Currently approved anti obesity drugs for long term use such
Currently approved anti-obesity drugs for long term use such as orlistat, lorcaserin and liraglutide are efficient in reduction of weight gain but are limited in usage due to their adverse effect profile and higher cost (Krentz et al., 2016; Mopuri and Islam, 2017). In caspofungin to this, plant derived molecules produce comparatively insignificant quantum of adverse effects and are affordable making them suitable agents for management of obesity (Mukherjee et al., 2015, Mopuri and Islam, 2017). Herbal teas were used from ancient times for their medicinal properties, especially in disorders related to cardiovascular and metabolic functions (Ravikumar, 2014). Currently there is an enhanced interest in herbal teas as remedy for obesity and associated complications, flowers of Hibiscus rosa sinensis are used widely for this purpose (Priya et al., 2016). Hibiscus rosa sinensis (Family: Malvaceae) an ornamental plant grown in India and China is known from ancient times for its medicinal properties. The major phytoconstituents reported in Hibiscus flowers are quercetin, cyanidin, thiamine, niacin, ascorbic acid, genistic acid, lauric acid, margaric acid, hentriacontane and calcium oxalate (Falade et al., 2009, Gomathi et al., 2008, Lim, 2014). It was popular in traditional medicine of various cultures as a wound healing agent, detoxifier, anti-fertility agent, anti hypertensive, hypolipidemic, anti-cancer agent, anti asthmatic agent and cardio-protective agent (Goldberg et al., 2016, Jadhav et al., 2015, Vincenta and Patel, 2016). Research findings reported wound healing, anti-fertility, anti hypertensive, hypolipidemic, anti asthmatic and cardio-protective properties of Hibiscus rosa sinensis (Afiune et al., 2017, Bhaskar and Nithya, 2012, Gauthaman et al., 2006, Gomathi et al., 2008, Khan et al., 2014, Pethe et al., 2017, Ruban and Gajalakshmi, 2012, Sachdewa and Khemani, 2003, Shewale et al., 2012). Despite the existence of reports on hypolipidemic potential of Hibiscus rosa sinensis flower extract, there exists a huge lacuna regarding the detailed mechanistic studies. Among various in vitro models for adipogenesis, mouse derived 3T3-L1 fibroblasts are well established and regularly used to study effect of compounds on adipogenic differentiation and characterizing their mechanism of action (Ruiz-Ojeda et al., 2016). In this scenario, the current investigation was designed to delineate possible molecular mechanism behind the lipid lowering effect of Hibiscus rosa sinensis using well established in vitro model of 3T3-L1 fibroblasts cells.
Materials and methods
Discussion Obesity, a complex health disease associated with dysregulation of adipose tissue is a serious concern. For first time our study demonstrated that a fraction of H. rosa sinensis ethyl acetate extracts which may have constituents like quercetin, kaempferol etc has significantly inhibited pre-adipocyte differentiation and lipid accumulation. Incubation of pre-adipocytes during differentiation has reduced lipid accumulation as assessed from Oil Red O staining and triglyceride measurements. Although there was significant difference observed between HRF treatment and standard treatment in reduction of lipid accumulation, it can be comparable. Lipolysis in adipose tissue is catalysed by adipose tissue triglyceride lipase (ATGL), which converts it to diacylglycerol (DAG). While hormone sensitive lipase (HSL) further hydrolyses DAG into monoacylglycerol, which is further hydrolysed by monoacylglycerol lipase releasing free fatty acids and glycerol (Ahmadian et al., 2010). Lipid droplets are coated with protein perilipin which upon phosphorylation by protein kinase A gets activated and induces lipolysis (Duncan et al., 2007). Higher levels of plasma free fatty acids are an independent risk factor for development of insulin resistance. It causes deposition of fatty acids in insulin sensitive tissues like liver and impairs insulin sensitivity, even it activates inflammatory cascade in adipose tissue worsening obesity (Morigny et al., 2016). Adipocyte differentiation has enhanced lipolysis, there was a slight non significant reduction in lipolysis observed with the HRF treatments. This decrease in lipolysis might be due to reduction in the levels of perilipin whose expression is enhanced after differentiation and is in line with activation of AMPK (Gaidhu et al., 2012). Anti lipolytic activity can be beneficial in reduction of insulin resistance, development of Type 2 diabetes and metabolic syndrome.