ABSTRACT
Objective:To evaluate the antibacterial activity and neuroprotective capacity of the ethanolic and aqueous extracts of Tarenaya spinosa (T.spinosa) as well as to determine and quantify some of its polyphenols by high performance liquid chromatography with diode-array detection (HPLC-DAD).Methods:The bacterial Escherichia coli,Staphylococcus aureus and Pseudomonas anuginosa strains,grown in Heart Agar Infusion,were tested.The drugs gentamicin,norfloxacin and imipenem were used to evaluate the modulating or antagonistic capacity of the T.spinosa extracts.The extract was analysed by HPLC-DAD to determine the main phenolic compounds.For the cell viability tests.individual heads of the Nauphoeta cinerea arthropod model were removed,homogenized in Trifluoromethyl ketone and centrifuged afterwards.Subsequently,20 μL of NaNO2 were added to the biological material,except in the control group,to evaluate the protection capacity of the extracts.The homogenate of the insect heads was incubated for 2 h in tubes containing tetrazolium bromide.Results:HPLC-DAD demonstrated that the ethanolic extract of T.spinosa presented caffeic acid as the major compound.The ethanolic extract also showed neuroprotective effects at concentrations ≥ 10 μg/mL,while aqueous extract was shown to have a protective effect only at the concentration of 100 μg/ mL.The aqueous extract demonstrated a clinically relevant antibacterial activity against the Staphylococcus aureus multidrug resistant strain-MDR,with MIC 512 μg/mL.However,when the extracts were associated with gentamicin and imipenem,a synergism was detected against Staphylococcus aureus and Escherichia coli MDR strains.Conclusions:Although it does not present an antibacterial action,the extracts of T.spinosa can be used in the pharmaceutical industries since its extracts show modulating action of drugs.Besides,these natural products have neuroprotective capacity.
ABSTRACT
Objective: To establish the chemical profile, and to evaluate the antibacterial and modulatory activity of the ethanolic extracts of the stalk's inner bark and heartwood of Secondatia floribunda. Methods: Quantification of total phenols and flavonoids was determined by the Folin-Ciocalteu method and aluminum chloride, respectively. Phenolic compounds were identified and quantified by HPLC-DAD (High Performance Liquid Chromatography-Diodearray Detector) and the Infrared Spectroscopy was performed using the measure by Attenuated Total Reflectance with Fourier Transform (ATR-FTIR). Antibacterial assays for determination of the Minimum Inhibitory Concentration (MIC) and modifi-cation of aminoglycosides were performed by microdilution. Results: Infrared spectra showed similar characteristics, having among its main absorption bands hydroxyl group (OH). The antibacterial activity showed clinically significant results for the strains of Staphylococcus aureus and Escherichia coli. In modulation assay, synergic and antagonistic effect for both extracts was observed. Heartwood extract in combination with antibiotics showed a significant MIC reduction at 19.8％(P<0.0001)-79.3％(P<0.01). Conclusions: This study is the first report of chemical and biological information of Secondatia floribunda suggesting that it is clinically relevant source of a new antibacterial therapy, especially due to the presence of significant levels of phenolic compounds.
ABSTRACT
Objective: To investigate the phenolic compounds composition and the inhibitory activity ofMangifera indica (M. indica) and Mucuna urens (M. urens) seeds extracts against some key enzymes (α-amylase, α-glucosidase and aldose reductase) implicated in the pathology and complications of type 2 diabetes in vitro. Methods: Reverse phase chromatographic quantification of the major flavonoids and phenolic acids in the seeds extracts was carried out using high performance liquid chromatography coupled with diode array detection. The inhibitory activities of the seeds extracts against α-amylase andα-glucosidase were estimated using soluble starch and ρ-nitrophenylglucopyranoside as their respective substrates. Inhibition of aldose reductase activity by the extracts was assayed using partially purified lens homogenate of normal male rat as source of enzyme; inhibition of Fe2+-induced lipid peroxidation by extracts was tested in rat pancreas homogenate.Results:The chromatography result revealed that extracts of both seeds had appreciable levels of some major flavonoids and phenolic acids of pharmacological importance, including gallic acid, chlorogenic acid, caffeic acid, ellagic acid, catechin, rutin, quercitrin, quercetin and kaempferol. Extracts of both seeds effectively inhibited α-amylase, α-glucosidase and aldose reductase activities in a dose-dependent manner, having inhibitory preference for these enzymes in the order of aldose reductase>α-glucosidase>α-amylase. With lower half-maximal inhibitory concentrations (IC50) against α-amylase, α-glucosidase, and aldose reductase, M. indica had stronger inhibitory potency against these enzymes than M. urens. Extracts of both seeds also inhibited Fe2+-induced lipid peroxidation in a dose-dependent pattern, with M. indica being more potent than M. urens.Conclusions:The results obtained provide support for a possible use of M. indica and M. urens seeds in managing hyperglycemia and preventing the complications associated with it in type 2 diabetes.