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Objective: To reach the recovery and identification of antioxidant polyphenolic compounds from Nephelium lappaceum L. (Mexican variety) husk using ultrasound-assisted extraction and liquid chromatography/mass spectrometry as well as the in vitro antioxidant activity. Methods: Rambutan husk extracts were obtained by ultrasound-assisted extraction, mass/ volume ratio, water/ethanol percentage and extraction time were evaluated. Once the best extraction condition of polyphenolic compounds was defined, a polyphenolic fraction was recovered using Ambetlite XAD-16. The total content of antioxidant polyphenolic compounds was determined by summation of the total hydrolysable polyphenol and total condensed polyphenol contents. Recovered compounds were identified by FTIR (ATR) spectroscopy and HPLC/ESI/MS. The antioxidant activity was carried out by ABTS, DPPH and lipid oxidation inhibition in vitro methods. Results: In Mexican variety rambutan husk, the total polyphenolic content was 487.67 mg/g, after ultrasound-assisted extraction. According to the HPLC/ESI/MS analysis 12 antioxidant polyphenolic compounds were identified, mostly ellagitannins such as geraniin, corilagin and ellagic acid. The antioxidant activity determined by ABTS, DPPH and lipid oxidation inhibition methods was demonstrated. The main functional groups of the identified compounds were determined by FTIR analysis. Conclusions: It was demonstrated that ultrasound-assisted extraction was effective and allowed the extraction and recovery of antioxidant polyphenolic compounds. Furthermore Mexican variety rambutan husk is an important source for recovering polyphenolic compounds with antioxidant activity, these compounds have potential application for the treatment/prevention of various diseases related to cancer and pathogenic microorganisms.

Background and aim. Acetylsalicylic acid (ASA) has been shown to downregulate HCV expression; however, the involved mechanisms are unknown. We used proteomic analysis to compare protein expression profiles between human hepatocarcinoma cells (Huh7) and Huh7-HCV cells harboring expression of non-structural HCV proteins, to elucidate the mechanism(s) involved in ASA-mediated downregulation of HCV replication.Material and methods. Both cell lines were treated or untreated with 4 mM ASA and harvested at 0, 24, 48 and 72 h to isolate total proteins, which were resolved by two-dimensional gel electrophoresis (2DE) to separate them by isoelectric point (pI), followed by fractionation by molecular weight (MW). Gels were scanned and analyzed with PD-Quest software V8.0.1, and proteins were elucidated by the specific pI and MW using TAGIDENT software. Statistics analysis included the t-test.Results and Discussion. Different protein patterns among hepatocytes expressing HCV-proteins in ASA treated and untreated cells were found. Among proteins differentially expressed in Huh7-HCV cells, we found proteins related to cell proliferation (MTMR6, FAM22, HDGF and HCF–1) after 24 h of ASA treatment; and upregulation of angiostatin, PI4KA and STAT–1 after 48 h of treatment. Finally, at 72 h of ASA exposure, we identified overexpression of adenyl-succinate synthase, 2’–3’-di-deoxyadenosine, ubiquitin-protein-ligase E6A, adenylosuccinate-lyase and ni-brin (NBN).Conclusion. We found that ASA induces different protein patterns in Huh7-HCV cells promoting activation of proteins involved in cell progression, repair of double strand breaks, proliferation, inhibition of apoptosis and growth stimulation at the same time that it decreased HCV expression.

This work was performed to study Castilla Rose (Purshia plicata) as a potential source of polyphenols obtained by solid-state fermentation (SSF)-assisted extraction using the microorganism Aspergillus niger GH1 and to evaluate the antioxidant activity of the extracted compounds. First, water absorption capacity (WAC) of the plant material, radial growth of the microorganism, determination of best fermentation conditions, and maximum accumulation time of polyphenols were tested. Then, a larger-scale fermentation, polyphenols isolation by column liquid chromatography (Amberlite XAD-16) and recovered compounds identification by HPLC-MS were made. Finally, the antioxidant activity of the recovered compounds was tested by ABTS, DPPH, and lipid oxidation inhibition assays. The best fermentation conditions were temperature 25 °C and inoculum 2 × 106 spores/g, while the maximum extraction time of polyphenols was 24 h (173.95 mg/g). The HPLC/MS analysis allowed the identification of 25 different polyphenolic compounds, and the antioxidant activity of the obtained polyphenols was demonstrated, showing ABTS assay the most effective with inhibition of 94.34%. [ABSTRACT FROM AUTHOR]