Abstract Ziziphora tenuior L. (Lamiaceae) is an aromatic herb used for its medicinal values against
fungi, bacteria. Micropropagation can be used for large-scale multiplication of essential oil producing
plants thus avoiding an overexploitation of natural resources. This work aims to develop a reliable
protocol for the in vitro propagation of Z. tenuior, and to compare the antioxidant activity
between in vitro propagated and wild plants.
The explants were sterilized and cultured on MS medium containing different concentrations of
growth regulators naphthalene acetic acid (NAA) or indole-3-butyric acid (IBA) with 0.5 mg/L of
kinetin (Kin) callus formation was 70.2% after 45 days of incubation in dark on medium supplemented
with 1.5 mg/L of NAA. After one month of callus culture on medium supplemented with
2 mg/L BA the shoot number was 5.12 and for the multiplication stage. The shoot number was
4.21 and length was 6.17 cm on medium supplemented with 1 mg/L Kin +0.1 mg/L NAA.
DPPH reagent was used to test the antioxidant activity. The aqueous and methanol extracts of
in vitro plants which were treated with 1.5 and 1 mg/L of kin plus 0.1 mg/L of NAA showed a strong
DPPH scavenging activity where IC50 was 0.307 and 0.369 mg/ml, respectively, while the IC50 of aqueous
and methanol extracts of wild plants was 0.516 and 9.229 mg/ml, respectively. Our results suggested
that plant growth regulators and in vitro culture conditions increased the antioxidant activity.