Pathogenic Microenvironment from Diabetic-Obese Visceral and Subcutaneous Adipocytes Activating Differentiation of Human Healthy Preadipocytes Increases Intracellular Fat, Effect of the Apocarotenoid Crocetin

Effect of Crocetin on Basal Lipolysis in 3T3-L1 Adipocytes

Crocetin (CCT) is a natural saffron-derived apocarotenoid that possesses healthy properties such as anti-adipogenic, anti-inflammatory, and antioxidant activities. Lipolysis is enhanced in obesity and correlates with a pro-inflammatory, pro-oxidant state. In this context, we aimed to investigate whether CCT affects lipolysis. To evaluate CCT's possible lipolytic effect, 3T3-L1 adipocytes were treated with CCT10μM at day 5 post-differentiation. Glycerol content and antioxidant activity were assessed using colorimetric assays. Gene expression was measured using qRT-PCR to evaluate the effect of CCT on key lipolytic enzymes and on nitric oxide synthase (NOS) expression. Total lipid accumulation was assessed using Oil Red O staining. CCT10μM decreased glycerol release from 3T3-L1 adipocytes and downregulated adipose tissue triglyceride lipase (ATGL) and perilipin-1, but not hormone-sensitive lipase (HSL), suggesting an anti-lipolytic effect. CCT increased catalase (CAT) and superoxide dismutase (SOD) activity, thus showing an antioxidant effect. In addition, CCT exhibited an anti-inflammatory profile, i.e., diminished inducible NOS (NOS2) and resistin expression, while enhanced the expression of adiponectin. CCT10μM also decreased intracellular fat and C/EBPα expression (a transcription factor involved in adipogenesis), thus revealing an anti-adipogenic effect. These findings point to CCT as a promising biocompound for improving lipid mobilisation in obesity.

Inhibitory effect of saffron, crocin, crocetin, and safranal against adipocyte differentiation in human adipose-derived stem cells

ETHNOPHARMACOLOGICAL RELEVANCE

Saffron (Crocus sativus L.) has been introduced as a potential promising natural antioxidant with anti-obesity properties. In Persian Medicine, saffron has been used to control appetite and obesity.

AIM OF THE STUDY

The present study aims to investigate the effect of saffron and its bioactive compounds on adipocyte differentiation in human adipose-derived stem cells (ADSCs).

MATERIALS AND METHODS

Flow-Cytometric analysis was performed to quantify the cell surface markers. The extracts cytotoxicity on hASCs was measured using alamarBlue® assay whereas their activities against adipocyte differentiation were studied using Oil Red O staining. The level of Peroxisome proliferator-activated receptor-γ (PPARγ), Fatty Acid Synthetase (FAS), and Glyceraldehyde-3-phosphate dehydrogenase (GAPHD) which are key proteins in cell differentiation was investigated by western blot analysis.

RESULTS

Flow-cytometry revealed the mesenchymal stem cells markers, CD44 and CD90, on ADSCs surface. The saffron, crocin, and crocetin significantly inhibited adipocyte differentiation while saffron up to 20 μg/mL and crocin, crocetin and safranal up to 20 μM did not exhibit cytotoxicity. The western blotting analysis revealed a remarkable reduction in the level of PPARγ, GAPDH, and FAS proteins by 10 and 20 μM of crocin and 2.5 and 5 μM of crocetin.

CONCLUSION

It seems that saffron, crocin, and crocetin could efficiently inhibit the differentiation of hASCs with benefits for the treatment and prevention of obesity.

The Phenotype of the Adipocytes Derived from Subcutaneous and Visceral ADMSCs Is Altered When They Originate from Morbidly Obese Women: Is There a Memory Effect?

Adipose tissue is an abundant source of mesenchymal stem cells (ADMSCs). Evidence has suggested that depot-specific ADMSCs (obtained from subcutaneous or visceral adipose tissue-subADMSCs or visADMSCs, respectively) account for differential responses of each depot to metabolic challenges. However, little is known about the phenotype and changes in metabolism of the adipocytes derived from ADMSCs of obese individuals. Therefore, we investigated the phenotypic and metabolic characteristics, particularly the lipid profile, of fully differentiated adipocytes derived from ADMSCs of lean and obese (with/without metabolic syndrome) postmenopausal women. We observed a depot-specific pattern, with more pronounced changes present in the adipocytes obtained from subADMSCs. Namely, chronic oversupply of fatty acids (present in morbid obesity) triggered an increase in CD36/SR-B2 and FATP4 protein content (total and cell surface), which translated to an increased LCFA influx (3H-palmitate uptake). This was associated with the accumulation of TAG and DAG in these cells. Furthermore, we observed that the adipocytes of visADMSCs origin were larger and showed smaller granularity than their counterparts of subADMSCs descent. Although ADMSCs were cultured in vitro, in a fatty acids-deprived environment, obesity significantly influenced the functionality of the progenitor adipocytes, suggesting the existence of a memory effect.