Adaptogenic-related activity and phenolic content of selected ginseng-like herbs in Thailand

Eleven plants traditionally as adaptogens were collected from the north and northeastern parts of Thailand and evaluated for adaptogenic-related properties as well as total phenolic and total flavonoid contents. Plant samples were extracted by various methods then were tested for in vitro antioxidant activity and were investigated for phenolic and flavonoid contents by spectrophotometric techniques. Tested extracts showed antioxidant activity with EC50 ranged from 14.50±1.04 to 783.68±19.94 and 11.18±2.60 to 745.24±24.54µg/mL using DPPH scavenging assay and thiobarbituric acid reactive substances (TBARS) method, respectively. Their total phenolic and total flavonoid contents are in the range of 1.93±0.04 to 31.74±1.08g% chlorogenic acid equivalent (g% CAE) and 0.38±0.01 to 12.39±1.40g% rutin equivalent (g% RE), respectively. The leaf decoction of Acanthopanax trifoliatus (ATD) exhibited strong antioxidant activity with high amount of phenolic and flavonoid contents. ATD was further tested for in vivo anti-anxiety activity using light-dark task [1] and hole-board test [2] with 30mg/kg Phenobarbital as a positive control. Animals orally receiving ATD at the concentrations of 500 to 1000mg/kg significantly (P<0.05) increased the number of entries (80%) and time spent (90%) in light chamber in light-dark task. For the hole-board test, animal group receiving 1000mg/kg ATD significantly increased the number of head-dip (37%). The results indicated that plant samples, especially the leaves of Acanthopanax trifoliatus possess antioxidant and anti-anxiety activities supports their ethnomedical uses as adaptogenic agents.

Acknowledgements: The Graduate Program Development under the Collaboration between Thailand Institute of Scientific and Technological Research and Universities.

References: 1. Crawley, J. et al. (1980) Pharmacol. Biochem. Behav. 13:167–170.

2. Treit, D. et al. (1981) Pharmacol. Biochem. Behav. 15(4):619–626.