Short-term hiit does not promote oxidative stress or muscle damage / Hiit de corto plazo no promueve estrés oxidativo o daños musculares / Hiit de curto prazo não promove estresse oxidativo ou danos musculares

ABSTRACT Introduction: High intensity interval training (HIIT) is a method that is widely used today. Objective: The present study aimed to evaluate the effects of HIIT on markers of oxidative stress and muscle damage in rats. Methods: The sample consisted of 60-day-old Wistar rats, divided into two groups: a control group (n=8) and an HIIT group (n=8). The training consisted of fourteen 20-second swimming sessions (loaded with weights equivalent to 14% of their body weight) with 10-second intervals between each session, performed for 12 consecutive days. Results: HIIT induced a reduction (−17.75%) in thiobarbituric acid reactive substances (an oxidative stress marker) in hepatic tissue (p=0.0482). There was also a reduction (−31.80%) in the HIIT group in the level of superoxide dismutase enzyme activity in the liver (p=0.0375). However, there were no differences between the groups in catalase, glutathione peroxidase, glutathione reductase, the total content of SH sulfhydryls, hydroperoxides, or carbonylated proteins in the hepatic tissue. No significant differences were found in any of these markers in the gastrocnemius muscle. The muscle damage markers creatinine kinase and lactate dehydrogenase were also similar between the groups in the gastrocnemius. Conclusion: The conclusion was that that short-term HIIT does not cause oxidative stress or muscle damage. Level of evidence I; High-quality randomized clinical trial with or without statistically significant difference, but with narrow confidence intervals.

RESUMEN Introducción: El entrenamiento en intervalos de alta intensidad (HIIT) es un método muy utilizado actualmente. Objetivo: El presente estudio tuvo como objetivo evaluar los efectos del HIIT en corto plazo sobre marcadores de estrés oxidativo y daño muscular en ratones. Métodos: La muestra consistió en ratones Wistar con 60 días de edad, divididos en dos grupos: grupo control (n = 8) y grupo HIIT (n = 8). El entrenamiento consistió en catorce sesiones de natación de 20 segundos (con cargas equivalentes a 14% del peso corporal) con intervalos de 10 segundos entre cada sesión, realizadas durante 12 días consecutivos. Resultados: El HIIT indujo una reducción (-17,75%) de las sustancias reactivas al ácido tiobarbitúrico (un marcador de estrés oxidativo) en el tejido hepático (p = 0,0482). También hubo reducción (~31,80%) en el grupo HIIT en el nivel de enzima superóxido dismutasa en el hígado (p=0,0375). Sin embargo, no hubo diferencias entre los grupos con relación a catalasa, glutatión peroxidasa, glutatión reductasa, tenor total de sulfhidrilos SH, hidroperóxidos o proteínas carboniladas en el tejido hepático. No fue encontrada ninguna diferencia significativa en ninguno de esos marcadores en el músculo gastrocnemio. Los marcadores de lesión muscular, creatinina quinasa y lactato deshidrogenasa también fueron similares entre los grupos en el gastrocnemio. Conclusión: Fue posible concluir que el HIIT de corta duración no causa estrés oxidativo o daño muscular. Nivel de evidencia I; Estudio clínico aleatorizado de alta calidad con o sin diferencia estadísticamente significativa, pero con intervalos de información estrechos.

RESUMO Introdução: O treinamento intervalado de alta intensidade (HIIT) é um método muito utilizado atualmente. Objetivo: O presente estudo objetivou avaliar os efeitos do HIIT em curto prazo sobre marcadores de estresse oxidativo e dano muscular em ratos. Métodos: A amostra consistiu em ratos Wistar com 60 dias de idade, divididos em dois grupos: grupo controle (n = 8) e grupo HIIT (n = 8). O treinamento consistiu em quatorze sessões de natação de 20 segundos (com cargas equivalentes a 14% do peso corporal) com intervalos de 10 segundos entre cada sessão, realizadas por 12 dias consecutivos. Resultados: O HIIT induziu uma redução (-17,75%) das substâncias reativas ao ácido tiobarbitúrico (um marcador de estresse oxidativo) no tecido hepático (p = 0,0482). Houve também redução (-31,80%) no grupo HIIT no nível de enzima superóxido dismutase no fígado (p = 0,0375). No entanto, não houve diferenças entre os grupos com relação a catalase, glutationa peroxidase, glutationa redutase, teor total de sulfidrilas SH, hidroperóxidos ou proteínas carboniladas no tecido hepático. Nenhuma diferença significativa foi encontrada em qualquer um desses mascadores no músculo gastrocnêmio. Os marcadores de lesão muscular, creatinina quinase e lactato desidrogenase, também foram semelhantes entre os grupos no gastrocnêmio. Conclusão: Foi possível concluir que o HIIT de curta duração não causa estresse oxidativo ou dano muscular. Nível de evidência I; Estudo clínico randomizado de alta qualidade com ou sem diferença estatisticamente significante, mas com intervalos de informação estreitos.

Effects of Resistance Training and Bowdichia virgilioides Hydroethanolic Extract on Oxidative Stress Markers in Rats Submitted to Peripheral Nerve Injury.

The objective of this study was to analyze the effects of the combination of resistance training (RT) and the hydroethanolic extract (EHE) of Bowdichia virgilioides as markers of oxidative stress (OS) in rats with peripheral nerve injury (PNI). Rats were allocated into six groups (n = 10): animals without interventions (C), animals with an exposed nerve but without injury, injured animals, trained and injured animals, injured animals that received EHE, and animals that received a combination of RT and EHE. RT comprised the climbing of stairs. EHE was orally administered (200 mg/kg) for 21 days after PNI induction. RT reduced the amount of lipoperoxidation in plasma (14.11%). EHE reduced lipoperoxidation in the plasma (20.72%) and the brain (41.36). RT associated with the extract simultaneously reduced lipoperoxidation in the plasma (34.23%), muscle (25.13%), and brain (43.98%). There was an increase in total sulhydrilyl levels (a) in the brain (33.33%) via RT; (b) in the brain (44.44%) and muscle (44.51%) using EHE; and (c) in the plasma (54.02%), brain (54.25%), and muscle using the combination of RT + EHE. These results suggest that RT associated with oral EHE results in a decrease in OS.

Effects of resistance training and turmeric supplementation on reactive species marker stress in diabetic rats.

BACKGROUND: Type 1 diabetes mellitus (T1DM) is a metabolic disease characterized by hyperglycemia and excessive generation of reactive oxygen species caused by autoimmune destruction of beta-cells in the pancreas. Among the antioxidant compounds, Curcuma longa (CL) has potential antioxidant effects and may improve hyperglycemia in uncontrolled T1DM/TD1, as well as prevent its complications (higher costs for the maintenance of health per patient, functional disability, cardiovascular disease, and metabolic damage). In addition to the use of compounds to attenuate the effects triggered by diabetes, physical exercise is also essential for glycemic control and the maintenance of skeletal muscles. Our objective is to evaluate the effects of CL supplementation associated with moderate- to high-intensity resistance training on the parameters of body weight recovery, glycemic control, reactive species markers, and tissue damage in rats with T1DM/TD1. METHODS: Forty male 3-month-old Wistar rats (200-250 g) with alloxan-induced T1DM were divided into 4 groups (n = 7-10): sedentary diabetics (DC); diabetic rats that underwent a 4-week resistance training protocol (TD); CL-supplemented diabetic rats (200 mg/kg body weight, 3x a week) (SD); and supplemented diabetic rats under the same conditions as above and submitted to training (TSD). Body weight, blood glucose, and the following biochemical markers were analyzed: lipid profile, aspartate aminotransferase (AST), alanine aminotransferase (ALT), uric acid, creatine kinase (CK), lactate dehydrogenase (LDH), and thiobarbituric acid reactive substances (TBARS). RESULTS: Compared to the DC group, the TD group showed body weight gain (↑7.99%, p = 0.0153) and attenuated glycemia (↓23.14%, p = 0.0008) and total cholesterol (↓31.72%, p ≤ 0.0041) associated with diminished reactive species markers in pancreatic (↓45.53%, p < 0.0001) and cardiac tissues (↓51.85%, p < 0.0001). In addition, compared to DC, TSD promoted body weight recovery (↑15.44%, p ≤ 0.0001); attenuated glycemia (↓42.40%, p ≤ 0.0001), triglycerides (↓39.96%, p ≤ 0.001), and total cholesterol (↓28.61%, p ≤ 0.05); and attenuated the reactive species markers in the serum (↓26.92%, p ≤ 0.01), pancreas (↓46.22%, p ≤ 0.0001), cardiac (↓55.33%, p ≤ 0.001), and skeletal muscle (↓42.27%, p ≤ 0.001) tissues caused by T1DM. CONCLUSION: Resistance training associated (and/or not) with the use of Curcuma longa attenuated weight loss, the hypoglycemic and hypolipidemic effects, reactive species markers, and T1DM-induced tissue injury.

Effects of 12 Weeks of Resistance Training on Cardiovascular Risk Factors in School Adolescents.

Background and objectives: The practice of physical exercise, especially resistance exercise, is important for the treatment and/or prevention of cardiovascular risk factors in adult individuals. However, there are few studies on its effects on adolescent individuals. Therefore, the aim of the present study was to evaluate the effects of applying a 12-week resistance training program on cardiovascular risk factors in adolescents. Materials and Methods: Thus, 122 adolescents aged 13-16 years of both genders participated in the study from school in the city of Lagarto, Sergipe (SE), Brazil, divided into two groups: Control Group (CG) and Group undergoing resistance training (RTG). Blood collection and anthropometric measurements were performed before and after the 12-week resistance training program (RTP). Results: After 12 weeks of the RTP in the adolescents, there was a reduction in the triglyceride variables (9.55%, p = 0.0286), Low-Density Lipoproteins (LDL) (5.42%, p = 0.0244), non-High-Density Lipoproteins (HDL) (5.40%, p = 0.0019), blood glucose (6.71%, p = 0.0040), systolic blood pressure (10.13%, p < 0.0001), as well as an increase in the body weight variable (1.73%, p = 0.0003). Conclusions: It was concluded that a 12-week RTP can prevent and/or alleviate the development of several chronic degenerative diseases in adulthood and that resistance training is important for maintaining the health of adolescents.

Antinociceptive and anti-inflammatory effect of Poincianella pyramidalis (Tul.) L.P. Queiroz.

ETHNOPHARMACOLOGY RELEVANCE: Poncianella pyramidalis (Leguminosae) is a Caatinga plant used in folk medicine because of its pharmacological properties, which include anti-inflammatory action. However, chemical compounds responsible for this effect have not yet been identified. AIM OF THE STUDY: This study aimed to evaluate the antioxidant, antinociceptive and anti-inflammatory effects of the ethyl acetate fraction from the inner bark of P. pyramidalis. MATERIAL AND METHODS: Total phenol content (TP) was estimated using the Folin-Ciocalteu reagent, while in vitro antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Chemical identification was done using LC-PDA/MS and LC-ESI/MS/MS. In vivo antinociceptive and anti-inflammatory properties were investigated using formalin, mechanical hypernociception and carrageenan-induced pleurisy assays in mice. RESULTS: TP was 525.08 ± 17.49 µg mg-1 gallic acid equivalent. The ethyl acetate fraction (EAF) inhibited 87.76% of the DPPH radical with an EC50 of 22.94 µg mL-1 and Antioxidant Activity Index of 1.74. LC-PDA/MS and LC-ESI/MS/MS identified 15 compounds that are mostly derived from gallic and ellagic acids. Regarding in vivo antinociceptive and anti-inflammatory activity, EAF (100 mg kg-1) significantly reduced the nociceptive response in the second phase of the formalin assay by 50% (p < 0.01) compared with the control group. In the hypernociception test, a significant (p < 0.001) anti-hyperalgesic effect of EAF (100 mg kg-1) was observed up to the third hour of evaluation (p < 0.001). In the carrageenan assay, EAF (100 mg kg-1) was shown to inhibit protein extravasation, increase total leukocytes and neutrophils, and inhibit mononuclear cells. CONCLUSION: These results demonstrate EAF from the inner bark of P. pyramidalis has strong in vitro antioxidant effect as well as in vivo antinociceptive and anti-inflammatory activities, which may be attributed to the bark being rich in phenolic compounds derived from gallic acid.

Whether or Not the Effects of Curcuma longa Supplementation Are Associated with Physical Exercises in T1DM and T2DM: A Systematic Review.

Diabetes mellitus is one of the most prevalent chronic diseases in the world; one of its main characteristics is chronic hyperglycemia. Pharmacotherapy and other alternatives such as regular exercise are among the therapeutic methods used to control this pathology and participate in glycemic control, as well as the ingestion of plant extracts with antioxidant effects. Among the different plants used for this purpose, curcumin has potential to be used to attenuate the hyperglycemic condition triggered by diabetes mellitus (DM). Some prior studies suggest that this plant has antioxidant and hypoglycemic potential. This review aims to evaluate the antioxidant and hypoglycemic potential of curcumin supplementation in Type 1 DM (T1DM) and Type 2 DM (T2DM). The search considered articles published between 2010 and 2019 in English and Portuguese, and a theoretical survey of relevant information was conducted in the main databases of scientific publications, including the Virtual Health Library and its indexed databases, PubMed, LILACS (Latin American and Caribbean Literature on Health Sciences-Health Information for Latin America and the Caribbean-BIREME/PAHO/WHO), and Scientific Electronic Library Online (SciELO). The associated use of turmeric and physical exercise has demonstrated antioxidant, anti-inflammatory, and hypoglycemic effects, suggesting that these could be used as potential therapeutic methods to improve the quality of life and survival of diabetic patients.

Ethanolic extract and ethyl acetate fraction of Coutoubea spicata attenuate hyperglycemia, oxidative stress, and muscle damage in alloxan-induced diabetic rats subjected to resistance exercise training program.

Gentianaceae family (such as Coutoubea spicata) contains iridoids and flavonoids with antidiabetic properties. However, there is no information available about the antidiabetic effects of C. spicata when combined with resistance exercise training (RET). This study evaluated the effects of the ethanolic extract (EE) and ethyl acetate fraction (EAF) of C. spicata on biochemical markers, muscle damage, and oxidative stress in diabetic rats submitted to RET. Alloxan-induced diabetic rats were distributed into 4 groups (each group, n = 8) treated with distilled water (TD), EE, EAF, or metformin and submitted to RET. Two groups without the disease (each group, n = 8) (sedentary control and trained control), as well as a sedentary diabetic group (n = 8) were included. Body weight and glycemia were evaluated weekly. After 30 days, lipid/lipoprotein profile, aspartate aminotransferase, alanine aminotransferase, muscle damage ((creatine kinase (CK) and lactate dehydrogenase (LDH)), and oxidative stress (malondialdehyde (MDA), sulfhydryl groups (SH), and ferric reducing antioxidant power) were evaluated. MDA and SH for pancreas, liver, heart, and muscle were evaluated. C. spicata extract and fraction combined with RET recovered body weight and reduced glycemia, muscle damage (CK: 36.83% and 21.45%; LDH: 49.83% and 68.55%), and low-density lipoprotein cholesterol (70.63%; 59.18%) and improved redox status (MDA: 50.33%, 39.74%; and SH: 53.97%; 76.41%), respectively, when compared with the TD group. C. spicata plus RET promoted anti-hyperglycemic, lipid-reducing, and antioxidant effects in diabetic rats. Novelty C. spicata presents anti-hyperglycemic and lipid-lowering effects potentiated by RET. C. spicata reduces muscle injury and increases antioxidant defense.

Anti-inflammatory, antinociceptive and antioxidant properties of Schinopsis brasiliensis bark.

ETHNOPHARMACOLOGICAL RELEVANCE: Schinopsis brasiliensis is a native plant from Brazil, popularly used in folk medicine to relieve pain and treat inflammation. This study evaluated the antinociceptive and anti-inflammatory activities and antioxidant properties of the hydroethanol extract (HEE) and ethyl acetate fraction (EAF) obtained from S. brasiliensis bark. MATERIALS AND METHODS: The HEE and EAF of S. brasiliensis bark (10, 30 and 100mg/kg, p.o.) were evaluated using models of analgaesia (formalin-induced licking and hot-plate models) or inflammation (licking response by formalin-induced and carrageenan-induced cell migration into the subcutaneous air pouch). The antioxidant activities of HEE and EAF (50, 100 and 200µg/ml) were evaluated using the lipoperoxidation method induced in egg yolk by 2'-azobis(2-amidinopropane) dihydrochloride (AAPH) and FeSO4. RESULTS: HEE and EAF presented a central antinociceptive effect (at 100mg/kg dose), increasing the baseline and area under the curve in the hot plate model. EAF (100mg/kg) significantly reduced (p< 0.005) the pain response in the first (45%) and second (35%) phases of the formalin-induced licking model, while HEE (100mg/kg) reduced (38%) only the pain response in the second phase. Regarding anti-inflammatory activity, EAF (100mg/kg) also inhibited the inflammatory process induced by subcutaneous carrageenan injection in the SAP model, reducing the amount of the cytokine TNF-α produced. CONCLUSION: HEE and EAF from S. brasiliensis bark show pharmacological interest because they were able to inhibit the peripheral and central transmission of pain. Our data also suggest that the anti-inflammatory activity caused by EAF exposure occurs through the inhibition of the pro-inflammatory cytokine TNF-α, also reducing the spreading of the inflammatory processes by neutralizing reactive oxygen species, which are by-products in the biosynthesis of pain mediators.

Passiflora cincinnata Extract Delays the Development of Motor Signs and Prevents Dopaminergic Loss in a Mice Model of Parkinson's Disease.

Passiflora cincinnata Masters is a Brazilian native species of passionflower. This genus is known in the American continent folk medicine for its diuretic and analgesic properties. Nevertheless, few studies investigated possible biological effects of P. cincinnata extracts. Further, evidence of antioxidant actions encourages the investigation of possible neuroprotective effects in animal models of neurodegenerative diseases. This study investigates the effect of the P. cincinnata ethanolic extract (PAS) on mice submitted to a progressive model of Parkinson's disease (PD) induced by reserpine. Male (6-month-old) mice received reserpine (0.1 mg/kg, s.c.), every other day, for 40 days, with or without a concomitant treatment with daily injections of PAS (25 mg/kg, i.p.). Catalepsy, open field, oral movements, and plus-maze discriminative avoidance evaluations were performed across treatment, and immunohistochemistry for tyrosine hydroxylase was conducted at the end. The results showed that PAS treatment delayed the onset of motor impairments and prevented the occurrence of increased catalepsy behavior in the premotor phase. However, PAS administration did not modify reserpine-induced cognitive impairments. Moreover, PAS prevented the decrease in tyrosine hydroxylase immunostaining in the substantia nigra pars compacta (SNpc) induced by reserpine. Taken together, our results suggested that PAS exerted a neuroprotective effect in a progressive model of PD.

Testing the extraction of DNA from human teeth exposed to different chemical solutions / Prueba de extracción de ADN de dientes humanos expuestos a diferentes soluciones químicas

The aim of this study was to evaluate the extraction of dental DNA exposed to different chemical solutions. The sample was composed by 15 subjects, from which 5 samples of oral mucosal cells (reference population) and 15 teeth (experimental population) were collected. The experimental population was divided in three equal parts, which were exposed to different chemical solutions, namely hydrochloric acid (HCl) at 37 %, formaldehyde (CH2O) at 10 % and sodium hypochlorite (NaOCl) at 2.5 %. The DNA from the oral mucosa was extracted using organic method, while the dental DNA was extracted using the AFDIL method, including amplification by PCR and sequencing through capillary electrophoresis. The DNA exposed to hydrochloric acid dissolved, lacking extraction. The exposure of teeth to formaldehyde and sodium hypochlorite did not interfere in the extraction of DNA, once the amplification was visible in both experimental populations. The present outcomes demonstrated that DNA extraction may be limited under exposure to chemical solutions.

El objetivo de este estudio fue evaluar la extracción de ADN dental expuesto a diferentes soluciones químicas. La muestra estuvo compuesta por 15 sujetos, de los cuales se recogieron 5 muestras de células de la mucosa oral (población de referencia) y 15 dientes (población experimental). La población experimental se dividió en tres partes iguales, que fueron expuestas a diferentes soluciones químicas, a saber, ácido clorhídrico (HCl) al 37 %, formaldehído (CH2O) al 10 % e hipoclorito de sodio (NaOCl) al 2,5 %. El ADN de la mucosa oral se extrajo utilizando el método orgánico, mientras que el ADN dental se extrajo utilizando el método AFDIL, incluyendo la amplificación por PCR y la secuenciación a través de electroforesis capilar. El ADN expuesto al ácido clorhídrico se disolvió, careciendo de extracción. La exposición de los dientes al formaldehído e hipoclorito de sodio no interfirió en la extracción de ADN, una vez que la amplificación era visible en ambas poblaciones experimentales. Los resultados actuales demostraron que la extracción de ADN puede ser limitada bajo la exposición a soluciones químicas.

Isolation of antioxidant phenolics from Schinopsis brasiliensis based on a preliminary LC-MS profiling.

The phenolic content of the ethanol extract of the stem bark of the Brazilian plant Schinopsis brasiliensis Engl. (Anacardiaceae) has been evaluated together with the antioxidant activity. The good antioxidant activity exhibited in the Trolox Equivalent Antioxidant Capacity (TEAC) assay (TEAC value = 3.04 mg/mL) encouraged us to investigate its constituents. An analytical approach based on LC-ESIMSn was applied to rapidly obtain a metabolite profile of the ethanol extract of the stem bark of S. brasiliensis. Sixteen phenolic compounds, among which five galloyl derivatives, never reported before, have been isolated and their structures have been unambiguously elucidated by extensive spectroscopic methods, including 1D (1H, 13C, TOCSY) and 2D (DQF-COSY, HMBC, and HSQC) NMR experiments. Moreover, the antioxidant activity of all the isolated compounds was evaluated, along with the cytotoxicity against the cancer cell lines A549 (human alveolar basal carcinoma) and Hela (human epitheloid cervix carcinoma). The previously undescribed compounds exhibited a high free-radical-scavenging activity, in the range of 1.10-1.86 mM. None of the tested compounds, in a range of concentrations between 12.5 and 100 µM, caused a significant reduction of the cell number.

Protective effect of a hydroethanolic extract from Bowdichia virgilioides on muscular damage and oxidative stress caused by strenuous resistance training in rats.

BACKGROUND: Natural antioxidants can reduce oxidative damage caused by high-intensity resistance training (RT). We investigated the in vitro antioxidant potential of hydroethanolic extract (HEE) from Bowdichia virgilioides on muscular damage and oxidative stress in rats subjected to high-intensity RT. METHODS: Thirty-two male Wistar rats were divided into four experimental groups: 1) control group (CG), oral administration (P.O.) of vehicle; 2) trained group (TG), vehicle-treated with RT; 3) B. virgilioides untrained group (BVG), treated with B. virgilioides HEE (200 mg/kg P.O.); and 4) trained B. virgilioides group (TBVG), treated with B. virgiliodes HEE (200 mg/kg P.O.). All animals were habituated to the training apparatus for 1 week. CT and TBVG animals were subjected to the training protocol, which consisted of three sets of 10 repetitions with 75% of the load established using the one-repetition maximum, for four weeks. CG and BVG animals were manipulated and fixed to the apparatus three times a week with no load. Treatment with B. virgilioides HEE or vehicle treatment was initiated after 25 days of RT (5 days; one dose per day). At the end of the experiments, plasmatic and gastrocnemius samples from all groups were obtained for the assessment of lipid peroxidation and creatine kinase activity. RESULTS: Compared to TG rats, TBVG rats showed decreases in plasma and gastrocnemius tissue lipid peroxidation by 55.68% (p <0.0001) and 66.61% (p <0.0012), respectively. Further, compared to TG rats TBVG rats showed decreases in plasma and gastrocnemius tissue oxidative stress by 62.83% (p <0.0005) and 54.97% (p <0.0197), respectively. CONCLUSIONS: B. virgilioides HEE treatment reduced markers of oxidative stress caused by high-intensity RT. Further, HEE treatment during training significantly reduced the markers of tissue damage.

Aqueous fraction from Costus spiralis (Jacq.) Roscoe leaf reduces contractility by impairing the calcium inward current in the mammalian myocardium.

ETHNOPHARMACOLOGICAL RELEVANCE: Brazilian folk medicine uses infusion of Costus spiralis leaf to help people to treat arterial hypertension and syndromes of cardiac hyperexcitability. AIM OF THE STUDY: Evaluate the aqueous fraction (AqF) effect on atrial contractility and investigate its mechanism of action. MATERIALS AND METHODS: The AqF effect on the cardiac contractility was studied on isolated electrically driven guinea pig left atria. Atropine and tetraethylammonium (TEA) were employed to investigate whether potassium contributes for the inotropic mechanism of the AqF. The role of calcium in this effect was also studied. This was done by analysing the AqF effect on the Bowditch's phenomenon, as well as by studying whether it could interfere with the concentration-effect curve for CaCl(2), isoproterenol, and BAY K8644. Mice isolated cardiomyocytes were submitted to a whole-cell patch-clamp technique in order to evaluate whether the L-type calcium current participates on the AqF effect. Furthermore, the intracellular calcium transient was studied by confocal fluorescence microscopy. RESULTS: AqF depressed the atrial contractile force. It was the most potent fraction from C. spiralis leaf (EC(50)=305 ± 41 mg/l) (crude extract: EC(50)=712 ± 41; ethyl acetate: EC(50)=788 ± 121; chloroform: EC(50)=8,948 ± 1,346 mg/l). Sodium and potassium content in the AqF was 0.15 mM and 1.91 mM, respectively. Phytochemical analysis revealed phenols, tannins, flavones, xanthones, flavonoids, flavonols, flavononols, flavonones, and saponins. Experiments with atropine and TEA showed that potassium does not participate of the inotropic mechanism of AqF. However, this fraction decreased the force overshoot characteristic of the Bowditch's phenomenon, and shifted the concentration-response curve for CaCl(2) (EC(50) from 1.12 ± 0.07 to 7.23 ± 0.47 mM) indicating that calcium currents participate on its mechanism of action. Results obtained with isoproterenol (1-1,000 pM) and BAY K8644 (5-2000nM) showed that AqF abolished the inotropic effect of these substances. On cardiomyocytes, 48mg/l AqF reduced (∼23%) the L-type calcium current density from -6.3 ± 0.3 to -4.9 ± 0.2 A/F (n=5 cells, p<0.05) and reduced the intracellular calcium transient (∼20%, 4.7 ± 1.2 a.u., n=42 cells to 3.7 ± 1.00 a.u., n=35 cells, p<0.05). However, the decay time of the fluorescence was not changed (control: 860 ± 32 ms, n=42 cells; AqF: 876 ± 26 ms, n=35 cells, p>0.05). CONCLUSIONS: The AqF of C. spiralis leaf depresses myocardial contractility by reducing the L-type calcium current and by decreasing the intracellular calcium transient. Despite the lack of data on the therapeutic dose of AqF used in folk medicine, our results support, at least in part, the traditional use of this plant to treat cardiac disorders.

Chemical composition, acute toxicity, and antinociceptive activity of the essential oil of a plant breeding cultivar of basil (Ocimum basilicum L.).

Ocimum basilicum L. is an aromatic herb used in Brazil to treat illnesses such as respiratory and rheumatic problems, vomiting, and pain. In the present study, the chemical composition, acute toxicity, and antinociceptive effects of the essential oil (EO) of the cultivar "Maria Bonita" obtained from O. basilicum L. PI 197442 genotype were evaluated in Swiss mice (20-35 g each). Lethal dose to cause 50 % death (LD50) was calculated from a dose-response curve (100-5000 mg/kg body wt.; n = 6) as 532 mg/kg body wt. In the acetic acid-induced writhing test (0.6 % i. p.), EO (50, 100, and 200 mg/kg body wt., n = 8, s. c.) was effective in reducing the abdominal contractions at all doses (48-78 %). In the hot-plate test, EO significantly increased the latency at 50 mg/kg body wt. at all times (37-52 %, n = 8, s. c.). However, the effects of morphine and EO at 50 mg/kg were reverted in the presence of naloxone, an opioid antagonist. In the formalin test, EO significantly reduced paw licking time in the first and second phases of pain at 200 mg/kg body wt. (38 and 75 %, respectively, n = 8, s. c.). The results suggested that the peripheral and central antinociceptive effects of EO are related to the inhibition of the biosynthesis of pain mediators, such as prostaglandins and prostacyclins, and its ability to interact with opioid receptors.

Pharmacological properties of lichen Cladonia clathrata.

Cladonia clathrata Ahti & L. Xavier-Filho (Cladoniaceae) is a lichen; several Cladonia species extracts have been used for various remedies in folk medicine. In order to evaluate the actions of this lichen, studies were performed on antinociceptive, anti-inflammatory, and antioxidant activities. The hydroalcoholic extract (HE) of C. clathrata stems was used in the following experiments. Oral treatment with the HE of C. clathrata elicited inhibitory activity (p < 0.001) on acetic acid-induced abdominal writhes at 100 (47.2%), 200 (47.2%), and 400 mg/kg (86.4%), and reduced the formalin-induced nociception on both the neurogenic (400 mg/kg, p < 0.01) and inflammatory phases (200 and 400 mg/kg, p < 0.01). It was not associated with non-specific effects, such as muscle relaxation or sedation. The HE reduced the carrageenan-induced edema formation at 100, 200, and 400 mg/kg (p < 0.05) and inhibited neutrophil migration into the peritoneal cavity at 400 mg/kg (p < 0.001). The HE of C. clathrata reacted with the DPPH radical and reduced the same by 50.19%, and exhibited an IC(50) value of 69.25 +/- 0.65 mug/mL. The HE of C. clathrata stems shows antinociceptive and anti-inflammatory activities, with a moderate antioxidant potential.

Effects of triterpene derivatives from Maytenus rigida on VEGF-induced Kaposi's sarcoma cell proliferation.

Betulinic acid (BA) is a naturally occurring lupane-type triterpene which exhibits a variety of biological activities including potent cytotoxic properties. On the basis of the structural similarity to BA, two lupane derivatives namely lup-20(29)-ene-3beta,30-diol (1) and lup-20(29)-ene-3beta,28-diol (2), along with two friedelane derivatives, namely friedelan-3-one (3) and friedelan-3beta-ol (4), isolated from the Brazilian plant Maytenus rigida, have been evaluated for their anti-proliferative effect. Similarly to BA, compounds 1 and 3 at 1 microM concentration significantly inhibited the VEGF-induced Kaposi's sarcoma (KS) cell proliferation by 50%. In contrast, this effect was not found in control endothelial cells (EC). Moreover, compounds 1 and 3 showed a dose-dependent effect on the apoptotic cell death, as detected by FACS analysis and caspase-3 assay. Specifically, at 10 microM concentration, apoptosis was significantly induced (from 45% to 55% of hypodiploid cells vs control cells) and showed the same potency order observed for the anti-proliferative effect at 1 microM, i.e., compound 3>BA>compound 1. Taking into account the interest given rise by BA as anticancer agent, the comparable anti-proliferative activity shown by compounds 1 and 3 and BA, can give an impulse to further investigate lupane and friedelane derivatives as cytotoxic agents.

Antinociceptive activity and toxicological study of aqueous extract of Egletes viscosa Less (Asteraceae) / Atividade antinociceptiva e estudo toxicológico de extrato aquoso de Egletes viscosa Lessa (Asteraceae)

Egletes viscosa Less (Asteraceae), popularly known as ômacelaõ or ômacela-da-terraõ, is a plant widely used in popular medicine due toits anti-inflammatory, bactericidal, antidiarrhoea, mio-relaxant, antispasmodic, antinociceptive, digestive, and anti-viral properties.Phytochemical screening of aqueous extract of Egletes viscosa (AEEV)revealed the high presence of flavonoids. This study examined the oralantinociceptive potential of AEEV in rodents using different concentrations (100, 200, and 400 mg/kg, p.o.). The results showed significant antinociceptive action when tested in writhing (200 and 400 mg/kg-p<0.05) and in the second phase of formalin tests(200 mg/kg-p<0.01 and 400 mg/kg-p<0.001). The inhibition (%) of extract in the writhing test was 63.4, 56.7, and 79.2% respectively for 200, 400, and acetyl salicylic acid (300 mg/kg); for the formalin test (second phase) results were 66.1, 84.7, and 96.2% respectively for 200, 400, and acetyl salicylic acid (300 mg/kg). Collectively, these observations suggest that AEEV is effective against continuous inflammatory pain. AEEV was well tolerated. In an acute toxicity test,oral administration of 5 g/kg of AEEV was performed and no mortality rate was observed. Similarly, in a subchronic toxicity study, no mortality was observed after 30 days of daily oral administration of 100 mg/kg of AEEV. There was no significant difference in the body and organ weights between control and experimental animals in both acute and subchronic toxicity tests. Pathological assays did not reveal any evidence of detectable differences in the gross appearance, as well as in thearchitectural or cellular pattern characteristics of the internal organsof the animals in both acute and subchronic tests. Nevertheless, significant differences were verified between males of the experimentaland control groups regarding the levels of hemoglobin and leukocytes...

Egletes viscosa Less (Asteraceae), popularmente conhecida como ômacelaõ ou ômacela-da-terraõ, é uma plantalargamente usada na medicina popular devido as suas propriedades: anti-inflamatória, bactericida, antidiarréica, mio-relaxante, anti-espasmódica,antinociceptiva, digestiva e anti-viral. Análise fitoquímica do extrato aquoso da Egletes viscosa (AEEV) mostrou elevada presença de flavonóides. Este estudo examinou o potencial antinociceptivo do AEEV em roedores usando diferentes concentrações (100, 200 and 400 mg/kg, p.o.). Os resultados mostraram significante efeito antinociceptivo quando testadas as doses (200 mg/kgp<0.01; 400 mg/kg-p<0.05) e na segunda fase dos testes com formalina (200 and 400 mg/kg-p<0.001). Este efeitoantinociceptivo foi similar ao ácido acetilsalicílico (300 mg/kg) nas doses de 200 e 400 mg/kg. Adicionalmente,estas observações sugerem que o AEEV é efetivo contra dores inflamatórias contínuas. AEEV foi bem tolerada. No teste de toxicidade aguda, utilizando uma administração oral de 5 g/kg de AEEV, não foi observado casos demortalidade. Da mesma maneira, no estudo subcrônico nenhuma mortalidade foi observada após 30 dias de administração oral diária de 100 mg/kg do AEEV. Não houve diferença significativa entre os pesos corporal e dos órgãos isolados quando comparados grupo controle e teste tanto no estudo agudo quanto subcrônico. Ensaioshistopatológicos não revelaram diferenças entre a aparência dos tecidos, assim como na estrutura celular dos órgãos dos animais do estudo agudo e subcrônico. No entanto, diferenças significativas foram verificadas entre osmachos do grupo experimental e controle quanto à hemoglobina e leucócitos. Conclui-se que o extrato estudado não induziu nenhum risco na maioria dos parâmetros avaliados e, ainda, mostrou efeito antinociceptivo. No entanto, o aumento dos níveis dehemoglobina e leucócitos devem ser melhor investigados.