Anti-inflammatory and antioxidant effects of Cistanche tubulosa flowers

Abstract

This study aims to evaluate the anti-inflammatory and antioxidant activity of the aqueous extract of the flowering parts of the plant Cistanche tubulosa. The extraction yield from decoction was approximately 26%, and chemical analyses showed that the extract contains a significant amount of polyphenolic compounds and flavonoids, estimated at 56.74 ± 1.54 micrograms of gallic acid equivalent / mg extract and 10,540 ± 0.474 micrograms of quercetin equivalent/mg extract, respectively. To study the plant’s anti-inflammatory activity, a red blood cell membrane stability test was conducted using blood from a healthy human donor, The results showed that the extract possessed a high ability to protect red blood cell membranes, with 100% protection at a concentration of 3 mg/mL, surpassing the efficacy of the reference drug diclofenac used as anti-inflammatory standard. The extract also exhibited antioxidant activity in DPPH and FRAP assays, demonstrating an effective ability to inhibit free radicals and reduce oxidized compounds, although its efficacy was lower than that of the reference antioxidant BHT, with IC50 135.41 ± 0.95 and 30.88 ± 2.16 mg/mL and EC50 178.86 ± 4.17 and 30.56 ± 0.79 mg/mL, respectively. In addition, the extract was found to have a significant protective effect against AAPH-induced hemolysis, with a concentration-dependent increase in the half-life of hemolysis (HT50). The recorded HT50 values were 68.80 ± 0.72 minutes and 122.30 ± 0.22 minutes for the extract and the ascorbic acid reference, respectively, at a concentration of 40 μg/mL. In conclusion, Cistanche tubulosa can be considered a promising source of anti-inflammatory and antioxidant compounds.