Comparative and Correlation Analysis of Flavonoid Components, Antioxidant Activity, and Anti‐Fatigue Effects in Sea Buckthorn Puree, Flavonoids, and Leaf Tea Extracts

Sea buckthorn serves a dual purpose as a food and medicinal source. This study compared the flavonoid content, antioxidant activity, and anti-fatigue effects of sea buckthorn puree (SBP), sea buckthorn flavonoid (SBF), and sea buckthorn leaf tea extract (SBLTE). The flavonoid contents of rutin, quercetin, kaempferol, and isorhamnetin were determined using high-performance liquid chromatography. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS⁺), and hydroxyl (OH·) radical scavenging assays. Anti-fatigue activity in mice was evaluated through weight-bearing swimming experiments. Moreover, correlation analysis among ingredients, antioxidant activity, and anti-fatigue activity was performed. SBF exhibited the lowest EC₅₀ value of 0.198 ± 0.005 mg/mL for the DPPH assay, whereas SBLTE exhibited the lowest EC₅₀ values of 4.56 ± 0.08 and 0.101 ± 0.00 mg/mL for ABTS⁺ and OH· radicals, respectively. All samples prolonged the exhaustive swimming time of mice (extension rate: 34.14 ± 2.78% to 82.99 ± 21.60%), with SBF exhibiting the highest superoxide dismutase (705.20 ± 21.28 U/mgprot). SBF exhibited the lowest lactic acid (7.63 ± 0.31 mmol/L) and lactate dehydrogenase (882.36 ± 5.10 U/L) levels. SBLTE exhibited the highest catalase activity (1204.80 ± 37.02 U/mgprot) and the lowest blood urea nitrogen value (11.22 ± 0.16 mg/dL). SBF and SBLTE groups exhibited the lowest creatine kinase levels at 857.69 ± 35.75 and 913.83 ± 33.68 U/L, respectively. Histological analysis indicated improved liver structure, and Pearson correlation revealed strong associations between radical scavenging and antioxidant enzyme levels. They could serve as key components in developing functional anti-fatigue foods. PRACTICAL APPLICATIONS: Sea buckthorn puree, leaf tea, and flavonoids are convenient, commercially available beverages with strong antioxidant and anti-fatigue activities. The results of this study can serve as product descriptions and provide useful guidance for consumers.