Aspalathin health benefit
Aspalathin is a green rooibos tea component. A dihydrochalcone and C-glycoside, it is the most abundant flavonoid in rooibos (Aspalathus linearis), which is well known as an herbal tea in many countries. Aspalathin appears to have in vitro antioxidant and antimutagenic effects. Aspalathin may also be helpful in blood sugar control.
Antioxidant benefit
Antioxidant activity of the dihydrochalcones Aspalathin and Nothofagin and their
corresponding flavones in relation to other Rooibos ( Aspalathus linearis )
Flavonoids, Epigallocatechin Gallate, and Trolox.
J Agricultural Food Chem. 2009; Snijman PW, Joubert E, Ferreira D, Li XC,
Ding Y, Green IR, Gelderblom WC. Snijman PW, Joubert E, Ferreira D, Ding
Y, Green IR, Gelderblom WC. Departments of Chemistry, Stellenbosch University, Matieland (Stellenbosch), South Africa.
The antioxidant activity of rooibos flavonoids, including the
dihydrochalcones aspalathin and nothofagin and their corresponding flavone
glycosides, was evaluated using the ABTS radical cation, metal chelating, and
Fe(II)-induced microsomal lipid peroxidation assays. Epigallocatechin gallate (EGCG)
and Trolox were used as reference standards. Optimized geometric conformers of
aspalathin and nothofagin, in addition to calculated physicochemical properties,
were considered to explain interaction with the microsomal membrane structure
and thus relative potency of the dihydrochalcones. The most potent radical
scavengers were aspalathin and EGCG, followed by
quercetin and nothofagin. The
least effective radical scavengers were isovitexin and vitexin. Quercetin and
EGCG were the most effective inhibitors of lipid peroxidation. Aspalathin and
catechin displayed similar potencies. Nothofagin was almost as ineffective as
its flavone glycoside analogues.
For blood sugar
Hypoglycemic effect of aspalathin, a rooibos tea
component from
Aspalathus linearis, in type 2 diabetic model db/db mice.
Phytomedicine. 2009. Kawano A, Nakamura H, Hata SI, Minakawa M, Miura Y,
Yagasaki K. Department of Applied Biological Science, Tokyo University of
Agriculture and Technology, Fuchu, Tokyo, Japan.
Effects of aspalathin on glucose metabolism were studied in vitro and in vivo.
We first examined the effect of aspalathin on glucose uptake by cultured L6
myotubes and on insulin secretion from cultured RIN-5F pancreatic beta-cells in
vitro, and then investigated the effect of dietary aspalathin on fasting blood
glucose level and conducted an intraperitoneal glucose tolerance test using type
2 diabetes model mice in vivo. Aspalathin dose-dependently and significantly
increased glucose uptake by L6 myotubes. It also significantly increased insulin
secretion from cultured RIN-5F cells at 100muM. Dietary aspalathin (0.1-0.2%)
suppressed the increase in fasting blood glucose levels of db/db mice for 5
weeks. Our results suggest that aspalathin has beneficial effects on glucose
homeostasis in type 2 diabetes through stimulating glucose uptake in muscle
tissues and insulin secretion from pancreatic beta-cells.
In Vitro Hepatic Biotransformation of Aspalathin and
Nothofagin, Dihydrochalcones of Rooibos (Aspalathus linearis), and Assessment of
Metabolite Antioxidant Activity.
J Agric Food Chem. 2009. van der Merwe JD, Joubert E, Manley M, de
Beer D, Malherbe CJ, Gelderblom WC.
Aspalathin
(2',3,4,4',6'-pentahydroxy-3'-C-beta-d-glucopyranosyldihydrochalcone) is the
major flavonoid present in the South African herbal tea rooibos. In vitro
metabolism of aspalathin and a structural analogue nothofagin, lacking the A
ring catechol group, was investigated by monitoring the formation of glucuronyl
and sulfate conjugates using Aroclor 1254 induced and uninduced rat liver
microsomal and cytosolic subcellular fractions. Following glucuronidation of
both aspalathin and nothofagin, HPLC-DAD, LC-MS, and LC-MS/MS analyses indicated
the presence of two metabolites: one major and one minor. Only one aspalathin
metabolite was obtained after sulfation, while no metabolites were observed for
nothofagin. Two likely sites of conjugation for aspalathin are 4-OH or 3-OH on
the A-ring. For nothofagin, the 4-OH (A-ring) and 6'-OH (B-ring) seem to be
involved. The glucuronyl conjugates of aspalathin lack any radical scavenging
properties in online postcolumn DPPH radical and ABTS radical cation assays.
Deconjugation assays utilizing glucuronidase and sulfatase resulted in the
disappearance of the metabolites, with the concomitant formation of the
unconjugated form in the case of the glucuronidated product. The balance between
conjugated and unconjugated forms of aspalathin could have important
implications regarding its role in affecting oxidative status in intra- and
extracellular environments in vivo.
amino acid benefit side effects