Lycopene supplementation promoted increased survival and decreased parasitemia in mice with severe malaria: comparison with N-acetylcysteine.

Oxidative stress is involved in the pathogenesis of malaria, causing anemia, respiratory complications, and cerebral malaria. To mitigate oxidative stress, we investigated the effect of nutritional supplementation whit lycopene (LYC) on the evolution of parasitemia and survival rate in mice infected with Plasmodium berghei ANKA (Pb), comparing to the effects promoted by N-acetylcysteine (NAC). Therefore, 175 mice were randomly distributed into 4 groups; Sham: untreated and uninfected animals; Pb: animals infected with Pb; LYC+Pb: animals treated with LYC and infected with Pb; NAC+Pb: animals treated with NAC and infected with Pb. The animals were followed for 12 days after infection, and survival and parasitemia rates were evaluated. There was a 40.1% increase in parasitemia in the animals of the Pb group on the 12th day, and a survival rate of 45%. LYC supplementation slowed the development of parasitemia to 19% and promoted a significative increase in the survival rate of 80% on the 12th day after infection, compared to the Pb group, effects superior to those promoted by NAC, providing strong evidence of the beneficial effect of LYC on in vivo malaria and stressing the importance of antioxidant supplementation in the treatment of this disease.

Anticancer Potential and Safety Profile of ß-Lapachone In Vitro.

Ipê is a plant of the Bignoniaceae family. Among the compounds extracted from this tree, lapachol is notable because its structural modification allows the production of ß-lapachone, which has anticancer properties. The objective of this work was to test this hypothesis at a cellular level in vitro and assess its potential safety for use. The following tests were performed: MTT cell viability assay, apoptotic index determination, comet assay, and micronucleus test. The results showed that ß-lapachone had a high cytotoxic capacity for all cell lines tested: ACP02 (gastric adenocarcinoma cells), MCF7 (breast carcinoma cells), HCT116 (colon cancer cells) and HEPG2 (hepatocellular carcinoma cells). Regarding genotoxicity, the exposure of cells to sublethal doses of ß-lapachone induced DNA damage (assessed by the comet assay) and nuclear abnormalities, such as nucleoplasmic bridges and nuclear buds (assessed by the micronucleus test). All tested cell lines responded similarly to ß-lapachone, except for ACP02 cells, which were relatively resistant to the cytotoxic effects of the compound in the MTT test. Our results collectively indicate that although ß-lapachone showed antiproliferative activity against cancer cell lines, it also caused harmful effects in these cells, suggesting that the use of ß-lapachone in treating cancer should be carried out with caution.

Participation of Oxidative Stress in the Activity of Compounds Isolated from Eleutherine plicata Herb.

From Eleutherine plicata, naphthoquinones, isoeleutherine, and eleutherol were isolated, and previous studies have reported the antioxidant activity of these metabolites. The present work evaluated the role of oxidative changes in mice infected with Plasmodium berghei and treated with E. plicata extract, fraction, and isolated compounds, as well as to verify possible oxidative changes induced by these treatments. E. plicata extracts were prepared from powder from the bulbs, which were submitted to maceration with ethanol, yielding the extract (EEEp), which was fractionated under reflux, and the dichloromethane fraction (FDMEp) was submitted for further fractionation, leading to the isolation of isoeleutherine, eleutherine, and eleutherol. The antimalarial activity was examined using the suppressive test, evaluating the following parameters of oxidative stress: trolox equivalent antioxidant capacity (TEAC), thiobarbituric acid reactive substances (TBARS), and reduced glutathione (GSH). Furthermore, the molecular docking of naphthoquinones, eleutherol, eleutherine, and isoeleutherine interactions with antioxidant defense enzymes was investigated, which was favorable for the formation of the receptor-ligand complex, according to the re-rank score values. Eleutherine and isoeleutherine are the ones with the lowest binding energy for catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GPx1), showing themselves as possible targets of these molecules in the involvement of redox balance. Data from the present study showed that treatments with E. plicata stimulated an increase in antioxidant capacity and a reduction in oxidative stress in mice infected with P. berghei, with naphthoquinones being responsible for reducing oxidative changes and disease severity.

Study of Genotoxicity, Activities on Caspase 8 and on the Stabilization of the Topoisomerase Complex of Isoeleutherin and Analogues.

This study evaluated the genotoxicity of Ethanol Extract (EEEp), Dichloromethane Fraction (FDCMEp) and isoeleutherin isolated from Eleutherine plicata, using the micronucleus test and the impact of structural alterations on toxicity and molecular docking (topoisomerase II and DNA complex). The extract was obtained by maceration and fractionation in a chromatography column. The genotoxicity was evaluated by the micronucleus test in human hepatoma cells (HepG2). Isoeleutherin was the starting molecule in the search for analogues by structural similarity, using the ZINC and e-Molecules databases. Isoeleutherin and analogues were subjected to in silico toxicity prediction, and compounds free of toxicological risks (CP13, CP14, CP17 and isoeleutherin) were selected for molecular docking in Topoisomerase II (PDB: 1ZXM). In the micronucleus test, isoeleutherin was less genotoxic. Among the 22 isoeleutherin analogues there were variations in the toxicity profile. Molecular docking studies showed that the compounds have good complementarity in the active site with important hydrogens bonds. Therefore, the structural changes of isoeleutherin led to the obtaining of a molecule with a lower mutagenic potential, and the CP13 can be considered a prototype compound for the development of new molecules with pharmacological potential.

Cytotoxicity and Genotoxicity Evaluation of Zanthoxylum rhoifolium Lam and In Silico Studies of Its Alkaloids.

The alkaloids isolated from Zanthoxylum rhoifolium have demonstrated great pharmacological potential; however, the toxic profiles of these extracts and fractions are still not well elucidated. This study evaluated the toxicity of the ethanol extract (EEZR) and neutral (FNZR) and alkaloid (FAZR) fractions. Chemical characterization was performed by chromatographic methods: thin-layer chromatography (TLC) and high-performance liquid chromatography coupled with diode array detection (HPLC-DAD). The cytotoxicity of the samples was evaluated in human hepatocellular carcinoma (HepG2) cells using the cell viability method (MTT) and mutagenicity by the Allium cepa assay (ACA). Alkaloids isolated from the species were selected for toxicity prediction using preADMET and PROTOX. The molecular docking of the topoisomerase II protein (TOPOII) was used to investigate the mechanism of cell damage. In the EEZR, FNZR, and FAZR, the presence of alkaloids was detected in TCL and HPLC-DAD analyses. These samples showed a 50% inhibitory concentration (IC50) greater than 400 µg/mL in HepG2 cells. In ACA, time- and concentration-dependent changes were observed, with a significant reduction in the mitotic index and an increase in chromosomal aberrations for all samples. Nuclear sprouts and a micronucleus of the positive control (PC) were observed at 10 µg/mL and in the FAZR at 30 µg/mL; a chromosomal bridge in FNZR was observed at 105 µg/mL, CP at a concentration of 40 µg/mL, and nuclear bud and mitotic abnormalities in the EEZR were observed at 170 µg/mL. The alkaloids with a benzophenanthridine were selected for the in silico study, as structural alterations demonstrated certain toxic effects. Molecular docking with topo II demonstrated that all alkaloids bind to the protein. In summary, the fractionation of Z. rhoifolium did not interfere with toxicity; it seems that alkaloids with a benzophenanthridine nucleus may be involved in this toxicity.

Oxidative Stress in Malaria: Potential Benefits of Antioxidant Therapy.

Malaria is an infectious disease and a serious public health problem in the world, with 3.3 billion people in endemic areas in 100 countries and about 200 million new cases each year, resulting in almost 1 million deaths in 2018. Although studies look for strategies to eradicate malaria, it is necessary to know more about its pathophysiology to understand the underlying mechanisms involved, particularly the redox balance, to guarantee success in combating this disease. In this review, we addressed the involvement of oxidative stress in malaria and the potential benefits of antioxidant supplementation as an adjuvant antimalarial therapy.

Evaluation of Genotoxicity and Toxicity of Annona muricata L. Seeds and In Silico Studies.

Cancer is a multifactorial organic dysfunction for which great efforts are being devoted in searching for new treatments and therapeutic adjuvants. Annona muricata is a fruit that has promising activity against several types of cancer, as it contains acetogenins, the metabolite group associated with this action. Thus, the objective of this study was to evaluate, in experimental models, the toxic behavior of an extract and fraction rich in acetogenins from A. muricata seeds and study the acetogenin, Annonacin, in silico. Phytochemical characterization was made by thin layer chromatography, spectroscopy in the infrared region and nuclear magnetic resonance. Toxicity was evaluated by tests of Allium cepa and Artemia salina, and in silico studies using the SwissDock servers DockThor, PharmMapper, ADMETLab, PreADME, Osiris and ProTox. The extract and fraction showed genotoxic activity against meristematic cells of A. cepa, reducing the mitotic index; however, the extract produced great deleterious effects on the system, even causing cell necrosis. In A. Saline, the extract was more toxic than the fraction, but both samples were considered toxic. Annonacin was effectively linked to complex I, and presented different activities regarding toxicity. Thus, the results of this study are promising, highlighting the anticancer potential of acetogenins.

Association of cerebral malaria and TNF-α levels: a systematic review.

BACKGROUND: Cerebral malaria is the most severe form of infection with Plasmodium falciparum characterized by a highly inflammatory response. This systematic review aimed to investigate the association between TNF-α levels and cerebral malaria. METHODS: This review followed the Preferred Reporting of Systematic Review and Meta-analyses (PRISMA) guidelines. The search was performed at PubMed, LILACS, Scopus, Web of Science, The Cochrane Library, OpenGrey and Google Scholar. We have included studies of P. falciparum-infected humans with or without cerebral malaria and TNF-α dosage level. All studies were evaluated using a risk of bias tool and the GRADE approach. RESULTS: Our results have identified 2338 studies, and 8 articles were eligible according to this systematic review inclusion criteria. Among the eight articles, five have evaluated TNF- α plasma dosage, while two have evaluated at the blood and one at the brain (post-Morten). Among them, only five studies showed higher TNF-α levels in the cerebral malaria group compared to the severe malaria group. Methodological problems were identified regarding sample size, randomization and blindness, but no risk of bias was detected. CONCLUSION: Although the results suggested that that TNF-α level is associated with cerebral malaria, the evidence is inconsistent and imprecise. More observational studies evaluating the average TNF-alpha are needed.

Flavopereirine-An Alkaloid Derived from Geissospermum vellosii-Presents Leishmanicidal Activity In Vitro.

Chemotherapy is limited in the treatment of leishmaniasis due to the toxic effects of drugs, low efficacy of alternative treatments, and resistance of the parasite. This work assesses the in vitro activity of flavopereirine on promastigote cultures of Leishmania amazonensis. In addition, an in silico evaluation of the physicochemical characteristics of this alkaloid is performed. The extract and fractions were characterized by thin-layer chromatography and HPLC-DAD, yielding an alkaloid identified by NMR. The antileishmanial activity and cytotoxicity were assayed by cell viability test (MTT). The theoretical molecular properties were calculated on the Molinspiration website. The fractionation made it possible to isolate a beta-carboline alkaloid (flavopereirine) in the alkaloid fraction. Moreover, it led to obtaining a fraction with greater antileishmanial activity, since flavopereirine is very active. Regarding the exposure time, a greater inhibitory effect of flavopereirine was observed at 24 h and 72 h (IC50 of 0.23 and 0.15 µg/mL, respectively). The extract, fractions, and flavopereirine presented low toxicity, with high selectivity for the alkaloid. Furthermore, flavopereirine showed no violation of Lipinski's rule of five, showing even better results than the known inhibitor of oligopeptidase B, antipain, with three violations. Flavopereirine also interacted with residue Tyr-499 of oligopeptidase B during the molecular dynamics simulations, giving a few insights of a possible favorable mechanism of interaction and a possible inhibitory pathway. Flavopereirine proved to be a promising molecule for its antileishmanial activity.

Leishmania amazonensis and Leishmania chagasi: In vitro leishmanicide activity of Virola surinamensis (rol.) warb.

Virola species have been used in traditional medicine as healing in skin infections. From V. surinanensis oil were isolated several sesquiterpene as the nerolidol which showed activity against species of Leishmania. The current study aimed to evaluate the leishmanicide activity and toxicity of extracts, fractions and surinamesin obtained from leaves of Virola surinamensis. Hexane, Ethyl Acetate, and Methanol extracts were obtained from powder of dry leaves of V. surinamensis. The hexane and ethyl acetate extracts were fractionated by silica gel column chromatography and increasingly polar gradient. The viability of L. chagasi and L. amazonensis promastigotes was assessed by tetrazolium salt assay (MTT). Peritoneal macrophages were exposed to L. amazonensis promastigotes. The treatment was performed with the extracts for 24 h. Then, the coverslips were stained and the infection index was determined. Cytotoxicity was determined in macrophage cells by peritoneum viability assay (MTT). The selectivity index was calculated as the product of cytotoxic concentration 50% and inhibitory concentration 50%. The hexane extract showed leishmanicide activity in promastigotes. The ethyl acetate, methanol extracts and fractions (C1-C6), were inactive against promastigote form of L. chagasi and L. amzazonensis. None extract showed effect on L. amazonensis amastigotes. All samples tested showed low cytotoxicity (CC50 > 500 µg/mL). The selectivity index of the hexane extract was greater than 5. The hexane extract of V. surinamensis was active against L. chagasi and L. amazonensis promastigotes. The extract fractionation did not increase significantly its antipromastigote activity. The surinamensin is probably not responsible for the activity. The extracts were inactive against amastigotes of L. amazonensis.

Oxidative Stress in Alzheimer's Disease: Should We Keep Trying Antioxidant Therapies?

The risk of chronic diseases such as Alzheimer's disease is growing as a result of the continuous increasing average life span of the world population, a syndrome characterized by the presence of intraneural neurofibrillary tangles and senile plaques composed mainly by beta-amyloid protein, changes that may cause a number of progressive disorders in the elderly, causing, in its most advanced stage, difficulty in performing normal daily activities, among other manifestations. Therefore, it is important to understand the underlying pathogenic mechanisms of this syndrome. Nevertheless, despite intensive effort to access the physiopathological pathways of the disease, it remains poorly understood. In that context, some hypotheses have arisen, including the recent oxidative stress hypothesis, theory supported by the involvement of oxidative stress in aging, and the vulnerability of neurons to oxidative attack. In the present revision, oxidative changes and redox mechanisms in Alzheimer's disease will be further stressed, as well as the grounds for antioxidant supplementation as adjuvant therapy for the disease will be addressed.

Aspidosperma species as sources of anti-malarials: uleine is the major anti-malarial indole alkaloid from Aspidosperma parvifolium (Apocynaceae).

BACKGROUND: Several species of the genus Aspidosperma (Apocynaceae) are used for the treatment of human malaria in Brazil and other meso- and South American countries. METHODS: Ethanol extract from Aspidosperma parvifolium trunk bark was submitted to acid-base extractions leading to alkaloid and neutral fractions. The alkaloid fraction was chromatographed over a silica gel column. Ethanol extract, fractions and uleine were analysed by HPLC-DAD, UPLC-ESI-MS/MS and HPLC-ESI-MicroTOF-MS. The anti-malarial activity was assayed against resistant and sensitive chloroquine Plasmodium falciparum strains by microscopic, [(3)H]-hypoxanthine incorporation and HRPII techniques. Cytotoxicity (CC50) was evaluated against Vero and HepG2 cell lines by the MTT technique; selectivity indexes (SI = CC50/IC50) were calculated. RESULTS: The major peak in the HPLC-DAD chromatograms of the ethanol extract, alkaloid and neutral fractions suggested the presence of uleine that was isolated from the alkaloid fraction by column chromatography and was characterized by spectroscopic methods. A total of 15 alkaloids, besides uleine, were identified in the alkaloid fraction by UPLC-DAD-ESI-MS/MS and HPLC-ESI-MicroTOF-MS. The ethanol extract from Aspidosperma parvifolium and the neutral fraction were moderately active against P. falciparum strains. The alkaloid fraction and uleine disclosed high anti-malarial activity against chloroquine-resistant P. falciparum strain (IC50 < 1 µg/mL). The ethanol extract, neutral fraction and uleine showed low cytotoxicity against Vero and HepG2 cell lines (CC50 > 300 µg/mL). The alkaloid fraction showed moderate cytotoxicity to HepG2 cell line (CC50 = 74.4 µg/mL). High SI values (>10) were determined for all samples. CONCLUSION: Ethanol extract from Aspidosperma parvifolium trunk bark afforded uleine that is the major constituent of the alkaloid fraction and disclosed a good in vitro anti-malarial activity. Moreover, 15 other indole alkaloids have been identified along with uleine.

Anti-malarial activity and toxicity assessment of Himatanthus articulatus, a plant used to treat malaria in the Brazilian Amazon.

BACKGROUND: Plasmodium falciparum has become resistant to some of the available drugs. Several plant species are used for the treatment of malaria, such as Himatanthus articulatus in parts of Brazil. The present paper reports the phyto-chemistry, the anti-plasmodial and anti-malarial activity, as well as the toxicity of H. articulatus. METHODS: Ethanol and dichloromethane extracts were obtained from the powder of stem barks of H. articulatus and later fractionated and analysed. The anti-plasmodial activity was assessed against a chloroquine resistant strain P. falciparum (W2) in vitro, whilst in vivo anti-malarial activity against Plasmodium berghei (ANKA strain) was tested in mice, evaluating the role of oxidative stress (total antioxidant capacity--TEAC; lipid peroxidation--TBARS, and nitrites and nitrates--NN). In addition, cytotoxicity was evaluated using the HepG2 A16 cell-line. The acute oral and sub-chronic toxicity of the ethanol extract were evaluated in both male and female mice. RESULTS: Plumieride was isolated from the ethyl acetate fraction of ethanol extract, Only the dichloromethane extract was active against clone W2. Nevertheless, both extracts reduced parasitaemia in P. berghei-infected mice. Besides, a significant reduction in pulmonary and cerebral levels of NN (nitrites and nitrates) was found, as well as in pulmonary TBARS, indicating a reduced oxidative damage to these organs. The ethanol extract showed low cytotoxicity to HepG2 A16 cells in the concentrations used. No significant changes were observed in the in vivo toxicity studies. CONCLUSIONS: The ethanol extract of H. articulatus proved to be promising as anti-malarial medicine and showed low toxicity.

N-acetyl cysteine and mushroom Agaricus sylvaticus supplementation decreased parasitaemia and pulmonary oxidative stress in a mice model of malaria.

BACKGROUND: Malaria infection can cause high oxidative stress, which could lead to the development of severe forms of malaria, such as pulmonary malaria. In recent years, the role of reactive oxygen species in the pathogenesis of the disease has been discussed, as well as the potential benefit of antioxidants supplementation. The aim of this study was to investigate the effects of N-acetyl cysteine (NAC) or mushroom Agaricus sylvaticus supplementation on the pulmonary oxidative changes in an experimental model of malaria caused by Plasmodium berghei strain ANKA. METHODS: Swiss male mice were infected with P. berghei and treated with NAC or AS. Samples of lung tissue and whole blood were collected after one, three, five, seven or ten days of infection for the assessment of thiobarbituric acid reactive substances (TBARS), trolox equivalent antioxidant capacity (TEAC), nitrites and nitrates (NN) and to assess the degree of parasitaemia. RESULTS: Although parasitaemia increased progressively with the evolution of the disease in all infected groups, there was a significant decrease from the seventh to the tenth day of infection in both antioxidant-supplemented groups. Results showed significant higher levels of TEAC in both supplemented groups, the highest occurring in the group supplemented with A. sylvaticus. In parallel, TBARS showed similar levels among all groups, while levels of NN were higher in animals supplemented with NAC in relation to the positive control groups and A. sylvaticus, whose levels were similar to the negative control group. CONCLUSION: Oxidative stress arising from plasmodial infection was attenuated by supplementation of both antioxidants, but A. sylvaticus proved to be more effective and has the potential to become an important tool in the adjuvant therapy of malaria.

Aspidosperma species as sources of antimalarials. Part III. A review of traditional use and antimalarial activity.

Several plant species belonging to the genus Aspidosperma are traditionally used in Brazil and other Meso- and South American countries for the treatment of malaria and fevers. These traditional uses were motivation for this review. A literature survey completed for this review has identified scientific bibliographical references to the use of 24 Aspidosperma species to treat malaria/fevers and to 19 species that have had their extracts and/or alkaloids evaluated, with good results, for in vitro and/or in vivo antimalarial activity. Indole alkaloids are typical constituents of Aspidosperma species. However, only 20 out of more than 200 known indole alkaloids isolated from this genus have been assayed for antimalarial activity. These data support the potential of Aspidosperma species as sources of antimalarials and the importance of research aimed at validating their use in the treatment of human malaria.

Nutritional supplementation with the mushroom Agaricus sylvaticus reduces oxidative stress in children with HIV.

BACKGROUND: The involvement of free radicals and oxidative stress in HIV infection has been extensively studied, and the benefits of antioxidant supplementation in animal studies have been demonstrated. However, few studies have demonstrated a benefit in clinical studies. OBJECTIVE: To verify the effects of dietary supplementation with Agaricus sylvaticus, a mushroom rich in antioxidants, on the oxidative profile of children born with HIV undergoing antiretroviral therapy. DESIGN: The sample included 24 children (both boys and girls) between two and eight years of age, of whom 10 were HIV positive and received supplementation with Agaricus sylvaticus for a three-month period, and 14 were HIV negative and received no supplementation. At the beginning and conclusion of the study, thiobarbituric acid-reactive substances (TBARS), nitrite and nitrate (NN), Trolox equivalent antioxidant capacity, and the antioxidant capacity of inhibition of diphenyl-picrilhidrazil (DPPH) free radicals were analyzed. RESULTS: Before supplementation, significantly higher values of TBARS and NN, but decreased values of DPPH, were observed in infected subjects when compared with HIV-negative subjects. After supplementation, a reduction of TBARS and NN values and an increase in DPPH and Trolox equivalent antioxidant capacity values were observed in HIV-positive subjects. CONCLUSIONS: The results of the present study suggest the involvement of oxidative stress in HIV infection, with the participation of NN synthesis. Additionally, supplementation reversed oxidative alterations and improved antioxidant defense in infected individuals, and may become a complementary strategy in the treatment of these patients.

HISTORIQUE: L'activité des radicaux libres et du stress oxydatif dans l'infection par le VIH a fait l'objet de nombreuses études, et les bienfaits des suppléments d'antioxydants ont été démontrés dans des études sur des animaux. Cependant, peu d'études en ont confirmé les avantages dans des études cliniques. OBJECTIF: Vérifier les effets de suppléments alimentaires contenant de l'Agaricus sylvaticus, un champignon riche en antioxydants, sur le profil oxydatif des enfants nés avec le VIH sous thérapie antirétrovirale. MÉTHODOLOGIE: L'échantillon se composait de 24 enfants (garçons et filles) de deux à huit ans, dont dix étaient positifs au VIH et ont reçu des suppléments d'Agaricus sylvaticus pendant trois mois, et 14 étaient négatifs au VIH est n'ont pas reçu de suppléments. Au début et à la fin de l'étude, les chercheurs ont analysé les substances réactives à l'acide thio-barbiturique (SRATB), les nitrites et les nitrates (NN), la capacité antioxydante en équivalent Trolox et la capacité antioxydante de l'inhibition des radicaux libres diphényl-picrylhydrazyl (DPPH). RÉSULTATS: Avant la prise de suppléments, les sujets infectés présentaient des valeurs considérablement plus élevées de SRATB et de NN, mais plus faibles de DPPH, que les sujets négatifs au VIH. Après la prise de suppléments, les valeurs de SRATB et de NN diminuaient tandis que celles de DPPH et de la capacité antioxydante en équivalent Trolox augmentaient chez les sujets positifs au VIH. CONCLUSIONS: D'après les résultats de la présente étude, le stress oxydatif est actif dans l'infection par le VIH, avec la participation de la synthèse des NN. De plus, des suppléments renversaient les altérations oxydatives et accroissaient la défense assurée par les antioxydants chez les sujets infectés. De tels suppléments pourraient devenir une stratégie complémentaire au traitement.

Linezolid and vancomycin for nosocomial infections in pediatric patients: a systematic review.

OBJECTIVE: To investigate the effectiveness of linezolid and vancomycin for the treatment of nosocomial infections in children under 12 years old. DATA SOURCES: This is a systematic review in which five randomized clinical trials about the effectiveness of linezolid and vancomycin, involving a total of 429 children with nosocomial infections, were evaluated. They were searched in scientific databases: PubMed, Bvs, and SciELO. SUMMARY OF FINDINGS: The main nosocomial infections that affected children were bacteremia, skin, and soft tissue infections followed by nosocomial pneumonia. Most infections were caused by Gram-positive bacteria, which all studies showed infections caused by Staphylococcus aureus, with methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci strains being isolated. Both linezolid and vancomycin showed high therapeutic efficacy against different types of nosocomial infections, ranging from 84.4% to 94% for linezolid and 76.9% to 90% for vancomycin. Patients receiving linezolid had lower rates of rash and red man syndrome compared to those receiving vancomycin. However, despite the adverse reactions, antimicrobials can be safely administered to children to treat nosocomial infections caused by resistant Gram-positive bacteria. CONCLUSION: Both linezolid and vancomycin showed good efficacy in the treatment of bacterial infections caused by resistant Gram-positive bacteria in hospitalized children. However, linezolid stands out regarding its pharmacological safety. Importantly, to strengthen this conclusion, further clinical trials are needed to provide additional evidence.

Anti-leishmanial activity of Eleutherine plicata Herb. and predictions of isoeleutherin and its analogues.

Introduction: Leishmaniasis is caused by protozoa of the genus Leishmania, classified as tegumentary and visceral. The disease treatment is still a serious problem, due to the toxic effects of available drugs, the costly treatment and reports of parasitic resistance, making the search for therapeutic alternatives urgent. This study assessed the in vitro anti-leishmanial potential of the extract, fractions, and isoeleutherin from Eleutherine plicata, as well as the in silico interactions of isoeleutherin and its analogs with Trypanothione Reductase (TR), in addition to predicting pharmacokinetic parameters. Methods: From the ethanolic extract of E. plicata (EEEp) the dichloromethane fraction (FDEp) was obtained, and isoeleutherin isolated. All samples were tested against promastigotes, and parasite viability was evaluated. Isoeleutherin analogues were selected based on similarity in databases (ZINK and eMolecules) to verify the impact on structural change. Results and Discussion: The extract and its fractions were not active against the promastigote form (IC50 > 200 µg/mL), while isoeleutherin was active (IC50 = 25 µg/mL). All analogues have high intestinal absorption (HIA), cell permeability was moderate in Caco2 and low to moderate in MDCK. Structural changes interfered with plasma protein binding and blood-brain barrier permeability. Regarding metabolism, all molecules appear to be CYP3A4 metabolized and inhibited 2-3 CYPs. Molecular docking and molecular dynamics assessed the interactions between the most stable configurations of isoeleutherin, analogue compound 17, and quinacrine (control drug). Molecular dynamics simulations demonstrated stability and favorable interactions with TR. In summary, fractionation contributed to antileishmanial activity and isoleutherin seems to be promising. Structural alterations did not contribute to improve pharmacokinetic aspects and analogue 17 proved to be more promising than isoeleutherin, presenting better stabilization in TR.

The Potential of DHA as Cancer Therapy Strategies: A Narrative Review of In Vitro Cytotoxicity Trials.

Docosahexaenoic acid (DHA), also known as omega-3 (n-3) polyunsaturated fatty acid (PUFA), is a natural compound that has demonstrated pharmacological activity against several malignant neoplasms. Available cancer treatments cause side effects, affect healthy cells, reduce the quality of life of patients and may cause resistance to antineoplastics. For these reasons, the search for new therapies is continuous. This narrative review aimed to compile information on in vitro experiments that study the cytotoxic effect of DHA or molecules derived from DHA in tumor and nontumor cells. This was performed to highlight the potential of DHA as a strategy for cancer therapy and to gather information, which will help researchers plan experimental designs and develop research to discover effective therapies against cancer. In addition, studies were presented that demonstrate the dose of DHA that can treat patients with cancer. Thus, a search was conducted for articles on the SCOPUS and Web of Science platforms, published until 2022, that analyzed the action of DHA against breast, lung, colorectal, prostate, stomach and liver cancers. Cytotoxic effects were observed in tumor and nontumor cell lines, and these results varied with the type of cell line studied, drug concentration, incubation time and treatment combination, i.e., with DHA alone, combined with other drugs and with molecules derived from DHA. In patients with cancer, in all analyzed studies, DHA intake was associated with eicosapentaenoic acid (EPA) and/or proteins to aid chemotherapy, and with this procedure, tumor reduction, chemotherapy tolerance and muscle mass gain were obtained. This work contributes to the community by demonstrating the possible applicability of DHA in the pharmaceutical area of oncological therapies.

In silico studies on cytotoxicity and antitumoral activity of acetogenins from Annona muricata L.

As life expectancy increases, the number of people affected by cancer is increasing. The available drugs still cause several adverse reactions, and it is important to look for less toxic drugs that act on resistant cancers. The present study evaluated the antitumor potential of acetogenins. Through a literature review, 44 acetogenins isolated from Annona muricata were selected and subjected to in silico studies to predict the physicochemical properties, pharmacokinetics (Preadmet and Admet lab), toxicity (Preadmet and Protox II) and molecular docking in caspase 3 (DockThor). For muricatacin, a literature review was carried out for antitumor activity and cytotoxicity. Only muricatacin met all physicochemical criteria, while all compounds showed high cutaneous and intestinal absorption (HIA), moderate permeability in Madin-Darby canine kidney and Caco2 cells, strongly bound plasma proteins, freely crossed the blood-brain barrier, inhibited CYP2C19, CYP2C9 and CYP3A4 and have an affinity for CYP3A4, being metabolized by it, an undesirable characteristic for antitumor drugs. All compounds were toxic in at least one model, while compound 28 was not carcinogenic in rats and mice. Compounds 13, 14, 15, 16, 17 and 28 were selected for molecular docking into Caspase 3. Docking showed hydrophobic interactions, hydrogen and covalent bonds performed to maintain the stability of caspase 3, and cis-uvariamicin IV stood out more through the energies and chemical bonds of this parameter. The chloroform fraction from the methanolic extract of the seeds showed activity against triple-negative breast cancer, both in vitro and in vivo, and only muricatacin has studies in which the antitumor activity was evaluated in vitro and showed to be very promising. In summary, muricatacin and cis-uvariamicin IV appear to be very promising as antitumors, especially cis-uvariamicin IV.