Screening for anti-adipogenic, pro-lipolytic and thermogenic plant extracts by models associating intestinal epithelial cells with human adipose cells.

PURPOSE: Excessive fat mass accumulation in obesity leads to diverse metabolic disorders, increased risks of cardiovascular diseases and in some cases, mortality. The aim of this study was to screen the actions of botanical extracts intended for oral use on human adipose tissue, using an in vitro screening model combining human intestinal cells with human adipose cells. This was to find the most effective extracts on lipid accumulation, UCP1 expression and ATP production in pre-adipocytes and on adipocyte lipolysis. METHODS: In this study, 25 individual plant extracts were screened for their effects on human adipose cells. Consequently, an original in vitro model was set up using the Caco-2 cell line, to mimic the intestinal passage of the extracts and then exposing human adipose cells to them. The biological actions of extracts were thus characterized, and compared with a coffee extract standard. The most effective extracts, and their combinations, were retained for their actions on lipid accumulation, the expression of the thermogenic effector UCP1 and ATP production in pre-adipocytes as well as on lipolysis activity of mature adipocytes. RESULTS: The biphasic culture system combining human Caco-2 cells with human adipose cells was verified as functional using the green coffee extract standard. Out of the 25 plant extracts studied, only 7 and their combinations were retained due to their potent effects on adipose cells biology. The data showed that compared to the coffee extract standard, Immortelle, Catechu, Carrot and Rose hip extracts were the most effective in reducing lipid accumulation and increased UCP1 expression in human pre-adipocytes. CONCLUSION: This study reveals the potential inhibitory effects on lipid accumulation and thermogenic activity of Immortelle, Catechu, Carrot and Rose hip extracts, and for the first time synergies in their combinations, using an in vitro model mimicking as closely as possible, human intestinal passage linked to adipose cells. These findings need to be confirmed by in vivo trials.

CCL5 promotes macrophage recruitment and survival in human adipose tissue.

OBJECTIVE: To examine the role of adipose-produced chemokine, chemokine ligand (CCL) 5, on the recruitment and survival of macrophages in human white adipose tissue (WAT). METHODS AND RESULTS: CCL5 levels measured by enzyme immunoassay in serum and by real-time polymerase chain reaction in WAT were higher in obese compared to lean subjects. CCL5, but not CCL2, secretion was higher in visceral compared to subcutaneous WAT. CCL5 mRNA expression was positively correlated with the inflammatory macrophage markers as CD11b, tumor necrosis factor-alpha, and IL-6 in visceral WAT (n=24 obese subjects), and was higher in macrophages than other WAT cells. We found that CCL5 triggered adhesion and transmigration of blood monocytes to/through endothelial cells of human WAT. Whereas in obese WAT apoptotic macrophages were located around necrotic adipocytes, we demonstrated that CCL5, but not CCL2, protected macrophages from free cholesterol-induced apoptosis via activation of the Akt/Erk pathways. CONCLUSIONS: CCL5 could participate in the inflammation of obese WAT by recruiting blood monocytes and exerting antiapoptotic properties on WAT macrophages. This specific role of CCL5 on macrophage survival with maintenance of their lipid scavenging function should be taken into account for future therapeutic strategies in obesity-related diseases.

Tasmannia lanceolata leaf extract alleviates stretch mark appearance in a randomized, placebo-controlled clinical trial in women and stimulates extracellular matrix synthesis in ex vivo human skin explants.

BACKGROUND: The leaves of Tasmannia lanceolata mainly contain polygodial that is known to exhibit a range of biological functions including anti-inflammatory effects. AIMS: These studies aimed to assess the effects of Tasmannia lanceolata extract (TLE) on skin and more particularly on stretch marks in women. PATIENTS/METHODS: A double-blind, randomized, placebo-controlled clinical study was carried out on 29 women, aged from 25 to 60 years, to investigate the effects of TLE on stabilized stretch marks. TLE and placebo products were topically applied daily for 8 weeks. Skin roughness and firmness of stretch marks were assessed by 2D and 3D photograph processing and analyses. Dermal density and thickness were evaluated using ultrasound, while stretch mark conditions (length, color, and depth) were determined by clinical scoring. Matricial proteins (pro-collagen I and elastin) and pro-matricial factors, like TGF-ß concentrations, were quantified from cultures of human skin explants presenting stretch marks, treated with TLE or vehicle control. RESULTS: Skin roughness of stretch marks was significantly reduced in the TLE group after 8 weeks of treatment. Skin firmness of stretch marks was significantly increased in the TLE group after 4 weeks of treatment, and this improved effect was maintained until the end of the study. Dermal density and thickness were significantly increased in the TLE group compared to the placebo group. Furthermore, TLE restored the dermal condition of the stretch mark skin, up to normal skin levels. In addition, pro-collagen I and elastin concentrations were found to be higher in the TLE-treated stretch mark skin explants compared to the untreated ones, associated with higher quantities of TGF-ß production. CONCLUSION: These results revealed that TLE could help improve the aspect of stabilized stretch marks in women by restoring the matricial environment.

A hyaluronic acid-based filler reduces lipolysis in human mature adipocytes and maintains adherence and lipid accumulation of long-term differentiated human preadipocytes.

The beneficial role of subcutaneous adipose tissue in skin rejuvenation derived from its capacity to fill the under-layer volumes but also from its ability to regulate the extracellular matrix production by dermis fibroblasts. Hyaluronic acid (HA), a major component of the extracellular matrix, is a commonly used injectable dermal filler showing excellent efficiencies to maintain tissue augmentation even after its biodegradation. To improve their stability, the HA molecules can also be "cross-linked" to each other. The effects of cross-linked HA-based fillers on the dermal structure are well known. For safety reasons, most of the physicians prefer to use the blunt cannula for injections. However, evidences showed that the cannula could not be located in the dermis, but it passes through immediate hypodermis and the long-lasting effect of cross-linked HA-based fillers may be related to its effects on adipose tissue. To test whether cross-linked HA has a direct effect on human adipocytes, we treated isolated adipocytes and precursors cells from human skin donors with cross-linked HA. Biochemical and cellular analysis demonstrated that treatment by cross-linked HA showed beneficial effects on differentiated cell adherence and survival as well as reduced basal and induced lipolysis in fully mature adipocytes. Taken together, these data showed that cross-linked HA promoted cell adherence and preserved the adipogenic capacity of preadipocytes during prolonged cell culture, bringing additional evidences of the beneficial role of cross-linked HA-based fillers in maintenance of the subcutaneous fat mass. This first study could defend a preventive approach to facial volume loss during natural aging.

Purple tulip extract improves signs of skin aging through dermal structural modulation as shown by genomic, protein expression and skin appearance of volunteers studied.

BACKGROUND: Purple tulip extract is a rich source of flavonoids which are powerful antioxidants and can hence be considered as an ideal candidate for use in skin care products. AIMS: We aimed to evaluate the effects of purple tulip extract on skin quality and to determine its molecular modes of interaction. METHODS: A pangenomic study on human skin fibroblasts was carried out to analyze multiple changes in gene expression. Ex vivo studies of human skin explants exposed to ultraviolet (UV) irradiation or H2 O2 were performed to assess modulations of protein expression. Finally, a clinical assay was carried out to evaluate the efficacy of purple tulip extract on skin appearance and condition of aged women. RESULTS: Genetic modulation analyses led us to infer the induction of many biological functions including cell differentiation, proliferation, migration, inflammatory responses, and matrix remodeling. The ex vivo studies revealed an enhancement of the collagen network and increased expression of glycosaminoglycans (GAG), fibronectin, and collagen VI. Finally, the clinical study highlighted the potential anti-aging properties of the purple tulip extract which decreased the relaxation of the oval face and improved skin elasticity after 28 days of treatment. Significant reductions of the length and depth of the nasolabial wrinkles were also observed. CONCLUSION: Our genomics data on the effect of purple tulip extract on the ex vivo UV-challenged skin showed that genes responsible for, among others, the upkeep of the skin, such as collagen induction, immune cell proliferation, and epidermal repair, were all up-regulated. More importantly, the clinical study corroborated these data by the visible and measurable effects of the topical purple tulip extract on the aged skin of 22 women, further demonstrating the beneficial impact of the extract on aged skin.

Macrophage-secreted factors promote a profibrotic phenotype in human preadipocytes.

White adipose tissue (WAT) in obese humans is characterized by macrophage accumulation the effects of which on WAT biology are not fully understood. We previously demonstrated that macrophage-secreted factors impair preadipocyte differentiation and induce inflammation, and we described the excessive fibrotic deposition in WAT from obese individuals. Microarray analysis revealed significant overexpression of extracellular matrix (ECM) genes in inflammatory preadipocytes. We show here an organized deposition of fibronectin, collagen I, and tenascin-C and clustering of the ECM receptor alpha5 integrin, characterizing inflammatory preadipocytes. Anti-alpha5 integrin-neutralizing antibody decreased proliferation of these cells, underlining the importance of the fibronectin/integrin partnership. Fibronectin-cultured preadipocytes exhibited increased proliferation and expression of both nuclear factor-kappaB and cyclin D1. Small interfering RNA deletion of nuclear factor-kappaB and cyclin D1 showed that these factors link preadipocyte proliferation with inflammation and ECM remodeling. Macrophage-secreted molecules increased preadipocyte migration through an increase in active/phosphorylated focal adhesion kinase. Gene expression and neutralizing antibody experiments suggest that inhibin beta A, a TGF-beta family member, is a major fibrotic factor. Interactions between preadipocytes and macrophages were favored in a three-dimensional collagen I matrix mimicking the fibrotic context of WAT. Cell-rich regions were immunostained for preadipocytes, proliferation, and macrophages in the vicinity of fibrotic WAT from obese individuals. In conclusion, an inflammatory environment leads to profound modifications of the human preadipocyte phenotype, producing fibrotic components with increased migration and proliferation. This phenomenon might play a role in facilitating the constitution of quiescent preadipocyte pools and eventually in the maintenance and aggravation of increased fat mass in obesity.

"Miliacin encapsulated by polar lipids stimulates cell proliferation in hair bulb and improves telogen effluvium in women".

BACKGROUND: Miliacin, the main triterpenoid from millet, is known to stimulate keratinocyte metabolism and proliferation. Polar lipids are able to form vesicles with active compounds and to improve their bioavailability. OBJECTIVES: We aimed to demonstrate potential benefits of a solution of miliacin encapsulated within polar lipids (MePL) on telogen effluvium prevention and hair condition in women. METHODS: After preliminary cell proliferation studies, a placebo-controlled, multicentric, randomized, double-blind trial was performed on sixty-five nonmenopausal women affected by telogen effluvium, to assess the efficacy of a 12-week oral supplementation with MePL. Telogen and anagen densities were determined by phototrichogram analysis. Scalp dryness and hair brightness were clinically evaluated using a Likert scale. RESULTS: MePL further enhanced cell proliferation in hair bulb from human scalp than miliacin alone. Compared to the placebo treatment, MePL supplementation significantly reduced telogen density after 12 weeks of treatment. An increase of anagen density was observed in both groups, although there was no significant difference between the two treatments. Scalp dryness was more decreased in the MePL group than in the placebo group. A better improvement of hair brightness was also observed after 12 weeks of supplementation with MePL. CONCLUSION: Twelve weeks of MePL supplementation significantly reduced the hair density in the telogen phase and, in parallel, improved scalp dryness and hair condition. These effects could be linked to MePL activity on cell proliferation in hair bulb. MePL is an original association of plant extract that could help to prevent and/or limit hair loss in women.

1,2-vinyldithiin from garlic inhibits differentiation and inflammation of human preadipocytes.

Obesity is a state of chronic low-grade inflammation. Limiting white adipose tissue (WAT) expansion and therefore reducing inflammation could be effective in preventing the progression of obesity and the development of associated complications. We investigated the effects of 1,2-vinyldithiin (1,2-DT), a garlic-derived organosulfur, on the differentiation and inflammatory state of human preadipocytes. Preadipocytes were prepared from subcutaneous adipose tissue of nonobese young women and differentiated in the presence of 1,2-DT. Inflammatory preadipocytes were obtained following treatment with human macrophage-secreted factors. 1,2-DT (100 micromol/L) significantly reduced gene expression of PPARgamma2 (-40%), CCAAT/enhancer binding protein-alpha (-25%), lipoprotein lipase (-22%), leptin (-30%), and adiponectin (-15%). Lipid accumulation was also significantly diminished in preadipocytes differentiated in the presence of 100 micromol/L 1,2-DT (-37%) compared with controls. Furthermore, 100 micromol/L 1,2-DT treatment for 10 d significantly reduced PPARgamma activity (-27%). The protein expression of perilipin and the secretion levels for 2 adipokines, leptin and adiponectin, were significantly diminished in 1,2-DT-cultured preadipocytes (-37, -51, and -43%, respectively). Moreover, the secretion of inflammatory molecules (interleukin-6 and monocyte chemoattractant protein-1) induced by macrophage-secreted factors was partially abolished in 100 micromol/L 1,2-DT-treated preadipocytes (-28 and -25%, respectively). In conclusion, we demonstrated that 1,2-DT, a garlic-derived organosulfur, has antiadipogenic and antiinflammatory actions on human preadipocytes and may be a novel, antiobesity nutraceutical.

Polar lipids from wheat extract oil improve skin damages induced by aging: Evidence from a randomized, placebo-controlled clinical trial in women and an ex vivo study on human skin explant.

BACKGROUND: Polar lipids from wheat (Triticum vulgare/aestivum) extract oil (WEO) are known to improve skin hydration. AIMS: These studies aimed to assess WEO benefits on the skin appearance of middle-aged women. METHODS: A double-blind, randomized, placebo-controlled clinical study was carried out on 64 healthy women, aged from 45 to 60 years, to investigate antiaging effects and benefits for the skin. The study lasted 20 weeks including 12 weeks of oral supplementation with WEO or placebo and 8 weeks of follow-up. Wrinkles in the "crow's-feet" area were evaluated by the Lemperle score. Skin hydration was measured using a corneometer, while roughness and radiance were determined by clinical scoring. Collagen content was quantified in human skin explants exposed to ultraviolet (UV) irradiations and treated with WEO or vehicle control. RESULTS: Compared to the placebo group, the Lemperle score was significantly reduced in the WEO group between W0 and W8 to reach a clinically significant 1 grade at W12. Facial hydration was significantly improved in the WEO group from W0 to W12, whereas leg hydration was significantly increased after 4 weeks and lasted throughout the supplementation period. Skin roughness and radiance were also significantly improved from W0 to W8 in the WEO group compared to placebo group. A higher collagen content was measured in the UV-irradiated skin explants treated with WEO compared to the untreated ones. CONCLUSION: These results confirmed the moisturizing effect of WEO and, for the first time, revealed its potential antiaging properties.

Should platelet-rich plasma be activated in fat grafts? An animal study.

BACKGROUND: The adjunction of platelet-rich plasma with graft fat has been the subject of a few clinical trials which have demonstrated its value in adipocyte survival. The aim of this study was to assess the different efficacies between activated and non-activated PRP on adipose cells in vitro and for adipose tissue graft survival in vivo. METHODS: The in vitro study assessed the effects of PRP on both the proliferation and adipocyte differentiation of adipose cells. For the in vivo study, 8 nude rats received 3 human fat injections as follows: 0.8 mL of fat + 0.2 mL of normal saline; 0.8 mL of fat + 0.2 mL of non-activated PRP; and 0.8 mL of fat + 0.2 mL of PRP activated with calcium chloride (CaCl2). The quantitative assessment of adipocyte survival was implemented after 3 months using histomorphometric analysis. Histological and immunohistochemical analysis were also performed to evaluate angiogenesis, inflammation and quality of adipocytes in the grafted tissue. RESULTS: We showed that activated PRP stimulated, in vitro, proliferation and differentiation of adipose cells. In vivo experiments indicated that CaCl2-activated PRP was more efficient than non-activated to prolong the survival of fat grafts in nude rats. The mean percentage areas occupied by viable adipocytes in the PRP-free group, non-activated PRP group and activated PRP group were 13%, 14% and 24% (p = 0.05%), respectively. Histological and immunohistochemical analysis revealed protective effect of activated PRP on inflammation and adipocyte death. CONCLUSION: This study showed that activation by CaCl2 improves the beneficial effects of PRP for fat graft maintenance.

Macrophage-secreted factors impair human adipogenesis: involvement of proinflammatory state in preadipocytes.

Obesity is considered a chronic low-grade inflammatory state. The white adipose tissue produces a variety of inflammation-related proteins whose expression is increased in obese subjects. The nonadipose cell fraction, which includes infiltrated macrophages, is a determinant source of inflammation-related molecules within the adipose tissue. Our working hypothesis is that macrophage infiltration affects fat expansion through a paracrine action on adipocyte differentiation. Human primary preadipocytes were then differentiated in the presence of conditioned media obtained from macrophages differentiated from blood monocytes. Preadipocytes treated by macrophage-conditioned medium displayed marked reduction of adipogenesis as assessed by decreased cellular lipid accumulation and reduced gene expression of adipogenic and lipogenic markers. In addition to this effect, the activation of macrophages by lipopolysaccharides stimulated nuclear factor kappaB signaling, increased gene expression and release of proinflammatory cytokines and chemokines, and induced preadipocyte proliferation. This phenomenon was associated with increased cyclin D1 gene expression and maintenance of the fibronectin-rich matrix. Anti-TNFalpha neutralizing antibody inhibits the inflammatory state of preadipocytes positioning TNFalpha as an important mediator of inflammation in preadipocytes. Strikingly, conditioned media produced by macrophages isolated from human adipose tissue exerted comparable effects with activated macrophages, i.e. decreased adipogenesis and increased inflammatory state in the preadipocytes. These data show that macrophage-secreted factors inhibit the formation of mature adipocytes, suggesting possible role in limiting adipose tissue expansion in humans.

Curative diet supplementation with a melon superoxide dismutase reduces adipose tissue in obese hamsters by improving insulin sensitivity.

SCOPE: Obesity-related metabolic syndrome is often associated with a decrease of insulin sensitivity, inducing several modifications. However, dietary antioxidants could prevent insulin resistance. We have previously shown the preventive effects of a melon superoxide dismutase (SOD) in obese hamsters. However, its antioxidant effects have never been studied on adipose tissue. METHODS AND RESULTS: We evaluated the effects of a 1-month curative supplementation with SODB on the adipose tissue of obese hamsters. Animals received either a standard diet or a cafeteria diet for 15 wk. Cafeteria diet induced obesity and related disorders, including insulin resistance and oxidative stress, in the abdominal adipose tissue. After SODB supplementation, the adipose tissue weight was decreased, probably by activating adipocytes lipolysis and thus reducing their size. SODB treatment also resulted in abdominal adipose tissue fibrosis reduction. Finally, SODB administration increased the expression of endogenous antioxidant enzymes and thus reduced oxidative stress and insulin resistance. The improvement of insulin sensitivity observed after SODB treatment could explain adipocyte lipolysis activation and fibrosis reduction. CONCLUSION: These findings demonstrate that a dietary SOD supplementation could be a useful strategy against obesity-related modifications in adipose tissue.

Cathepsins in human obesity: changes in energy balance predominantly affect cathepsin s in adipose tissue and in circulation.

CONTEXT: Recent studies in humans and mice suggest the implication of the cysteine proteases cathepsins S, L, and K in vascular and metabolic complications of obesity. OBJECTIVE: Our objective was to identify clinically relevant forms of cathepsin in human obesity. DESIGN AND SETTING: We conducted a prospective study on two independent cohorts. PARTICIPANTS AND INTERVENTIONS: The first cohort includes 45 obese women eligible for gastric surgery (age, 39 +/- 1.6 yr; body mass index, 47 +/- 0.99 kg/m(2)) and 17 nonobese women (age, 38 +/- 1.8 yr; body mass index, 21 +/- 0.44 kg/m(2)). The second cohort comprises 29 obese women (age, 57 +/- 0.8 yr; body mass index, 34 +/- 0.69 kg/m(2)) undergoing 6 months of medically supervised caloric restriction. MAIN OUTCOMES: Cathepsin S, L, and K mRNA levels were determined in surgical adipose tissue biopsies. The proteins were measured in conditioned medium of adipose tissue explants and in circulation. RESULTS: Obese subjects had a 2-fold increase in cathepsin S mRNA in adipose tissue as compared with normal-weight subjects and an increased rate (1.5-fold) of cathepsin S release in adipose tissue explants. Cathepsin S circulating concentrations were increased with obesity (+30%) and reduced after weight reduction (P < 0.05 for both). By contrast, cathepsin L was unaffected in adipose tissue and serum; cathepsin K was undetectable in circulation and unchanged in adipose tissue. CONCLUSION: In humans, cathepsin S is more influenced than cathepsins L and K by changes in energy balance in adipose tissue and circulation. This opens new avenues to explore whether selective inhibition of this protease could reduce cardiovascular risk and ameliorate metabolic status in obese subjects.

Activin a plays a critical role in proliferation and differentiation of human adipose progenitors.

OBJECTIVE: Growth of white adipose tissue takes place in normal development and in obesity. A pool of adipose progenitors is responsible for the formation of new adipocytes and for the potential of this tissue to expand in response to chronic energy overload. However, factors controlling self-renewal of human adipose progenitors are largely unknown. We investigated the expression profile and the role of activin A in this process. RESEARCH DESIGN AND METHODS: Expression of INHBA/activin A was investigated in three types of human adipose progenitors. We then analyzed at the molecular level the function of activin A during human adipogenesis. We finally investigated the status of activin A in adipose tissues of lean and obese subjects and analyzed macrophage-induced regulation of its expression. RESULTS: INHBA/activin A is expressed by adipose progenitors from various fat depots, and its expression dramatically decreases as progenitors differentiate into adipocytes. Activin A regulates the number of undifferentiated progenitors. Sustained activation or inhibition of the activin A pathway impairs or promotes, respectively, adipocyte differentiation via the C/EBPß-LAP and Smad2 pathway in an autocrine/paracrine manner. Activin A is expressed at higher levels in adipose tissue of obese patients compared with the expression levels in lean subjects. Indeed, activin A levels in adipose progenitors are dramatically increased by factors secreted by macrophages derived from obese adipose tissue. CONCLUSIONS: Altogether, our data show that activin A plays a significant role in human adipogenesis. We propose a model in which macrophages that are located in adipose tissue regulate adipose progenitor self-renewal through activin A.

Role of serum amyloid a in adipocyte-macrophage cross talk and adipocyte cholesterol efflux.

CONTEXT: Acute phase serum amyloid A (A-SAA) is secreted by hepatocytes in response to injury and is regulated by proinflammatory cytokines. In obese humans, adipocytes are also a major contributor to circulating A-SAA levels. OBJECTIVE: We aimed to investigate the role and regulation of A-SAA in human adipose tissue (AT). DESIGN: An approach combining microarrays and the FunNet bioinformatics tool was applied to human AT fractions (i.e. adipocytes vs. stroma vascular fraction) to hypothesize genes and functions related to A-SAA. Experiments with human AT from 37 obese subjects and human multipotent adipose-derived stem (hMADS) cells were used to confirm the microarray driven hypotheses. RESULTS: Microarray analysis highlighted the relationship between A-SAA and stroma vascular fraction inflammatory genes, and between A-SAA and adipocyte-expressed ATP-binding cassette (ABC) transporters. We confirmed that serum amyloid A (SAA) protein is expressed in sc AT of obese subjects (n = 37, body mass index = 49.3 +/- 1.5 kg/m(2)) and showed that SAA protein expression correlated with adipocyte size (R = 0.44; P = 6.10(-3)), macrophage infiltration (R = 0.61; P = 10(-4)), and ABC subfamily A1 protein expression (R = 0.43; P = 9.10(-3)). IL-1beta, TNF-alpha, and human AT macrophage-conditioned medium significantly induced A-SAA secretion (from 2.6 to 7.6 fold) in hMADS cells. Recombinant SAA induced cholesterol ABC subfamily A1-dependent efflux from hMADS adipocytes by 4.3-fold in a dose-dependent manner. CONCLUSION: This work provides original insight suggesting that A-SAA is a player in the dialogue between hypertrophied adipocytes and macrophages through its regulation of adipocyte cholesterol efflux.