Effect of Sodium Chloride on Flavone Biosynthesis and Antioxidant Activitiesin Hairy Root Culture of Scutellaria baicalensis

Background: Scutellaria baicalensis is a traditional medicinal plant that is rich in bioactive flavonoids, the accumulation of which can be impacted by environmental factors, including salinity. We aimed to determine the effects of different sodium chroride (NaCl) concentrations on the growth, flavonoid biosynthesis, and antioxidant activity of S. baicalensis hairy root cultures.BR/Methods and Results: We examined the effects of NaCl at various concentrations (0, 30, 50, 100, 200, and 300 mM) on biomass production, flavonoid content, and antioxidant properties of S. baicalensis hairy roots and found that biomass production was impaired by salinity, with 50 mM NaCl significantly reducing the biomass. High performance liquid chromatography of flavonoids at different salinity levels indicated high levels of baicalin, baicalein, and wogonin at an NaCl concentra- tion of 100 mM (moderate salinity-induced metabolic activation). Flavonoid synthesis was inhibited under high salinity conditions (200 mM - 300 mM NaCl); under these conditions, some flavonoids were undetectable. Higher radical scavenging and redox potentials were detected at an NaCl concentration of 100 mM, with lower ICsub50/sub values in DPPH and ABTS, and reducing power antioxidant assays (compared to control conditions).BR/Conclusions: These results emphasize the importance of moderate salt stress in promoting bioactive compound production by S. baicalensis, providing information on its potential for cultivation under stress-adapted conditions and practical applications for medical use.