The effect of different boron compounds on nutrient digestibility, intestinal nutrient transporters, and liver lipid metabolism.

BACKGROUND: Gastrointestinal health is essential for maintaining a healthy lifestyle. Improving nutrient absorption and energy metabolism are the critical targets for intestinal health. This study aimed to determine the effects of different boron (B) derivatives on nutrient digestibility, intestinal nutrient transporters, and lipid metabolism in rats. METHODS: Twenty-one rats were allocated to three groups (n = 7) as follows: (i) Control, (ii) Sodium pentaborate pentahydrate (SPP), and (iii) boric acid (BA). The rats were fed a chow diet (AIN-93M) and supplemented with 8 mg/kg elemental B from SPP (45.2 mg/kg BW) and BA (42.7 mg/kg BW) via oral gavage every other day for 12 weeks. The nutrient digestibility of rats in each group was measured using the indigestible indicator (chromium oxide, Cr2 O3, 0.20%). At the end of the experiment, animals were decapitated by cervical dislocation and jejunum, and liver samples were taken from each animal. The nutrient transporters and lipid-regulated transcription factors were determined by RT-PCR. RESULTS: The nutrient digestibility (except for ash) was increased by SPP and BA supplementation (p < 0.05). SPP and BA-supplemented rats had higher jejunal glucose transporter 1 (GLUT1), GLUT2, GLUT5, sodium-dependent glucose transporter 1 (SGLT1), fatty acid transport protein-1 (FATP1), and FATP4 mRNA expression levels compared to nonsupplemented rats (p < 0.0001). BA-supplemented rats had remarkably higher peroxisome proliferator-activated receptor gamma (PPARγ) levels than nonsupplemented rats (p < 0.0001). In contrast, sterol regulatory element-binding protein 1c (SREBP-1c), liver X receptor alpha (LxR-α), and fatty acid synthase (FAS) levels decreased by SPP supplementation compared to other groups (p < 0.05). DISCUSSION: SPP and BA administration enhanced nutrient digestibility, intestinal nutrient transporters, and liver lipid metabolism in rats.

Evaluation of pea/rice and amylopectin/chromium as an alternative protein source to improve muscle protein synthesis in rats.

BACKGROUND: A preclinical study reported that the combination of an amylopectin/chromium complex (ACr) of branched-chain amino acids (BCAA) significantly enhanced muscle protein synthesis (MPS). This study was conducted to determine the effects of the addition of ACr complex to a pea/rice (PR) protein on MPS, insulin, muslin levels, and the mTOR pathway in exercised rats. METHODS: Twenty-four rats were divided into three groups: (i) exercise (Ex); (ii) Ex + PR 1:1 blend (0.465 g/kg BW); (iii) Ex + PR + ACr (0.155 g/kg BW). On the day of single-dose administration, after the animals were exercised at 26/m/min for 2 h, the supplement was given by oral gavage. The rats were injected with a bolus dose (250 mg/kg BW, 25 g/L) of deuterium-labeled phenylalanine to determine the protein fractional synthesis rate (FSR) one h after consuming the study product. RESULTS: The combination of PR and ACr enhanced MPS by 42.55% compared to the Ex group, while Ex + PR alone increased MPS by 30.2% over the Ex group (p < 0.0001) in exercised rats. Ex + PR plus ACr significantly enhanced phosphorylation of mTOR and S6K1 (p < 0.0001), and 4E-BP1 (p < 0.001) compared to the Ex (p < 0.0001). PR to ACr also significantly increased insulin and musclin levels (p < 0.0001) in exercised rats. Additionally, compared to Ex + PR alone, Ex + PR + ACr enhanced mTOR (p < 0.0001) and S6K1 (p < 0.0001) levels. CONCLUSION: These data suggested that PR + ACr may provide an alternative to animal proteins for remodeling and repairing muscle by stimulating MPS and mTOR signaling pathways in post-exercised rats. More preclinical and clinical human studies on combining pea/rice and amylopectin/chromium complex are required.

Magnesium Picolinate Improves Bone Formation by Regulation of RANK/RANKL/OPG and BMP-2/Runx2 Signaling Pathways in High-Fat Fed Rats.

Magnesium (Mg) deficiency may affect bone metabolism by increasing osteoclasts, decreasing osteoblasts, promoting inflammation/oxidative stress, and result in subsequent bone loss. The objective of the present study was to identify the molecular mechanism underlying the bone protective effect of different forms of Mg (inorganic magnesium oxide (MgO) versus organic magnesium picolinate (MgPic) compound) in rats fed with a high-fat diet (HFD). Forty-two Wistar albino male rats were divided into six group (n = 7): (i) control, (ii) MgO, (iii) MgPic, (iv) HFD, (v) HFD + MgO, and (vi) HFD + MgPic. Bone mineral density (BMD) increased in the Mg supplemented groups, especially MgPic, as compared with the HFD group (p < 0.001). As compared with the HFD + MgO group, the HFD + MgPic group had higher bone P (p < 0.05) and Mg levels (p < 0.001). In addition, as compared to MgO, MgPic improved bone formation by increasing the levels of osteogenetic proteins (COL1A1 (p < 0.001), BMP2 (p < 0.001), Runx2 (p < 0.001), OPG (p < 0.05), and OCN (p < 0.001), IGF-1 (p < 0.001)), while prevented bone resorption by reducing the levels of RANK and RANKL (p < 0.001). In conclusion, the present data showed that the MgPic could increase osteogenic protein levels in bone more effectively than MgO, prevent bone loss, and contribute to bone formation in HFD rats.

Effects of magnesium biotinate supplementation on serum insulin, glucose and lipid parameters along with liver protein levels of lipid metabolism in rats.

The objective of this study was to investigate the effects of a novel form of biotin (magnesium biotinate) on serum glucose, lipid profile, and hepatic lipid metabolism-related protein levels in rats. Forty-two rats were divided into six groups and fed a standard diet-based egg white powdered diet supplemented with either d-biotin at 0.01, 1, or 100 mg/kg BW or magnesium biotinate at 0.01, 1, or 100 mg/kg BW for 35 days. Neither form of biotin influenced (p > 0.05) serum glucose or insulin concentrations. Serum total cholesterol and triglyceride decreased with biotin from both sources (p < 0.05). Concentrations were lower with magnesium biotinate when comparing the 1 mg/kg dose (p < 0.05). Serum, liver, and brain biotin and liver cyclic guanosine monophosphate (cGMP) concentrations were greater when rats were treated with magnesium biotinate versus d-biotin, particularly when comparing the 1 and 100 mg/kg dose groups (p < 0.05). Both biotin forms decreased the liver SREBP-1c and FAS and increased AMPK-α1, ACC-1, ACC-2, PCC, and MCC levels (p < 0.05). The magnitudes of responses were more emphasized with magnesium biotinate. Magnesium biotinate, compared with a commercial d-biotin, is more effective in reducing serum lipid concentrations and regulating protein levels of lipid metabolism-related biomarkers.

Lutein/zeaxanthin isomers regulate neurotrophic factors and synaptic plasticity in trained rats

Background/aim: This study was conducted to elucidate the effects of lutein/zeaxanthin isomers (L/Zi) on lipid metabolism, oxidative stress, NF-κB/Nrf2 pathways, and synaptic plasticity proteins in trained rats. Materials and methods: Wistar rats were distributed into four groups: 1) control, 2) L/Zi: rats received L/Zi at the dose of 100 mg/kg by oral gavage, 3) exercise, 4) exercise+L/Zi: rats exercised and received L/Zi (100 mg/kg) by oral gavage. The duration of the study was eight weeks. Results: Exercise combined with L/Zi reduced lipid peroxidation and improved antioxidant enzyme activities of muscle and cerebral cortex in rats (p < 0.001). In the Exercise + L/Zi group, muscle and cerebral cortex Nrf2 and HO-1 levels increased, while NF-κB levels decreased (p <0.001). Also, L/Zi improved BDNF, synapsin I, SYP, and GAP-43 levels of the cerebral cortex of trained rats (p < 0.001). The highest levels of BDNF, synapsin SYP, and GAP-43 in the cerebral cortex were determined in the Exercise+L/Zi group. Conclusion: These results suggested that exercise combined with L/Zi supplementation might be effective to reduce neurodegeneration via improving neurotrophic factors and synaptic proteins, and oxidative capacity in the cerebral cortex.

Effects of supplementing different chromium histidinate complexes on glucose and lipid metabolism and related protein expressions in rats fed a high-fat diet.

BACKGROUND: The objective of this study was to investigate the effects of different chromium histidinate (CrHis) complexes added to the diet of rats fed a high-fat diet (HFD) on body weight changes, glucose and lipid metabolism parameters, and changes in biomarkers such as PPAR-γ, IRS-1, GLUTs, and NF-κB proteins. METHODS: Forty-two Sprague-Dawley rats were divided equally into six groups and fed either a control, an HFD, or an HFD supplemented with either CrHis1, CrHis2, CrHis3, or a combination of the CrHis complexes as CrHisM. RESULTS: Feeding an HFD to rats increased body weights, HOMA-IR values, fasting serum glucose, insulin, leptin, free fatty acid, total cholesterol, low-density lipoprotein cholesterol, and MDA concentrations as well as AST activities, and decreased serum and brain serotonin concentrations compared with rats fed a control diet (P < 0.0001). The levels of the PPAR-γ, IRS-1, and GLUTs in the liver and brain decreased, while NF-κB level increased, with feeding an HFD (P < 0.05). Although all the CrHis supplements reversed the negative effects of feeding an HFD (P < 0.05), the CrHis1 complex was most effective in changing the protein levels, while CrHisM was most effective in influencing certain parameters such as body weight and serum metabolites. CONCLUSION: The results of the present work suggest that the CrHis1 complex is most potent for alleviating the negative effects of feeding an HFD. The efficacy of CrHisM is likely due to the presence of the CrHis1 complex.

A Novel Integrated Active Herbal Formulation Ameliorates Dry Eye Syndrome by Inhibiting Inflammation and Oxidative Stress and Enhancing Glycosylated Phosphoproteins in Rats.

Dry eye syndrome (DES) is a chronic condition of the eye with insufficient production of tears leading to inadequate lubrication of eyes. Symptoms of DES are associated with discomfort and redness of the eye, blurred vision, and tear film instability which leads to the damaged ocular surface. Inflammation and oxidative stress play a significant role in the pathogenesis of the disease. In this study, the protective effect of different doses (100 or 200 mg/kg) of a novel multi-component oral formulation of lutein/zeaxanthin, curcumin, and vitamin D3 (LCD) was evaluated using a rat model with benzalkonium chloride (BAC)-induced dry eye syndrome. The formulation was administered orally to rats for 4 weeks. We observed a significant improvement in tear volume, tear breakup time, tear film integrity, and reduction in overall inflammation in rats fed with the LCD at dose 200 mg/kg performing better than 100 mg/kg. Furthermore, the formulation helped in lowering oxidative stress by increasing antioxidant levels and restored protective tear protein levels including MUC1, MUC4, and MUC5AC with 200 mg of LCD having the most significant effect. The results strongly suggest that the combination of lutein/zeaxanthin, curcumin, and vitamin-D3 is effective in alleviating the symptoms of dry eye condition with a multi-modal mechanism of action.

The effects of chromium picolinate on glucose and lipid metabolism in running rats.

BACKGROUND: Chromium picolinate (CrPic) is commonly used to reduce muscle fatigue after exercise. We aimed to elucidate the effects of CrPic on glucose and lipid metabolism and the expression of glucose transporters in exercised rats. METHODS: Forty-two male Wistar rats (8-week-old) were distributed into six groups (n = 7) as follows: Control, CrPic, Chronic Exercise (CEx), CEx + CrPic, Acute Exercise (AEx), and AEx + CrPic. CEx consists of 30 m/min, 30 min/day, and 5 days/week for 6 weeks. CrPic was supplemented at 400 µg elemental Cr/kg of diet for 6 weeks. In the AEx groups, animals were run on the treadmill at 30 m/min until exhaustion. RESULTS: CEx significantly lowered blood glucose (BG), total cholesterol (TC) and triglyceride (TG) levels, but elevated insulin concentration (IC), compared with control (P < 0.05). CEx significantly decreased the level of malondialdehyde (MDA) in the serum, liver, and muscle while AEx elevated it (P < 0.001 for all). CrPic significantly decreased BG, TC, TG levels, and increased IC with a remarkable effect in CEx rats (P < 0.01). CrPic also significantly reduced serum, liver, and muscle MDA levels (P < 0.001). Both AEx and CEx increased the expression of liver glucose transporter 2 (GLUT-2) and muscle GLUT-4 with the highest level in CEx rats (P < 0.05). Moreover, CrPic supplementation significantly elevated GLUT-2 and GLUT-4 expressions in the liver and muscle of sedentary and exercise-treated rats (P < 0.05). CONCLUSION: CrPic improves various metabolic parameters and reduces oxidative stress in CEx and AEx rats by decreasing BG, TC, TG, MDA levels in serum and elevating GLUT-2 and GLUT-4 expression in the liver and muscle samples. The efficacy of CrPic was more pronounced in CEx rats.

Effects of allyl isothiocyanate on insulin resistance, oxidative stress status, and transcription factors in high-fat diet/streptozotocin-induced type 2 diabetes mellitus in rats.

Allyl isothiocyanate (AITC), a dietary phytochemical found in some cruciferous vegetables, is commonly used as an antimicrobial, anticancer, and antioxidant agent. In the present study, we investigated the effects of AITC on insulin resistance and transcription factors in a diabetic rat model. A total of 42 Wistar rats were divided into six groups and orally treated for 12 weeks as follows: (i) control; (ii) AITC (100 mg/kg body weight [BW]); (iii) high fat diet (HFD); (iv) HFD + AITC (100 mg/kg BW); (v) HFD + streptozotocin (STZ, 40 mg/kg BW); and (vi) HFD + STZ + AITC. Administration of AITC reduced blood glucose, total cholesterol, triglycerides, and creatinine levels, but increased (P < 0.001) total antioxidant capacity. In AITC-treated rats, the glucose transporter-2, peroxisome proliferator-activated receptor gamma, p-insulin receptor substrate-1, and nuclear factor erythroid-derived 2 in the liver and kidney were increased while nuclear factor-kappa B was downregulated (P < 0.05). In conclusion, AITC possesses antidiabetic, antioxidant, and anti-inflammatory activities in HFD/STZ-induced T2DM in rats. These findings may further justify the importance of AITC in phytomedicine.