Beetroot Extract Increases the Expression of Uncoupling Protein 1 in Primary Brown Adipocytes in Vitro

Abstract

Increasing energy expenditure is a common and ideal way to prevent obesity which is defined as the accumulation of excess body fat, especially adipose tissue. The human body has two types of adipose tissues, white and brown adipose tissues. White adipose tissue stores excess calories as fat, which is evidently connected to developing obesity. On the other hand, brown adipose tissue utilizes stored and circulating fat by a non‐shivering thermogenesis which is promoted by uncoupling protein (UCP) 1, a critical protein to generate heat. With the evidence of metabolically active brown adipose tissue in human body, it is noted that activation of brown adipose tissue may be a potential way to improve obese condition. Although various studies have been performed to activate brown adipose tissue, there is limited information regarding foods in the activation of brown adipose tissue. Beetroot (Beta vulgaris) is a root vegetable commonly found in grocery markets and consumed by most people worldwide. Some studies have shown the beneficial possibilities of beetroot especially in obese conditions, but it still remains unclear. The aim of this study was to examine the effect of beetroot extract in brown adipocytes through a non‐shivering thermogenesis. Briefly, brown preadipoctyes were isolated from interscapular brown adipose tissue of 4 week‐old male C57BL/6 mice, cultured and then differentiated to become mature brown adipocytes, characterized by multilocular lipid droplets. The cells were treated with beetroot extract (200ug/ml) 2 days before harvesting for RNA extraction. The expression of genes that are involved in the regulation of a non‐shivering thermogenesis were measured using real‐time PCR. Treatment using beetroot extract increased the expression of UCP1 gene. However peroxisome proliferator‐activated receptor (PPAR) α and PPAR‐γ coactivator 1 α genes, transcriptional factors involved in regulating UCP1 were not changed. Interestingly PPARγ gene was increased, which may be indicated as an accelerated differentiation. Nuclear respiratory factor 1 gene which is related to mitochondria biogenesis was slightly increased. Taken together, this data suggests anti‐obesity effect of beetroot by increasing UCP1 in a non‐shivering thermogenesis of brown adipocytes.Support or Funding InformationSupported by USDA.