ABSTRACT
We have previously, for the first time, demonstrated that hot water extracts of Cyclopia maculata and Cyclopia subternata, endemic South African plants that are consumed as herbal teas, inhibit adipogenesis in 3T3-L1 adipocytes. The aim of this study was to extend the anti-obesity investigations of these plants by quantifying lipolysis in mature 3T3-L1 adipocytes. Glycerol concentration in culture supernatants was used as a marker of adipocyte lipolysis. Isoproterenol, a ß-adrenergic agonist and a known lipolytic agent, was used as a positive control in our assays. Lipolysis was stimulated by all extracts, although statistical significance was noted for fermented (oxidised) C. maculata only. A concentration of 80µg/ml of C. maculata extract induced maximal lipolysis (1.8-fold, p<0.001). The increased lipolysis was accompanied by an increase in the expression of hormone sensitive lipase (1.6-fold, p<0.05) and perilipin (1.6-fold, p<0.05). The plant extracts, at the concentration range assayed (0-100µg/ml), were not cytotoxic in terms of mitochondrial dehydrogenase and adenosine-5'-triphosphate activity. These results showed that C. maculata stimulates lipolysis in mature 3T3-L1 adipocytes, providing further support for the anti-obesity effects of Cyclopia spp.
Subject(s)
Adipogenesis/drug effects , Carrier Proteins/drug effects , Cyclopia Plant/chemistry , Lipolysis/drug effects , Phosphoproteins/drug effects , Plant Extracts/pharmacology , Sterol Esterase/drug effects , 3T3-L1 Cells , Adipocytes/drug effects , Adipocytes/metabolism , Adrenergic beta-Agonists/pharmacology , Animals , Anti-Obesity Agents/chemistry , Anti-Obesity Agents/isolation & purification , Anti-Obesity Agents/pharmacology , Carrier Proteins/metabolism , Glycerol/analysis , Glycerol/metabolism , Isoproterenol/pharmacology , Mice , Perilipin-1 , Phosphoproteins/metabolism , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plants, Medicinal , South Africa , Sterol Esterase/metabolismABSTRACT
The stems, leaves and flowers of Cyclopia have been consumed as a herbal tea 'honeybush tea' to treat various medical ailments since the 19th century. Plant polyphenols are reported to inhibit adipogenesis in cell and animal models of obesity. The aim of this study was to assess the effect of hot water extracts of two Cyclopia species, C. maculata and C. subternata on obesity in an in vitro model. The total polyphenol content of unfermented C. subternata, unfermented C. maculata and fermented C. maculata extracts was 25.6, 22.4 and 10.8g GAE/100g, respectively. The major compounds present in the extracts were: the flavonoid, phloretin-3',5'-di-C-glucoside in C. subternata, the xanthone, mangiferin in unfermented C. maculata and the flavanone, hesperidin in fermented C. maculata. All of the plant extracts inhibited intracellular triglyceride and fat accumulation, and decreased PPARγ2 expression. The higher concentrations of unfermented C. maculata (800 and 1600µg/ml) and C. subternata (1600µg/ml) were cytotoxic in terms of decreased mitochondrial dehydrogenase activity. Both fermented and unfermented C. maculata, at concentrations greater than 100µg/ml, decreased cellular ATP content. Cyclopia maculata and C. subternata inhibit adipogenesis in vitro, suggesting their potential as anti-obesity agents.
