Toxicological profiling of Citrullus colocynthis (L.) Schrad: Microbial contamination, pesticide residues, aflatoxin levels, and heavy metal analysis

Abstract

Citrullus colocynthis (L.) Schrad, commonly known as Hanzal in Arabic, is a perennial desert vine from the Cucurbitaceae family with a long-standing reputation in traditional medicine. The pulp of its fruit, utilized for managing a variety of conditions such as diabetes, respiratory disorders, gastrointestinal issues, and inflammation, is rich in bioactive compounds including glycosides, flavonoids, alkaloids, cucurbitacins, and essential oils. With growing global interest in herbal medicines, ensuring the safety and quality of these natural products has become paramount. This study aimed to evaluate critical safety parameters, microbial load, heavy metal content, aflatoxins, and pesticide residues, in a market-obtained sample of C. colocynthis, in accordance with WHO guidelines. The plant material was authenticated, processed, and analyzed using established protocols: microbiological assays for bacteria and fungi, ICP-MS for heavy metals, LC-MS/MS for aflatoxins, and GC-MS/MS for pesticide residues. The results demonstrated that the total microbial count, as well as the levels of heavy metals (lead, mercury, arsenic, cadmium), aflatoxins, and a broad spectrum of pesticide residues, were all below the permissible limits. These findings affirm the safety of C. colocynthis for therapeutic use and underscore the necessity of stringent quality control measures in the production of herbal medicines.