ABSTRACT
Litchi chinensis Sonn seeds and pericarp are used in popular medicine as antioxidant, anticancer, antiviral, analgesic, antipyretic, immunomodulatory agent and others. However, literature on litchi leaves extract and the main compound procyanidin A2 (PA2) activities are scarce. Here, we investigated the anti-inflammatory activity of L. chinensis leaves extract and the main compound PA2 using in vitro and in vivo assays. We used the pleurisy and air-pouch model induced by carrageenan, substance P, histamine, bradykinin or lipopolysaccharide (LPS) in mice. The PA2 effects were also evaluated using carrageenan-induced pleurisy and LPS-induced air-pouch. In addition, LPS-induced NO2- production and cytotoxicity were quantified using peritoneal neutrophils recruited by oyster glycogen previously treated with L. chinensis extract or PA2. Animals orally treated with L. chinensis leaves extract exhibited a reduction on carrageenan-induced paw edema. Furthermore, the extract reduced the leukocyte migration and the protein leakage in the pleurisy model induced by carrageenan, substance P, histamine and bradykinin. The main compound in the leaves extract, PA2 reduced the paw edema and cell migration into the carrageenan-inflamed tissue. The data obtained in the LPS-induced air pouch model show that the extract and PA2 inhibit the in vivo neutrophil migration. In addition, the leaves extract and PA2 did not affect the neutrophil viability and reduces NO2- production. Taken together, the data herein obtained showed the modulatory actions of L. chinensis leaves extract on leukocyte migration to inflamed tissue, suggesting its therapeutic application to acute inflammatory process. In addition, it may be supposed that PA2 could be related with these actions, as it is the main compound of L. chinensis leaves extract