New dimer and trimer of chalcone derivatives from anti-inflammatory and antinociceptive extracts of Schinopsis brasiliensis roots.

ETHNOPHARMACOLOGY RELEVANCE: Schinopsis brasiliensis Engl. is an endemic tree of the Brazilian semi-arid regions belonging to the Anacardiaceae family. It is the main representative of the genus Schinopsis, mostly native to Brazil and popularly known as "braúna" or "baraúna". Different parts of this plant are employed in Brazilian folk medicines to treat inflammation in general, sexual impotence, cough, and influenza. AIM OF THE STUDY: This work describes the antinociceptive (acetic acid-induced writhing and formalin-induced nociception) and anti-inflammatory (paw edema and neutrophil migration) activities of the extract of the root of S. brasiliensis. Besides, the evaluation of total phenolic compounds and antioxidant, antimicrobial (including MRSA bacteria), and acetylcholinesterase inhibition activities were also determined. MATERIAL AND METHODS: The pure compounds were isolated by different chromatographic techniques and their chemical structures have been unambiguously elucidated based on extensive spectroscopic methods, including 1D (1H, 13C, DEPT, and NOEdiff) and 2D (HSQC, HMBC, and NOESY) NMR experiments, MS data, and comparison with the literature data of similar compounds. The antinociceptive and anti-inflammatory activities were evaluated by acid acetic writhing test, formalin paw edema, and by the investigation of neutrophil migration to the peritoneal cavities of mice. For antimicrobial evaluation were determined MIC and MBC, antioxidant activities were obtained by TPC and DPPH tests, and AChE inhibition by Elmann's methodology. RESULTS: The extracts showed antinociceptive and anti-inflammatory activities and two unusual new compounds, a cyclobutanyl chalcone trimer (schinopsone A) and a cyclohexene-containing chalcone dimer (schinopsone B), with six known compounds were isolated from the active extracts. Additionally, the acetylcholinesterase inhibitory activity for isolated compounds was reported for the first time in this study. Molecular docking studies indicated that the isolated compounds are responsible for the interaction with anti-inflammatory targets (COX 1 and 2 and LOX) with variable binding affinities, indicating a possible mechanism of action of these compounds. CONCLUSIONS: These findings indicate for the first time the correlation between the anti-inflammatory activity different enriched polyphenol-organic soluble fractions of S. brasiliensis, and it contributes to the understanding of the anti-inflammatory potential of S. brasiliensis.

Potential therapeutic effects of green tea on obese lipid profile - a systematic review.

Background: Green tea, obtained from the plant Camellis sinensis, is one of the oldest drinks in the world and contains numerous bioactive compounds. Studies have demonstrated the efficacy of green tea in preventing obesity and cardiovascular diseases that may be related to the reduction of lipid levels. Aim: This study aimed to evidence, through a systematic review, the therapeutic potential of green tea on the lipid profile in preclinical studies in obese animals and clinical studies in obese individuals. Methods: This systematic review follows the recommendations of the preferred report items for systematic reviews and meta-analyses. The electronic databases, PubMed (Medline), Science Direct, Scopus, and Web of Science were consulted. Articles from January 2009 to December 2019 were selected. Results: This search resulted in twenty-nine articles were included cirtically reviewed. In experimental studies, green tea administration has been shown to reduce total cholesterol, triglycerides and low-density lipoprotein cholesterol in animals exposed to obesity-inducing diet. In humans' studies green tea was not shown to be effective for obese lipid control. Because supplementation with green tea extract reduced total cholesterol, triglycerides, low-density lipoprotein for three months at a specific dose. Conclusion: Therefore, green tea appears to act as a protective agent for dyslipidemia in obesity-induced animals. In human studies, green tea has not been shown to be effective in controlling obese lipids.

Chemical Strategies towards the Synthesis of Betulinic Acid and Its More Potent Antiprotozoal Analogues.

Betulinic acid (BA, 3ß-hydroxy-lup-20(29)-en-28-oic acid) is a pentacyclic triterpene acid present predominantly in Betula ssp. (Betulaceae) and is also widely spread in many species belonging to different plant families. BA presents a wide spectrum of remarkable pharmacological properties, such as cytotoxic, anti-HIV, anti-inflammatory, antidiabetic and antimicrobial activities, including antiprotozoal effects. The present review first describes the sources of BA and discusses the chemical strategies to produce this molecule starting from betulin, its natural precursor. Next, the antiprotozoal properties of BA are briefly discussed and the chemical strategies for the synthesis of analogues displaying antiplasmodial, antileishmanial and antitrypanosomal activities are systematically presented. The antiplasmodial activity described for BA was moderate, nevertheless, some C-3 position acylated analogues showed an improvement of this activity and the hybrid models-with artesunic acid-showed the most interesting properties. Some analogues also presented more intense antileishmanial activities compared with BA, and, in addition to these, heterocycles fused to C-2/C-3 positions and amide derivatives were the most promising analogues. Regarding the antitrypanosomal activity, some interesting antitrypanosomal derivatives were prepared by amide formation at the C-28 carboxylic group of the lupane skeleton. Considering that BA can be produced either by isolation of different plant extracts or by chemical transformation of betulin, easily obtained from Betula ssp., it could be said that BA is a molecule of great interest as a starting material for the synthesis of novel antiprotozoal agents.

Phytoestrogen Agathisflavone Ameliorates Neuroinflammation-Induced by LPS and IL-1ß and Protects Neurons in Cocultures of Glia/Neurons.

Inflammation and oxidative stress are common aspects of most neurodegenerative diseases in the central nervous system. In this context, microglia and astrocytes are central to mediating the balance between neuroprotective and neurodestructive mechanisms. Flavonoids have potent anti-inflammatory and antioxidant properties. Here, we have examined the anti-inflammatory and neuroprotective potential of the flavonoid agathisflavone (FAB), which is derived from the Brazilian plant Poincianella pyramidalis, in in vitro models of neuroinflammation. Cocultures of neurons/glial cells were exposed to lipopolysaccharide (LPS, 1 µg/mL) or interleukin (IL)-1ß (10 ng/mL) for 24 h and treated with FAB (0.1 and 1 µM, 24 h). FAB displayed a significant neuroprotective effect, as measured by nitric oxide (NO) production, Fluoro-Jade B (FJ-B) staining, and immunocytochemistry (ICC) for the neuronal marker ß-tubulin and the cell death marker caspase-3, preserving neuronal soma and increasing neurite outgrowth. FAB significantly decreased the LPS-induced microglial proliferation, identified by ICC for Iba-1/bromodeoxyuridine (BrdU) and CD68 (microglia M1 profile marker). In contrast, FAB had no apparent effect on astrocytes, as determined by ICC for glial fibrillary acidic protein (GFAP). Furthermore, FAB protected against the cytodestructive and proinflammatory effects of IL-1ß, a key cytokine that is released by activated microglia and astrocytes, and ICC showed that combined treatment of FAB with α and ß estrogen receptor antagonists did not affect NF-κB expression. In addition, qPCR analysis demonstrated that FAB decreased the expression of proinflammatory molecules TNF-α, IL-1ß, and connexins CCL5 and CCL2, as well as increased the expression of the regulatory molecule IL-10. Together, these findings indicate that FAB has a significant neuroprotective and anti-inflammatory effect in vitro, which may be considered as an adjuvant for the treatment of neurodegenerative diseases.

Acetylcholinesterase inhibitory activities and bioguided fractionation of the Ocotea percoriacea extracts: HPLC-DAD-MS/MS characterization and molecular modeling of their alkaloids in the active fraction.

In vitro acetylcholinesterase activities of the hexane, dichloromethane, ethyl acetate, n-butanol and aqueous extracts of leaves of Ocotea percoriacea Kosterm. (Lauraceae) were evaluated. The bioguided fractionation of the most active extract (dichloromethane) using silica gel open-column chromatography led to an active alkaloidal fraction composed of isocorydine N-oxide, isocorydine N-oxide derivative, palmatine, roemerine and roemerine N-Oxide. The identification of the chemical structure of these compounds was carried out with high-performance liquid chromatography coupled to electrospray ionization multiple-stage mass spectrometry (HPLC-ESI-MS/MS). Aiming to understand their inhibitory activities, these alkaloids were docked into a 3D model of Electrophorus electricus Acetylcholinesterase (EelAChE) built in the Modeller 9.18 employing homology modeling approach. The results suggest that the alkaloids had the same binding mode and, possibly, the inhibition mechanism of classic drugs (ex. tacrine and donepezil). The structural difference of these compounds opens a new opportunity for the optimization of leading compounds.

Toxicological evaluation of the biflavonoid, agathisflavone in albino Swiss mice.

Agathisflavone (AGF) is a biflavonoid with a number of important biological and pharmacological activities, such as antioxidant, antimicrobial, and neuroprotective effects. However, its toxicological effects have not been fully investigated. Accordingly, the aim of this study was to investigate the toxicological effects of AGF in mice. For this purpose, the median lethal dose 50% (LD50) was determined along with the anatomic and histopathological parameters (weight, alimentation, excretion, biochemical, and hematological) in fertile untouched female Swiss mice. Results suggest that during the treatment, no deaths were reported at 300 and 2000 mg/kg (n = 03/group, p.o.). Moreover, AGF did not cause significant change in the above mentioned parameters in test animals when compared with the control group (0.05% Tween 80 dissolved in 0.9% saline). Taken all together, this non-clinical toxicological study revealed that AGF has an LD50 larger than 2000 mg/kg and did not change significantly the hematological, biochemical, histopathological, behavioral, as well as physiological parameters in the female mice.

Seasonal variation in the chemical composition of two chemotypes of Lippia alba.

Lippia alba is a popular Brazilian herb known as 'cidreira' that presents several chemotypes which exhibit different chemical profile and they are widely used as seasonings and traditional medicine. This work describes the seasonal variation of metabolites of polar extracts of carvone and linalool chemotypes, identified by GC-MS analyses of the essential oils. A methodology was elaborated in order to obtain a seasonal variation in the chemical composition of leaf employing HPLC-DAD. Acteoside, isoacteoside, geneposidic acid, 8-epi-loganin, mussaenoside, luteolin 7-O-glucoside, apigenin 7-O-glucuronide and tricin 7-O-diglucuronide have been isolated and identified for validation procedures and chromatographic analysis. Geneposidic acid was presented in all samples, in contrast to the 8-epi-loganin and, mussaenoside which were presented only in the carvone-chemotype. Acteoside was the major metabolite detected from July to November while tricin-7-O-diglucuronide was the major compound in all other months. Besides, phenylpropanoids are predominant in winter and flavonoids in summer season.

Evaluation of anti-inflammatory, antinociceptive and biological activities of Cenostigma macrophyllum standardized extracts and determination and quantification of the main metabolites.

The stem barks and leaves of Cenostigma macrophyllum are used in Brazilian folk medicines in the treatment of stomach and intestinal diseases. However, there are no reports of chromatographic methods used to evaluate the bioactives of its standardized extracts and for biological evaluation. An analytical method was developed and validated for simultaneous determination and quantification of the bioactive phenolics gallic acid, methyl gallate, ellagic acid and, the biflavonoids agathisflavone and amentoflavone in the leaves and stem bark of C. macrophyllum. HPLC operating conditions were optimized and the parameters such as selectivity, linearity, precision, accuracy, LOD, LOQ and, robustness of the method were also evaluated. Robustness was evaluated using a multivariate optimization technique. Linear relationships within the range of investigated concentrations were observed with their correlation coefficients greater than 0.9991. The method was validated for repeatability (RSD ≤ 2.88%), intermediate precision (RSD ≤ 3.38%) with recovery between 84.12 and 106.64% and the RSD less than 3.40% and proved to be robust. Besides, antioxidant, acetylcholinesterase inhibition, anti-inflammatory and antinociceptive activities of the standardized hydromethanolic extracts of leaves and stem bark of this species were evaluated. The method was successfully applied in the quantification of the gallic acid, methyl gallate, ellagic acid, agathisflavone and amentoflavone of standardized extracts. The results showed the present method developed was simple, sensitive, reproducible, accurate and precise. The standardized hydromethanolic extracts of leaves and stem bark of C. macrophyllum showed antioxidant activity (EC50 69.09 and 83.06 µg mL-1), acetylcholinesterase inhibition (52.23 and 83.36%) and they were able to inhibit the formalin-induced nociception and also reduced the edema formations at 100 mg kg-1 doses. The anti-inflammatory potentials were evaluated by the decrease of the Cg-induced neutrophils migrations at the same doses.

Cardiovascular effects of a labdenic diterpene isolated from Moldenhawera nutans in conscious, spontaneously hypertensive rats.

CONTEXT: The labdenic diterpene labd-8(17)-en-15-oic acid (labd-8) isolated from a methanolic extract of Moldenhawera nutans Queiroz & Alkin (Leguminosae) has hypotensive and tachycardiac properties in normotensive rats. A part of the hypotensive effect was due to a reduction in the sympathetic nerve drive to vessels, an event admittedly enhanced in spontaneously hypertensive rats (SHRs). OBJECTIVES: We assessed whether the cardiovascular effects induced by labd-8 could be enhanced in SHRs. MATERIALS AND METHODS: For in vivo experiments, arterial and venous catheters were implanted under anesthesia for blood pressure recording and drug administration, respectively. For in vitro experiments, thoracic aorta rings were suspended in organ baths containing warm (37 °C) perfusion medium that was continuously bubbled with carbogen. RESULTS: Intravenous injection of labd-8 (1, 3, 5, and 10 mg/kg) induced similar dose-dependent hypotension and tachycardia in both SHRs and Wistar-Kyoto rats (WKY). In SHRs, only the tachycardia response to labd-8 was significantly reduced by pretreatment with methylatropine or propranolol. However, both cardiovascular effects of labd-8 were reduced by hexamethonium while remained unchanged by l-NAME. In isolated aortic preparations from SHRs, labd-8 (1-1000 µg/mL) relaxed potassium-induced contractions with an IC50 (geometric mean [95% confidence interval]) value (536.5 [441.0-631.9] µg/mL) significantly greater than that (157.6 [99.1-250.5] µg/mL) obtained in preparations from WKY rats. CONCLUSION: In SHRs, the hypotension induced by labd-8 is associated with a reflex tachycardia and seems mediated partly through withdrawal of sympathetic vasomotor tone and partly through an active vasorelaxation. Its magnitude was not enhanced when compared with WKY rats likely because of impaired vasorelaxant effects of labd-8 in preparations from SHRs.

Cytotoxicity of the diterpene 14-O-methyl-ryanodanol from Erythroxylum passerinum in an astrocytic cells model.

Plant secondary metabolites, such as, specifically, alkaloids and terpenes, may present psychoactive properties that modify the function of the central nervous system (CNS) and induce neurotoxicity. Neurotoxicity involves the response of glial cells, mainly astrocytes, which play a fundamental role in the control of homeostasis of the CNS. Some Erythroxylum species are indigenous to the state of Bahia in Brazil. This study investigated the cytotoxic activity of the diterpene AEP-1, extracted from the fruit of E. passerinum in a GL-15 cell line, astrocytic, glial cells model. The effects on cell viability, analyzed by the MTT assay, demonstrated a dose-dependent cytotoxic effect, with maximum effect at 500 µg/mL of AEP-1, and with a reduction of about 40 and 47% on cellular viability after 24 h and 72 h treatment, respectively. Evidence for induction of apoptosis by AEP-1 was first obtained when GL-15 glial cells were incubated with 250 µg/mL AEP-1 causing reniform and/or pyknotic nuclei and apoptotic bodies revealed by chromatin staining with Hoechst 33258. Increase in DNA fragmentation was also observed by comet assays in cells incubated with 500 µg/mL of AEP-1. Moreover, cells exposed to a sub toxic dose of AEP-1 (250 µg/mL) showed significant changes in morphology--contraction of the cytoplasm and expansion of cellular projections--signifying the presence of astrocytic cytoskeletal protein and glial fibrillary acidic protein (GFAP). These findings indicated astrocytic cells as the target for terpene AEP-1 and suggest the involvement of glial cells with psychoactive symptoms observed in humans and animals after consumption of fruits of plants of the genus Erythroxylum.

Biological Effect of Leaf Aqueous Extract of Caesalpinia pyramidalis in Goats Naturally Infected with Gastrointestinal Nematodes.

Forty-eight goats naturally infected with gastrointestinal nematodes were randomly divided into four groups (n = 12): negative control (G1) (untreated), positive control (G2) (treated with doramectin, 1 mL/50 Kg b.w.), and G3 and G4 treated with 2.5 and 5 mg/Kg b.w. of a leaf aqueous extract of Caesalpinia pyramidalis (CP). Fecal and blood samples were regularly collected for the evaluation of fecal egg count (FEC), hematological and immunological parameters to assess the anthelmintic activity. In treated animals with CP, there was noted a significant reduction of 54.6 and 71.2% in the mean FEC (P < 0.05). An increase in IgA levels was observed in G3 and G4 (P < 0.05), during the experimental period, suggesting that it was stimulated by the extract administration. In conclusion, the results showed that CP provoked a protective response in infected animals treated with them. This response could be partly explained by the CP chemical composition.

Anti-leishmanial and immunomodulatory activities of extracts from Portulaca hirsutissima and Portulaca werdermannii.

Ethyl acetate and chloroform extracts from aerial parts of Portulaca werdermannii and P. hirsutissima were tested in lymphoproliferation assays and axenic cultures of Leishmania amazonensis and Trypanosoma cruzi. Both extracts of P. werdermannii and P. hirsutissima had a potent inhibitory activity on lymphocyte proliferation. On the contrary, only the chloroformic extract of both plants inhibited L. amazonensis growth, without effect on T. cruzi cultures. These results indicate these Portulaca species as potential sources of new active molecules for the treatment of leishmaniasis and immune-mediated pathologies.

Mechanisms underlying the cardiovascular effects of a labdenic diterpene isolated from Moldenhawera nutans in normotensive rats.

Cardiovascular effects of Labd-8 (17)-en-15-oic acid (Labd-8), a labdenic diterpene isolated from methanolic extract of Moldenhawera nutans were investigated in normotensive rats. Additionally, this study examined the role of autonomic nervous system in the mediation of these cardiovascular effects. In pentobarbital-anesthetized rats, bolus intravenous (i.v.) injection of Labd-8 (1-10 mg/kg) induced dose-dependent hypotensive and tachycardiac responses. After cervical bivagotomy, hypotensive responses to Labd-8 were significantly enhanced whereas the tachycardia was completely abolished. In conscious rats, Labd-8 (1-10 mg/kg, i.v.) also decreased blood pressure and increased heart rate in a dose-dependent manner. Pretreatment with methylatropine (1 mg/kg, i.v.) or propranolol (2 mg/kg, i.v.) significantly reduced the tachycardia evoked by Labd-8 without affecting the hypotension. Blockade of ganglionic neurotransmission with hexamethonium (30 mg/kg, i.v.) reduced and abolished the hypotensive and tachycardic effects of Labd-8, respectively. However, hypotensive effects of Labd-8 were not reduced by pretreatment with N(w)-nitro-L-arginine methyl ester (L-NAME; 20 mg/kg, i.v.), a nitric oxide synthase inhibitor. In rat endothelium-containing aorta preparations, Labd-8 (1-1000 micro g/ml) induced a concentration-dependent reduction of potassium (60 mM)-induced contraction [IC(50) (geometric mean +/-95% confidence interval)=313.6 (191.4-513.8) micro g/ml], an effect that remained unaffected [IC(50)=440.8 (225.1-863.3) micro g/ml] by removal of vascular endothelium. These results show that i.v. treatment with Labd-8-induced dose-dependent hypotensive and tachycardiac effects in both conscious and anesthetized rats. The tachycardia is mediated reflexly through inhibition of vagal and activation of sympathetic drive to the heart. The hypotension is mainly due to withdrawal of sympathetic tone to the vasculature and also partly to an active vascular relaxation. Released nitric oxide from vascular endothelial cells is not involved in the mediation of Labd-8-induced hypotension.

Oleanolic Acid, a pentacyclic triterpene attenuates the mustard oil-induced colonic nociception in mice.

Many natural terpenoid compounds from plants exhibit antinociceptive property but very few studies have addressed their efficacy in visceral models of nociception. The present study evaluated the antinociceptive potential of oleanolic acid, a pentacyclic triterpene in the mouse model of colonic nociception induced by mustard oil. We further examined the possible participation of opioid, alpha2-adrenergic, and transient receptor potential vanilloid 1 (TRPV1)-receptors in its mechanism. Mice were pretreated orally with oleanolic acid (3, 10, 30 mg/kg) or vehicle, and the pain-related behavioral responses to intracolonic injection of mustard oil was analysed. Oleanolic acid significantly suppressed the mustard oil-induced nociceptive behaviors at test doses of 10 and 30 mg/kg, in a dose-related manner. The antinociceptive effect of oleanolic acid (30 mg/kg) was significantly blocked by pretreatment with the opioid antagonist, naloxone (2 mg/kg, i.p.), while the alpha2-adrenoceptor antagonist, yohimbine (2 mg/kg, s.c.), had no effect. Pretreatment with ruthenium red (3 mg/kg, s.c.), a non-competitive TRPV1 antagonist alone caused significant inhibition of mustard oil-induced nociception but its co-administration with oleanolic acid produced neither antagonism nor potentiation of oleanolic acid antinociception. In the open-field test that detects sedative or motor abnormality, mice received 30 mg/kg oleanolic acid did not show any per se influence, but significantly inhibited the mustard oil-induced decrease in ambulation frequency. These data demonstrate the visceral antinociceptive potential of oleanolic acid that involves an opioid mechanism and possibly a modulatory influence on vanilloid-receptors, which needs further study.