Propriétés antioxydante, anti-inflammatoire et immunomodulatrice des extraits d’Asphodelus microcarpus

Abstract

The present work aims to evaluate the antioxidant, anti-inflammatory, analgesic and immunomodulatory activities of the methanolic (ME) and aqueous (AE) extracts of the different parts of Asphodelus microcarpus, a plant of the Liliaceae family. The determination of the amounts of polyphenols and flavonoids has shown that ME are richer than AE, in polyphenols (377-755,03 et 164-704 mgEAG/g, respectively) and flavonoids (15.37-42.2 and 7.6-25.93 mg ER/g, respectively). Six tests were carried out for the study of the antioxidant activity of the extracts: DPPH, ABTS, OH• scavenging, ferrous iron chelation, reducing power and β-carotene / linoleic acid. The quantitative evaluation of the scavenging power on DPPH showed that the LAE and LME extracts are the most active with IC50 values of 33.33 and 98 μg / mL, respectively. Furthermore, the LME, LAE and APAE extracts proved to be the most active as scavengers of the ABTS+ radical with respective IC50 of 22, 29, 55.3 and 55.6 μg / mL. The most important inhibition effects of the radical are obtained with the extracts EAPA, EATF, EMPA and EMTF IC50 value (IC50 value 90, 650, 822 and 839 μg/mL respectively). The chelating capacity test of ferrous ions showed that the aqueous extracts, APAE, SFAE and RAE are good chelators with IC50 of the order of 60, 63 and 79 μg/mL. All the methanolic and aqueous extracts of Asphodelus microcarpus have a remarkable reducing power in the following order: APME > SFME > LME > LAE > SFAE > APAE > RAE > RME Inhibition of linoleic acid/β-carotene oxidation showed relatively high antioxidant activity for LAE, APAE, SFAE and SFME (I% = 99%, 96.14%, 94.6% and 88.02). The antiinflammatory and immunomodulatory effects have been studied in vivo in animal models. The two induced inflammation tests, 'Carrageenan Induced Paw Edema: CIPE' and 'Xylen Induced Ear Edema: XIEE' showed that APME and RME extracts produced a significant antiedematogenic effect (p <0.05) with the dose of 500 mg / kg for CIPE after 6 h (58.04%, 58.75%, respectively). All methanolic extracts (100, 300 and 500 mg / kg) showed significant (p < 0.05) inhibition of edema for XIEE. In formaline-induced arthritis in the rat, oral treatment with 50, 100 or 200 mg/kg of ME and AE revealed significant inhibition of paw swelling of 38.11-60.4% and 50- 89.11%, respectively. The immunomodulatory effect of methanolic (ME) and aqueous (AE) extracts of the plant at 50, 100 and 200 mg / kg resulted in significant immunostimulation of antibody production in mice immunized with sheep red blood cells of 19–88% and 23–80% respectively . The in vivo study showed a significant peripheral analgesic effect of the acetic acid type at doses of 100, 300 and 500 mg / kg with inhibition percentages of 86-100% and 83-88%, respectively for EM and EA, effect comparable to that of aspirin. In conclusion, the aqueous and methanolic extracts of A. microcarpus have interesting anti-inflammatory, antioxidant, anti-arthritic, analgesic and immunostimulatory properties. This study supports the traditional use of this plant for the treatment of certain inflammation-related disorders and could provide a pharmacological basis for the therapeutic use of Asphodelus microcarpus in cases of inflammation and immunodeficiency.