Le Profil Phénolique et la Capacite Antioxydante d’Aloe Vera L

Abstract

Aloe vera L or Aloe barbadensis Miller Burm.f, 1768 is one of the most powerful and wellknown medicinal plants. Its use dates back to more than 5,000 years, and today it has a worldwide reputation, particularly for the direct scavenging of reactive oxygen species (ERO). The aim of this study was to investigate the antioxidant potential of methanolic extracts of Aloe vera (Aloe barbadensis Miller) leaves from the M'sila, Sétif and Eulma regions. Qualitative analysis by TLC, determination of total polyphenol and flavonoid content, DPPH anti-free radical activity. Qualitative TLC analysis of methanolic extracts revealed the probable presence of certain flavonoids (quercetin, rutin) and acids (ferulic acid, tannic acid, gallic acid and ascorbic acid) in our extracts. The quantitative results for polyphenols and flavonoids showed that the three Aloe vera L studied had almost identical high concentrations of phenolic110,78 ± 0,19, 110,39 ± 0,30, 110,03 ± 0,68 μg EAG/mg of extract in this particular order: Av 1, Av 2 et Av 3 and flavonoid content that contains the rate of quercetin and of rutin : (38,55 µg et 55,67 µg), (38,31 µg et 55,61 µg) and (37,30 µg et 55,37 µg) in this particular order : Av 1, Av 2 et Av 3. The antioxidant capacity of the three Aloe vera L was assessed in vitro by a test DPPH anti-free radical activity. The results obtained showed that the antioxidant potential of the three methanolic leaf extracts was not negligible l’Av 02 (CI50 = 0.0919 ± 0.0039 mg/ml) the one that contains the biggest antioxydant potential followed by l’Av 03 (CI50 = 0.128 ± 0.0014 mg/ml) then Av 01(CI50= 0.145 ± 0.0012 mg/ml. The results of this study show that Aloe vera leaves have promising antioxidant properties, with a wide range of applications in various fields.