Supercritical Extracts from Arctium lappa as a Potential Inhibitor for the Activation of Complement System

Abstract

Arctium lappa is a perennial species of the Asteraceae family originally from Europe and Asia. Considered a weed species in the southern region of Brazil, it is popularly used as a natural anti-inflammatory. The complement system is an important component of the innate immune response. However, its exacerbated activation can lead to harmful conditions like autoimmune and inflammatory disorders. Plants that inhibit the activation of complement can be a promising tool in the treatment of inflammatory diseases. Here, we evaluated the effect of A. lappa leaves extracts on the activation of the classical and alternative pathways of complement system. Two extracts were obtained under supercritical conditions using scCO2 with ethanol as cosolvent, at 313.15K, 15 MPa (E1) and 25 MPa (E2). Classical and alternative activation were evaluated using complement fixation test. Different concentrations of A. lappa extracts E1 and E2 showed an inhibitory effect on both complement pathways, and heparin was used as control. The IC50 of E1, E2, and heparin were 28.26, 20.12 and 92.54 µg/mL for classical and 26.12, 27.70, 27.78 µg/mL for the alternative pathway. Results demonstrate that A. lappa is a promising complementary treatment for diseases associated with complement activation.

Inhibitory Effect of Supercritical Extracts from Arctium lappa L. on the Lectin Pathway of the Complement System

“…Also, a polysaccharide fraction of A. lappa extracts showed a dose dependent anti‐edematogenic activity and an antinociceptive effect on carrageenan‐induced paw edema in mice . In addition, supercritical extracts from A. lappa leaves were able to inhibit the classical and alternative pathways, as well as the lectin pathway. However, the mechanism involved with the complement modulation needs to be elucidated.…”

“…The main biologic active compounds shared by the four extracts were lupeol acetate, phytol and α ‐amyrin ( Table ). It is noteworthy that the compounds lupeol acetate and phytol were found in greater proportion among the components of A. lappa extracts that had an inhibitory effect on the activation of the classical and alternative complement pathways . Lupeol acetate, a pharmacologically active triterpenoid, has several potential therapeutic properties such as antiprotozoal, antitumor, cardioprotective, antinociceptive, and anti‐inflammatory activities both in vivo and in vitro .…”

“…Recently, Fontana et al . showed that supercritical extracts of A. lappa leaves presented inhibitory effect on the activation of classical and alternative complement pathways . Plants containing relevant biological properties represent an advantageous alternative treatment for different diseases, being used ‘in natura’ or as a source for the development of new drugs .…”

Phytochemicals and Biological Activities of Burdock (Arctium lappa L.) Extracts: A Review

“…Recent studies demonstrated that A. lappa extracts were able to modulate the complement system. [62,63] The complement system is an important part of the immune defense promoting inflammation, phagocytosis, killing of pathogens and acts as a bridge connecting the innate and acquired response. [115] However, the complement can be excessively activated when deregulated, promoting inflammatory and age-related diseases [116] and because of that the system has been considered a therapeutic target for several inflammatory diseases.…”

“…[115] However, the complement can be excessively activated when deregulated, promoting inflammatory and age-related diseases [116] and because of that the system has been considered a therapeutic target for several inflammatory diseases. [117,118] Fontana et al ( 2019) [62] demonstrated that A. lappa extracts inhibited the activation of both the classical and alternative complement pathways. The terpene compounds, lupeol acetate, amyrin acetate, and diterpene phytol were the main components with described biological action of A. lappa extracts in experiments.…”