Octanoic Acid-Enrichment Diet Improves Endurance Capacity and Reprograms Mitochondrial Biogenesis in Skeletal Muscle of Mice.

Background: Medium Chain Fatty Acids (MCFAs) are a dietary supplement that exhibit interesting properties, due to their smaller molecular size. The acute consumption of MCFAs is expected to enhance exercise performance. However, the short-term effects of MCFAs on endurance performance remains poorly understood. The aim of our study is to evaluate the octanoic acid (C8)-rich diet effect on endurance capacity, and to explore their molecular and cellular effects. Methods: C57BL/6J mice were fed with a chow diet (Control group) or an octanoic acid-rich diet (C8 diet) for 6 weeks. Spontaneous activity, submaximal and maximal exercise tests were carried out to characterize the exercise capacities of the mice. Beta-oxidation and mitochondrial biogenesis pathways were explored in skeletal muscle by RT-qPCR, Western Blot (Quadriceps) and histochemical staining (Gastrocnemius). Results: Mice fed with a C8-rich diet presented a higher spontaneous activity (p < 0.05) and endurance capacities (p < 0.05) than the control, but no effect on maximal effort was observed. They also presented changes in the skeletal muscle metabolic phenotype, with a higher number of the oxidative fibers, rich in mitochondria. At the molecular level, the C8-diet induced an AMPK activation (p < 0.05), associated with a significant increase in PGC1a and CS gene expression and protein levels. Conclusion: Our study provided evidence that C8-enrichment as a food supplementation improves endurance capacities and activates mitochondrial biogenesis pathways leading to higher skeletal muscle oxidative capacities.

Genetic diversity and verbascoside content in natural populations of Pyrostegia venusta (Ker Gawl.) Miers.

BACKGROUND: Pyrostegia venusta (Ker Gawl.) Miers occurs in threatened biodiversity hotspots of Cerrado and Atlantic forest biomes in Brazil and is used in traditional medicine to treat various respiratory and skin diseases. METHODS AND RESULTS: This study (i) examined the genetic diversity and structure of six natural populations of P. venusta from different Brazilian regions using sequence-related amplified polymorphism (SRAP) markers; and (ii) compared the intra- and inter-populational levels of the bioactive component verbascoside using high-performance liquid chromatography. The population from Nova Mutum, Mato Grosso, presented the highest genetic variability (Nei index H = 0.2759; Shannon index I = 0.4170; 85.14% polymorphic loci), whereas the population from Araxá, Minas Gerais, presented the lowest genetic variability (H = 0.1811; I = 0.2820; 70.27% polymorphic loci). The intra-populational variability (79%) was significantly higher (p = 0.001) than the inter-populational variability (21%). The populations were clustered into two groups but their genetic differentiation was not associated with geographical origin (Mantel test, r = 0.328; p > 0.05). The verbascoside content significantly differed (p > 0.05) among the six populations and between the individuals from each population. The highest verbascoside levels (> 200 µg/mg extract) were detected in populations from Araxá and Serrana, while the lowest verbacoside levels were detected in populations from Paranaíta and Sinop. CONCLUSIONS: This is the first report on the use of SRAP markers to analyze genetic variability in the family Bignoniaceae. Our findings shall help to better understand the genetic and chemical diversity of P. venusta populations, as well as provide useful information to select the most appropriate individuals to prepare phytomedicines.

Momordica charantia L. improves airway hyperresponsiveness and suppresses inflammation in a murine model of allergic asthma.

OBJECTIVE: To evaluate the effect of a hydroethanolic extract of Momordica charantia L. ("bitter melon", Cucurbitaceae) leaves (MCHA) on ovalbumin (OVA)-induced asthma model. Balb/c mice were sensitized twice and challenged for 4 alternate days with OVA and then treated with MCHA (500 mg/kg) for 7 consecutive days. METHODS: Control groups received treatment with normal saline or dexamethasone (2 mg/kg) on the same day. We assessed in vivo bronchial hyperresponsiveness and ex-vivo inflammation and mucus production in bronchoalveolar lavage (BAL), lung homogenates, and lung tissue. RESULTS: MCHA significantly improved airway hyperresponsiveness near baseline levels. MCHA administration significantly improved airway and lung inflammation, demonstrated by decreased total and inflammatory cells in BAL, lower levels of IL-5 and IL-13 in lung homogenate, and fewer inflammatory cells in lung tissue. Additionally, MCHA significantly diminished goblet cells in lung tissue. CONCLUSIONS: Administration of a hydroethanolic extract of M. charantia leaves was effective in treating OVA-induced asthma in an animal model.

Genetic diversity among genotypes of Uncaria guianensis (Aubl.) J.F. Gmel. maintained in an in vitro germplasm bank.

Phytotherapeutic preparations from Uncaria guianensis (Aubl.) J.F. Gmel. (Rubiaceae) are marketed worldwide and are mainly used for their anti-inflammatory activity. The species has not yet been domesticated and is threatened by deforestation and overexploitation. It is, therefore, important to preserve and manage this genetic resource in germplasm banks, so that the extractive provision of plant material can be replaced by cultivated production. The aim of this study was to evaluate the genetic diversity among 20 genotypes maintained under in vitro conditions using 9 primers start codon targeted (SCoT) polymorphism, and to determine the concentrations of the pentacyclic oxindole alkaloids (POAs); mitraphylline and isomitraphylline in methanolic extracts by high-performance liquid chromatography (HPLC). Plantlets were cultivated on woody plant medium supplemented with 20 g.L-1 sucrose and 4.4 µM benzylaminopurine and incubated under a 16 h photoperiod for 45 days. SCoT analysis separated the genotypes into four divergent clusters and confirmed significant genetic diversity with up to 70% dissimilarity. Moreover, HPLC revealed considerable chemical variability and allowed the separation of the tested genotypes into high, medium and low producers of mitraphylline/isomitraphylline. Genotypes with the highest concentrations of POAs originated from the state of Acre and Amapá, while those with the lowest levels were from the state of Pará. The results demonstrate that the genetic diversity within the in vitro germplasm bank is sufficient to support breeding studies, selection of elite genotypes and the large-scale multiplication of plants that could serve as feedstock for the industrial-scale production of phytomedicines. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-03016-y.

Aqueous extracts from Uncaria tomentosa (Willd. ex Schult.) DC. reduce bronchial hyperresponsiveness and inflammation in a murine model of asthma.

ETHNOPHARMACOLOGICAL RELEVANCE: Uncaria tomentosa (Willd. Ex Schult) DC is used by indigenous tribes in the Amazonian region of Central and South America to treat inflammation, allergies and asthma. The therapeutic properties of U. tomentosa have been attributed to the presence of tetracyclic and pentacyclic oxindole alkaloids and to phenolic acids. AIMS OF THE STUDY: To characterize aqueous bark extracts (ABE) and aqueous leaf extracts (ALE) of U. tomentosa and to compare their anti-inflammatory effects. MATERIALS AND METHODS: Constituents of the extracts were identified by ultra performance liquid chromatography-mass spectrometry. Anti-inflammatory activities were assessed in vitro by exposing lipopolysaccharide-stimulated macrophage cells (RAW264.7-Luc) to ABE, ALE and standard mitraphylline. In vivo assays were performed using a murine model of ovalbumin (OVA)-induced asthma. OVA-sensitized animals were treated with ABE or ALE while controls received dexamethasone or saline solution. Bronchial hyperresponsiveness, production of Th1 and Th2 cytokines, total and differential counts of inflammatory cells in the bronchoalveolar lavage (BAL) and lung tissue were determined. RESULTS: Mitraphylline, isomitraphylline, chlorogenic acid and quinic acid were detected in both extracts, while isorhyncophylline and rutin were detected only in ALE. ABE, ALE and mitraphylline inhibited the transcription of nuclear factor kappa-B in cell cultures, ALE and mitraphylline reduced the production of interleukin (IL)-6, and mitraphylline reduced production of tumor necrosis factor-alpha. Treatment with ABE and ALE at 50 and 200 mg kg-1, respectively, reduced respiratory elastance and tissue damping and elastance. ABE and ALE reduced the number of eosinophils in BAL, while ALE at 200 mg kg-1 reduced the levels of IL-4 and IL-5 in the lung homogenate. Peribronchial inflammation was significantly reduced by treatment with ABE and ALE at 50 and 100 mg kg-1 respectively. CONCLUSION: The results clarify for the first time the anti-inflammatory activity of U. tomentosa in a murine model of asthma. Although ABE and ALE exhibited distinct chemical compositions, both extracts inhibited the production of pro-inflammatory cytokines in vitro. In vivo assays revealed that ABE was more effective in treating asthmatic inflammation while ALE was more successful in controlling respiratory mechanics. Both extracts may have promising applications in the phytotherapy of allergic asthma.

A standardized methanol extract of Eclipta prostrata (L.) L. (Asteraceae) reduces bronchial hyperresponsiveness and production of Th2 cytokines in a murine model of asthma.

ETHNOPHARMACOLOGICAL RELEVANCE: Eclipta prostrata (L.) L. (Asteraceae) has been used in Brazilian traditional medicine to treat asthma and other respiratory illnesses. AIMS OF THE STUDY: To investigate the effects of different doses of a standardized extract of E. prostrata using a murine model of allergen induced asthma. MATERIALS AND METHODS: Balb/c mice were sensitized twice with ovalbumin (OVA) administered intraperitoneally and challenged over four alternate days with nasal instillations of OVA solution. The standardized methanol extract of E. prostrata was administered in doses of 100, 250 and 500mgkg-1 concomitantly with nasal instillation over seven consecutive days. Control animals were treated with dexamethasone or saline solution. Bronchial hyperresponsiveness, production of Th1 and Th2 cytokines, allergen sensitization, airway and lung inflammation, mucous secretion and airway remodeling were assessed. RESULTS: The concentrations of chemical markers in the standardized methanol extract were 0.02% oroboside, 1.69% demethylwedelolactone and 1.71% wedelolactone. Treatment with 250mgkg-1 of extract, which provided 0.745, 4.22 and 4.30mgkg-1day-1 of oroboside, demethylwedelolactone and wedelolactone, respectively, significantly reduced (P<0.05) respiratory resistance and elastance. Such effects were comparable with those produced by dexamethasone. The total number of inflammatory cells and eosinophils in the bronchoalveolar lavage and the concentrations of interleukin (IL)-4, IL-5 and IL-13 in lung homogenate were significantly reduced (P<0.05) by the methanol extract of E. prostrata. CONCLUSION: The results presented herein demonstrate for the first time the anti-inflammatory activity of E. prostrata in a murine model of asthma, thereby supporting the ethnopharmacological uses of the plant.