Quantification of Xylopic Acid and Chromatographic Fingerprint Evaluations of the Dried Fruits of Xylopia Aethiopica From Four African Countries

Abstract

Background: The fruits of Xylopia aethiopica (Dunal) A. Rich, (herein called XYA), family Annonaceae, commonly known as "Guinea pepper", "Ethiopian pepper" or "Negro pepper", are widely used in traditional African medicines to treat a wide array of diseases including malaria, fungal infections, rheumatism, arthritis, etc. Scientific investigations have ascribed the following activities to the fruits of XYA; anti-diabetic, anti-inflammatory, antimicrobial, antiplasmodial, analgesic, anti-nociceptive, anti-proliferative, spermatogenic and neuropharmacological effects. The main active principle reported is xylopic acid (XA), a kaurene diterpene. This study aimed to develop and validate a simple HPLC/UV (high performance liquid chromatography -ultraviolet detection) analytical method for the quantification of XA that can be reproduced in poor-resource settings where advanced analytical detection techniques such as HPLC-MS are unavailable. Materials and Methods: Thus in this study, a simple C18 solid-phase extraction (SPE) column-pretreatment ─ HPLC/UV analytical procedure was developed for the quantification of XA in the dried fruits of XYA from four African countries, Benin, Cameroon, Ghana and Nigeria. The samples of XYA from the four countries were assessed for similarities using chromatographic fingerprinting. Results: The HPLC method was validated for linearity, limits of detection and quantification, precision and accuracy. The samples of XYA from Cameroon were found to have the highest average content of XA while those from Benin had the lowest average content of XA.

A review of pharmacological effects of xylopic acid

“…Example, fruit samples from Cameroon were found to have the highest average content (0.7983 mg/g) followed by Ghana (0.5969 mg/g), Nigeria (0.5469 mg/g) and Benin (0.5302 mg/g). 5 Quantification of the content of xylopic acid in the other plant sources has not yet been reported.…”

“…X. aethiopica is a spice globally used to prepare variety of cuisine. 5 This implies all categories of people including pregnant women and children are exposed to both the beneficial and potential harmful effect of xylopic acid. It is important to caution men of child bearing age to avoid or reduce the consumption of the fruit of X. aethiopica due to the potential harmful effect on reproduction.…”