Title : Anti-obesity activity of Viburnum opulus phenolic rich extract in L6 cell line
Changes in lifestyle such as increased consumption of high-caloric foods combined with reduced physical activity, are known to play an important role in the worldwide increase of obesity. Obesity is closely associated with metabolic disturbances like hypertension, dyslipidemia and hyperglycemia and may lead to premature death.
The adipose tissue plays an important role in buffering the postprandial flux of dietary fat into the circulation via suppression of the free fatty acids (FFA) release into circulation, as well as increase of plasma triacyloglycerols (TAG) clearance. However, in obesity state there are observed increased release of circulating FFA and their higher uptake by skeletal muscle. Oversupply of FFA drives an adaptive increase in mitochondrial b-oxidation, which, without an increase in energy demand, leads to incomplete fatty acid oxidation, increased redox pressure on the electron transport chain, decreased mitochondrial potential, elevated production of reactive oxygen species (ROS) and oxidative stress, development of insulin resistance and cellular damage.
The plant Viburnum opulus (L.), known as guelder rose, possess strong antioxidant activity due to high content of phenolic compounds. Recent studies have shown that juice obtained from V. opulus fruit, as well as extracts from pomace, have ability to decrease FFA and enhance glucose uptake by Caco-2 cells.
The presented research focuses on the guelder rose fruit phenolic compounds identification as well as on their influence on FFA uptake by rat skeletal myoblast cell line L6. There were two phenolic compounds extracts characterised: fresh juice (FJ) and juice purified by solid phase extraction (PJ). Data obtained from UPLC analysis showed that in V. opulus juice the dominant phenolic compound is chlorogenic acid, which accounts for 70% of total phenolic compounds. Juice is also a rich source of flavanols, such as (+)-catechin, procyanidin B1, procyanidin B2, anthocyanins – cyanidin-3-O-glucoside, cyanidin-3-O-sambubioside and quercetin glycosides.
In biological studies for induction of hyperlipidaemia there were used oleic and palmitic acids (OA, PA). Experiments have shown that in L6 cells PJ inhibits cellular lipids accumulation and reduces ROS production after cells preincubation with palmitic acid. V. opulus preparations also increased mitochondrial potential connected with higher production of ATP. PJ improved the FFA-induced insulin resistance in myoblast through enhancing glucose analogue uptake.