Centaurea benedicta L.: uma fonte de cnicina com perspectiva para o tratamento de inflamação cutânea

Abstract

Centaurea benedicta L., known as "cardo-santo", is used in traditional medicine as tonic, antidepressant, anti-inflammatory, antibacterial and antiseptic. The presence of substances, such as cnicin, a sesquiterpene lactone, may be responsible for its therapeutic properties. The present study aimed to evaluate the topical anti-inflammatory activity of the extract and cnicin obtained from C. benedicta leaves in experimental models. After collection, leaves were extracted with dichloromethane and ethanol (9:1 v/v) by foliar washing for acquisition of extract ECB. Then, ECB was characterized by chromatography on UPLC-MS-Q/TOF equipment and cnicin (CNI) isolated in Vacuum Liquid Column and identified by chromatography and mass spectrometry. The topical anti-inflammatory activity was evaluated by the ear edema method induced by phlogistic agents (Croton oil, phenol, capsaicin and histamine) at the doses of 0.1, 0.5 and 1 mg/ear. Myeloperoxidase (MPO), N-acetyl-β-D- glucosaminidase (NAG), nitric oxide (NO) and histopathological analysis were assessed. Data were demonstrated as mean ± standard error and analysis of variance (ANOVA) followed by the Student-Newman-Keuls test was used to measure the degree of significance (p < 0.05). Using UPLC-MS-Q/TOF, with a chromatographic profile, at the retention time of 4.85 (positive mode) and 4.87 (negative mode), and fragmentation spectrum, cnicin was identified. After 24 hours of treatment, ECB (59.76, 76.07 and 82.22% in increasing doses) and CNI (39.59, 56.00 and 69.79% in increasing doses) decreased the thickness of the edema. ECC (68.07, 76.60 and 78.60%, 0.1, 0.5 and 1 mg/ear, respectively) and CNI (89.64, 94.32 and 94.72% at respective doses of 0.1, 0.5 and 1 mg/ear) also reduced the weight. MPO and NAG activities and NO levels were reduced. Histopathological analysis revealed that edema thickness, leukocytes and vasodilation were inhibited after ECB and CNI treatment. At doses of 0.1, 0.5 and 1mg/ear, the thickness (ECB = 48.10, 54.10 and 55.10% and CNI = 35.30, 47.60 and 47.10%, respectively) and weight (ECB = 51.20, 58.70 and 62.50% and CNI = 65.80, 72.40 and 76.10%, respectively) were decreased after induction of phenol edema. ECB inhibited the action of the capsaicin by reducing the thickness (37.75, 43.11 and 58.10% at the doses of 0.1, 0.5 and 1 mg/ear, respectively) and the weight of the ears at 34.01 (0.1 mg/ear), 44.24 (0.5 mg/ear) and 55.80% (1 mg/ear), while CNI was not effective. Ninety minutes after the induction by histamine, ECB and CNI reduced the thickness and weight of ear edema. The results suggest that ECB and CNI from C. benedicta leaves present topical anti-inflammatory activity, opening new possibilities for the treatment of disorders associated with inflammatory processes in the skin.