Comparison of the anti-inflammatory effects of Sinapis alba and Brassica juncea in mouse models of inflammation

Background: Sinapis Semen is derived from the dried mature seeds of Sinapis alba L. or Brassica juncea (L.) Czern. et Coss. Traditionally, the seeds from S. alba are called White Sinapis Semen while those from B. juncea are called Yellow Sinapis Semen. Purpose: The present study aimed to compare the chemical composition and the anti-inflammatory effects of 50% aqueous ethanol extracts of the White Sinapis Semen (EWSS) and Yellow Sinapis Semen (EYSS) using both acute (12-O-tetradecanoylphorbol-acetate (TPA)- and arachidonic acid (AA)-induced mouse ear edema) and chronic (multiple applications of croton oil (CO)) inflammatory models. Methods: The anti-inflammatory effects of EWSS and EYSS were determined by measuring the ear thickness and myeloperoxidase (MPO) activity. The anti-inflammatory mechanism was explored by measuring the protein and mRNA levels of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta and IL-6 in the ear of the TPA-treated mice. Results: The results showed that both EWSS and EYSS significantly decreased the ear thickness in both the TPA- and AA-induced acute models, as well as in the CO-induced chronic model. In addition, EWSS and EYSS could markedly inhibit the MPO activity in the ears of TPA-, AA- or CO-treated mice. Moreover, EWSS and EYSS also remarkably inhibited the protein and mRNA levels of TNF-alpha and IL-6 in the ears of TPA-treated mice. Comparatively, EWSS exerted more potent anti-inflammatory effect than that of EYSS. Conclusion: Our results revealed that both EWSS and EYSS are effective anti-inflammatory agents against acute and chronic inflammatory processes, and EWSS possess more potent anti-inflammatory effect than EYSS. The anti-inflammatory effect of the two herbs may be mediated, at least in part, by suppressing the mRNA expression of a panel of inflammatory mediators including TNF-alpha, IL-6 and IL-1 beta.