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 identify the main chemical classes of compounds from aqueous extract of Enterolobium contortisiliquum (E. contortisiliquum) seed bark and to evaluate its anti-bacterial activity, as well as its potential to increase the activity of antibiotics against strains of Staphylococcus aureus,Pseudomonas aeruginosa and Escherichia coli. Methods: Different classes of compounds in the aqueous extract of E.contortisiliquum were evaluated based on the visual changes in the coloration and the formation of pre-cipitate after the addition of specific reagents.The antibacterial activity of the extract and its potential to increase of antibiotic activity of antibiotics drugs, gentamicin and nor-floxacin was determined by using the microdilution method. Results: Our results demonstrated that the following secondary metabolites were pre-sented in E. contortisiliquum seed bark: flavones, flavonols, xanthones, flavononols, chalcones, aurones,flavones and catechins. The extract itself had very low antibacterial activity against all bacterial strains tested (MIC ≥ 1 024 μg/mL), but there was an in-crease in the antibiotic activity of gentamicin and norfloxacin when combined in the sub-inhibitory concentration (i.e.,MIC/8). Conclusions: Our data suggests that E.contortisiliquum seed bark may be an alternative source for new drugs with the potential to increase antibiotic activity against different strains of bacteria.
ABSTRACT
Objective: To evaluate the antioxidant and radical scavenging activities of Solanum anguivi fruit (SAG) and its possible effect on mitochondrial permeability transition pore as well as mitochondrial membrane potential (ΔΨm) isolated from rat liver. Methods: Antioxidant activity of SAG was assayed by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power, iron chelation and ability to inhibit lipid peroxidation in both liver and brain homogenate of rats. Also, the effect of SAG on mitochondrial membrane potential and mitochondrial swelling were determined. Identification and quantification of bioactive polyphenolics was done by HPLC-DAD. Results: SAG exhibited potent and concentration dependent free radical-scavenging activity (IC50/DPPH=275.03±7.8 μg/mL). Reductive and iron chelation abilities also increase with increase in SAG concentration. SAG also inhibited peroxidation of cerebral and hepatic lipids subjected to iron oxidative assault. SAG protected against Ca2+ (110 μmol/L)-induced mitochondrial swelling and maintained theΔΨm. HPLC analysis revealed the presence of gallic acid [(17.54±0.04) mg/g], chlorogenic acid (21.90±0.02 mg/g), caffeic acid (16.64±0.01 mg/g), rutin [(14.71±0.03) mg/g] and quercetin [(7.39±0.05) mg/g]. Conclusions:These effects could be attributed to the bioactive polyphenolic compounds present in the extract. Our results suggest that SAG extract is a potential source of natural antioxidants that may be used not only in pharmaceutical and food industry but also in the treatment of diseases associated with oxidative stress.