Adipose and non-adipose perspectives of plant derived natural compounds for mitigation of obesity.

ETHNOPHARMACOLOGICAL RELEVANCE: Phyto-preparations and phyto-compounds, by their natural origin, easy availability, cost-effectiveness, and fruitful traditional uses based on accumulated experiences, have been extensively explored to mitigate the global burden of obesity. AIM OF THIS REVIEW: The review aimed to analyse and critically summarize the prospect of future anti-obesity drug leads from the extant array of phytochemicals for mitigation of obesity, using adipose related targets (adipocyte formation, lipid metabolism, and thermogenesis) and non-adipose targets (hepatic lipid metabolism, appetite, satiety, and pancreatic lipase activity). Phytochemicals as inhibitors of adipocyte differentiation, modulators of lipid metabolism, and thermogenic activators of adipocytes are specifically discussed with their non-adipose anti-obesogenic targets. MATERIALS AND METHODS: PubMed, Google Scholar, Scopus, and SciFinder were accessed to collect data on traditional medicinal plants, compounds derived from plants, their reported anti-obesity mechanisms, and therapeutic targets. The taxonomically accepted name of each plant in this review has been vetted from "The Plant List" (www.theplantlist.org) or MPNS (http://mpns.kew.org). RESULTS: Available knowledge of a large number of phytochemicals, across a range of adipose and non-adipose targets, has been critically analysed and delineated by graphical and tabular depictions, towards mitigation of obesity. Neuro-endocrinal modulation in non-adipose targets brought into sharp dual focus, both non-adipose and adipose targets as the future of anti-obesity research. Numerous phytochemicals (Berberine, Xanthohumol, Ursolic acid, Guggulsterone, Tannic acid, etc.) have been found to be effectively reducing weight through lowered adipocyte formation, increased lipolysis, decreased lipogenesis, and enhanced thermogenesis. They have been affirmed as potential anti-obesity drugs of future because of their effectiveness yet having no threat to adipose or systemic insulin sensitivity. CONCLUSION: Due to high molecular diversity and a greater ratio of benefit to risk, plant derived compounds hold high therapeutic potential to tackle obesity and associated risks. This review has been able to generate fresh perspectives on the anti-diabetic/anti-hyperglycemic/anti-obesity effect of phytochemicals. It has also brought into the focus that many phytochemicals demonstrating in vitro anti-obesogenic effects are yet to undergo in vivo investigation which could lead to potential phyto-molecules for dedicated anti-obesity action.

Genome-wide identification and expression profiling of chitinase genes in tea (Camellia sinensis (L.) O. Kuntze) under biotic stress conditions.

Chitinases are a diverse group of enzymes having the ability to degrade chitin. Chitin is the second most abundant polysaccharide on earth, predominantly found in insect exoskeletons and fungal cell walls. In this study, we performed a genome-wide search for chitinase genes and identified a total of 49 chitinases in tea. These genes were categorized into 5 classes, where an expansion of class V chitinases has been observed in comparison to other plant species. Extensive loss of introns in 46% of the GH18 chitinases indicates that an evolutionary pressure is acting upon these genes to lose introns for rapid gene expression. The promoter upstream regions in 65% of the predicted chitinases contain methyl-jasmonate, salicylic acid and defense responsive cis-acting elements, which may further illustrate the possible role of chitinases in tea plant's defense against various pests and pathogens. Differential expression analysis revealed that transcripts of two GH19 chitinases TEA028279 and TEA019397 got upregulated during three different fungal infections in tea. While GH19 chitinase TEA031377 showed an increase in transcript abundance in the two insect infested tea tissues. Semi-quantitative RT-PCR analysis revealed that five GH19 chitinases viz. TEA018892, TEA031484, TEA28279, TEA033470 and TEA031277 showed significant increase in expression in the tea plants challenged with a biotrophic pathogen Exobasidium vexans. The study endeavours in highlighting biotic stress responsive defensive role of chitinase genes in tea.

1α, 25-dihydroxy Vitamin D3 containing fractions of Catharanthus roseus leaf aqueous extract inhibit preadipocyte differentiation and induce lipolysis in 3T3-L1 cells.

BACKGROUND: To investigate the potential of Catharanthus roseus leaf aqueous crude extract (CRACE) as a regulator of adipocyte development and function. METHODS: 3T3-L1 adipogenesis model was used to investigate the effect of CRACE on adipogenesis. 3T3-L1 preadipocytes (for adipogenic differentiation) and mature 3T3-L1 adipocytes (for adipocyte function) were treated with non-toxic doses of CRACE. The outcomes were corroborated by intracellular lipid accumulation, expression of pro-and anti-adipogenic effector molecules. To investigate CRACE mediated lipolysis, cAMP accumulation, glycerol release and phosphorylation of key effector molecules were tested in treated mature adipocytes. Finally, the extract was fractionated to identify the active molecule/s in the extract. RESULTS: CRACE significantly reduced adipocyte differentiation by modulating PPARγ expression. At early stage CRACE directly targeted Lipin1 expression and consequently impacted KLF7, subsequently expression of GATA2, CEBPα, SREBP1c were targeted, with PPARγ expression, particularly curtailed. While CRACE significantly reduced several lipogenic genes like FAS and GPD1 in mature adipocytes, concomitantly, it greatly increased lipolysis resulting in decreased lipid accumulation in mature adipocytes. The increase in lipolysis was due to decreased Akt activation, increased cAMP level, and PKA activity. The fractionation of CRACE allowed identification of two fractions with potent anti-adipogenic activity. Both the fractions contained 1α, 25-dihydroxy Vitamin D3 as major component. CONCLUSIONS: 1α, 25-dihydroxy Vitamin D3 containing CRACE can be developed into an effective anti-obesity formulation that decreases adipogenesis and increases lipid catabolism.

Arginylation regulates adipogenesis by regulating expression of PPARγ at transcript and protein level.

Protein modification by arginylation regulates protein stability, function and interaction. The loss of arginylation disrupts a diverse set of fundamental cellular processes from proliferation to death. In the current study, role of arginylation in cell differentiation is investigated. Using in vitro preadipocyte differentiation model, it was observed that the inhibition or knockout (KO) of arginyltransferase 1 (ATE1) severely hindered differentiation of preadipocytes into mature adipocytes. Absence of arginylation inhibited expression of two key adipogenic transcription factors PPARγ and C/EBPα, and their downstream adipogenic genes (FABP4, GLUT4, PLN1). Arginylation did not affect the induction of C/EBPß and C/EBPδ, the up-stream regulators of PPARγ gene. However, absence of arginylation affected PPARγ protein expression, independent of its transcript level. The constitutive expression of PPARγ1 protein in Ate1 KO cells as well as ATE1 inhibitor treated wild type cells were dampened due to increased proteasome mediated degradation of PPARγ1 in the absence of arginylation in the cells. Taken together these observations suggested arginylation mediated transcriptional regulation of PPARγ and C/EBPα was downstream of C/EBPß and C/EBPδ, and that the arginylation mediated regulation of PPARγ protein expression may play a role in this process. The inhibition of arginylation in mature adipocytes also reduced expression of lipogenesis genes and decreased fat accumulation in differentiated adipocytes. Thus, the current study shows that arginylation is essential for preadipocyte differentiation and maturation which are thought to be key factors in the maintenance of adipose tissue homeostasis.

Effect of maleylation on physicochemical and functional properties of rapeseed protein isolate.

Influence of maleylation on the physicochemical and functional properties of rapeseed protein isolate was studied. Acylation increased whiteness value and dissociation of proteins, but reduced free sulfhydryl and disulfide content (p < 0.05). Intrinsic fluorescence emission and FTIR spectra revealed distinct perturbations in maleylated proteins' tertiary and secondary conformations. Increase in surface hydrophobicity, foaming capacity, emulsion stability, protein surface load at oil-water interface and decrease in surface tension at air-water interface, occurred till moderate level of modification. While maleylation impaired foam stability, protein solubility and emulsion capacity were markedly ameliorated (p < 0.05), which are concomitant with decreased droplet size distribution (d 32). In-vitro digestibility and cytotoxicity tests suggested no severe ill-effects of modified proteins, especially up to low degrees of maleylation. The study shows good potential for maleylated rapeseed proteins as functional food ingredient.