Rhodiola Rosea: From the Adaptogenic Role to the Anti-Adipogenic Effect?

Abstract

EditorialMany natural phytonutrients have beneficial effects on health [1,2]. In addition, several botanicals have received positive attention, based on their relative safety and the accumulation of evidence of their antiadipogenic and metabolic effects in animals and humans [3]. Natural products can decrease of lipid absorption, energy intake, lipogenesis, pre-adipocyte differentiation and proliferation or increase of energy expenditure, and lipolysis [4]. These properties exist in specific flavonoids [5], chlorogenic acid from green coffee bean [6], and carnosic acid in rosemary [7]. Extracts from Rhodiola rosea (RR) root is poorly characterized for its properties on adipocytes and only recently it has been proposed for a the adjuvant treatment of obesity against obesity [8].RR is a popular plant in traditional medical systems in the Nordic countries, Eastern Europe and Asia. It belongs to the family of Crassulaceae with a notoriety for stimulating physical endurance, attention span, memory, and work productivity [9][10][11]. The genus Rhodiola contains more than 100 different species, and at least 20 of these are used in traditional Asian medicine [12,13]. However, the most of all animal and human studies has been conducted on RR, so whether other species confer the same health benefits is unknown [14,15].Researches on the RR root phytochemistry has revealed the presence of six distinct groups of chemical compounds: phenylpropanoids (rosavin, rosin, rosarin), phenylethanol derivatives (salidroside, tyrosol); flavonoids (rodiolin, rodionin, rodiosin, acetylrodalgin, tricin), monoterpernes (rosiridol, rosaridin), triterpenes (daucosterol, beta-sitosterol) and phenolic acids (chlorogenic and hydroxycinnamic, gallic acids) [9,16].According to the Soviet Pharmacopeia [17,18], the extracts of RRprimarily in the form of water/alcohol tinctures or dried root extractare standardized for both rosavins and salidroside. RR extracts used in most human clinical studies were standardized to minimum 3% rosavins and 0.8-1% salidroside, because the naturally occurring ratio of these compounds in RR root is approximately 3:1 [14].The main effects of genus Rhodiola described are adaptogenic that means 'natural herbal products which are non-toxic in normal doses, produce a non-specific response, and have a normalizing physiologic influence' and stress protective [19,20]. Moreover, Rhodiola has been described as antioxidant [21][22][23] [32,33], and immunostimulating [34][35][36]. Recently, many other benefits from the use of RR has been found including its ability to regulate blood sugar levels for diabetics and to activate the lipolytic processes [37], mobilizing lipids from adipose tissue to the natural fat burning system of body for weight reduction [8]. In combination with Citrus aurantium, RR has been found to decrease visceral fat weight by 30% of rats fed with high fat diet, having a direct effect on sympathetic tone and on hypothalamic norepinephrine secretion [8]. Although detailed molecular mechanism of the lipid loweri...