Anti-inflammatory and anti-angiogenesis effect of bee pollen methanolic extract using air pouch model of inflammation

BACKGROUND AND PURPOSE: Research on new drugs with a natural source and low side effects is a priority in pharmacology studies. The present study was conducted to investigate the anti-inflammatory and anti-angiogenesis effects of bee pollen extract in the air pouch model of inflammation. EXPERIMENTAL APPROACH: To achieve this goal, male rats were moderately anesthetized and then 20 and 10 mL of sterile air were subcutaneously injected into the intrascapular area of the back of the rat on first and third days, respectively. On day 6, inflammation was induced by intrapouch injection of carrageenan. Normal saline in the control group and bee pollen methanolic extract (50, 100, and 200 mg/pouch) were administered at day 6, simultaneously with carrageenan, and then for 2 consecutive days only normal saline and the extracts were injected. Following sacrificing the rats the pouch was opened and the exudate volume, leukocyte accumulation, granulation tissue weight, vascular endothelial growth factor (VEGF), interleukin 1beta, and tumor necrosis factor alpha (TNF-α) concentrations were determined 3 days after induction of inflammation. In order to investigate the angiogenesis, the granulation tissue was removed, homogenized in the Drabkin’s reagent, and then centrifuged. The supernatant was filtered and the hemoglobin concentration was determined using a spectrophotometer. RESULTS: Bee pollen extract significantly decreased the exudate volume, leukocyte accumulation, granulation tissue weight, angiogenesis, VEGF, and TNF-α concentration. CONCLUSION AND IMPLICATIONS: The findings of the current study revealed that bee pollen methanolic extract has an anti-inflammatory and anti-angiogenesis effect, which could be attributed to the inhibition of VEGF and TNF-α production in the inflammatory exudates.