Effects of fermented rooibos (Aspalathus linearis) on adipocyte differentiation.
Rooibos (Aspalathus linearis) contains a rich complement of polyphenols, including flavonoids, considered to be largely responsible for its health promoting effects, including combatting obesity. The purpose of this study was to examine the effect of fermented rooibos hot water soluble solids on in vitro adipocyte differentiation by using differentiating 3T3-L1 adipocytes. Hot water soluble solids were obtained when preparing an infusion of fermented rooibos at "cup-of-tea" strength. The major phenolic compounds (>5 mg/g) were isoorientin, orientin, quercetin-3-O-robinobioside and enolic phenylpyruvic acid-2-O-β-D-glucoside. Treatment of 3T3-L1 adipocytes with 10 μg/ml and 100 μg/ml of the rooibos soluble solids inhibited intracellular lipid accumulation by 22% (p<0.01) and 15% (p<0.05), respectively. Inhibition of adipogenesis was accompanied by decreased messenger RNA (mRNA) expression of PPARγ, PPARα, SREBF1 and FASN. Western blot analysis exhibited decreased PPARα, SREBF1 and AMPK protein expression. Impeded glycerol release into the culture medium was observed after rooibos treatment. None of the concentrations of rooibos hot water soluble solids was cytotoxic, in terms of ATP content. Interestingly, the higher concentration of hot water soluble solids increased ATP concentrations which were associated with increased basal glucose uptake. Decreased leptin secretion was observed after rooibos treatment. Our data show that hot water soluble solids from fermented rooibos inhibit adipogenesis and affect adipocyte metabolism, suggesting its potential in preventing obesity.
Diabetes Discovery Platform, South African Medical Research Council, P.O. Box 19070, Tygerberg 7505, South Africa. Electronic address: micheline.sanderson@mrc.ac.za.
Micheline
M
Sanderson
Diabetes Discovery Platform, South African Medical Research Council, P.O. Box 19070, Tygerberg 7505, South Africa.
Sithandiwe E
SE
Mazibuko
Post-Harvest and Wine Technology Division, Agricultural Research Council (ARC) Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa; Department of Food Science, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602, South Africa.
Elizabeth
E
Joubert
Post-Harvest and Wine Technology Division, Agricultural Research Council (ARC) Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa.
Dalene
D
de Beer
Diabetes Discovery Platform, South African Medical Research Council, P.O. Box 19070, Tygerberg 7505, South Africa.
Rabia
R
Johnson
Diabetes Discovery Platform, South African Medical Research Council, P.O. Box 19070, Tygerberg 7505, South Africa.
Carmen
C
Pheiffer
Diabetes Discovery Platform, South African Medical Research Council, P.O. Box 19070, Tygerberg 7505, South Africa.
Johan
J
Louw
Diabetes Discovery Platform, South African Medical Research Council, P.O. Box 19070, Tygerberg 7505, South Africa.
Christo J F
CJ
Muller
D041721:3T3-L1 Cells; D000255:Adenosine Triphosphate / Q000378:metabolism; D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism; D050156:Adipogenesis / Q000187:drug effects*; D000818:Animals; D036903:Aspalathus / Q000737:chemistry*; D054890:Fatty Acid Synthase, Type I / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D020738:Leptin / Q000378:metabolism; D051379:Mice; D009765:Obesity / Q000235:genetics / Q000378:metabolism* / Q000517:prevention & control; D047492:Peroxisome Proliferator-Activated Receptors / Q000378:metabolism; D010636:Phenols / Q000494:pharmacology* / Q000627:therapeutic use; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D012333:RNA, Messenger / Q000378:metabolism; D051780:Sterol Regulatory Element Binding Protein 1 / Q000378:metabolism
D020738:Leptin; D047492:Peroxisome Proliferator-Activated Receptors; D010636:Phenols; D010936:Plant Extracts; D012333:RNA, Messenger; C497388:Srebf1 protein, mouse; D051780:Sterol Regulatory Element Binding Protein 1; D000255:Adenosine Triphosphate; D054890:Fatty Acid Synthase, Type I; D005947:Glucose; D005990:Glycerol
3T3-L1 adipocytes; AMPK; Adipocyte metabolism; Adipogenesis; Glucose uptake; Leptin; Rooibos (Aspalathus linearis)