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

ETHNOPHARMACOLOGICAL RELEVANCE

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.

AIM OF THE STUDY

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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

Bioactive composition of Reevesia formosana root and stem with cytotoxic activity potential

Three lignanoids and three terpenoids, along with 40 known compounds were isolated from Reevesia formosana.

Xysmalobium undulatum (uzara) - review of an antidiarrhoeal traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Xysmalobium undulatum, commonly known as uzara, is traditionally used as an antidiarrhoeal and to treat stomach cramps, dysmenorrhoea and afterbirth cramps. In addition, it was reportedly used to treat anxiety and other conditions relating to mental health.

AIM OF THE REVIEW

To unite the botanical aspects, ethnopharmacology, phytochemistry, biological activity, pharmacokinetic and pharmacodynamic data, toxicity and commercial aspects of the scientific literature available on uzara.

METHOD

An extensive review of the literature covering 1917-2014 was carried out. Electronic databases including Scopus, Pubmed, Google Scholar and Google were used to assemble the data. All abstracts, full-text articles and books written in English and German were examined and included.

RESULTS

The phytochemistry of uzara has been comprehensively investigated and at least 18 compounds have been isolated and characterised. Uzara contains mainly cardenolide glycosides such as uzarin and xysmalorin and cardenolide aglycones such as uzarigenin and xysmalogenin. Limited scientific studies on the biological activity of uzara have been done. In vitro antisecretory antidiarrhoeal action was confirmed. Central nervous system activity was conflicting, in vitro and in vivo (animals) studies were inconclusive and no clinical studies have been performed. No antimutagenic effects have been reported and no toxicity up to date has been associated with uzara consumption. Significant cross-reactivity of uzara compounds with commercial digoxin and digitoxin assays may interfere with therapeutic drug monitoring.

CONCLUSIONS

The key traditional uses associated with uzara have been investigated in vitro and in vivo (animal), but clinical trial data is lacking.

Structures, chemotaxonomic significance, cytotoxic and Na+,K+-ATPase inhibitory activities of new cardenolides from Asclepias curassavica

New cardenolides with potent cytotoxic and Na⁺,K⁺-ATPase inhibitory activities were isolated from the ornamental milkweed Asclepias curassavica.

Electrophysiological and inotropic effects of natural amino-deoxyglyco-cardenolides

The electrophysiological, inotropic and chronotropic effects of the two first natural amino-dexoyglyco-cardenolides, mitiphylline and holarosine B, were studied. Mitiphylline has qualitatively the same properties as those of common cardiac glycosides but is more potent; holarosine B has a similar action on cardiac electrophysiological parameters of the guinea pig heart but is less potent. The difference in activity between these two compounds could be attributed to the configuration in 5-and 17-positions of the genins. Holarisone B has the particularity of increasing the action potential plateau amplitude and its duration in rat heart; this could be part of the role of the aminosugar moiety.