Amphipterygium adstringens (Schltdl.) Schiede ex Standl (Anacardiaceae): An Endemic Plant with Relevant Pharmacological Properties

Abstract

Diseases, such as cancer, peptic ulcers, and diabetes, as well as those caused by drug-resistant infectious agents are examples of some of the world's major public health problems. Amphipterygium adstringens (Schltdl.) Schiede ex Standl is an endemic tree to Mexico. Its stem bark has been used medicinally since pre-Hispanic times, but in recent decades it has been scientifically proven that it has properties that help counteract some diseases; extracts with organic solvents of the plant are outstanding for their anticancer, gastroprotective, and antimicrobial properties; terpenes and long-chain phenols have been identified as the main active compounds. Currently, overharvesting is causing a sharp reduction in natural populations due to an increase in demand for the stem bark by people seeking to improve their health and by national and transnational companies seeking to market it. Because of the growing interest of the world population and the scientific community, we reviewed recent studies on the bioactive properties of A. adstringens. Through the orderly and critical compendium of the current knowledge of A. adstringens, we provide a reference for future studies aimed at the rational use and protection of this valuable endemic natural resource.

Keywords: Amphipterygium adstringens; Anacardiaceae; anacardic acids; anticancer activity; cuachalalate; long-chain phenols; triterpenes.

Figure 1

(a) A. adstringens trees in the dry season; (b) stem bark of tree showing smooth outer bark with lenticels; (c) traditional debarking; (d) traditionally dried stem bark, and (e) resin secretion from the stem bark induced by mechanical damage. Pictures taken by J.L. Díaz-Núñez in “Los Sauces” (Tepalcingo, Morelos, Mexico), February 2022.

Figure 2

(a) A. adstringens tree in the rainy season, (b) whitish debarked stem commonly associated with female trees, (c) reddish debarked stem is associated with male trees, (d) female flowers, and (e) fruits. Pictures taken by M. Sotelo taken in Cuauchichinola (Mazatepec, Morelos, Mexico), June 2020.

Figure 3

A. adstringens sketch showing the structure of the leaves, fruits, and male (left) and female (right) flowers. Color pencil drawing by Eunice Romero, 2022.

Figure 4

Geographic distribution of A. adstringens. The blue dots indicate locations where samples were collected. The World Information Network on Biodiversity (REMIB, CONABIO), W³Tropicos^®-Missouri Botanical Garden Database, National Herbarium of Mexico (MEXU), Herbarium-Hortorio (CHAPA, COLPOS), National School of Biological Sciences (ENCB-IPN), Institute of Ecology, A.C-Xalapa (IE-XAL), Autonomous Metropolitan University (UAMIZ), Luz María Villarreal de Puga Herbarium (IBUG), María Agustina Batalla Herbarium (FCME) and Chapingo Autonomous University Herbarium (CHAP). Qgis version 3.16, OSGeo (Beaverton, USA) software was used. (https://www.qgis.org/es/site/; accessed on 13 June 2022).

Figure 5

Primary modes of widespread use of the stem bark of A. adstringens for the treatment of diseases or injuries. (a) The Essay on Mexican Materia Medica is one of the first manuscripts where the medicinal use of the plant is reported (https://archive.org/details/61540040R.nlm.nih.gov/page/n3/mode/2up; accessed on 28 June 2022); (b) pulverized stem bark and (c) boiled aqueous extract of the stem bark with the production of foam (after shaking) that is indicative of the presence of saponins.

Figure 6

Phytochemicals identified in the stem bark of A. adstringens. The most abundant bioactive compounds in the extracts with organic solvents are indicated in blue. (I) Thin-layer chromatography (TLC) revealed 10% vanillin in sulfuric acid (hexane/ethyl acetate, 7:3). The TLC plate is stimulated with shortwave (II) and longwave (III) ultraviolet light, with which the anacardic acid mixture is visualized (hexane/ethyl acetate, 1:1). In the case of the “other compounds” quadrant, these have only been identified by employing HPLC, GC/MS, or qualitative assays. The chromatoplate was made with compounds isolated and characterized by our research group.

Figure 7

Pharmacological properties of A. adstringens stem bark extracts and main bioactive metabolites. Anticancer [5,6,7,42,43,45,49,50,51,52,53,54,55], anti-inflammatory [7,48], gastroprotective [57,58,59,60,61], antimicrobial [5,9,46,47,62,63], anti-virulence [64,65], wound healing [10], and hypocholesterolemic activity [44].