Aster glehni Extract Containing Caffeoylquinic Compounds Protects Human Keratinocytes through the TRPV4-PPARδ-AMPK Pathway

Aster glehni Extract, Including Caffeoylquinic Acids as the Main Constituents, Induces PPAR β/δ-Dependent Muscle-Type Change and Myogenesis in Apolipoprotein E Knockout Mice

To probe the functions of Aster glehni (AG) extract containing various caffeoylquinic acids on dyslipidemia, obesity, and skeletal muscle-related diseases focused on the roles of skeletal muscle, we measured the levels of biomarkers involved in oxidative phosphorylation and type change of skeletal muscle in C2C12 cells and skeletal muscle tissues from apolipoprotein E knockout (ApoE KO) mice. After AG extract treatment in cell and animal experiments, western blotting, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) were used to estimate the levels of proteins that participated in skeletal muscle type change and oxidative phosphorylation. AG extract elevated protein expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), phosphorylated 5'-AMP-activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor beta/delta (PPARβ/δ), myoblast determination protein 1 (MyoD), and myoglobin in skeletal muscle tissues. Furthermore, it elevated the ATP concentration. However, protein expression of myostatin was decreased by AG treatment. In C2C12 cells, increments of MyoD, myoglobin, myosin, ATP-producing pathway, and differentiation degree by AG were dependent on PPARβ/δ and caffeoylquinic acids. AG extract can contribute to the amelioration of skeletal muscle inactivity and sarcopenia through myogenesis in skeletal muscle tissues from ApoE KO mice, and function of AG extract may be dependent on PPARβ/δ, and the main functional constituents of AG are trans-5-O-caffeoylquinic acid and 3,5-O-dicaffeoylquinic acid. In addition, in skeletal muscle, AG has potent efficacies against dyslipidemia and obesity through the increase of the type 1 muscle fiber content to produce more ATP by oxidative phosphorylation in skeletal muscle tissues from ApoE KO mice.

Buspirone Induces Weight Loss and Normalization of Blood Pressure via the Stimulation of PPARδ Dependent Energy Producing Pathway in Spontaneously Hypertensive Rats

Introduction

Buspirone, as a partial agonist for a 5-hydroxytryptamine (serotonin) receptor 1A (5-HT1A), has been prescribed as an anxiolytic drug for patients. In addition, the lowering effect of serotonin on blood pressure was reported in hypertensive animal model. We investigated the therapeutic mechanism of buspirone against lipid metabolism disturbed by hypertension of early stage via hypertensive and obese animal model.

Methods

The levels of various biomarkers related to lipid metabolism and hypertension were estimated through the measurement of body weight and fat weight, blood analysis, western blotting, immunohistochemistry, and staining methods.

Results

The lipid accumulation was lowered in differentiated 3T3-L1 cells by buspirone treatments of 50 and 100 μM compared with untreated differentiated control. Body weight and abdominal fat weight were lowered in spontaneously hypertensive rats (SHRs) administered with buspirone of 10 mg/kg/day for 4 weeks than 8-week untreated group. Triglyceride (TG) level was decreased in SHRs administered with buspirone of 5 and 10 mg/kg/day compared to 8-week untreated group. High-density lipoprotein (HDL)-cholesterol concentration was elevated by buspirone 10 mg/kg/day treatment compared to 8-week untreated group. Blood pressures in SHRs were lowered by buspirone treatments of 5 and 10 mg/kg/day compared with 8-week untreated group. Protein levels for peroxisome proliferator-activated receptor δ (PPARδ), 5' adenosine monophosphate-activated protein kinase (AMPK), and PPARγ coactivator-1 alpha (PGC-1α) were increased both in C₂C₁₂ cells treated by buspirone of 100 μM and in SHRs administered by buspirone of 1, 5, and 10 mg/kg/day compared to untreated control cells and 8-week untreated group. Fat cell numbers decreased in 8-week untreated group were increased in SHRs administered by buspirone treats of 1, 5, and 10 mg/kg/day. Protein expression levels for angiotensin II type 1 receptor (AT1R) and vascular cell adhesion molecule 1 (VCAM1) were increased in 8-week untreated group compared to 4-week group, however, they were decreased by buspirone treatments of 1, 5, and 10 mg/kg/day.

Conclusion

Buspirone may induce the losses of body weight and abdominal fat weight through the activation of PPARδ dependent catabolic metabolism producing energy, and eventually, the ameliorated lipid metabolism could normalize high blood pressure.