No abstract

Phillygenin, as an active ingredient of Forsythia suspensa, possesses a wide range of biological and pharmacological activity. However, its development and application are restricted due to its poor bioavailability and low solubility. Our work aimed to develop a self-microemulsifying drug delivery system to improve the oral bioavailability of phillygenin. The composition of the self-microemulsifying drug delivery system was preliminary screened by the pseudo-ternary phase diagram. Subsequently, the central composite design method was employed to optimize the prescription of the self-microemulsifying drug delivery system loaded with phillygenin. The prepared self-microemulsifying drug delivery system of phillygenin was characterized in terms of morphology, droplet size distribution, polydispersity index and stability. Then, the in vitro dissolution and the oral bioavailability were analyzed. The optimized self-microemulsifying drug delivery system of phillygenin consisted of 27.8% Labrafil M1944CS, 33.6% Cremophor EL, 38.6% polyethylene glycol 400 (PEG-400) and 10.2 mg/g phillygenin loading. The prepared self-microemulsifying drug delivery system of phillygenin exhibited spherical and uniform droplets with small size (40.11 ± 0.74 nm) and satisfactory stability. The in vitro dissolution experiment indicated that the cumulative dissolution rate of the self-microemulsifying drug delivery system of phillygenin was significantly better than that of free phillygenin. Furthermore, after oral administration in rats, the bioavailability of phillygenin was significantly enhanced by the self-microemulsifying drug delivery system. The relative bioavailability of the self-microemulsifying drug delivery system of phillygenin was 588.7% compared to the phillygenin suspension. These findings suggest that the self-microemulsifying drug delivery system of phillygenin can be a promising oral drug delivery system to improve the absorption of phillygenin.

Forsythia suspensa (Thunb.) Vahl (Oleaceae) leaves are valuable sources of phillygenin. This study aimed to isolate phillygenin from F. suspensa leaves and examine its analgesic and anti‐inflammatory effects. Phillygenin was successfully extracted and isolated from F. suspensa leaves after fermentation. Phillygenin significantly reduced the number of writhing induced by acetic acid, prolonged the latency period in the hot plate test, and inhibited the xylene‐induced ear edema and carrageenan‐induced paw edema in mice. IL‐6, TNF‐α, IL‐1β, NO, and PGE2 levels in the carrageenan‐induced paw edema were notably reduced after pretreatment with phillygenin. Phillygenin significantly decreased the iNOS and COX‐2 protein expressions and the IκB‐α and NF‐κB p65 phosphorylation. This study demonstrated that phillygenin is a potential therapeutic candidate for managing pain and inflammation‐mediated disorders. The study contributes to the comprehensive development and utilization of F. suspensa leaves for economic and health care. Practical applications Phillygenin is one of the major active ingredients in Forsythia suspensa. But the content of phillygenin in F. suspensa is very low which limits its application. Phillygenin has potential pharmacological activity and anti‐inflammatory properties. However, the potential effects of phillygenin on analgesic activity have not been clarified. Furthermore, the data on its anti‐inflammatory activity in vivo are relatively limited. This study evaluated the analgesic activity for the first time and the acute anti‐inflammatory effect of phillygenin from F. suspensa leaves by fermentation, which indicated phillygenin is a potential therapeutic candidate for managing pain and inflammation‐mediated disorders.

Rape (Brassica napus L.) bee pollen (RBP) is a functional food rich in nutrients obtained by worker bees collecting rape pollen and mixing it with nectar and bee salivary enzymes. The study aimed to investigate the protective impact of RBP on renal tissue damage and modulating gut microbiota in diabetic rats. We established a diabetic model of rat via streptozotocin injection, then the rats were treated with RBP for 6 weeks. Results showed that RBP significantly suppressed fasting glucose, reduced oxidative stress and prevented renal pathological changes as well as renal function damage in diabetic rats. In addition, RBP reduced the levels of serum inflammatory cytokines (tumor necrosis factor‐α, monocyte chemoattractant protein‐1, C‐reaction protein, interleukin (IL)‐6, IL‐1β, and IL‐18), and the expression levels of transforming growth factor‐β1, p‐Smad2, and p‐Smad3 in the kidney. Moreover, RBP supplementation also improved the gut microbial dysregulation in diabetic rats. Based on the results, RBP can improve kidney tissue damage in diabetic rats. This study will promote the development of RBP functional food.