In vivo topical anti-inflammatory activity of Cymbopogon citratus infusion: Flavonoids contribution

Abstract

Cymbopogon citratus (DC). Stapf, is a tropical perennial shrub originated from Southeast Asia. In traditional medicine, aqueous extracts of dried leaves are used for the treatment of several inflammation-based pathologies [1]. Our previous results demonstrated that lemongrass lipid-free infusion (CcI) had different types of phenolic compounds [2], flavonoid fraction (CcF) presenting significant anti-inflammatory activity [3]. In this work, the potential activity of CcI as a topical anti-inflammatory was evaluated in vivo. CcI was obtained as previously described by Figueirinha [2]. Then an oil/water emulsion was prepared, according to the following composition: stearic acid (14%, w/w), oleic acid (10% w/w), triethanolamine (1.2%, w/w), glycerol (13.5%, w/w), propylene glycol (5%, w/w), CcI (1%, w/w) and water (q.s. 100%, w/w). Release tests were performed using static Franz diffusion cells. The formulations were applied in the donor compartments and aliquots of the receptor fluid were collected at specific time points. Chemical composition of all collected samples was obtained by HPLC-PDA. The evaluation of the in vivo anti-inflammatory activity was performed by the carrageenan-induced rat paw edema model [4]. Release experiments lead to the identification of many phenolic compounds from CcI in the receptor medium and the quantification of six flavonoids. Since flavonoids were the most abundant compounds, CcF was incorporated into the cream formulation, and tested through the anti-inflammatory in vivo model. CcI (1%) and CcF (0.6%) exhibited an edema reduction of 34 and 43%, respectively. In conclusion, it can be inferred that phenolic compounds, and mainly flavonoids, from Cymbopogon citratus may be incorporated in a topical formulation and even exert a remarkable anti-inflammatory effect in vivo.