## 3 Results and Discussion
### Enzyme Inhibition Activity  
The \(\alpha\)-amylase inhibitory activity of the extracts, given as IC50, varied from \(1.95\pm 0.04\) mg/mL to \(36.99\pm 0.13\) mg/mL.  
The lowest IC50 value was obtained by the ethyl acetate extract (\(1.95\pm 0.04\) mg/mL), which is close to that calculated for the standard solution acarbose (\(1.21\pm 0.07\) mg/mL). Water extract presented the highest IC50 value (Table 3). The \(\alpha\)-amylase inhibitory activity was correlated with the total phenolic content (r = 0.931), phosphomolybdenum test (r = 0.982), and the CUPRAC reducing power (r = 0.967) assays (Table S1-Supplementary Material).  
Alpha-amylase is a key enzyme implicated in different metabolic disorders such as diabetes and obesity. It is responsible for the hydrolysis of 1,4-\(\alpha\)-glucoside bonds of the oligo and polysaccharides, so as the final product, glucose, can be utilized by the organism to generate energy [40]. However, \(\alpha\)-amylase hyperactivity, can lead to excessive production of glucose, which finally results to high blood sugar levels. In this way, different therapeutic approaches aim at inhibiting the \(\alpha\)-amylase activity, by using synthetic drug formulations. Nonetheless, undesirable side effects are common. For this reason, medicinal plants are being studied for their potential \(\alpha\)-amylase inhibitory activity: Different plant extracts have been tested, while emphasis is given on the \(\alpha\)-amylase inhibitory activity of the flavonoids which is strongly related to their structure [42].  
The tyrosinase inhibitory activity of the extracts given as IC50, varied from \(1.25\pm 0.01\) mg/mL to \(2.71\pm 0.42\) mg/mL. All the extracts inhibited tyrosinase. In particular, the lowest IC50 value was estimated for the methanolic extract of, the plant, while the highest IC50 value was calculated for the aqueous extract (Table 3). In addition, tyrosinase inhibitory activity was correlated with luteolin and TFC (r = 0.985 and 0.995 respectively).  
Tyrosinase is an enzyme implicated in melanogenesis. It catalyzes the hydroxylation of l-tyrosine to 3,4 dihydroxyphenylalanine (DOPA) and the oxidation of DOPA to dopaquinone. Melanin is responsible for skin pigmentation and also a skin defense compound. However, overproduction can lead to a variety of diseases such as dermal melanocytosis, melasma and post-inflammatory hyperpigmentation. Downregulation of tyrosinase activity is a therapeutic approach regarding hyperpigmentation disorders. Among the most common depigmentation agents used is hydroquinone, which is however related to various adverse effects [43]. For this reason, various plant extracts have been tested for their capacity to inhibit tyrosinase [44]. Results of these studies are promising, as they indicate that molecules produced by natural sources are great inhibitors of tyrosinase.  
Data regarding the enzyme inhibition activity of _Z. taurica_ subsp. _cleanoides_ extracts against \(\alpha\)-amylase and tyrosinase are not previously available. However, in a recent study, _Ziziphora taurica_ subsp. _taurica_, was examined for its \(\alpha\)-amylase and tyrosinase inhibitory activity [45]. Our data are  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Samples** & **\(\alpha\)-Amylase Inhibition** & **Tyrosinase Inhibition** \\ \hline Ethyl acetate & \(1.95\pm 0.04\)2  & \(1.40\pm 0.06\)3  \\ Methanol & \(3.97\pm 0.08\)4  & \(1.25\pm 0.01\)5  \\ Water & \(36.99\pm 0.13\)5  & \(2.71\pm 0.42\)6  \\ Acarbose & \(1.21\pm 0.07\)6  & - \\ Kojic acid & - & \(0.37\pm 0.02\)6  \\ \hline \hline \end{tabular}
\end{table}
Table 3: Enzyme inhibition activity (IC50: mg/mL) of _Z. taurica_ subsp. _cleanoides_ extracts 6.  
in accordance with [PERSON] et al. [45], and potentiate the fact that _Ziziziphora_ species are potential alternative candidates against glucose metabolism and hyperpigmentation disorders.