Beyond Viscum album: Mistletoe physiology and the pharmacological potential of the extensive Loranthaceae family

Abstract

Ethnopharmacological relevance: Mistletoe extracts from the genus Viscum are widely recognized for their complementary use in cancer therapies. However, many other mistletoe species are employed in ethnopharmacology around the world. The Loranthaceae family is broadly distributed and closely linked to local populations due to its medicinal uses.

Aim of the study: This review integrates biological and pharmacological perspectives to highlight the Loranthaceae family as a biodiverse resource of emerging pharmacological importance, considering its distribution, phytochemical diversity, and therapeutic potential.

Materials and methods: A bibliographic search was conducted in PubMed, Scopus, Web of Science, and Google Scholar. Studies on biogeography, ecology, plant physiology, phytochemistry, bioactivity, and pharmacology of Viscaceae and Loranthaceae were included. Both qualitative and quantitative syntheses of the available information were carried out.

Results: Loranthaceae species are predominantly distributed in the Southern Hemisphere. Their broad biogeographic history has favored considerable evolutionary diversification. The physiology of mistletoes responds to seasonal variations and to biotic and abiotic stresses that influence the accumulation of bioactive compounds. Evidence is presented for 38 Loranthaceae species, showing strong consistency between their traditional uses and the bioactivities investigated. Among these, antioxidant and antitumoral effects, protection of organs and tissues, immunomodulatory properties, antimicrobial and antiviral activity, antidiabetic potential, cardiovascular regulation, neuroactive effects, and cholesterol-lowering activity stand out. A great diversity of secondary metabolites is evident across all species reviewed, including twelve compounds described for the first time through the study of these parasitic plants, such as phenolic glycosides, cyanogenic glycosides, and lupeol-based triterpenoid esters. Future perspectives in biomedicine and biotechnology emphasize the need to continue investigating these plants.

Conclusions: Mistletoes of the Loranthaceae family represent a valuable source of chemical and genetic resources with significant pharmacological potential. Their wide distribution and diversity of bioactive compounds position them as promising candidates for drug discovery. Nevertheless, further research is required to elucidate specific mechanisms and to evaluate their effects at subclinical and clinical levels.

Keywords: Bioactive compounds; Cancer; Loranthaceae; Mistletoe; Pharmacology; Phytochemistry; Viscum.