Anti-allergic and Antioxidative Activities of Some Compounds from Thai Medicinal Plants

Abstract

Evaluation of the anti-allergic and antioxidative activities of compounds from Thai medicinal plants demonstrated that lawsone methyl ether significantly exhibited the inhibitory effect on degranulation in RBL-2H3 cells with an EC₅₀ of 26.71 µM, while quercetin, a standard control, had an EC₅₀ of 10.02 µM. Other compounds from Thai medicinal plants including lucidin-ω-methyl ether, bergenin, homorapanone, strictosidinic acid and barakol, had no effect on the degranulation assay. In a DPPH radical scavenging assay, strictosidinic acid and barakol were more potent than the positive control, BHT. The EC₅₀ values of strictosidinic acid and barakol were 27.68 and 39.62 µM, respectively. Other tested compounds, including lawsone methyl ether, bergenin, homorapanone and lucidin-ω-methyl ether, had weak antioxidative activities or no activity. In a nitrite assay, only lawsone methyl ether reduced nitrite production with an EC₅₀ of 10.27 µM in RAW 264.7 cells. In conclusion, lawsone methyl ether suppresses degranulation in RBL-2H3 cells and reduces nitrite production in RAW 264.7 cells whereas strictosidinic acid and barakol have an antiradical action against DPPH.

Keywords::

• Thai medicinal plants
• anti-allergic
• antioxidative