Antioxidant potential and phenolic composition of Cistanche tinctoria: A comparative study of crude, flavonoid, and tannin extracts

The antioxidant capacity and phenolic composition of Cistanche tinctoria (Orobanchaceae) were evaluated in the crude, flavonoid, and tannin extracts prepared from air-dried flowers using methanol, ethyl acetate, and acetone, respectively. The highest extraction yield (11.3 %) was obtained with the crude extract. The elevated total phenolic (168 ± 24 mg GAE/g) and flavonoid (27 ± 3 mg QE/g) contents in the crude extract were revealed. The tannin extract exhibited the highest antioxidant activity (IC50 8 ± 2 µg/mL), but, in terms of antioxidant and antiradical properties, all extracts were significantly less effective than ascorbic acid. The flavonoid extract demonstrated the greatest hemolysis inhibition (23 %). The highest absorbance (0.432) was observed for the tannin extract at a concentration of 0.1 mg/mL. Based on the high-performance liquid chromatography analysis, chlorogenic acid and naringenin were identified as the major phenolic compounds in the crude extract. The results validate the health benefits of phenolic compounds in C. tinctoria and highlight further research priorities for its applied and medicinal use.