Camellia japonica bee pollen is one of the major types of bee pollen in China and exhibits antioxidant and anti-inflammatory activities. The aims of our study were to evaluate the effects and the possible mechanism of Camellia japonica bee pollen polyphenols on the treatment of hyperuricemia induced by potassium oxonate (PO). The results showed that Camellia japonica bee pollen ethyl acetate extract (CPE-E) owned abundant phenolic compounds and strong antioxidant capabilities. Administration with CPE-E for two weeks greatly reduced serum uric acid and improved renal function. It inhibited liver xanthine oxidase (XOD) activity and regulated the expression of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), organic anion transporter 1 (OAT1), organic cation transporter 1 (OCT1) and ATP-binding cassette superfamily gmember 2 (ABCG2) in kidneys. Moreover, CPE-E suppressed the activation of the toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB (TLR4/MyD88/NF-κB) signaling pathway and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in PO-treated mice, and related inflammatory cytokines were reduced. CPE-E also modulated gut microbiota structure, showing that the abundance of Lactobacillus and Clostridiaceae increased in hyperuicemic mice. This study was conducted to explore the protective effect of CPE-E on hyperuricemia and provide new thoughts for the exploitation of Camellia japonica bee pollen.

Schisandrachinensisbee pollen has been used as a health food in China for centuries; however, its bioactive constituents and functions are not very clear. In this study, we investigated the phenolic compounds of Schisandrachinensisbee pollen extract (SCPE) by UHPLC-Q-Orbitrap-HRMS/HPLC-DAD-ECD and its prevention from nonalcoholic fatty liver disease (NAFLD) and modulation of gut microbiota in high fat diet induced obese C57BL/6 mice. The results showed that 12 phenolic compounds were identified in SCPE, and naringenin, rutin and chrysin were the main constituents. The content of naringenin reached 1.89 mg/g, and total phenolic content (TPC) of SCPE were 101.83 mg GA/g. After obese mice were administrated with SCPE at 7.86 and 15.72 g/kg BW for 8 weeks, body weight gains were reduced by 18.23% and 19.37%. SCPE could decrease fasting blood glucose, cut down the lipid accumulation in serum and liver, lessen oxidative injury and inflammation in obesity mice. Moreover, SCPE could effectively inhibit the formation of NAFLD by inhibition of LXR-α, SREBP-1c and FAS genes expression, and modulate the structural alteration of gut microbiota in obesity mice. These findings suggested that SCPE could attenuate the features of the metabolism syndrome in obesity mice, which can be used to prevent obesity and NAFLD of human beings.

L-ascorbic acid (vitamin C, VC), an essential nutrient obtained from the diet to maintain various vital signs for the human body, is a crucial indicator of food quality and nutritional value. Herein, high-performance liquid chromatography with electrochemical detection (HPLC-ECD) was developed and validated with the advantages of higher sensitivity, simpler operation processes, and more rapid detection in measuring VC levels in honey samples when compared with the common methods (titration, spectrophotometric, and HPLC-DAD methods). The results of the HPLC-ECD methodological validation showed that the limit of detection (LOD) was 0.0043 µg mL⁻¹; the relative standard deviations (RSDs) of the intra- and inter-day values were between 2.51% and 5.15%, and the regression coefficient was >0.999 in the linear range of 0.1 to 20 µg mL⁻¹. The validated HPLC-ECD method was also successfully utilized to evaluate the VC levels in different varieties of honey samples with various storage durations as well as in fruit and biological samples. This study provided a perspective for the further accurate determination of VC content in food and biological samples.