Adrián Paredes

Antimicrobial activity of three baccharis species used in the traditional medicine of Northern Chile.

The antimicrobial activities of aqueous ethanol and chloroform extracts of three Baccharis species currently used in Northern Chile folk medicine for the treatment of several infectious and inflammatory disorders were tested against Gram-positive and negative bacteria and fungal spp. using the agar-disc diffusion assay. The results indicated that the activity was more pronounced against Gram-positive than against Gram-negative bacteria and yeast. No significant differences on the antibacterial activity were observed in the aqueous ethanol versus chloroform extracts. None of the plant extracts evaluated exhibited any activity against ten fungi tested.

SECONDARY METABOLITES FROM FOUR MEDICINAL PLANTS FROM NORTHERN CHILE: ANTIMICROBIAL ACTIVITY AND BIOTOXICITY AGAINST Artemia salina

Antibacterial activity and biotoxicity against Artemia salina of chloroform and alcohol extracts and isolated products from four plants used in ethnomedicine in northern Chile is reported. Nine compounds already identified were isolated from aerial parts of Artemisia copa Phil., Acantholippia punensis Botta, Ephedra andina Poepp. ex C. A . Mey and Haplopappus rigidus Phil : 3,5 xad dihydroxy xad 6, 7, 3, 4 xad tetramethoxyflavone, lupeol, b xad amyrine , b xad sitosterol, ephedrine, 2 xad ethylhexanol phthalate , 18 xad acetoxy xad cis xad cleroda xad 3,13 Z xad dien xad 15 xad oic acid, 5,4 xad dihydroxy xad7xad methoxyflavanone and 3,5,7 xad trihydroxy xad 6, 4 xad dimethoxyflavone

Acute oral toxicity and anti-inflammatory activity of hydroalcoholic extract from Lampaya medicinalis Phil in rats

BackgroundAlgesia and inflammation are related with several pathological conditions. It is known that many drugs available for the treatment of these problems cause unwanted side effects. This study was aimed at evaluating acute toxicity and anti-inflammatory activity of Lampaya medicinalis Phil. (Verbenaceae) widely used in the folk medicine of Northern Chile against rheumatism, arthritis and body joints pain.ResultsOral administration of hydroalcoholic extract (HAE) at the highest dose of 3000 mg/ Kg body weight resulted in no mortalities or evidence of significant behavioral changes. Histological examination revealed normal architecture and no significant adverse effects were observed on the liver, kidney, heart, lung or ovaries and testicles. The results suggest that the oral administration of hydroalcoholic extract (HAE) from Lampaya medicinalis did not produce any toxic effect in rats. Hydroalcoholic extract (HAE) significantly inhibited the carrageenan-induced rat paw edema in dose – response relationship, at test doses of 37.5, 75, 150 and 300 mg/Kg body weight. Maximum inhibition (61.98u2009±u20092.69%) was noted at 300 mg/Kg after 2 h of drug treatment carrageenan induced paw edema, whereas indomethacin produced 47.90u2009±u20091.16% of inhibition. The inhibitory values of edema at 3 h postcarrageenan were 31.04±0.75%, 40.51u2009±u20092.36%, 48.97u2009±u20091.14% and 56.87u2009±u20090.41% for 37.5, 75, 150, and 300 mg/kg of extract respectively. Indomethacin (10 mg/Kg) gave a percentage inhibition of 49.44u2009±u20091.44. HAE (300 and 150 mg/kg) induced an anti-inflammatory effect greater than (or comparable) with the effect of indomethacin from 2nd to 4th hours of the experiment.ConclusionsOur results reveal for first time that compounds contained in the hydroalcoholic extract of Lampaya medicinalis Phil exert anti-inflammatory effect and the oral administration is safe and non toxic up to dose level 3000 mg/kg body weight. The anti-inflammatory activity may be associated with the presence of flavonoids. These findings also justify the traditional use of the plant for treating pain.

Antioxidant activities of Lampaya medicinalis extracts and their main chemical constituents

BackgroundLampaya medicinalis Phil. (Verbenaceae) is a plant used by Aymara and Quechua ethnic groups from Northern Chile as folk medicine in the treatment and cure of various diseases. The aim of this study was to investigate the in vitro antioxidant activity, total phenols content, total flavonoids content, total antioxidant activity, reducing power, brine shrimp cytotoxicity and identify the principal chemical constituents.MethodsThe crude hydroethanolic extract (HEE) and its partitioned fraction: hexane (HF), dichloromethane (DF), ethyl acetate (EAF), n-butanol (BF) and soluble residual aqueous fraction (RWF) were evaluated for their antioxidant activity using different assays namely, DPPH, ABTS, FRAP, β-carotene bleaching assay. The content of total phenolics and total flavonoids were measured by Folin-Ciocalteau and by the AlCl3 colorimetric method, respectively. Reducing power was determined by phosphomolybdate and hexacyanoferrate (III) methods. Biotoxicity assays were performed on shrimps of Artemia salina. The EAF was fractionated using chromatographic methods.ResultsConsiderable amount of phenolic and flavonoid contents were recorded in the hydroethanolic extract (HEE) and its derived fractions. Although HEE and all its derived fractions exhibited good antioxidant activities, the most distinguished radical scavenging potential was observed for ethyl acetate fraction (EAF). EAF showed the higher radical scavenging activity by DPPH (95%) and by ABTS (98%), antioxidant activity by FRAP (158.18 ± 5.79xa0mg equivalent Trolox/g fraction), β-carotene bleaching assay (86.8%), the highest total phenols content (101.26 ± 1.07xa0mg GAE/g fraction), the highest total flavonoids content (66.26 ± 3.31xa0μg quercetin/g fraction). The EAF extract showed an reducing power of 78% and 65% using the phosphomolybdate and hexacyanoferrate (III) assays, respectively.Four flavonoids, two p-hydroxyacetophenone derivatives and one iridoid were isolated from Lampaya medicinalis for the first time.ConclusionEtOAc soluble fraction (EAF) shows the strongest antioxidant activity, and it can be attributed to its high content in phenolic and flavonoid compounds. It can be concluded that L.medicinalis can be used as an effective natural source of antioxidant, as ethnomedicine and as a commercial basis for the development of nutraceuticals.

Antioxidant activity of 50% aqueous--ethanol extract from Acantholippia deserticola.

The antioxidant properties oí Acantholippia deserticola, a herb used in traditional northern Chilean medicine was studied using free radical-generating systems. The 50% aqueous-ethanol extract oí Acantholippia deserticola protected against non-enzymatic lipid peroxidation in microsomal membranes of rat, induced by an Fe++-ascorbate system and measured spectrophotometrically by the TBARS test, and had strong free radical scavenging capacities on stable ABTS and DPPH radicals. The results shows that the IC50 value of the 50% aqueous-ethanolic extract of A.deserticola is 18 +/- 0.5 microg/mL in DPPH radical-scavenging, 15 +/- 0.8 microg/mL in lipid peroxidation , Total Antioxidant Activity (TAA) is 0.95 mM of Trolox per mg/mL of extract. The total phenolics content of extract is 725 +/- 12 mg of gallic acid equivalent per g of dried extract. The results indicate that the 50% aqueous-ethanol extract of Acantholippia deserticola clearly has antioxidant properties.

CONSTITUENTS OF HELENIUM ATACAMENSE Cabr.

Constituents of Helenium atacamense Cabr were investigated following a preliminary screening of the biotoxicity against Artemia salina and the antitumoral activity of ethanol extract . Three compounds already identified were isolated from aerial parts of Helenium atacamense Cabr, and their structures were elucidated as helenalin, quercetin and 3-O-methylquercetin based on mass and various nuclear magnetic resonance techniques . Quercetin and 3- O- methylquercetin were tested by using TEAC Test

Effect of phenylephrine and endothelium on vasomotion in rat aorta involves potassium uptake

Vasomotion is defined as the rhythmic contractions in blood vessels, consisting of two components: vasoconstriction and oscillations of the plasma membrane potential. To determine whether vasomotion is associated with changes in K+ uptake, we measured the effect of phenylephrine (PE) and acetylcholine (ACh) on the K+ uptake and vascular reactivity in rat aortic rings. We found that the incubation of aortic rings with 10−7xa0M PE (210xa0±xa028xa0mg maximum amplitude), and 10−6xa0M ACh (177xa0±xa06xa0mg maximum amplitude) produced the highest rhythmic contractions. Both 10−7xa0M PE and 10−6xa0M ACh significantly increased K+ uptake in endothelium-intact aorta versus control (121xa0% PE, 117xa0% ACh). Removal of the endothelium blunted rhythmic contractions and decreased K+ uptake in presence of vasoactive substances (88xa0% PE, 81xa0% ACh). The inhibition of nitric oxide synthase with 10−4xa0M l-NNA significantly reduced the rhythmic contractions, and it was reversed in the presence of 10−8xa0M sodium nitroprusside (SNP; a nitric oxide donor). Also, we found that 10−4xa0M l-NNA significantly decreased the effect of 10−7xa0M PE on K+ uptake in aortic rings (104xa0% PExa0+xa0l-NNA vs. control). The incubation of endothelium-denuded rings with 10−8xa0M SNP significantly increased the K+ uptake (116xa0% SNP vs. control), similar to those observed in the presence of 10−6 M ACh. The inhibition of protein kinase G with KT-5823 blocked SNP-mediated increase in K+ uptake. In conclusion, these data suggest that a certain range of K+ uptake is necessary to induce the rhythmic contractions in response to vasoactive substances.

Aqueous extract from leaf of Artocarpus altilis provides cardio-protection from isoproterenol induced myocardial damage in rats: Negative chronotropic and inotropic effects

ETHNOPHARMACOLOGICAL RELEVANCEnThe leaves of Artocarpus altilis (Parkinson ex F.A.Zorn, Fosberg) (Moraceae) are used in the management of hypertension; this study assessed the cardio-protective effects of the leaf extract on isoproterenol (ISO) induced myocardial damage in rats.nnnMATERIAL AND METHODSnTwenty (20) adult male Sprague-Dawley rats (175-230g) were divided into 5 groups. Group 1 (Control), 2 (AA) received 50mg/Kg Artocarpus altilis (AA) only; 3 (ISO) received 85mg/Kg ISO only; 4 (ISO+AA/50) and 5 (ISO+AA/100) received 50 and 100mg/Kg AA respectively for 6 days, after induced with ISO twice (85mg/Kg) at a 24-h period. Blood pressure readings were taken before and after the administering of ISO using the tail cuff method. ECG was performed on anaesthetized rats. Cardiac contractility was measured in isolated right atrial muscles. Assessment of myocardial infarct (MI) size, heart/body weight ratio, biochemical, hematological and histo-morphological parameters were conducted at the end of seven days. An aqueous extract from leaves of A. altilis was analyzed for organic compounds using UHPLC mass spectrometry.nnnRESULTSnISO induced myocardial damage through an elevation of the heart rate (HR), infarct size and ECG distortions. Treatment with AA significantly (p˂0.05) reduced heart/body weight ratio (49%), MI (96%), HR (27%), sympathovagal imbalance (36%) and serum cardiac biomarkers (AST, LDH, HDL, triglycerides and CCK) caused by ISO. AA decreased the beat frequency of isolated right atrium (11%) cause by ISO, an action similar to propranolol (beta-adrenergic antagonist; 20%), but showed no significant changes in the QTc intervals of the ECG (suggesting no cardio-toxic drug-herb interactions), Thirty nine compounds were detected using high resolution LC-MS analysis (HPLC-Orbitrap-APCI-MS) in the extract. Pure compounds, as gallic acid and rutin, presented a higher negative chronotropic effect, similar to propranolol.nnnCONCLUSIONnOral administration of aqueous extract of Artocarpus artilis has cardio-protective functions in myocardial injury, in part, by decreasing the HR, reduced contractility and infarct size. These findings may explain the cardio-protective use of A. altilis in traditional medicine.

Hydroalcoholic extract and pure compounds from Senecio nutans Sch. Bip (Compositae) induce vasodilation in rat aorta through endothelium-dependent and independent mechanisms.

ETHNOPHARMACOLOGICAL RELEVANCEnSenecio nutans Sch. Bip. (Compositae) is an endemic plant of South America, and is used in herbal medicine in Andean communities for treating acute mountain sickness. Currently, the direct effects of hydroalcoholic extract of S. nutans (HAE S. nutans) or its isolated compounds on the vascular system are not well described. The aim of this study was to determine the effects and mechanism of action of S. nutans on vascular function in healthy rats.nnnMATERIAL AND METHODSnSeven compounds were isolated from the HAE S. nutans, and their structures were characterized using spectroscopic techniques as 1D and 2D NMR, and mass spectrometry. Vascular reactivity experiments were carried out in rat aorta. S. nutans-dependent vasodilation and phenylephrine-dependent contraction were measured in endothelium-intact and endothelium-denuded aortic rings of male rats.nnnRESULTSnSeven pure compounds were isolate from HAE S. nutans, but two pure compounds showed significant vasodilation in rat aorta: 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone (compound E) and 5-acetyl-6-hydroxy-2-isopropenyl-2,3-dihydrobenzofurane (compound G). Although HAE S. nutans induced vasodilation in absence of endothelium, the vasodilation in intact aorta, via NO, was higher. HAE S. nutans reduced calcium-dependent contraction in endothelium-intact, but not in endothelium-denuded aortic rings.nnnCONCLUSIONnHAE S. nutans and its isolated compounds caused vasodilation in rat aorta in absence of endothelium, suggesting its vasodilator properties is endothelium-dependent (NO) and or independent, and may involve a modulation of the calcium channels. This result is of clinical interest as potential therapy control of blood pressure.

Hypotensive and antihypertensive effects of a hydroalcoholic extract from Senecio nutans Sch. Bip. (Compositae) in mice: Chronotropic and negative inotropic effect, a nifedipine-like action.

ETHNOPHARMACOLOGICAL RELEVANCEnSenecio nutans Sch. Bip. (Compositae) is an endemic plant of South America used in the management of acute mountain sickness in the Andean communities. Currently, the direct effects of hydroalcoholic extract from S. nutans on the cardiovascular system are unknown. The aim of this study was to determine the effects and mechanism of action of S. nutans on cardiovascular function in normotensive and Angiotensin II (1μg/mL) hypertension mice models.nnnMATERIAL AND METHODSnBlood pressure and ECG measurements were simultaneously carried out on the mice and rats. The isolated right atrium, papillary muscle of the left ventricle and isolated heart of rat were used to study the cardiac functions and mechanisms.nnnRESULTSnS. nutans (40mg/Kg) induced a 30% and 12% significant (p<0.05) reduction of the mean arterial pressure (MAP) in normotensive and hypertensive mice respectively. This decrease was as a result of decrease in heart rate (HR) in normotensive (25%) and hypertensive model (31%). It also decreased the sinus rhythm in isolated right atrium of rat. Compared with Losartan, a known anti-hypertensive, S. nutans caused a dose-dependent negative inotropic effect (dP/dtmax) on Langendorff isolated heart system. While Losartan, decreased the MAP by 30% but had no effect on heart rate. The calcium blocker nifedipine had similar effects as S. nutans, decreasing the beat frequency of isolated right atrium and contractility of papillary muscle of the left ventricle of rat.nnnCONCLUSIONnThe results suggest an important clinical function in hypertension therapy, as S. nutans could decrease the blood pressure in hypertensive mice by decreasing the HR and contractility, leading to a reduction in myocardial oxygen demand.