Aspalathin from Rooibos (Aspalathus linearis): A Bioactive C-glucosyl Dihydrochalcone with Potential to Target the Metabolic Syndrome

Abstract

Aspalathin is a C-glucosyl dihydrochalcone that is abundantly present in Aspalathus linearis. This endemic South African plant, belonging to the Cape Floristic region, is normally used for production of rooibos, a herbal tea. Aspalathin was valued initially only as precursor in the formation of the characteristic red-brown colour of “fermented” rooibos, but the hype about the potential role of natural antioxidants to alleviate oxidative stress, shifted interest in aspalathin to its antioxidant properties and subsequently, its potential role to improve metabolic syndrome, a disease condition interrelated with oxidative stress. The potential use of aspalathin or aspalathin-rich rooibos extracts as a condition-specific nutraceutical is hampered by the limited supply of green rooibos (i.e., “unfermented” plant material) and low levels in “fermented” rooibos, providing incentive for its synthesis. In vitro and in vivo studies relating to the metabolic activity of aspalathin are discussed and cellular mechanisms by which aspalathin improves glucose and lipid metabolism are proposed. Other aspects covered in this review, which are relevant in view of the potential use of aspalathin as an adjunctive therapy, include its poor stability and bioavailability, as well as potential adverse herb-drug interactions, in particular interference with the metabolism of certain commonly prescribed chronic medications for hyperglycaemia and dyslipidaemia.

Metabolic Impact of Flavonoids Consumption in Obesity: From Central to Peripheral

“…Several studies have demonstrated that, either from natural sources or synthetic, chalcones can impact on glucose and lipid metabolism and their health benefits have been studied in relation to type 2 diabetes [ 379 ]. Chalcones have shown hypoglycemic capacity, the ability to modulate food intake and activate AMPK, as well as antioxidant, anti-inflammatory, anticancer, anti-obesity, hepatoprotective and neuroprotective properties [ 380 , 381 , 382 , 383 , 384 , 385 , 386 , 387 , 388 , 389 , 390 , 391 , 392 ] Although there are no many studies in humans the effects of chalcones in the obese phenotype in animal models are similar to the ones described for other flavonoids, thus suggesting a potential therapeutic role of these group of bioactive compounds.…”

“…According to these data, aspalathin a C-glucosyl dihydrochalcone present in rooibos tea from Aspalathus linearis, also activated AMPK and reduced the expression of hepatic enzymes and transcriptional regulators that are associated with either gluconeogenesis and/or lipogenesis ( Acc, Fasn, Scd) in diabetic ob/ob mice [ 388 , 398 ]. Furthermore, Aspalathin-enriched green rooibos extract (GRE) improved hepatic insulin resistance via the regulation of the PI3K/AKT and AMPK Pathways [ 399 ].…”

Modulation of Oxidative Stress and Hyperglycemia by Rheum spiciformis in Alloxan Induced Diabetic Rats and Characterization of Isolated Compound

“…Antioxidative mechanisms that operate inside our body protect us against oxidative stress induced damage and repair damaged biomolecules. Thus intake of is considered critical to protect against various oxidative stress related diseases [29,30]. Diabetes mellitus is one of the chronic metabolic disorders characterized by an increased level of glucose in blood (hyperglycemia).…”

Skeletal Muscle as a Therapeutic Target for Natural Products to Reverse Metabolic Syndrome

“…Although aspalathin was known to be uniquely found in rooibos [22], recent evidence has shown that this C-linked dihydrochalcone glucoside c a nb ed e t e c t e di nt r a c ea m o u n t si nt w oo t h e rs p e c i e so fAcacia pendula [23]. Aspalathin is considered to have a poor bioavailability profile in different experimental settings as reviewed by Muller et al [24] and Johnson et al [25]. While Stalmach et al [26], using high-performance liquid chromatography-mass spectrometry method, showed that O-methyl-aspalathin-O-glucuronide and eriodictyol-O-sulfate were the main metabolites excreted following ingestion of rooibos extract containing 10-fold higher levels of aspalathin in human subjects.…”