Phytochemical, antimicrobial, antioxidant and antigenotoxic potentials of Cyperus rotundus extracts

AbstractThe aqueous, ethyl acetate, methanolic and Total Oligomer Flavonoids (TOF) enriched extracts, obtained from the aerial parts of Cyperus rotundus, were investigated for their contents in phenolic compounds. Antioxidative activity using the NBT/riboflavin assay system, antimicrobial activity against Gram positive and Gram negative bacterial reference strains as well as antigenotoxic activity tested with the SOS chromotest assay were also studied. Significant antibacterial activity against reference strains; Staphylococcus aureus, Enterococcus faecalis, Salmonella enteritidis and Salmonella typhimurium, was detected in the presence of ethyl acetate and TOF enriched extracts. In addition to their antimicrobial activity, the same extracts showed a significant ability to inhibit nitroblue tetrazolium reduction by the superoxide radical in a non enzymatic O2.− generating system, and were also able to reduce significantly the genotoxicity induced by nifuroxazide and Aflatoxin B1. The antioxidant, antimicrobial and antigenotoxic activities exhibited by C. rotundus depend on the chemical composition of the tested extracts

Physiological responses and fruit quality of four peach cultivars under sustained and cyclic deficit irrigation in center-west of Tunisia

In arid and semi-arid regions, the research and application of new irrigation techniques that economize water without altering tree performance and fruit quality is a challenge. The aim of this study was to investigate the effect of two different deficit irrigation strategies on tree physiology and fruit quality of four Prunus persica cultivars: two early-ripening cultivars (Flordastar and Early Maycrest), a mid-season cultivar (Rubirich), and a late-ripening cultivar (O'Henry). During two consecutive seasons (2016 and 2017), three different irrigation treatments were established: i) Full Irrigation (FI; 100% ET c ), ii) Sustained Deficit Irrigation (SDI; 50% ET c ) and iii) Cyclic Deficit Irrigation (CDI; trees irrigated at 100% field capacity whenever the soil moisture dropped to 50% field capacity). Tree water status, gas exchange, yield, fruit pomology and the concentrations of the main sugars and organic acids were determined. Deficit irrigation decreased net photosynthesis rate, stomatal conductance and transpiration rate while it improved instantaneous water use efficiency (WUEins). In O'Henry cultivar, WUEins increased from 3.21 μ mol mmol –1 in FI to 7.04 μmol mmol –1 in CDI during harvest. Deficit irrigation significantly reduced shoot growth in the four cultivars. Furthermore, SDI decreased the yield significantly (from 41 to 26.3 kg in O'Henry cultivar during 2016), fruit size and weight while CDI increased soluble solids and sugar contents and decreased titratable acidity. The total sugar content increased significantly under deficit irrigation in all cultivars studied. In conclusion, CDI seems to be the best strategy in semi-arid regions, since it can save water and improve fruit quality parameters

Relationship correlation of antioxidant and antiproliferative capacity of Cyperus rotundus products towards K562 erythroleukemia cells

A Total Oligomers Flavonoids (TOFs) and ethyl acetate extracts of Cyperus rotundus were analyzed, in vitro, for their antioxidant activity using several biochemical assays: the xanthine (X)/xanthine oxidase (XO), the lipid peroxidation induced by H2O2 in K562 human chronic myelogenous leukemia cells and the DNA damage in pKS plasmid DNA assay induced by H2O2/UV-photolysis and for their apoptotic effect. TOF and ethyl acetate extracts were found to be efficient in inhibiting xanthine oxidase with IC50 values of 240 and 185 μg/ml and superoxide anion with IC50 values of 150 and 215 μg/ml, respectively. Also, all the extracts tested were effective in reducing the production of thiobarbituric acid reactive substances (TBARS) and were able to protect against H2O2/UV-photolysis induced DNA damage. The highest activity, measured as equivalents of MDA concentration, was observed in the ethyl acetate extract (MDA = 2.04 nM). In addition, the data suggest that only TOF enriched extract exerts growth inhibition on K562 cells through apoptosis induction. Therefore, these extracts were subjected to further separation by chromatographic methods. Thus, three major compounds (catechin, afzelechin and galloyl quinic acid) were isolated from the TOF enriched extract and five major compounds (luteolin, ferulic acid, quercetin, 3-hydroxy, 4-methoxy-benzoic acid and 6,7-dimethoxycoumarin) from ethyl acetate extract. Their structures were determined by spectroscopic data analysis and comparison with the literature. In addition, we evaluate the biological activities of the catechin, ferulic acid and luteolin. This investigation has revealed that the luteolin was the most active in reducing the production of TBARS (MDA = 1.5 nM), inhibiting significantly the proliferation of K562 cells (IC50 = 25 μg/ml) and protecting against H2O2/UV-photolysis induced DNA damage. In conclusion, the study reveals that the ability of C. rotundus to inhibit the enzyme xanthine oxidase (XO), the lipid peroxidation and to exert apoptotic effect, may explain possible mechanisms by which C. rotundus exhibits its health benefits