## 3 Results and Discussion
### Total Polyphenol, Flavonoid and Phenolic Acid Content
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Sample**} & **TPC** & **TFC** & **TPAC** \\  & **(mg GAE/g DM)** & **(mg QE/g DM)** & **(mg CAE/g DM)** \\ \hline _Primula veris_ L. & 49.27 \(\pm\) 2.51 \({}^{\text{e}}\) & 48.35 \(\pm\) 3.77 \({}^{\text{a}}\) & 22.77 \(\pm\) 1.44 \({}^{\text{f}}\) \\ _Urtica dioica_ L. & 38.67 \(\pm\) 1.88 \({}^{\text{fg}}\) & 10.11 \(\pm\) 1.07 \({}^{\text{h}}\) & 18.04 \(\pm\) 2.11 \({}^{\text{fg}}\) \\ _Ribes nigrum_ L. & 70.12 \(\pm\) 3.77 \({}^{\text{d}}\) & 7.08 \(\pm\) 2.29 \({}^{\text{i}}\) & 22.18 \(\pm\) 0.99 \({}^{\text{f}}\) \\ _Fragaria vesca_ L. & 124.52 \(\pm\) 5.05 \({}^{\text{a}}\) & 39.04 \(\pm\) 0.28 \({}^{\text{b}}\) & 34.85 \(\pm\) 0.99 \({}^{\text{e}}\) \\ _Mentha piperita_ L. & 71.67 \(\pm\) 6.29 \({}^{\text{cd}}\) & 21.22 \(\pm\) 0.01 \({}^{\text{f}}\) & 84.61 \(\pm\) 4.71 \({}^{\text{b}}\) \\ _Thymus serpyllum_ L. & 119.52 \(\pm\) 1.89 \({}^{\text{a}}\) & 40.89 \(\pm\) 0.94 \({}^{\text{b}}\) & 102.31 \(\pm\) 2.89 \({}^{\text{a}}\) \\ _Salvia officinalis_ L. & 48.51 \(\pm\) 7.86 \({}^{\text{ef}}\) & 28.44 \(\pm\) 0.81 \({}^{\text{d}}\) & 31.67 \(\pm\) 0.22 \({}^{\text{e}}\) \\ _Potentilla anserina_ L. & 37.13 \(\pm\) 8.79 \({}^{\text{gh}}\) & 32.31 \(\pm\) 3.23 \({}^{\text{c}}\) & 12.73 \(\pm\) 2.72 \({}^{\text{gh}}\) \\ _Equisetum arvense_ L. & 19.58 \(\pm\) 0.63 \({}^{\text{j}}\) & 10.90 \(\pm\) 0.13 \({}^{\text{gh}}\) & 13.06 \(\pm\) 0.83 \({}^{\text{gh}}\) \\ _Melissa officinalis_ L. & 85.42 \(\pm\) 13.19 \({}^{\text{b}}\) & 28.65 \(\pm\) 1.62 \({}^{\text{d}}\) & 77.47 \(\pm\) 12.98 \({}^{\text{c}}\) \\ _Rosa canina_ L. & 80.96 \(\pm\) 8.17 \({}^{\text{bc}}\) & 3.21 \(\pm\) 1.62 \({}^{\text{j}}\) & 61.78 \(\pm\) 0.33 \({}^{\text{d}}\) \\ _Calendula officinalis_ L. & 14.54 \(\pm\) 2.19 \({}^{\text{i}}\) & 13.61 \(\pm\) 0.54 \({}^{\text{g}}\) & 5.49 \(\pm\) 0.56 \({}^{\text{i}}\) \\ _Matricaria chamomilla_ L. & 32.02 \(\pm\) 0.63 \({}^{\text{hg}}\) & 12.71 \(\pm\) 0.41 \({}^{\text{gh}}\) & 9.81 \(\pm\) 0.22 \({}^{\text{hi}}\) \\ _Achillea millefolium_ L. & 19.65 \(\pm\) 0.32 \({}^{\text{j}}\) & 9.69 \(\pm\) 0.40 \({}^{\text{hi}}\) & 14.67 \(\pm\) 0.28 \({}^{\text{gh}}\) \\ _Tropacolum majus_ L. & 26.99 \(\pm\) 7.29 \({}^{\text{hi}}\) & 24.13 \(\pm\) 2.96 \({}^{\text{e}}\) & 13.39 \(\pm\) 0.11 \({}^{\text{gh}}\) \\ _Plantago lanccolata_ L. & 66.27 \(\pm\) 5.39 \({}^{\text{d}}\) & 25.04 \(\pm\) 0.69 \({}^{\text{e}}\) & 76.89 \(\pm\) 8.15 \({}^{\text{c}}\) \\ \hline \hline \end{tabular}  
Mean \(\pm\) standard deviation; TPC—Total polyphenol content; TPC—Total flavonoid content; TPAC—Total phenolic acid content; GAE—gallic acid equivalent; QE—quercetin equivalent; CAE—caffe acid equivalent; different letters in a column denote mean values that statistically differ one from another; dry matter.  
\end{table} 
Table 2: Total polyphenol, flavonoid and phenolic acid contents of tested medicinal herbs. and various other neurodegenerative diseases. Accumulation of polyphenols in tissues is the most important phase of polyphenol metabolism as it enables the concentration of polyphenic substances necessary for the biological effects to manifest [36]. Polyphenols also help induce antioxidant enzymes, such as glutathione peroxidase, catalase and superoxide dismutase, which break down hydroperoxides, peroxide hydrogen and superoxide anions, respectively. Additionally, they help to inhibit the expression of enzymes such as xanthine oxidase [37]. A statistically significant (P < 0.05) regression coefficient was observed in our study between the total polyphenol content and the antioxidant activity determined with the phosphomolybdenum method (r = 0.892). The total content of flavonoids in the tested medicinal plants ranged from 3.21 \(\pm\) 1.62 mg QE/g to 48.35 \(\pm\) 3.77 mg QE/g.