Silymarin Chemotype and Content in Wild Iranian Milk Thistle (Silybum marianum L.)

Mirzaabolghasemi, Mohammad Amin; Pirmoradi, Mohammad Reza; Raghami, Mahmoud Reza; Martinelli, Tommaso

doi:10.22034/jmpb.2025.369015.2008

Silymarin Chemotype and Content in Wild Iranian Milk Thistle (Silybum marianum L.)

Articles in Press

Document Type : Research Paper

Authors

¹ Section of Plant Breeding and Biotechnology, Department of Horticulture, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, 7718897111, Rafsanjan, Iran

² Council for Agricultural Research and Economics, Research Centre for Plant Protection and Certification (CREA-DC), Loc. Cascine del Riccio, Via di Lanciola 12/A; 50125, Firenze, Italy

10.22034/jmpb.2025.369015.2008

Abstract

Milk thistle (Silybum marianum (L.) Gaertn.) of the Asteraceae family is recognized as a valuable medicinal herb, primarily due to the presence of silymarin - a complex of flavonolignans concentrated in its fruits. Naturally occurring milk thistle populations can contain individuals of uniform chemotype or mixtures of multiple chemotypes, though only three (A, B, and C) have been documented so far. This research investigated the silymarin chemotype and content across 18 wild milk thistle populations gathered from various Iranian regions and cultivated under uniform environmental conditions. Eight populations were classified as chemotype B, while the remainder consisted of mixed chemotypes. The mean silymarin content was found to be 32.68 ± 2.46 mg/g dry weight, with population 23 exhibiting the highest level (47.94 mg/g) and population 21 the lowest (21.87 mg/g). Additionally, 16 individual plants from four heterogeneous populations were assessed, revealing the known chemotypes A, B, and C, and identifying a novel chemotype (designated E) for the first time. This finding highlights significant chemical diversity in Iranian milk thistle. Both A and B chemotypes were widespread, with no clear geographic pattern. Overall, these findings enrich the understanding of milk thistle chemodiversity and offer insights useful for breeding programs aimed at enhancing silymarin yield and quality.

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