Morphological Characteristics, Distribution, Secondary Metabolites and Biological Activities of Rhodiola L.

Members of the genus Rhodiola L. are perennial herbaceous plants indigenous to high altitudes in the Arctic, throughout the central Himalayan Mountain regions, Qinghai-Tibetan Plateau and to the European Alps. Nearly, 84 Rhodiola species (including subspecies and varieties) are recorded worldwide. For thousands of years, Rhodiola species has been in use as an important adaptogen, hemostatic, and tonic in traditional Tibetan medicines (TTM). The review describes the morphological characteristics of Rhodiola species, provides information about their distribution, summarizes the secondary metabolites of R. rosea that is the predominant species screened in efficacy studies, and compares the differences of secondary metabolites among other species such as R. crenulata, R. sachlinesis and R. sacra. Rhodiola L containing numerous active chemical compounds: phenyl propanoids, phenylethanol derivatives, flavanoids, terpenes, and phenolic acids. These compounds have important biological activities, such as adaptogenic/adaptogen, antioxidant, antifatigue, anticancer, postponing ageing, immunomodulatory, cardioprotective, metabolic effects, and antineuronal apoptosis effects.