Occurrence and characterization of fungal species in medicinal plants from South Africa

Fungal contamination of medicinal plants poses significant health risks due to the potential production of mycotoxins. In South Africa (SA), medicinal plants are widely used in traditional healthcare, but their safety is often compromised by fungal colonization. This study investigated 36 different medicinal plants purchased from Faraday Muthi Market, Johannesburg, SA, for fungal level using both macro- and microscopic approaches, and their identities were confirmed by molecular means. The fungal loads of the mycoflora recovered from the medical plants ranged from 1.8 × 10⁴ CFU/g to 2 × 10⁷ CFU/g, exceeding the WHO regulatory limit of 1 × 10³ CFU/g. Furthermore, a total of 164 fungal species from nine genera, including Aspergillus (39.6%), Penicillium (19.5%), and Fusarium (9.7%), other notable fungal genera such as Alternaria (5.5%), Mucor (5.4%), Rhizopus (5.4%), Chaetomium (4.2%), Cladosporium (3.6%), Emericella nidulans (3.6%) and Epicoccum (3.0%) were also recovered from the medicinal plants. Furthermore, A. niger (10.97%) was the most prevalent among all the identified fungal species. Consuming fungal-contaminated medicinal plants poses significant human health risks. The findings highlights the need for strict quality control during the cultivation, harvesting, and processing of medicinal plants in South Africa and across Africa to mitigate fungal contamination risks. Future research should focus on developing strategies to reduce fungal loads in medicinal plants.