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The conversion of skeletal muscle fiber from fast-twitch to slow-twitch is crucial for sustained contractile and stretchable events, energy homeostasis, and anti-fatigue ability. The purpose of our study was to explore the mechanism and effects of garcinol on the regulation of skeletal muscle fiber type transformation. Forty 21-day-old male C57/BL6J mice (n = 10/diet) were fed a control diet or a control diet plus garcinol at 100 mg/kg (Low Gar), 300 mg/kg (Mid Gar), or 500 mg/kg (High Gar) for 12 weeks. The tibialis anterior (TA) and soleus muscles were collected for protein and immunoprecipitation analyses. Dietary garcinol significantly downregulated (p < 0.05) fast myosin heavy chain (MyHC) expression and upregulated (p < 0.05) slow MyHC expression in the TA and soleus muscles. Garcinol significantly increased (p < 0.05) the activity of peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) and markedly decreased (p < 0.05) the acetylation of PGC-1α. In vitro and in vivo experiments showed that garcinol decreased (p < 0.05) lactate dehydrogenase activity and increased (p < 0.05) the activities of malate dehydrogenase and succinic dehydrogenase. In addition, the results of C2C12 myotubes showed that garcinol treatment increased (p < 0.05) the transformation of glycolytic muscle fiber to oxidative muscle fiber by 45.9%. Garcinol treatment and p300 interference reduced (p < 0.05) the expression of fast MyHC but increased (p < 0.05) the expression of slow MyHC in vitro. Moreover, the acetylation of PGC-1α was significantly decreased (p < 0.05). Garcinol promotes the transformation of skeletal muscle fibers from the fast-glycolytic type to the slow-oxidative type through the p300/PGC-1α signaling pathway in C2C12 myotubes. [ABSTRACT FROM AUTHOR]

Disorder of hepatic glucose metabolism is the characteristic of late-pregnant sows. The purpose of our study was to look into the mechanism of garcinol on the improvement of hepatic gluconeogenic enzyme in late-pregnant sows. Thirty second- and third-parity sows (Duroc × Yorkshire × Landrace, n 10/diet) were fed a basal diet (control) or that diet supplemented with 100 mg/kg (Low Gar) or 500 mg/kg (High Gar) garcinol from day 90 of gestation to the end of farrowing. The livers were processed to measure enzymatic activity. Hepatocytes from pregnant sows were transfected with P300/CBP-associating factor (PCAF) small interfering RNA (siRNA) or treated with garcinol. Dietary garcinol had no effect on average daily feed intake, body weight (BW), backfat and BW gain of late-pregnant sows. Garcinol promoted plasma glucose levels in pregnant sows and newborn piglets. Garcinol up-regulated hepatic gluconeogenic enzyme expression and decreased PCAF activity. Garcinol had no effect on the expression of PPAR-γ co-activator 1α (PGC-1α) and Forkhead box O1 (FOXO1) but significantly increased their activity and decreased their acetylation in late-pregnant sows. Transfection of PCAF siRNA to hepatocytes of pregnant sows increased PGC-1α and FOXO1 activities. Furthermore, in hepatocytes of pregnant sows, garcinol treatment also up-regulated the activities of PGC-1α and FOXO1 and inhibited the acetylation of PGC-1α and FOXO1. Garcinol improves hepatic gluconeogenic enzyme expression in late-pregnant sows, and this may be due to the mechanism of down-regulating the acetylation of PGC-1α and FOXO1 induced by PCAF in isolated hepatocytes. [ABSTRACT FROM AUTHOR]

Background: Increased hepatic glycolysis and lipogenesis are characteristic of pregnancy.Objectives: The present study aimed to investigate the mechanism of garcinol on the amelioration of hepatic pyruvate and triglyceride (TG) accumulation in mid-to-late pregnant rats.Methods: Forty Sprague-Dawley pregnant rats (aged 9 wk, n = 10/diet) were fed a basal diet (control) or that diet plus garcinol at 100 ppm (Low Gar), 300 ppm (Mid Gar), or 500 ppm (High Gar) for 14 d. The livers were processed for Western blotting analyses and measuring enzymatic activity and pyruvate and TG concentrations. Hepatocytes from other pregnant Sprague Dawley rats were transfected with P300/CBP associating factor (PCAF) short interfering (si)RNAs; hepatocytes from nonpregnant Sprague-Dawley rats with overexpression of PCAF were treated with garcinol (5 μM). The activity and acetylation of upstream stimulatory factor (USF-1) and glycolytic enzymes were analyzed.Results: Dietary garcinol significantly decreased (P < 0.05) concentrations of hepatic and plasma TG (27.1-45.8%) and total cholesterol (25.3-49.5%), plasma free fatty acids (24.4-37.8%), and hepatic pyruvate (31.5-43.5%) and lactate (33.4-65.7%) in mid-to-late pregnant rats. Garcinol promoted (P < 0.05) antioxidant capacity in the liver and plasma by 27.4-32.1%. Garcinol downregulated (P < 0.05) lipid synthesis-related enzyme expression by 30.6-85.3% and decreased (P < 0.05) glycolytic enzyme activities by 22.5-74.6% and PCAF activity by 18.6-55.4%. Transfection of PCAF siRNAs to hepatocytes of pregnant rats decreased USF-1 and glycolytic enzyme activities by PCAF; garcinol treatment downregulated (P < 0.05) the acetylation and activities of USF-1 and glycolytic enzymes by 35.6-83.7%.Conclusions: Garcinol attenuates hepatic pyruvate and TG accumulation in the liver of mid-to-late pregnant rats, which may be due to downregulating the acetylation of USF-1 and the glycolytic enzymes induced by PCAF in isolated hepatocytes. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the effects of dietary garcinol supplementation during late gestation (from the 90th day of pregnancy; day 90) and lactation on the acid–base balance of the umbilical cord blood and performance of sows and piglets. Sixty sows (Duroc × Yorkshire × Landrace; second- or third-parity; n = 20) were randomly divided into 3 gestation (day 90 of pregnancy) or lactation treatments, control diet (CON; basal diet), basal diet with 200 mg garcinol, and basal diet with 600 mg garcinol per kg of feed. The body weight (BW); backfat thickness and litter size of the sows; and birth weight, weaning weight, and mortality of piglets were recorded. Sows' blood and piglets' umbilical cord blood were collected for the measurements of hematological parameters and antioxidative and immune indexes, and acid–base balance parameters, respectively. The colostrum and milk and fecal samples of the sows were also collected for analysis of milk composition and apparent total tract nutrient digestibility. Garcinol had no effect on the BW and backfat thickness of the sows but significantly increased the birth weight and weaning weight of piglets (P < 0.05) and decreased the mortality (P < 0.05). Moreover, the white blood cell counts and neutrophil count, mean cell hemoglobin, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activity in the plasma of the sows were increased more significantly (P < 0.05) in the garcinol groups than that in the CON group, whereas the malondialdehyde (MDA) content was decreased (P < 0.05). The garcinol treatment significantly increased the pH, HCO3− and base excess values (P < 0.05), whereas it decreased the pCO2 and lactate content (P < 0.05) in the umbilical blood. Dry matter (DM), ash, and ether extract in the colostrum were similar between groups (P > 0.05), whereas the garcinol significantly increased the crude protein (CP) in the milk. In addition, the content of immunoglobulin A (IgA) and immunoglobulin G (IgG) in the plasma of piglets and in colostrum and milk of sows were increased more significantly (P < 0.05) in the garcinol groups than that in the CON group. The apparent total tract nutrient digestibility was similar between treatments. Collectively, this study indicates that sows fed with garcinol in late gestation and lactation showed improved maternal health and antioxidative status, milk protein content, acid–base balance in the umbilical cord blood, and growth performance in piglets, showing promise in natural plant extract nutrition for sows. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of dietary garcinol (0, 200, 400 and 600 mg/kg) on the growth performance, meat quality, postmortem glycolysis and antioxidative capacity of finishing pigs. Dietary garcinol increased pigs' average daily gain, pH 24h , a* and myoglobin content of longissimus dorsi (LM) (P < 0.05), and decreased feed/gain ratio, the L* 24h , glycolytic potential, drip loss, shear force, and backfat depth (P < 0.05). The glutathione peroxidase (GPx), catalase (CAT) and total antioxidative capacity (T-AOC) were significantly increased by garcinol (P < 0.05), while the activity of lactate dehydrogenase (LDH) and malonaldehyde (MDA) content were decreased (P < 0.05). Moreover, garcinol decreased the p300/CBP-associated factor (PCAF) activity, the acetylation level and activities of glycolysis enzymes phosphoglycerate kinase 1 (PGK1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase-3 (PFKFB3) (P < 0.05). The results of this study showed that garcinol decreased postmortem glycolysis, and this may be due to the mechanism of decreasing glycolytic enzyme acetylation induced by PCAF. The present study indicates that garcinol can facilitate the growth performance of pigs and improve pork quality by changing postmortem glycolysis and antioxidative capacity. [ABSTRACT FROM AUTHOR]