• Title/Summary/Keyword: Adenosine $A2_A$ receptor

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Comparison of the Effects of Pharmacopuncture Extracts with Hominis placenta Pharmacopuncture and Wild Ginseng Pharmacopuncture on the Differentiation of C2C12 Myoblasts into Myotubes through Regulation of the AMPK/SIRT1 Signaling Pathway (자하거약침액과 산삼약침액의 C2C12 근아세포에서의 AMPK/SIRT1 신호전달을 통한 근 분화 유도 및 에너지 대사 증진 효과 비교)

  • Ji Hye Hwang;Hyo Won Jung
    • Journal of Korean Medicine for Obesity Research
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    • v.23 no.2
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    • pp.60-68
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    • 2023
  • Objectives: This study was conducted to compare the effects of Hominis placenta (Jahage, J) and wild ginseng (SanSam, S) pharmacopuncture drugs on muscle differentiation and energy metabolism regulation in C2C12 myotubes. Methods: The C2C12 myoblasts were differentiated into myotubes for 5 days by replacing in medium containing 2% horse serum and then treated with J and S pharmacopuncture extract at different concentrations for 24 hr. The expression of myosin heavy chain and energy metabolism-regulating factors, myosin heavy chain (MHC), nuclear respiratory factor-1 (NRF-1), and proliferator-activated receptor γ coactivator-1 alpha (PGC-1α) were determined in C2C12 myotubes by western blot. Additionally, the phosphorylation of AMPK and the expression of mitochondrial biogenesis, including sirtuin 1 (SIRT1) were determined in the myotubes. Results: As a result, treatment with J and S pharmacopuncture extract at 0.1 and 1 mg/mL increased the MHC expression in C2C12 myotubes compared with non-treated cells, but only S pharmacopuncture was shown a significant and distinct increase in the expression. Expression of TFAM and NRF-1 was also shown significant increases in S and J pharmacopuncture in C2C12 myotubes compared to non-treated cells. The phosphorylation of AMPK and the expression of PGC-1α and SIRT1 showed increased expression in S and J pharmacopuncture compared to non-treated cells. The effect of low-dose of J pharmacopuncture on the phosphorylated adenosine monophosphate-activated protein kinase (AMPK) and PGC-1α expression was greater than that of S pharmacopuncture. Conclusions: In conclusion, both J and S pharmacopuncture promote muscle differentiation in C2C12 myoblasts into myotubes and energy metabolism through the AMPK/SIRT1 signaling pathway. This indicates that the pharmacopuncture with tonic herbal medicines can help to improve skeletal muscle function.

Cyanidin-3-glucoside Inhibits ATP-induced Intracellular Free $Ca^{2+}$ Concentration, ROS Formation and Mitochondrial Depolarization in PC12 Cells

  • Perveen, Shazia;Yang, Ji Seon;Ha, Tae Joung;Yoon, Shin Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.4
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    • pp.297-305
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    • 2014
  • Flavonoids have an ability to suppress various ion channels. We determined whether one of flavonoids, cyanidin-3-glucoside, affects adenosine 5'-triphosphate (ATP)-induced calcium signaling using digital imaging methods for intracellular free $Ca^{2+}$ concentration ([$Ca^{2+}$]i), reactive oxygen species (ROS) and mitochondrial membrane potential in PC12 cells. Treatment with ATP ($100{\mu}M$) for 90 sec induced [$Ca^{2+}$]i increases in PC12 cells. Pretreatment with cyanidin-3-glucoside ($1{\mu}g/ml$ to $100{\mu}g/ml$) for 30 min inhibited the ATP-induced [$Ca^{2+}$]i increases in a concentration-dependent manner ($IC_{50}=15.3{\mu}g/ml$). Pretreatment with cyanidin-3-glucoside ($15{\mu}g/ml$) for 30 min significantly inhibited the ATP-induced [$Ca^{2+}$]i responses following removal of extracellular $Ca^{2+}$ or depletion of intracellular [$Ca^{2+}$]i stores. Cyanidin-3-glucoside also significantly inhibited the relatively specific P2X2 receptor agonist 2-MeSATP-induced [$Ca^{2+}$]i responses. Cyanidin-3-glucoside significantly inhibited the thapsigargin or ATP-induced store-operated calcium entry. Cyanidin-3-glucoside significantly inhibited the ATP-induced [$Ca^{2+}$]i responses in the presence of nimodipine and ${\omega}$-conotoxin. Cyanidin-3-glucoside also significantly inhibited KCl (50 mM)-induced [$Ca^{2+}$]i increases. Cyanidin-3-glucoside significantly inhibited ATP-induced mitochondrial depolarization. The intracellular $Ca^{2+}$ chelator BAPTA-AM or the mitochondrial $Ca^{2+}$ uniporter inhibitor RU360 blocked the ATP-induced mitochondrial depolarization in the presence of cyanidin-3-glucoside. Cyanidin-3-glucoside blocked ATP-induced formation of ROS. BAPTA-AM further decreased the formation of ROS in the presence of cyanidin-3-glucoside. All these results suggest that cyanidin-3-glucoside inhibits ATP-induced calcium signaling in PC12 cells by inhibiting multiple pathways which are the influx of extracellular $Ca^{2+}$ through the nimodipine and ${\omega}$-conotoxin-sensitive and -insensitive pathways and the release of $Ca^{2+}$ from intracellular stores. In addition, cyanidin-3-glucoside inhibits ATP-induced formation of ROS by inhibiting $Ca^{2+}$-induced mitochondrial depolarization.

PKA-Mediated Regulation of B/K Gene Transcription in PC12 Cells

  • Choi, Mi-Hyun;Kim, Ho-Shik;Choi, Sung-Ho;Kim, Mi-Young;Jang, Yoon-Seong;Jang, Young-Min;Lee, Jeong-Hwa;Jeong, Seong-Whan;Kim, In-Kyung;Kwon, Oh-Joo
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.6
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    • pp.333-339
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    • 2005
  • B/K protein is a novel protein containing double C2-like domains. We examined the specific signaling pathway that regulates the transcription of B/K in PC12 cells. When the cells were treated with forskolin ($50{\mu}M$), B/K mRNA and protein levels were time-dependently decreased, reaching the lowest level at 3 or 4 hr, and thereafter returning to the control level. Chemicals such as dibutyryl-cAMP, cellpermeable cyclic AMP (cAMP) analogue and CGS21680, adenosine receptor $A_{2A}$ agonist, also repressed the B/K transcription. However, 1,9-dideoxyforskolin did not show inhibitory effect on B/K transcription, suggesting direct involvement of cAMP in the forskolin-induced inhibition of B/K transcription. Effect of forskolin, dibutyryl cAMP and CGS21680 was significantly reduced in PKA-deficient PC12 cell line (PC12-123.7). One cAMP-response element (CRE)-like sequence (B/K CLS) was found in the promoter region of B/K DNA, and electrophoretic mobility shift assay indicated its binding to CREM and CREB. Forskolin significantly suppressed the promoter activity in CHO-K1 cells transfected with the constructs containing B/K CLS, but not with the construct in which B/K CLS was mutated (AC:TG). Taken together, we suggest that the transcription of B/K gene in PC12 cells may be regulated by PKA-dependent mechanism.

Induction of Apoptosis by Ethanol Extract of Cnidium officinale in Human Leukemia U937 Cells through Activation of AMPK (천궁 에탄올 추출물의 AMPK 활성화를 통한 U937 인체 혈구암세포의 apoptosis 유발)

  • Jeong, Jin-Woo;Choi, Yung Hyun;Park, Cheol
    • Journal of Life Science
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    • v.25 no.11
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    • pp.1255-1264
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    • 2015
  • Cnidium officinale, a traditional herb, has diverse beneficial pharmacological activities, such as anti-inflammatory, antioxidant, anticancer, and antiangiogenesis effects. However, the cellular and molecular mechanisms of apoptosis by C. officinale are poorly defined. The present study investigated the proapoptotic effects of water, ethanol, and methanol extract of C. officinale (WECO, EECO, and MECO, respectively) in human leukemia U937 cells. The antiproliferative activity of EECO was higher than that of WECO and MECO. The antiproliferative effect of EECO treatment in U937 cells was associated with the induction of apoptotic cell death, including increased populations of annexin-V positive cells, the formation of apoptotic bodies, DNA fragmentation, and increased numbers of cells with a loss of mitochondrial membrane potential (MMP, Δψm). EECO-induced apoptotic cell death was associated with upregulation of death receptor 4 (DR4) and down-regulation of cellular inhibitor of apoptosis protein-1 (cIAP-1), Bcl-2, and total Bid. The EECO treatment also induced the proteolytic activation of caspases (-3, -8, and -9), and degradation of caspase-3 substrate proteins, such as poly(ADP-ribose) polymerase (PARP), β-catenin, and phospholipase C-γ1 (PLCγ1). In addition, the EECO treatment effectively activated the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. However, compound C, a specific inhibitor of AMPK, significantly reduced EECO-induced apoptosis. These results indicate that AMPK is a key regulator of apoptosis in response to EECO in human leukemia U937 cells.

Effects of Ethanol Extract of Sargassum horneri on Adipocyte Differentiation and Adipogenesis in 3T3-L1 Preadipocytes (괭생이모자반 에탄올 추출물이 3T3-L1 지방전구세포의 분화 및 adipogenesis에 미치는 영향)

  • Kwon, Da Hye;Choi, Yung Hyun;Kim, Byung Woo;Hwang, Hye Jin
    • Journal of Life Science
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    • v.29 no.2
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    • pp.209-214
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    • 2019
  • Sargassum horneri (Turner) C. Agardh is a marine brown algae widely distributed in the North Pacific Ocean. It is known for its anti-inflammatory and anti-atopic effects. In this study, we determined the effects of ethanol extract of Sargassum horneri (Turner) C. Agardh (EESH) on anti-obesity activities in 3T3-L1 preadipocytes. Our results indicated that treatment with EESH decreased the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner, as confirmed by a decrease in lipid droplet content observed by oil red O staining. The concentrations of cellular triglycerides were also reduced in 3T3-L1 cells after treatment with EESH. Triglyceride content was inhibited by 13%, 16%, and 23% after treatment with 250, 500, and $1,000{\mu}g/ml$ of EESH in 3T3-L1 cells, respectively. Western blotting analysis showed that EESH suppressed adipogenic transcription factor expression in a dose dependent manner. Specifically, it suppressed cytidine-cytidine-adinosine-adenosine-thymidine (CCAAT) /enhancer binding proteins $(C/EBP){\alpha}$, $C/EBP{\beta}$ and peroxisome proliferator-activated receptor $(PPAR){\gamma}$. This indicated that EESH could control the expression of adipogenic transcription factors and inhibit the differentiation of adipocytes. Taken together, these findings demonstrated that EESH showed anti-obesity effects and could have potential uses in the field of nutraceuticals.

Effects of stocking density on the homeostasis of uric acid and related liver and kidney functions in ducks

  • Peiyi Lin;Sui Liufu;Jinhui Wang;Zhanpeng Hou;Yu Liang;Haiyue Wang;Bingxin Li;Nan Cao;Wenjun Liu;Yunmao Huang;Yunbo Tian;Danning Xu;Xiujin Li;Xinliang Fu
    • Animal Bioscience
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    • v.37 no.5
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    • pp.952-961
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    • 2024
  • Objective: Stocking density (SD) is an important issue in the poultry industry, which is related to the production performance, intestinal health and immune status. In the present study, the effects of SD on the metabolism and homeostasis of uric acid as well as the related functions of the liver and kidney in ducks were examined. Methods: A total of 360 healthy 56-day-old Shan-ma ducks were randomly divided into the low stocking density (n = 60, density = 5 birds/m2), medium stocking density (n = 120, density = 10 birds/m2) and high stocking density groups (HSD; n = 180, density = 15 birds/m2). Samples were collected in the 3rd, 6th, and 9th weeks of the experiment for analysis. Results: The serum levels of uric acid, lipopolysaccharide and inflammatory cytokines (interleukin-1β [IL-1β], IL-8, and tumor necrosis factor-α [TNF-α]) were increased significantly in the HSD group. Serious histopathological lesions could be seen in both the livers and kidneys in the HSD group in the 9th week. The mRNA expression levels of inflammatory cytokines (IL-8 and TNF-α) and related pathway components (toll-like receptor 4, myeloid differentiation primary response gene 88, and nuclear factor-κB) were increased significantly in both the livers and kidneys in the HSD group. The mRNA expression levels of enzymes (adenosine deaminase, xanthine oxidase, phosphoribosyl pyrophosphate amidotransferase, and phosphoribosyl pyrophosphate synthetase 1) related to the synthesis of uric acid increased significantly in the livers in the HSD group. However, the mRNA expression level of solute carrier family 2 member 9, which plays an important role in the excretion of uric acid by the kidney, was decreased significantly in the kidneys in the HSD group. Conclusion: These results indicated that a higher SD could cause tissue inflammatory lesions in the liver and kidney and subsequently affect the metabolism and homeostasis of uric acid, and is helpful for guiding decisions related to the breeding and production of ducks.

The effects of Allomyrina dichotoma larval extract on palmitate-induced insulin resistance in skeletal muscle cells (장수풍뎅이 유충 추출물이 고지방산 처리 골격근세포의 인슐린 저항성에 미치는 영향)

  • Kim, Kyong;Sim, Mi-Seong;Kwak, Min-Kyu;Jang, Se-Eun;Oh, Yoon Sin
    • Journal of Nutrition and Health
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    • v.55 no.4
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    • pp.462-475
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    • 2022
  • Purpose: Allomyrina dichotoma larvae are one of the approved edible insects with nutritional value and various functional and medicinal properties. Previously we have demonstrated that the Allomyrina dichotoma larval extract (ADLE) ameliorates hepatic insulin resistance in high-fat diet (HFD)-induced diabetic mice through the activation of adenosine monophosphate-activated protein kinase (AMPK). This study investigated the effects of ADLE on insulin resistance in the skeletal muscle and explored mechanisms for enhancing the glucose uptake in palmitate (PAL)-treated C2C12 myotubes. Methods: To induce insulin resistance, the differentiated C2C12 myotubes were treated with PAL (0.5 mM) for 24 hours, and then treated with a 0.5 mg/ml concentration of ADLE, and the resultant effects were measured. The expression levels of glucose transporter-4 (GLUT4), AMPK, and the mitochondrial metabolism-related proteins were analyzed by western blotting. The mRNA expression levels of lipogenesis- related genes were determined by quantitative reverse-transcriptase PCR. Results: The exposure of C2C12 myotubes to 0.5 mg/ml of ADLE increased cell viability significantly compared to PAL-treated cells. ADLE upregulated the protein expression of GLUT4 and enhanced glucose uptake in the PAL-treated cells. ADLE increased the phosphorylated AMPK in both the PAL-treated C2C12 myotubes and HFD-treated skeletal muscle. The reduced expression levels of peroxisome-proliferator-activated receptor gamma co-activator-1 alpha (PGC1α) and uncoupling protein 3 (UCP3) due to the PAL and HFD treatment were reversed by the ADLE treatment. The citrate synthase activity was also significantly increased with the PAL and ADLE co-treatment. Moreover, the mRNA and protein expressions of fatty acid synthesis-related factors were reduced in the PAL and HFD-treated muscle cells, and this effect was significantly attenuated by the ADLE treatment. Conclusion: ADLE activates AMPK, which in turn induces mitochondrial metabolism and reduces fatty acid synthesis in C2C12 myotubes. Therefore, ADLE could be useful for preventing or treating insulin resistance of skeletal muscles in diabetes.

Modification of Endothelium on Contractile Response of Brain Vessels to Contracting Agents (혈관 수축제의 뇌혈관 수축반응에 대한 혈관근 내피세포의 역할)

  • Kook, Young-Johng;Baik, Yung-Hong;Kim, Jong-Keun;Choi, Bong-Kyu;Choi, Soo-Hyung;Kim, Yung-In
    • The Korean Journal of Pharmacology
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    • v.24 no.2
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    • pp.203-216
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    • 1988
  • To delineate the mechanisms of vasoconstriction and vasodilation in cerebral arteries the effects of some vasoconstrictors and calcium antagonists on the basilar artery (BA) and arterial circle of Willis (WC) were examined and also the role of endothelium in the action of these drugs was investigated in pigs, cats and rabbits. In pig cerebral arteries, dose-dependent contractile responses were elicited by KCI, histamine, 5-hydroxytryptamine (5-HT) and angiotensin, but norepinephrine (NE), phenylephrine (PE) and epinephrine (EP) elicited dose-dependent contractions only under pretreatment with propranolol 10-6 M. The magnitudes of maximal contractile effects of these drugs were different from each other, and 5-H~ was the largest and angiotensin the smallest. Some calcium antagonists dose-dependently inhibited KCI (35 mM)-induced contraction and the order of potency in inhibiting the contraction was nifedipine > > diltiazem > flunarizine > oxybutynin > isosorbide dinitrate (ISDN) > glyceryl trinitrate. 5-HT (10-6 M)-induced contraction was dosedependently inhibited by nifedipine but slightly inhibited by diltiazem and ISDN. In rings with intact endothelium, KCI (35 mM)-induced contraction was not affected by acetylcholine (ACh) but $PGF_{2{\alpha}}$ (lO-SM)-induced contraction was dose-dependently relaxed by ACh and adenosine. This endothelium-dependent relaxation was not affected by nifedipine (l0-6M)-pretreatment but markedly inhibited by methylene blue (50,uM)-pretreatment. In the porcine arterial rings without endothelium, ACh had no effect or even contracted the $PGF_{2{\alpha}}-induced$ contraction. However, the dosedependent relaxing effect of ACh appeared when the deendothelized porcine ring and rabbit thoracic aorta with intact endotheli urn were simultaneously suspended into a bath and this relaxing effect was also inhibited by methylene blue-pretreatment. In cat cerebral arteries, 5-HT and NE elicited dose-dependent contractile responses and ACh also produced dose-dependent contraction regardless of the existence of endothelium. ACh-induced contraction was most prominent. 5-HT (IO-SM)induced contraction was not relaxed but contracted additionally by ACh even in the intact endothelial ring. In rabbit cerebral arteries, 5-HT and NE elicited dose-dependent contractile responses and 5-HT-induced contraction was more prominent. In the intact endothelial preparations, 5-HT (lO-s M)-induced contraction was markedly relaxed by the addition of ACh( IO-SM) and this endothelium-dependent relaxing effect was inhibited by atropine (l0-7M)-pretreatment but notaffected by diltiazem (l0-6M)-pretreatment. These results suggest that ACh elicits endotheliumdependent relaxing effect mediated by muscarinic receptors in cerebral arteries of pig and rabbit, and that ACh acts as vasoconstrictor in cat cerebral artery.

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Anti-Obesity Effects and the Regulation of Energy Metabolism in Skeletal Muscle Tissues of Allii Fistulosi Bulbus Extract in High Fat Diet-Induced Obesity Mice (총백추출물의 고지방식이 유도 비만 마우스에서의 항비만 효과 및 근육조직에서의 에너지대사 조절기전 연구)

  • Yoon Yong Choi;Hyeon Soo Lee;Su Yeon Baik;Sumin Lim;Hyo Won Jung;Seok Yong Kang;Yong-Ki Park
    • Journal of Korean Medicine for Obesity Research
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    • v.22 no.2
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    • pp.102-114
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    • 2022
  • Objectives: We investigated the effects of Allii Fistulosi Bulbus (AFB) on high fat diet (HFD)-induced obesity in mice and the regulation of energy metabolism in muscle tissues of mice. Methods: The C57BL/6 mice (6 weeks, male) were fed a HFD for 8 weeks and then administrated with AFB extract at 500 mg/kg (p.o.) once daily for 4 weeks. The body weight (BW), muscle weight, calorie intake, fasting blood glucose (FBG) and serum glucose, insulin, and low-density lipoprotein-cholesterol (LDL-C) levels were measured in mice. It was also observed the histological changes of pancreas, liver, and fat tissues with hematoxylin and eosin staining. It was investigated the phosphorylation of insulin receptor substrate 1 (IRS-1), Ser/Thr kinase (AKT), and adenosine monophosphate-activated protein kinase (AMPK), and the expression of phosphoinositide 3-kinase, glucose transporter type 4 (GLUT4), and sirtuin1 (Sirt1) in gastrocnemius tissues by western blot, respectively. Results: The increases of BWs, calorie intakes and FBG levels in obesity mice were decreased significantly by the administration of AFB extract. The AFB extract administration was reduced significantly serum levels of glucose, insulin, and LDL-C in obesity mice. The AFB extract inhibited lipid accumulation in liver tissues, hyperplasia of pancreatic islets, and enlargement of fat tissues in obesity mice. The phosphorylation of IRS-1 and AKT was increased significantly in muscle tissues and AMPK phosphorylation and the GLUT4 and Sirt1 expression were decreased significantly in muscle tissues after the AFB administration. Conclusions: Our study indicates that AFB extract improves symptoms of obesity through regulation of energy regulating proteins in muscle tissues.

Major ginsenosides from Panax ginseng promote aerobic cellular respiration and SIRT1-mediated mitochondrial biosynthesis in cardiomyocytes and neurons

  • Huang, Qingxia;Lou, Tingting;Lu, Jing;Wang, Manying;Chen, Xuenan;Xue, Linyuan;Tang, Xiaolei;Qi, Wenxiu;Zhang, Zepeng;Su, Hang;Jin, Wenqi;Jing, Chenxu;Zhao, Daqing;Sun, Liwei;Li, Xiangyan
    • Journal of Ginseng Research
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    • v.46 no.6
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    • pp.759-770
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    • 2022
  • Background: Aerobic cellular respiration provides chemical energy, adenosine triphosphate (ATP), to maintain multiple cellular functions. Sirtuin 1 (SIRT1) can deacetylate peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) to promote mitochondrial biosynthesis. Targeting energy metabolism is a potential strategy for the prevention and treatment of various diseases, such as cardiac and neurological disorders. Ginsenosides, one of the major bioactive constituents of Panax ginseng, have been extensively used due to their diverse beneficial effects on healthy subjects and patients with different diseases. However, the underlying molecular mechanisms of total ginsenosides (GS) on energy metabolism remain unclear. Methods: In this study, oxygen consumption rate, ATP production, mitochondrial biosynthesis, glucose metabolism, and SIRT1-PGC-1α pathways in untreated and GS-treated different cells, fly, and mouse models were investigated. Results: GS pretreatment enhanced mitochondrial respiration capacity and ATP production in aerobic respiration-dominated cardiomyocytes and neurons, and promoted tricarboxylic acid metabolism in cardiomyocytes. Moreover, GS clearly enhanced NAD+-dependent SIRT1 activation to increase mitochondrial biosynthesis in cardiomyocytes and neurons, which was completely abrogated by nicotinamide. Importantly, ginsenoside monomers, such as Rg1, Re, Rf, Rb1, Rc, Rh1, Rb2, and Rb3, were found to activate SIRT1 and promote energy metabolism. Conclusion: This study may provide new insights into the extensive application of ginseng for cardiac and neurological protection in healthy subjects and patients.