Brazilian green propolis: anti-inflammatory property by an immunomodulatory activity

Abstract

The immunomodulatory and anti-inflammatory activities of green propolis extracts from Apis mellifera were investigated using acute and chronic inflammation models. Swiss mice were anesthetized and a cotton pellet granuloma was implanted in subcutaneous tissue. Then the mice were divided into six groups and received apyrogenic water or different propolis extracts by oral route (5 mg/kg). According to the treatment the groups were designated as E1A, E1B, E10, E11, and E12. The control group received apyrogenic water. The treatment was performed by six days when the mice were killed. The blood and the bronchoalveolar lavage (BAL) were collected to measure the leukocyte recruitment. In acute pulmonary inflammation, Balb/c mice received lipopolysaccharide (LPS) of Escherichia coli by intranasal route for three days. Concomitantly the mice received by oral route apyrogenic water (control) or E10 and E11 propolis extracts. BAL was performed to assess the inflammatory infiltrate and cytokine quantification. The results showed that the E11 extract has anti-inflammatory property in both models by the inhibition of proinflammatory cytokines and increase of anti-inflammatory cytokines suggesting an immunomodulatory activity.

Figure 1

Treatment protocol for the granuloma model.

Figure 2

Treatment protocol for the LPS induced pulmonary inflammation model.

Figure 3

The effect of treatment with an aqueous propolis extract from Apis mellifera in cotton pellet granuloma. Swiss mice that received a cotton implant on the back were treated orally for 6 days with a daily dose of 5 mg/kg and were compared to controls, which received apyrogen water at the same intervals. At the end of treatment, the cotton implants were removed, and total wet weight (a) and the dry weight (b) were determined after 48 hours at 37°C. The difference between wet weight and dry weight determined the edema (c). The data represent the mean ± SD of six animals/group. *P < 0.05 compared to control group.

Figure 4

The cellular profile of the bronchoalveolar lavage fluid of mice with granulomatous inflammation. Swiss mice that were treated orally for six days with a daily dose of 5 mg/kg were compared to controls, which received apyrogenic water at the same intervals. After treatment, BALs were collected and the different cell-types were counted. (a) The number of cells in the bronchoalveolar lavage fluid of mice with granulomatous inflammation orally treated with extracts of propolis from Apis mellifera. (b) The percentage of cells in bronchoalveolar lavage fluid of mice with granulomatous inflammation orally treated with extracts of propolis from Apis mellifera. The data represent the mean ± SD of six animals/group.  *P < 0.05 compared to control group. ^§Monocytes, P < 0.05 compared to control. ^#neutrophils, P < 0.05 compared to control. ^@lymphocytes, P < 0.05 compared to control.

Figure 5

The cellular profile of bronchoalveolar lavage fluid of mice with lung inflammation induced by LPS. Balb/c mice that were treated orally for 4 days with a daily dose of 5 mg/kg were compared to controls, which received apyrogen water at the same intervals. Induction was done for three consecutive days. One day before the induction of inflammation by LPS, animals were treated with apyrogen water (control), maintained for four days, and then the animals were sacrificed 24 hours after the last LPS treatment, when the bronchoalveolar lavage was performed. (a) The number of cells in the bronchoalveolar lavage fluid of mice with pulmonary inflammation induced by LPS intranasally (in.). (b) The percentage of cells in the bronchoalveolar lavage fluid of mice with pulmonary inflammation induced by LPS intranasally (in.). The data represent the mean ± SD of six animals/group.  *P < 0.05 compared to control group treated with propolis extracts from Apis mellifera. ^@lymphocytes, P < 0.05 compared to control.

Figure 6

The effect of treatment with propolis extracts of Apis mellifera on cytokine production in the supernatant of bronchoalveolar lavage. Balb/c mice that were treated orally for 4 days with a daily dose of 5 mg/kg were compared to controls which received apyrogenic water at the same intervals. Induction was done for three consecutive days. One day before the induction of inflammation by LPS, the animals were treated with apyrogen water (control) for four days, and then the animals were sacrificed 24 hours after the last LPS treatment when the bronchoalveolar lavage was performed. The concentrations of IL-6 (a), TNF-α (b), TGF-β (c), and IL-10 (d) were determined by ELISA. The data represent the mean ± SD of six animals/group.  *P < 0.05 compared to control group.