ABSTRACT
Objectives: Our research measures the essential oil analysis mineral substance profiles, total phenolic substance content, free radical scavenger properties, antioxidant capacity, and enzyme inhibitory activity of Sideritis akmanii Aytaç, Ekici & Dönmez, 1996. Materials and Methods: A mixture of S. akmanii plant roots and stems were used. Essential fatty acid components of S. akmanii were determined by gas chromatography-mass spectrometry and bioelement concentrations by inductively coupled plasma optical emission spectrometry. The antioxidant activity of extracts was screened by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, total phenolic content, total antioxidant status (TAS), total oxidant status (TOS) analysis. Cholinesterase (ChE), α-glucosidase, α-amylase, and tyrosinase inhibitory activity was determined. Results: The results demonstrated that the phenolic substance content was higher in methanol extract (144.08±2.01 µg gallic acid equivalent/mg extract). DPPH scavenging effect of S. akmanii methanol extract (73.2%) was higher than acetone extract (60.1%). TAS values of extract methanol and acetone were 2.32±0.4 and 2.38±0.2 µmol trolox Eq /g, TOS values were 4.88±0.6 and 5.04±0.5 µmol H2O2 Eq/g, and oxidative stress index values were 2.1±0.3 and 2.11±0.24 arbitrary units, respectively. Hexadecanoic acid (17.9%) was found as the main component in the plant essential oil. S. akmanii species was prominent with high Mg and Al concentrations. Anti-ChE activity was determined that acetone extract (42.95%±0.90; 217.37±0.81 mg galantamine equivalents [(GALAEs)/g] exhibited higher than methanol (33.33%±1.81; 208.76±1.62 mg GALAE/g). α-Amylase inhibition was high in methanol extract [53.62±1.85 mmol angiotensin converting enzymes (ACEs)/g extract] compared to acetone (47.73±0.92 mmol ACEs/g extract). The tyrosinase inhibitory activity of S. akmanii was determined very low inhibition of the reference compound. Conclusion: It has been determined that S. akmanii Aytaç, Ekici & Dönmez extracts have antioxidant properties and can inhibit acetylcholinesterase, α-glucosidase, α-amylase enzymes. This study is informative on future studies on S. akmanii a highly bioavailable species and very extensive studies should be carried out.
ABSTRACT
In recent years, it is very important to find more safe and natural antioxidants than biological sources to replace synthetic antioxidants. The antioxidant properties of 22 lactic acid bacteria were investigated in vitro in the present study. The conducted in vitro antioxidant assays included scavenging the 2,2-diphenyl-1-picrylhydrazil (DPPH) free radical, metal (Fe+2) ion chelation, hydroxyl radical and superoxide radical scavenging properties, and anti-lipid peroxidation. Analysis of DPPH free radical scavenging property of microorganisms demonstrated that Lactobacillus plantarum IH14L (90.34 ± 0.40%) strain exhibited the highest activity. The highest Fe+2 chelation activity was observed with Lactobacillus curvatus GH5L (75.98 ± 5.35%), while the lowest chelation activity was observed with L. plantarum IH14L (19.80 ± 0,05). The highest and lowest hydroxyl radical scavenging strains were L. plantarum IH16L (82.25 ± 1.60%) and L. plantarum IH26L (35.60 ± 4.50) strains, respectively. Comparison of superoxide radical scavenging activities of the microorganisms demonstrated that these activities ranged between 21.63 ± 1.32% and 7.22 ± 0.04%. A positive correlation was identified between the hydroxyl radical scavenging activity of the microorganisms and the anti-lipid peroxidation property. It was found that they had the potential for use in nutritional and probiotic applications as protective and natural antioxidants.
