitted to studies of QSAR and molecular docking. A combined analysis was performed, based on ligand and structure, followed by the prediction of absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties. The results showed that the combined analysis was able to select 139 potentially active and multitarget lignans targeting two or more enzymes, among them are c-Jun N-terminal kinase 3 (JNK-3), protein tyrosine phosphatase 1B (PTP1B), nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1), NADPH quinone oxidoreductase 1 (NQO1), phosphodiesterase 5 (PDE5), nuclear factor erythroid 2-related factor 2 (Nrf2), cycloxygenase 2 (COX-2), and inducible nitric oxide synthase (iNOS). The authors conclude that compounds (06) austrobailignan 6, (11) anolignan c, (19) 7-epi-virolin, (64) 6-[(2R,3R,4R,5R)-3,4-dimethyl-5-(3,4,5-trimethoxyphenyl)oxolan-2-yl]-4-methoxy-1,3-benzodioxole, (116) ococymosin, and (135) mappiodoinin b have probabilities that confer neuroprotection and antioxidant activity and represent potential alternative AD treatment drugs or prototypes for the development of new drugs with anti-AD properties.

Computer-Aided Drug Design for the Identification of Novel Antischistosomal Compounds.

Schistosomiasis is a chronic neglected tropical disease, highlighted by the presence of Schistosoma worms, which presents in advanced cases in approximately 80 countries, affecting almost 300 million people. The treatment is based on only one drug, praziquantel, a drug discovered in the 1970s that shows moderate efficacy against the adult parasite, but low efficacy against the larval stages of the parasite. Therefore, the use of only one drug has brought concerns and losses on drug-resistance cases, necessitating the development of new effective chemotherapeutic agents against Schistosoma species. One of the strategies that have been implemented in drug development is the computer-aided drug design (CADD), investigating the structural characteristics of the compounds and targets in order to understand their actions and biological activities through 3D virtual manipulation, as the QSAR applied to ligands and molecular docking applied to a respective biological target. These studies help to extract information and characteristics relevant to the activity, as well as to predict potential applications and activity. Therefore, this chapter will present the main validated biological targets of the genus Schistosoma, as thioredoxin glutathione reductase (TGR), histone deacetylases (HDAC 1, HDAC 8), dihydroorotate dehydrogenase, sirtuin protein and cathepsin L1, as well as reports of CADD in literature applied to the development of drugs against schistosomiasis, providing compounds with high pharmacological potential and high specificity.

Virtual Screening and the In Vitro Assessment of the Antileishmanial Activity of Lignans.

Leishmaniasis is endemic in at least 98 countries. Due to the high toxicity and resistance associated with the drugs, we chose lignans as an alternative, due to their favorable properties of absorption, distribution, metabolism, excretion, and toxicity (ADMET). To investigate their leishmanicidal potential, the biological activities of a set of 160 lignans were predicted using predictive models that were built using data for Leishmania major and L. (Viannia) braziliensis. A combined analysis, based on ligand and structure, and several other computational approaches were used. The results showed that the combined analysis was able to select 11 lignans with potential activity against L. major and 21 lignans against L. braziliensis, with multitargeting effects and low or no toxicity. Of these compounds, four were isolated from the species Justicia aequilabris (Nees) Lindau. All of the identified compounds were able to inhibit the growth of L. braziliensis promastigotes, with the most active compound, (159) epipinoresinol-4-O-ß-d-glucopyranoside, presenting an IC50 value of 5.39 µM and IC50 value of 36.51 µM for L. major. Our findings indicated the potential of computer-aided drug design and development and demonstrated that lignans represent promising prototype compounds for the development of multitarget drugs against leishmaniasis.

Computer-aided Drug Design Investigations for Benzothiazinone Derivatives Against Tuberculosis.

BACKGROUND: Tuberculosis (Mycobacterium tuberculosis) is an infectious bacterial disease with the highest levels of mortality worldwide, presenting numerous cases of resistance. In silico studies, which elaborate chemical and biological models in computational tools and make it possible to interpret molecular characteristics, are among the methods used in the search for new drugs. OBJECTIVE: In this perspective, our aim was to use QSAR and molecular modeling to propose possible pharmacophores from benzothiazinone derivatives. METHODS: In this study, a set of 69 benzothiazinone derivatives, together with computational tools such as molecular descriptor analysis in chemometrics, metabolic prediction, and molecular coupling to 4 proteins: DprE1, InhA, PS, and DHFR important for the bacillus were investigated. RESULTS: The chemometric model computed in the Volsurf+ program presented good predictive values for both amphiphilicity and molecular volume. These are essential for biological activity. Metabolites from the cytochrome isoforms CYP3A4 and 2D6 interactions revealed coupling divergences which, noting that the metabolites did not present changes to the QSAR proposed pharmacophore structures, may be due to the reaction medium and existing differences in the benzothiazinone structures. Similarly, molecular docking with the four TB enzymes presented good interactions for the more active compounds. The fragments found using QSAR (being essential for biological activity) also presented as being essential for ligand-protein site interactions. CONCLUSION: From the benzothiazinone derivative series evaluated, compound 11026134 presented the best profile in all study analyses, noting that the trifluoromethyl, nitro group, and piperazine fragment with aliphatic hydrocarbon groups are likely pharmacophores for the benzothiazinones studied.

In Silico Studies for Bacterystic Evaluation against Staphylococcus aureus of 2-Naphthoic Acid Analogues.

BACKGROUND: Staphylococcus aureus is a gram-positive spherical bacterium commonly present in nasal fossae and in the skin of healthy people; however, in high quantities, it can lead to complications that compromise health. The pathologies involved include simple infections, such as folliculitis, acne, and delay in the process of wound healing, as well as serious infections in the CNS, meninges, lung, heart, and other areas. AIM: This research aims to propose a series of molecules derived from 2-naphthoic acid as a bioactive in the fight against S. aureus bacteria through in silico studies using molecular modeling tools. METHODS: A virtual screening of analogues was done in consideration of the results that showed activity according to the prediction model performed in the KNIME Analytics Platform 3.6, violations of the Lipinski rule, absorption rate, cytotoxicity risks, energy of binder-receptor interaction through molecular docking, and the stability of the best profile ligands in the active site of the proteins used (PDB ID 4DXD and 4WVG). RESULTS: Seven of the 48 analogues analyzed showed promising results for bactericidal action against S. aureus. CONCLUSION: It is possible to conclude that ten of the 48 compounds derived from 2-naphthoic acid presented activity based on the prediction model generated, of which seven presented no toxicity and up to one violation to the Lipinski rule.

Identification of Essential 2D and 3D Chemical Features for Discovery of the Novel Tubulin Polymerization Inhibitors.

BACKGROUND: Tubulin polymerization inhibitors interfere with microtubule assembly and their functions lead to mitotic arrest, therefore they are attractive target for design and development of novel anticancer compounds. OBJECTIVE: The proposed novel and effective structures following the use of three-dimensionalquantitative structure activity relationship (3D-QSAR) pharmacophore based virtual screening clearly demonstrate the high efficiency of this method in modern drug discovery. METHODS: Combined computational approach was applied to extract the essential 2D and 3D features requirements for higher activity as well as identify new anti-tubulin agents. RESULTS: The best quantitative pharmacophore model, Hypo1, exhibited good correlation of 0.943 (RMSD=1.019) and excellent predictive power in the training set compounds. Generated model AHHHR, was well mapped to colchicine site and three-dimensional spatial arrangement of their features were in good agreement with the vital interactions in the active site. Total prediction accuracy (0.92 for training set and 0.86 for test set), enrichment factor (4.2 for training set and 4.5 for test set) and the area under the ROC curve (0.86 for training set and 0.94 for the test set), the developed model using Extended Class FingerPrints of maximum diameter 4 (ECFP_4) was chosen as the best model. CONCLUSION: Developed computational platform provided a better understanding of requirement features for colchicine site inhibitors and we believe the results of this study might be useful for the rational design and optimization of new inhibitors.

p-Cymene attenuates cancer pain via inhibitory pathways and modulation of calcium currents.

BACKGROUND: Oncological pain is one of the most prevalent and difficult-to-treat symptoms in patients with cancer. p-Cymene (PC) is a monoterpene found in more than 100 different plant species, endowed with various pharmacological properties-particularly antinociceptive. HYPOTHESIS/PURPOSE: PC has antinociceptive effect in a model of oncologic pain due to the activation of the descending inhibitory pathway of pain. STUDY DESIGN: A pre-clinical, longitudinal, blind and randomized study. METHODS: Male Swiss mice were induced with S180 cells in the right hind paw, then treated daily with PC (12.5, 25 and 50 mg/kg, s.c.) and screened for mechanical hyperalgesia, spontaneous nociception, nociception induced by non-noxious palpation, tumor growth, changes in the neuromuscular function and existence of bone degradation in the tumor area. The effect of PC on Ca2+ currents (electrophysiological records), histological and neurochemical changes (immunofluorescence for Fos) were also evaluated. RESULTS: PC reduced (p < 0.05) the mechanical hyperalgesia, the spontaneous (p < 0.001) and non-noxious palpation (p < 0.001) nociceptions, not changing the tumor development, neuromuscular function or histopathological aspects of the paw affected. PC reduced Fos expression in the spinal cord (p < 0.001) and increased this expression in the PAG (p < 0.05) and in the NRM (p < 0.01). PC decreased the density of calcium channel currents (p < 0.05). CONCLUSION: These results suggest the antinociceptive effect of PC on oncologic pain, probably acting in both ascending and descending pain pathways, and modulating the calcium channel currents in order to exert its effects.

Active Essential Oils and Their Components in Use against Neglected Diseases and Arboviruses.

The term neglected diseases refers to a group of infections caused by various classes of pathogens, including protozoa, viruses, bacteria, and helminths, most often affecting impoverished populations without adequate sanitation living in close contact with infectious vectors and domestic animals. The fact that these diseases were historically not considered priorities for pharmaceutical companies made the available treatments options obsolete, precarious, outdated, and in some cases nonexistent. The use of plants for medicinal, religious, and cosmetic purposes has a history dating back to the emergence of humanity. One of the principal fractions of chemical substances found in plants are essential oils (EOs). EOs consist of a mixture of volatile and hydrophobic secondary metabolites with marked odors, composed primarily of terpenes and phenylpropanoids. They have great commercial value and were widely used in traditional medicine, by phytotherapy practitioners, and in public health services for the treatment of several conditions, including neglected diseases. In addition to the recognized cytoprotective and antioxidative activities of many of these compounds, larvicidal, insecticidal, and antiparasitic activities have been associated with the induction of oxidative stress in parasites, increasing levels of nitric oxide in the infected host, reducing parasite resistance to reactive oxygen species, and increasing lipid peroxidation, ultimately leading to serious damage to cell membranes. The hydrophobicity of these compounds also allows them to cross the membranes of parasites as well as the blood-brain barrier, collaborating in combat at the second stage of several of these infections. Based on these considerations, the aim of this review was to present an update of the potential of EOs, their fractions, and their chemical constituents, against some neglected diseases, including American and African trypanosomiasis, leishmaniasis, and arboviruses, specially dengue.

Antiprotozoal investigation of 20 plant metabolites on Trypanosoma cruzi and Leishmania amazonensis amastigotes. Atalantoflavone alters the mitochondrial membrane potential.

The study aims to evaluate the antiprotozoal activities of 20 plant metabolites on Trypanosoma cruzi and Leishmania amazonensis amastigotes. Compounds 1-20 were obtained and identified by using chromatographic and spectroscopic techniques. The antiparasitic assays were performed on the intracellular form of T. cruzi and L. amazonensis using human leukaemic THP-1 cells as the host. The mechanism of action of the most active compounds was explored in silico by molecular docking using T. cruzi trypanothione reductase (TR) as a target, whereas the in vitro studies were performed by enzymatic assay using T. cruzi recombinant TR. In addition, the mitochondrial membrane potential was evaluated by flow cytometry. Two flavonoids, one triterpene and three acetogenins showed from high to moderate trypanocidal activities with IC50 values ranging 3.6-37.2 µm while three of the metabolites were moderately leishmanicidal. The molecular docking study revealed interactions between TR and the most trypanocidal compounds 1 (abyssinone IV) and 2 (atalantoflavone). In contrast, both showed no effect on TR in vitro. For the mitochondrial membrane potential assay, atalantoflavone (2) displayed a dose-dependent depolarization. On the basis of the aforementioned results, this compound's structure could be chemically explored in order to develop more potent trypanocidal derivatives.

Virtual Screening of Natural Products to Select Compounds with Potential Anticancer Activity.

Cancer is the main cause of death, so the search for active agents to be used in the therapy of this disease, is necessary. According to studies conducted, substances derived from natural products have shown to be promising in this endeavor. To these researches, one can associate with the aid of computational chemistry, which is increasingly gaining popularity, due to the possibility of developing alternative strategies that could help in choosing an appropriate set of compounds, avoiding unnecessary expenses with resources that would generate unwanted substance. Thus, the objective of this study was to carry out an approach to several studies that apply different methods of virtual screening to select natural products with potential anticancer activity. This review presents reports of studies conducted with some natural products, such as coumarin, quinone, tannins, alkaloids, flavonoids and terpenes.

Toxicological evaluation in silico and in vivo of secondary metabolites of Cissampelos sympodialis in Mus musculus mice following inhalation.

The ethanolic extract of the leaves of Cissampelos sympodialis showed great pharmacological potential, with inflammatory and immunomodulatory activities, however, it showed some toxicological effects. Therefore, this study aims to verify the toxicological potential of alkaloids of the genus Cissampelos through in silico methodologies, to develop a method in LC-MS/MS verifying the presence of alkaloids in the infusion and to evaluate the toxicity of the infusion of the leaves of C. sympodialis when inhaled by Swiss mice. Results in silico showed that alkaloid 93 presented high toxicological potential along with the products of its metabolism. LC-MS/MS results showed that the infusion of the leaves of this plant contained the alkaloids warifteine and methylwarifteine. Finally, the in vivo toxicological analysis of the C. sympodialis infusion showed results, both in biochemistry, organ weights and histological analysis, that the infusion of C. sympodialis leaves presents a low toxicity.

Virtual screening of secondary metabolites of the genus Solanum with potential antimicrobial activity

ABSTRACT Infectious diseases are a health problem today and have high mortality rates with a wide diversity of potentially pathogenic microorganisms. Research that is based either on the search for new drugs from plants or on the improvement of phytotherapeutics is prominent and continues to play an important role nowadays. From this perspective, use of in silico studies to carry out investigations of new molecules potentially active for methicillin-resistant Staphylococcus aureus and Escherichia coli using an in-house database with 421 different secondary metabolites selected from the literature from Solanum genus was performed. We also realized an in vitro study with strains of S. aureus and E. coli and compared the results. Two databases from ChEMBL were selected, the first one with activity against methicillin-resistant S. aureus and another against E. coli. The compounds were classified according to the pIC50 values to generate and validate the model using a "Random Forest". The "Random Forest" prediction model for methicillin-resistant S. aureus obtained an accuracy of 81%, area under the Receiver Operating Characteristic curve of 0.885, selecting eight molecules with an active potential above 60%. The prediction model for E. coli obtained an accuracy rate of 88%, area under the Receiver Operating Characteristic curve of 0.932, selecting four molecules with potential probability above 84%. Rutin proved to be potentially active in the in silico study for S. aureus and E. coli. Microbiological tests have shown that rutin has activity only for E. coli. An interaction study with strains of S. aureus ATCC 25923, a standard strain sensitive to all antibiotics, and SAM-01, a multidrug-resistant strain, was designed. There was interaction only between rutin and oxacillin, one of the three antibiotics studied in the interaction, for the strain SAM-01, reducing the resistance of this strain.