Polyphenols rich fraction from Geoffroea decorticans fruits flour affects key enzymes involved in metabolic syndrome, oxidative stress and inflammatory process.

Geoffroea decorticans (chañar), is widely distributed throughout Northwestern Argentina. Its fruit is consumed as flour, arrope or hydroalcoholic beverage. The chañar fruits flour was obtained and 39 phenolic compounds were tentatively identified by HPLC-MS/MS(n). The compounds comprised caffeic acid glycosides, simple phenolics (protocatechuic acid and vanillic acid), a glycoside of vanillic acid, p-coumaric acid and its phenethyl ester as well as free and glycosylated flavonoids. The polyphenols enriched extract with and without gastroduodenal digestion inhibited enzymes associated with metabolic syndrome, including α-amylase, α-glucosidase, lipase and hydroxyl methyl glutaryl CoA reductase. The polyphenolic extract exhibited antioxidant activity by different mechanisms and inhibited the pro-inflammatory enzymes (ciclooxygenase, lipoxygenase and phospholipase A2). The polyphenolic extract did not showed mutagenic effect by Ames test against Salmonella typhimurium TA98 and TA100 strains. These findings add evidence that chañar fruit flour may be considered a functional food with preventive properties against diseases associated with oxidative stress, inflammatory mediators and metabolic syndrome.

An improved DNA isolation technique for PCR detection of Strongyloides stercoralis in stool samples.

Strongyloides stercoralis is a nematode that causes severe infections in immunocompromised patients. The low parasitic burden of chronically infected patients makes diagnosis difficult to achieve by conventional methods. Here, an in-house (IH) method for the isolation of parasite DNA from stools and a PCR assay for the molecular diagnosis of S. stercoralis were optimized. DNA yield and purity improved with the IH method which included a step of incubation of stool samples with a glycine-SDS buffer and mechanical disruption prior to DNA extraction. For the PCR assay, the addition of bovine serum albumin was required to neutralize inhibitors present in stool. The analytical sensitivity of the PCR using DNA as template, isolated with the IH method, was superior to the commercial one. This study demonstrates that a combined method that adds the step of glycine-SDS buffer incubation plus mechanical disruption prior to DNA isolation with the commercial kit increased PCR sensitivity to levels of the IH method. Finally, our assay was tested on 17 clinical samples. With the IH method for DNA isolation, a S. stercoralis specific band was detected by PCR in the first stool sample in all patients (17/17), while with the commercial kit, our S. stercoralis-specific band was only observed in 7 samples. The superior efficiency of the IH and combined methods over the commercial kit was demonstrated when applied to clinical samples with low parasitic burden. These results show that the DNA extraction procedure is a key to increase sensitivity of the S. stercoralis PCR assay in stool samples. The method developed here could help to improve the molecular diagnosis of S. stercoralis.

Bioaccumulation and transformation of methylmercury and selenite using zebrafish (Danio Rerio) larvae as a model.

Bioaccumulation and possible transformation of methylmercury and selenite has been checked on a 72 h-cycle of bioaccumulation and depuration using larvae from zebrafish. The larvae were exposed to methylmercury and selenite at concentrations of 1% and 0.1% of their LC(50) values. Quantitative extraction of methylmercury and selenite from exposed larvae was achieved by using ultrasonic probe-assisted extraction (USP), thus reducing extraction time and solvent consumption. Extracted species collected at different exposure times were characterized and quantified by liquid chromatography coupled to ICP-MS. Bioconcentration factors (BCFs) were estimated by two procedures: (i) as the ratio of the contaminant concentration in larvae and exposure media (BCF(48 h)) and (ii) fitting contaminant concentration in larvae to bioaccumulation models that describe uptake and depuration processes (BCF(k)). The BCFs obtained for methylmercury were 5000 and 2333 for larvae exposed to 1 µg L(-1) and 10 µg L(-1), respectively; while for selenite the BCF was 74 for larvae exposed to 10 µg L(-1). The good correlation between the BCFs found and those previously reported in the literature shows the proposed method as a good and promising alternative to the OECD Bioconcentration Test 305. Actually, the use of zebrafish larvae reduces the bioaccumulation test time from forty two (OECD Bioconcentration Test 305) to three days. In addition, potential biotransformation of both methylmercury and selenite was evaluated by LC-ICP-MS. For this purpose, a method for species extraction in small size samples by using ultrasonic probe sonication was developed.

Comparative study of antioxidant and anti-inflammatory activities and genotoxicity of alcoholic and aqueous extracts of four Fabiana species that grow in mountainous area of Argentina.

ETHNOPHARMACOLOGICAL RELEVANCE: Fabiana species (Solanaceae family) extracts have long been used in Argentinean traditional medicine as anti-inflammatories, antiseptic, bone fractures and others diseases, but there is no scientific evidence which supports their use. AIM OF THE STUDY: The present study was conducted to evaluate the ability of aqueous and ethanolic extracts of four Fabiana species (Fabiana bryoides Phil., Fabiana punensis A.C. Arroyo, Fabiana densa J. Rèmy and Fabiana patagonica Speg.) to inhibit key enzymes in inflammatory processes, free radical scavenging properties and genotoxic effects. MATERIALS AND METHODS: HPLC-DAD of aqueous and ethanolic extracts from four Fabiana species was established. All Fabiana extracts were evaluated on their ability to inhibit hyaluronidase and lipoxygenase enzymes to assess their activity against inflammatory mediators. Antioxidant capacity was determined using the 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assays and ß-carotene-linolenic acid assay. Genotoxicity was evaluated by the Ames assay. RESULTS: The results indicated that the chromatographic patterns of four Fabiana species were different in quantity and absorption intensity of peaks. The alcoholic extract of Fabiana punensis was the most active scavenger of DPPH and ABTS(+) radicals (SC(50) values of 3.85 ± 0.24 and 2.56 ± 0.10 µgGAE/mL, respectively). Fabiana patagonica extracts exhibited the highest peroxyl radical scavenging activity compared with the other three taxa (IC(50) values between 1.00 ± 0.04 and 4.46 ± 0.40 µg GAE/mL for all extracts) and anti-lipoxygenase activity with IC(50) values between 12.5 and 15.5 µg GAE/mL. The absence of mutagenicity indicates that the DNA does not seem to be a relevant target for these extracts. Fabiana bryoides ethanolic extract showed an interesting effect: it inhibited spontaneous mutagenesis, which could be considered as an antimutagenic effect in the TA98 (+S9) and TA100 (+S9/-S9) strains. The potency differences found between the species could be consequence of the different phytochemical pattern observed by HPLC. CONCLUSIONS: The inhibitory effects on lipoxygenase and hyaluronidase, free radical scavenging activities and lack of genotoxicity of Fabiana extracts may support the folk use of Fabiana punensis, Fabiana patagonica, Fabiana bryoides and Fabiana densa as inhibitor of inflammatory mediators.

Antimicrobial activity of selected plant species from "the Argentine Puna" against sensitive and multi-resistant bacteria.

AIM: The plant species reported here are traditionally used in the "Puna" or "Altiplano" of Argentina for ailments related to bacterial infections. The aim of this study was to evaluate their antimicrobial properties against a panel of sensitive and multi-resistant gram-positive and gram-negative bacteria. MATERIALS AND METHODS: The antimicrobial activity of tinctures and aqueous extracts (Baccharis boliviensis, Chiliotrichiopsis keidelii, Chuquiraga atacamensis, Fabiana bryoides, Fabiana densa, Fabiana punensis, Frankenia triandra, Parastrephia lucida, Parastrephia lepidophylla, Parastrephia phyliciformis, Tetraglochin cristatum) was determined using the agar macrodilution and broth microdilution methods recommended by the Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS). The antibiotic resistant clinical strains were isolated from nosocomial infection in human lesions of skin and soft parts. RESULTS: The ethanolic extracts of 11 plant species inhibited the growth of one or more of the following strains: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae, Morganella morganii, Pseudomonas aeruginosa. Ethanol extracts (tinctures) of aerial parts of Baccharis, Fabiana and Parastrephia showed the highest levels of antibacterial activity on methicillin, oxacillin and gentamicin resistant Staphylococcus with MIC values from 20 to 150 microg/ml. Baccharis boliviensis and Fabiana bryoides were more active than the other plant species on Enterococcus faecalis with different phenotype. The most interesting activity on multi-resistant gram-negative strains was obtained from Chuquiraga atacamensis. Parastrephia species showed activity against Enterobacter cloacae, Pseudomonas aeruginosa and Proteus mirabilis. The ethanolic extracts exhibited stronger activity and broader spectrum of action than aqueous extracts. The extracts were bactericidal in most cases. CONCLUSIONS: The presence of antibacterial activity in Puna plant extracts against multi-resistant bacteria give support to their traditional use for treating conditions associated with microorganisms in humans and animals and consequently seems promising for the treatment of multi-resistant bacteria.