Melittin is a principle toxic peptide of bee venom. It is known as a strong anti-inflammatory agent and used as traditional medicine for treatment of different types of diseases. 5-HT contributes at early stages on inflammatory processes in response to the local inflammation. However, the anti-inflammatory effect of melittin on the gastrointestinal (GI) tract has not been elucidated. The aim of the present study was to investigate the physiological changes of melittin on mice jejunum treated with indomethacin to induce inflammation. This study was performed on adult Swiss male mice. These mice divided into 4 groups (7 mice for each group): Control group: mice treated with distilled water; Indomethacin group treated with indomethacin (50 mg/kg) for 1day; Melittin group treated daily with melittin (10 or 40 µg/kg) for 3, 5 and 10 days; Indomethacin-melittin group treated with indomethacin followed by the above melittin doses. Samples from the jejunum were collected and prepared for physiological studies. Physiological study showed a significant increase of pro-inflammatory mediator 5-HT in the mucosal tissues of inflamed jejunum compared to control (337 vs 150 pg/ml), while this level was gradually reduced by melittin treatment 10 µg/kg for 3, 5 and 10 days (202, 185 and 170 pg/ml, P<0.05 respectively) and by melittin treatment 40 µg/kg for 3, 5 and 10 days (188, 163 and 148 pg/ml P<0.05 respectively). Melittin attenuated the inflammation of jejunum by inhibiting the release of pro-inflammatory mediator (5-HT). These data supported the potential use of melittin as anti-inflammatory therapy of GI inflammation.

Keywords: Melittin. Anti-inflammatory. Gastrointestinal.

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