Potential of Ocotea indecora (Schott) Mez essential oil nanoemulsion in schistosomiasis control: Molluscicidal effects.

Schistosomiasis is a neglected disease transmitted through contaminated water in populations with low basic sanitation. The World Health Organization recommends controlling the intermediate host snails of the Biomphalaria genus with the molluscicide niclosamide. This work aims to evaluate the biocidal potential of the nanoemulsion prepared with the essential oil of Ocotea indecora leaves for the control of the mollusk Biomphalaria glabrata, intermediate host of the Schistosoma mansoni, the etiologic agent of schistosomiasis.

Pyrones isolated from Annona acutiflora exhibit promising cytotoxic effects on cancer cell lines.

This work discusses the ongoing challenge of cancer, focusing on therapy issues such as chemotherapy resistance and adverse drug effects. It emphasizes the need for new anticancer agents with improved efficacy and fewer side effects, exploring natural products from plant sources. The Annonaceae family, specifically the Annona genus, is highlighted for its medicinal properties, including anti-inflammatory and anticancer effects. The study focuses on the isolation and elucidation of the substances present in Annona acutiflora leaves. The methodology involves chromatographic and spectroscopy techniques. The isolated compounds, (6S)-5'-oxohepten-1'E,3'E-dienyl)-5,6-dihydro-2H-pyran-2-one (1), (6R)-5'-oxohepten-1'Z,3'E-dienyl)-5,6-dihydro-2H-pyran-2-one (2) and (6R)-5'-oxohepten-1'Z,3'E-dienyl)-5,6-dihydro-2H-pyran-2-one (3) were investigated for cytotoxicity assays on cancer cell lines and normal cells. Results show promising cytotoxic activity, particularly with compound 3, demonstrating potential activity against oral cancer (43.18µM), hepatocarcinoma (17.24µM), melanoma (5.39µM), and colon cancer (59.03µM). The compound outperforms carboplatin in selectivity against oral cancer (S.I. 2.15) and melanoma (S.I. 17.22). The study concludes by suggesting the potential of these α-pyrones as effective and less toxic alternatives for cancer therapy.

Brazilian Green Propolis' Artepillin C and Its Acetylated Derivative Activate the NGF-Signaling Pathways and Induce Neurite Outgrowth in NGF-Deprived PC12 Cells.

Artepillin C is the most studied compound in Brazilian Green Propolis and, along with its acetylated derivative, displays neurotrophic activity on PC12 cells. Specific inhibitors of the trkA receptor (K252a), PI3K/Akt (LY294002), and MAPK/ERK (U0126) signaling pathways were used to investigate the neurotrophic mechanism. The expression of proteins involved in axonal and synaptic plasticity (GAP-43 and Synapsin I) was assessed by western blotting. Additionally, physicochemical properties, pharmacokinetics, and drug-likeness were evaluated by the SwissADME web tool. Both compounds induced neurite outgrowth by activating the NGF-signaling pathways but through different neuronal proteins. Furthermore, in silico analyses showed interesting physicochemical and pharmacokinetic properties of these compounds. Therefore, these compounds could play an important role in axonal and synaptic plasticity and should be further investigated.

Characterization and Inhibitory Effects of Essential Oil and Nanoemulsion from Ocotea indecora (Shott) Mez in Aspergillus Species.

The Aspergillus genus, the etiological agent of aspergillosis, is an important food contaminant and mycotoxin producer. Plant extracts and essential oils are a source of bioactive substances with antimicrobial potential that can be used instead of synthetic food preservatives. Species from the Lauraceae family and the Ocotea genus have been used as traditional medicinal herbs. Their essential oils can be nanoemulsified to enhance their stability and bioavailability and increase their use. Therefore, this study sought to prepare and characterize both nanoemulsion and essential oil from the Ocotea indecora's leaves, a native and endemic species from the Mata Atlântica forest in Brazil, and evaluate the activity against Aspergillus flavus RC 2054, Aspergillus parasiticus NRRL 2999, and Aspergillus westerdjikiae NRRL 3174. The products were added to Sabouraud Dextrose Agar at concentrations of 256, 512, 1024, 2048, and 4096 µg/mL. The strains were inoculated and incubated for up to 96 h with two daily measurements. The results did not show fungicidal activity under these conditions. A fungistatic effect, however, was observed. The nanoemulsion decreased the fungistatic concentration of the essential oil more than ten times, mainly in A. westerdjikiae. There were no significant changes in aflatoxin production.

Molluscicidal and Cercaricidal Effects of Myrciaria floribunda Essential Oil Nanoemulsion.

Schistosomiasis is a tropical disease transmitted in an aqueous environment by cercariae from the Schistosoma genus. This disease affects 200 million people living in risk areas around the world. The control of schistosomiasis is realized by chemotherapy, wastewater sanitation, health education, and mollusk control using molluscicidal agents. This work evaluates the effects of a nanoemulsion containing essential oil from Myrciaria floribunda leaves as a molluscicidal and cercaricidal agent against Biomphalaria glabrata mollusks and Schistosoma mansoni cercariae. The Myrciaria floribunda essential oil from leaves showed nerolidol, ß-selinene, 1,8 cineol, and zonarene as major constituents. The formulation study suggested the F3 formulation as the most promising nanoemulsion with polysorbate 20 and sorbitan monooleate 80 (4:1) with 5% (w/w) essential oil as it showed a smaller droplet size of approximately 100 nm with a PDI lower than 0.3 and prominent bluish reflection. Furthermore, this nanoemulsion showed stability after 200 days under refrigeration. The Myrciaria floribunda nanoemulsion showed LC50 values of 48.11 µg/mL, 29.66 µg/mL, and 47.02 µg/mL in Biomphalaria glabrata embryos, juveniles, and adult mollusks, respectively, after 48 h and 83.88 µg/mL for Schistosoma mansoni cercariae after 2 h. In addition, a survival of 80% was observed in Danio rerio, and the in silico toxicity assay showed lower overall human toxicity potential to the major compounds in the essential oil compared to the reference molluscicide niclosamide. These results suggest that the nanoemulsion of Myrciaria floribunda leaves may be a promising alternative for schistosomiasis control.

In vitro comparison between antimicrobial and antibiofilm effects of Green Propolis and Baccharis dracunculifolia against Staphylococcus pseudintermedius isolate.

Staphylococcus pseudintermedius is the leading cause of canine pyoderma. Honeybee products are common to treat this and other types of infections. High average annual population loss of bees has been observed. This study evaluated antibacterial and antibiofilm profile of Green Propolis and Baccharis dracunculifolia against S. pseudintermedius and the chemical similarities among both. Ethanolic extracts were produced and chemically characterized. The isolates were subjected to treatment with the extracts in both planktonic and sessile forms. Green propolis minimum inhibitory concentration (MIC) was 0.156 mg / mL, and minimum bactericidal concentration (MBC) was 0.312mg / mL. Baccharis dracunculifolia extract MIC and MBC was 0.312mg / mL and 2.5 mg / mL, respectivelly. Both extracts reduced SD55 formation of biofilm at minimum inhibitory concentration and at 1/8 minimum inhibitory concentration. The results observed in relation to ED99, were similar for both extracts. Besides that, similar chemical indicators between both extracts, including the presence of Artepellin C, suggest that the Baccharis dracunculifolia extract could be an alternative to the Green Propolis extract in the treatment of staph infections.

Myrciaria Genus: Bioactive Compounds and Biological Activities.

The Myrtaceae family is of angiosperms, imposing its size and economic, cultural, and scientific importance. The genus Myrciaria, belonging to this family, has 33 species currently accepted, many of which are research targets aimed at elucidating their bioactive compounds and biological activities. Most species of the Myrciaria genus have terpenes in their composition, mainly mono and sesquiterpenes, and phenolic compounds such as tannins, phenolic acids, and flavonoids. Other secondary metabolites are also observed, such as alkaloids, steroids, coumarins, saponins, and naphthoquinones. These bioactive compounds are closely related to these species' most diverse biological activities: antioxidant, anti-inflammatory, analgesic, antiproliferative, antimicrobial, antiparasitic, insecticide, metabolic, protective, and nutraceutical. This work aims to provide a review of secondary metabolites and medicinal properties related to the genus Myrciaria, thus stimulating further studies on the species of this genus.

Repellency effect of Pilocarpus spicatus A. St.-Hil essential oil and nanoemulsion against Rhipicephalus microplus larvae.

Rhipicephalus microplus, the cattle tick, is a major cause of economic losses in bovine production. Due to the widespread acaricidal resistance to commercially available products, as well as their toxicity and environmental impact, alternative control methods are required. Nanoformulations produced from plant extracts as bioactive substances are very promising as innovative acaricidal agents. Thus, the aim of this study was to evaluate the in vitro repellent activity of Pilocarpus spicatus essential oil and its nanoemulsion against R. microplus, using larval repellent test (RT). The essential oil was extracted by hydrodistillation, using a Clevenger-type apparatus. The nanoemulsion was prepared with 5% essential oil, 5% tween 80, and 90% water, using the phase inversion method (50 mg/mL). Limonene was the major component (46.8%) of the essential oil, as determined by gas chromatography-mass spectrometry (GC/MS) and confirmed by flame ionization detection (GC/FID). According to the RT results, the essential oil had a repellent activity greater than 69%, from concentrations of 3.12 mg/mL (69.81 ± 10%) to 50 mg/mL (98.10 ± 0.6%), whereas the nanoemulsion at 50 mg/mL presented repellent activities of 97.14 ± 1.37% and 97.89 ± 0.52% 6 and 10 h after treatment, respectively. These values regarding to total repellency were very close to those calculated for mortality corrected by Abbott's formula. The phase inversion method preserved the chemical and physical characteristics of the essential oil since both reached an equal repellent effect at the same concentration. Therefore, P. spicatus essential oil and nanoemulsion had excellent repellent activities against R. microplus larvae, demonstrating its potential for future use as an alternative for tick control.

Anti-Leishmania amazonensis activity of the terpenoid fraction from Eugenia pruniformis leaves.

Leishmaniasis is caused by protozoan parasites belonging to the genus Leishmania and includes cutaneous, mucocutaneous and visceral clinical forms. Drugs currently available for leishmaniasis treatment present high toxicity, and development of parasite resistance. Plants constitute an important source of compounds with leishmanicidal potential. This study aimed to evaluate the anti-Leishmania amazonensis activity of the terpenoid fraction of Eugenia pruniformis leaves (TF-EpL). TF-EpL was active against the promastigote and intracellular amastigote forms of L. amazonensis with IC50(24h) value of 43.60µg/mL and 44.77µg/mL, respectively. TF-EpL altered the cell cycle of the parasite, increasing 2.32-fold the cells in the Sub-G0/G1 phase. TF-EpL also changed the ΔΨm and increased ROS and the number of annexin-V-PI positive promastigotes, which suggests incidental death. ß-sitosterol, ursolic acid, corosolic acid and asiatic acid were isolated from TF-EpL. The results showed the antileishmanial activity of E. pruniformis terpenoids and its potential for further studies as a source of new drugs for leishmaniasis.

Nanoemulsion containing essential oil from Xylopia ochrantha Mart. produces molluscicidal effects against different species of Biomphalaria (Schistosoma hosts).

BACKGROUND: This work describes a chemical study of the essential oil from leaves of Xylopia ochrantha, an endemic Annonaceae species from Brazil, and its activity against Biomphalaria species. Considering its poor solubility in aqueous medium, the essential oil was nanoemulsified to evaluate its action on controlling some mollusc species of genus Biomphalaria, snail hosts of Schistosoma mansoni that causes schistosomiasis, which mainly affects tropical and subtropical countries. OBJECTIVES: The main aims of this work were to analyse the chemical composition of essential oil from X. ochrantha, and to evaluate the effect of its nanoemulsion on molluscs of genus Biomphalaria and their oviposition. METHODS: Chemical analysis was performed by gas chromatography coupled to mass spectrometry. Nanoemulsions were prepared by a low energy method and characterised by particle size and polydispersity index. Biological assays evaluating the mortality of adult species of B. glabrata, B. straminea and B. tenagophila and their ovipositions upon contact with the most stable nanoemulsion during 24 and 48 h were performed. FINDINGS: Chemical analysis by mass spectrometry revealed the majority presence of bicyclogermacrene and germacrene D in the essential oil. The formulation with a hydrophilic-lipophilic balance (HLB) of 9.26 was the most suitable for the oil delivery system. This nanoemulsion caused the mortality in B. tenagophila, B. straminea and B. glabarata of different sizes at levels ranging from 50 to 100% in 48 h. Additionally, the formulation could inhibit the development of deposited eggs. CONCLUSION: Thus, these results suggest the use of nanoemulsified essential oil from X. ochrantha as a possible alternative in controlling some Biomphalaria species involved in the schistosomiasis cycle.

Exploring the Insecticide and Acaricide Potential of Development Regulators obtained from Restinga vegetation from Brazil.

As a part of our continuing search for insect and arthropod development regulators from Brazilian restinga vegetation of the Rio de Janeiro State, crude extracts, purified fractions and essential oils were submitted to screening tests seeking for biological activities on the development of the insects Rhodnius prolixus, Dysdercus peruvianus, Oncopeltus fasciatus and Rhipicephalus (Boophilus) microplus. Up to now, 102 secondary metabolites have been detected in the fractions, among them monoterpenes, sesquiterpenes and two triterpenes which were obtained from the species, Eugenia sulcata, Pilocarpus spicatus, Manilkara subsericea, Myrciaria floribunda and Zanthoxylum caribaeum. These secondary plant metabolites are considered of interest for the use of studies related to arthropod endocrinology, vector-parasite interaction system, and population control of vector insect and agricultural pest. The observed biological activities were surprisingly high, involving increased mortality, molting and metamorphosis inhibition, paralysis, corporeal deformities, apparition of permanent nymphs, of adultoids and juvenoids, partial or total inhibition of oviposition and egg hatching. These compounds are now being studied further to determine if they may or may not be useful in controlling insect populations and/or interfere with the life cycle and vector transmission of parasites to animal and human populations.

Exercise Training Plus Sildenafil Treatment: Role on Autonomic and Inflammatory Markers.

The current study aimed to determine the effects of sildenafil-associated aerobic exercise training (ET) on the physical performance, hemodynamic, autonomic and inflammatory parameters of rats. Male Wistar rats were randomly assigned to: sedentary rats placebo-treated (SP); sedentary rats sildenafil-treated (SS); trained rats placebo-treated (TP); and trained rats sildenafil-treated (TS). Sildenafil treatment consisted of 8 weeks of daily oral gavage (1.5 mg/kg), one hour before the session of ET (60-75% of maximal running speed, 5 days/week, for 8 weeks). After ET period, physical capacity, hemodynamic, autonomic and skeletal muscle inflammatory profile were assessed. Chronic sildenafil treatment causes an additional increase of physical capacity in aerobically trained rats. However, these beneficial effects were accompanied by unwanted alterations, as increased of arterial pressure and peripheral sympathetic modulation, as well as exacerbated inflammatory status on skeletal muscle of rats. Taken together, these data suggest the positive and negative effects of sildenafil chronic administration, associated to aerobic ET, at doses used in clinical practice. This report stresses the importance of paying greater attention to the indiscriminate use of this substance in high-performance sports.

Phenolic compounds from Viscum album tinctures enhanced antitumor activity in melanoma murine cancer cells.

Cancer is one of the biggest problems in public health worldwide. Plants have been shown important role in anticancer research. Viscum album L. (Santalaceae), commonly known as mistletoe, is a semi-parasitic plant that grows on different host trees. In complementary medicine, extracts from European mistletoe (Viscum album L.) have been used in the treatment of cancer. The study was conducted to identify chemical composition and antitumor potential of Viscum album tinctures. Chemical analysis performed by high resolution chromatography equipped with high resolution mass spectrometer identified caffeic acid, chlorogenic acid, sakuranetin, isosakuranetin, syringenin 4-O-glucoside, syringenin 4-O-apiosyl-glucoside, alangilignoside C and ligalbumoside A compounds. Some of these compounds are probably responsible for the reduction of tumoral cellular growth in a dose-dependent manner. It was observed that melanoma murine cells (B16F10) were more sensitive to V. album tinctures than human leukaemic cells (K562), besides non-tumoral cells (MA-104) had a much lower cytotoxicity to them. Apoptotic-like cells were observed under light microscopy and were confirmed by a typical DNA fragmentation pattern. Additionally, flow cytometry results using Annexin-V/FITC permitted to quantify increased expression of early and late apoptotic markers on tumoral cells, confirming augmented Sub G0 population, which was probably associated with a consistent decrease in G1, and an increase in S or G2/M populations. Results indicate the chemical composition of V. album tinctures influences the mechanisms of in vitro tumoral cell death, suggesting a potential use in cancer pharmacotherapy research.

Plants of Brazilian restingas with tripanocide activity against Trypanosoma cruzi strains.

Chagas disease is caused by the Trypanosoma cruzi affecting millions of people, and widespread throughout Latin America. This disease exhibits a problematic chemotherapy. Benznidazole, which is the drug currently used as standard treatment, lamentably evokes several adverse reactions. Among other options, natural products have been tested to discover a novel therapeutic drug for this disease. A lot of plants from the Brazilian flora did not contain studies about their biological effects. Restinga de Jurubatiba from Brazil is a sandbank ecosystem poorly studied in relation to plant biological activity. Thus, three plant species from Restinga de Jurubatiba were tested against in vitro antiprotozoal activity. Among six extracts obtained from leaves and stem parts and 2 essential oils derived from leave parts, only 3 extracts inhibited epimastigote proliferation. Substances present in the extracts with activity were isolated (quercetin, myricetin, and ursolic acid), and evaluated in relation to antiprotozoal activity against epimastigote Y and Dm28 Trypanosoma cruzi strains. All isolated substances were effective to reduce protozoal proliferation. Essentially, quercetin and myricetin did not cause mammalian cell toxicity. In summary, myricetin and quercetin molecule can be used as a scaffold to develop new effective drugs against Chagas's disease.

Antiproliferative activity in tumor cell lines, antioxidant capacity and total phenolic, flavonoid and tannin contents of Myrciaria floribunda.

Myrciaria floribunda (H. West ex Willd.) O. Berg, Myrtaceae, is a native plant species of the Atlantic Rain Forest, from north to south of Brazil. The lyophilized ethyl acetate extract from the leaves of M. floribunda was investigated for its antiproliferative activity in tumor cell lines, antioxidant capacity and its total phenolic, flavonoid and tannin contents. Antiproliferative activity was tested in vitro against seven human cancer cells and against immortalized human skin keratinocytes line (HaCat, no cancer cell). Antioxidant activity was determined using 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbing capacity (ORAC) assays and total phenolic, flavonoid and tannin contents were determined by spectrophotometric techniques. Ethyl acetate extract of M. floribunda exhibited antiproliferative activity against cancer cell lines with total growth inhibition (TGI) between 69.70 and 172.10 µg/mL. For HaCat cell, TGI value was 213.60 µg/mL. M. floribunda showed a strong antioxidant potential: EC50 of 45.89±0.42 µg/mL and 0.55±0.05 mmol TE/g for DPPH and ORAC, respectively. Total phenolic content was 0.23±0.013g gallic acid equivalents (GAE)/g extract and exhibited 13.10±1.60% of tannins content. The content of flavonoid was 24.08±0.44% expressed as rutin equivalents. These results provide a direction for further researches about the antitumoral potential of M. floribunda.

Baccharis reticularia DC. and Limonene Nanoemulsions: Promising Larvicidal Agents for Aedes aegypti (Diptera: Culicidae) Control.

Baccharis reticularia DC. is a plant species from the Asteraceae family that is endemic to Brazil. Despite the great importance of Baccharis genus, no study has been carried out regarding either the phytochemical composition of B. reticularia or the evaluation of its larvicidal potential. Considering the intrinsic immiscibility of essential oils, this study shows larvicidal nanoemulsions containing the B. reticularia phytochemically characterized essential oil and its main constituent against Aedes aegypti. The major compound found was d-limonene (25.7%). The essential oil inhibited the acetylcholinesterase, one of the main targets of insecticides. The required hydrophile-lipophile balance of both nanoemulsions was 15.0. The mean droplet sizes were around 90.0 nm, and no major alterations were observed after 24 h of preparation for both formulations. After 48 h of treatment, the estimated LC50 values were 118.94 µg mL-1 and 81.19 µg mL-1 for B. reticularia essential oil and d-limonene nanoemulsions, respectively. Morphological alterations evidenced by scanning electron micrography were observed on the larvae treated with the d-limonene nanoemulsion. This paper demonstrated a simple and ecofriendly method for obtaining B. reticularia essential oil and d-limonene aqueous nanoemulsions by a non-heating and solvent-free method, as promising alternatives for Aedes aegypti control.

A new tropane alkaloid from the leaves of Erythroxylum subsessile isolated by pH-zone-refining counter-current chromatography.

Tropane alkaloids are bioactive metabolites with great importance in the pharmaceutical industry and the most important class of natural products found in the Erythroxylum genus. However, these compounds are usually separated by traditional chromatographic techniques, in which the sample is progressively purified in multiple chromatographic steps, resulting in a time- and solvent-consuming procedure. In this work we present the isolation of a novel alkaloid, 6ß,7ß-dibenzoyloxytropan-3α-ol, together with the two known 3α-benzoyloxynortropan-6ß-ol and 3α,6ß-dibenzoyloxytropane alkaloids, directly from the crude alkaloid fraction from the leaves of Erythroxylum subsessile, by using a single run pH-zone-refining counter-current chromatography method. The ethyl acetate/water (1:1, v/v) biphasic solvent system with triethylamine and HCl as retention and eluter agents, respectively, was used to isolate tropane alkaloids for the first time. The structures of the isolated alkaloids were elucidated by spectroscopic methods.

Protective Effect of the Plant Extracts of Erythroxylum sp. against Toxic Effects Induced by the Venom of Lachesis muta Snake.

Snake venoms are composed of a complex mixture of active proteins that induce toxic effects, such as edema, hemorrhage, and death. Lachesis muta has the highest lethality indices in Brazil. In most cases, antivenom fails to neutralize local effects, leading to disabilities in victims. Thus, alternative treatments are under investigation, and plant extracts are promising candidates. The objective of this work was to investigate the ability of crude extracts, fractions, or isolated products of Erythroxylum ovalifolium and Erythroxylum subsessile to neutralize some toxic effects of L. muta venom. All samples were mixed with L. muta venom, then in vivo (hemorrhage and edema) and in vitro (proteolysis, coagulation, and hemolysis) assays were performed. Overall, crude extracts or fractions of Erythroxylum spp. inhibited (20%-100%) toxic effects of the venom, but products achieved an inhibition of 4%-30%. However, when venom was injected into mice before the plant extracts, hemorrhage and edema were not inhibited by the samples. On the other hand, an inhibition of 5%-40% was obtained when extracts or products were given before venom injection. These results indicate that the extracts or products of Erythroxylum spp. could be a promising source of molecules able to treat local toxic effects of envenomation by L. muta venom, aiding in the development of new strategies for antivenom treatment.

Physical activity on endothelial and erectile dysfunction: a literature review.

Physical inactivity, diabetes, hypertension, dyslipidemia, smoking and obesity were associated with imbalance in oxidative stress, leading to endothelial dysfunction. Such dysfunction is present in both cardiovascular disease (CVD) and erectile dysfunction (ED). ED is the persistent inability to achieve or sustain an erection sufficient for satisfactory sexual performance and is one of the first manifestations of endothelial damage in men with CVD risk factors. The purpose of this article is to review the results of studies involving physical activity, CVD, endothelial dysfunction and ED in order to verify its applicability for improving the health and quality of life of men with such disorders. There is consistent evidence that endothelial damage is intimately linked to ED, and this manifestation seems to be associated with the appearance CVDs. On the other hand, physical activity has been pointed out as an important clinical strategy in the prevention and treatment of CVDs and ED mainly associated with improvement of endothelial function. However, further experimental and clinical prospective investigations are needed to test the role of physical exercises in the modulation of endothelial function and their implications on erectile function and the appearance of CVDs.

Cardioprotection afforded by exercise training prior to myocardial infarction is associated with autonomic function improvement.

BACKGROUND: It has been suggested that exercise training (ET) protects against the pathological remodeling and ventricular dysfunction induced by myocardial infarction (MI). However, it remains unclear whether the positive adjustments on baroreflex and cardiac autonomic modulations promoted by ET may afford a cardioprotective mechanism. The aim of this study was to evaluate the effects of aerobic ET, prior to MI, on cardiac remodeling and function, as well as on baroreflex sensitivity and autonomic modulation in rats. METHODS: Male Wistar rats were divided into 4 groups: sedentary rats submitted to Sham surgery (C); trained rats submitted to Sham surgery (TC); sedentary rats submitted to MI (I), trained rats submitted to MI (TI). Sham and MI were performed after ET period. After surgeries, echocardiographic, hemodynamic and autonomic (baroreflex sensitivity, cardiovascular autonomic modulation) evaluations were conducted. RESULTS: Prior ET prevented an additional decline in exercise capacity in TI group in comparison with I. MI area was not modified by previous ET. ET was able to increase the survival and prevent additional left ventricle dysfunction in TI rats. Although changes in hemodynamic evaluations were not observed, ET prevented the decrease of baroreflex sensitivity, and autonomic dysfunction in TI animals when compared with I animals. Importantly, cardiac improvement was associated with the prevention of cardiac autonomic impairment in studied groups. CONCLUSIONS: Prior ET was effective in changing aerobic capacity, left ventricular morphology and function in rats undergoing MI. Furthermore, these cardioprotective effects were associated with attenuated cardiac autonomic dysfunction observed in trained rats. Although these cause-effect relationships can only be inferred, rather than confirmed, our study suggests that positive adaptations of autonomic function by ET can play a vital role in preventing changes associated with cardiovascular disease, particularly in relation to MI.