Uzara (Xysmalobium undulatum) - An underutilized anti-diarrhoeic and spasmolytic herbal remedy

Uzara, Xysmalobium undulatum (L.) W.T.Aiton, a herbal medicine for diarrhoea and smooth-muscle cramps is little-known outside Germany, where it has had a market presence for ∼110 years. The early introduction of this Southern African medicinal plant into Europe and the US was entrepreneurially driven, similar to buchu (Agathosma spp.) and Umckaloabo (Pelargonium sidoides DC.). Much of its history of commercialization, from its origin, identity and supply chain to its composition and clinical evidence of efficacy and safety, has been poorly studied and/or scantly published.

The aim of this review is to uncover enough data to create a coherent timeline, many of which are published here for the first time, and to evaluate all published data, mostly historical and/or elusive, to corroborate Uzara's status as a safe and efficacious botanical medicine.

Multiple searches were conducted in the PubMed, Scopus, Web of Science, Science Direct, and Google Scholar databases with the following keywords: all scientific and common plant names combined with taxonomy, nomenclature, ethnobotany, traditional use, ecology, cultivation, sustainability, economy, trade, CITES, chemistry, biochemistry, compounds, pre-clinical, pharmacology, clinical, RCT, safety, toxicology, veterinary, review for the period of 1600-2022. Reference sections of selected publications were searched manually. Additionally, product registration databases of national competent health authorities in Europe were consulted for products, license holders and formulations.

The authors find an underutilized potential of uzara as anti-diarrhoeic (with or without underlying infection) and spasmolytic remedy. A by-product of this review is a largely inclusive bibliography of publications on uzara.

Further clinical research supporting antidiarrhoeal and spasmolytic efficacy would be desirable.