Stability of an Aqueous Extract of Larrea divaricata Cav. during a Simulated Digestion Process

Abstract

Larrea divaricata Cav. (Zygophyllaceae) is a South American plant widely distributed in Argentina that isused in folk medicine to treat inflammatory diseases. The aqueous extract is known to have well-documented biological activities such as antitumour, immunomodulatory, antimicrobial, antiinflammatory and antioxidant.However, its stability in gastrointestinal fluids is unknown. The latter is an important factor to assure the bioavailability of plant extracts intended to be administered via the oral route. The aim of this work was to study the stability of a lyophilized aqueous extract of L. divaricata compressed as a pill. To this end, the main polyphenol compound found in the extract, that is, the nordihydroguaiaretic acid, the total polyphenols and flavonoidscontent and the antioxidant activity such as diphenylpicrylhydrazyl scavenger activity and reducing power were assayed after subjecting the extract to different incubation times in simulated digestive fluids. The HPLC andspectroscopic methods were employed. Although the levels of polyphenols and flavonoids decreased upon incubation in gastric and intestinal fluids, the extract maintained its antioxidant activity related to the presenceof nordihydroguaiaretic acid. These results are promising and encourage the potential use of the extract by the oral route as a supplement or phytomedicine with antioxidant activity.