Biotin and chromium histidinate improve glucose metabolism and proteins expression levels of IRS-1, PPAR-γ, and NF-κB in exercise-trained rats

Understanding Cr(III) Action on Mitochondrial ATP Synthase and AMPK Efficacy: Insights from Previous Studies-a Review

Chromium supplementation has been notably recognized for its potential health benefits, especially in enhancing insulin sensitivity and managing glucose metabolism. However, recent studies have begun to shed light on additional mechanisms of action for chromium, expanding our understanding beyond its classical effects on the insulin-signaling pathway. The beta subunit of mitochondrial ATP synthase is considered a novel site for Cr(III) action, influencing physiological effects apart from insulin signaling. The physiological effects of chromium supplementation have been extensively studied, particularly in its role in anti-oxidative efficacy and glucose metabolism. However, recent advancements have prompted a re-evaluation of chromium's mechanisms of action beyond the insulin signaling pathway. The discovery of the beta subunit of mitochondrial ATP synthase as a potential target for chromium action is discussed, emphasizing its crucial role in cellular energy production and metabolic regulation. A meticulous analysis of relevant studies that were earlier carried out could shed light on the relationship between chromium supplementation and mitochondrial ATP synthase. This review categorizes studies based on their primary investigations, encompassing areas such as muscle protein synthesis, glucose and lipid metabolism, and antioxidant properties. Findings from these studies are scrutinized to distinguish patterns aligning with the new hypothesis. Central to this exploration is the presentation of studies highlighting the physiological effects of chromium that extend beyond the insulin signaling pathway. Evaluating the various independent mechanisms of action that chromium impacts cellular energy metabolism and overall metabolic balance has become more important. In conclusion, this review is a paradigm shift in understanding chromium supplementation, paving the way for future investigations that leverage the intricate interplay between chromium and mitochondrial ATP synthase.

Does the peroral chromium administration in young Hariana calves reduce the risk of calf diarrhea by ameliorating insulin response, lactose intolerance, antioxidant status, and immune response?

BACKGROUND

The reduction in insulin sensitivity during rumen development may predispose dairy calves towards lactose intolerance, which could be the reason behind neonatal calf diarrhea (NCD). Chromium (Cr) results in a range of effects when fed to ruminants, but most studies have shown improved insulin sensitivity. The aim of this study was to determine the effect of Cr supplementation on insulin sensitivity, lactose intolerance, diarrhoea and antioxidant, and immune response in young Hariana calves.

METHODS

A total of 20 milk-fed Hariana calves were randomly assigned to 1 of 2 treatments, each consisted of 10 calves: (1) a control group without supplemental Cr and (2) a 0.15 mg Cr as Cr-picolinate (CrPic)/kg BW0.75 supplemented group (Cr0.15).

RESULTS

A more rapid glucose disappearance with unaltered insulin kinetics during intravenous glucose tolerance test (IVGTT) and oral lactose tolerance test (OLTT) indicates greater insulin sensitivity in Cr supplemented calves. Better insulin sensitivity in Cr supplemented calves was further confirmed by higher values of the quantitative insulin sensitivity check index (QUICKI), revised quantitative insulin sensitivity check index (RQUICKI) and insulin receptor substrate-1 (IRS-1) and lower (P < 0.05) values of homeostasis model assessment-insulin resistance (HOMA-IR) and glucose-to-insulin ratio in Cr supplemented calves during IVGTT. Cr supplementation resulted in a lower (P < 0.05) serum cortisol concentration, whereas serum non-esterified fatty acid (NEFA) concentrations during IVGTT did not differ among the groups. The rise in serum glucose concentrations within 2 h post lactose infusion during OLTT peaked at more than twice the basal glucose concentration, therefore calves were not considered as lactose intolerant. Within monthly blood samples, concentrations of serum insulin were similar among treatments, whereas the Cr supplemented group had lower (P < 0.05) serum glucose concentration and glucose-to-insulin ratio compared with the control group. No treatment differences were detected in the biomarkers of antioxidant status and immunity. Serum Cr concentrations were higher (P < 0.05) in Cr supplemented calves while concentrations of other studied minerals were remained unaltered. The incidence, duration of diarrhea, and faecal score were better (P < 0.05) in calves fed on Cr supplemented diet whereas, no treatment effect was observed on average daily gain (ADG). During the study period, no calves died, and no calves were found to have pneumonia, navel or joint disease.

CONCLUSION

Feeding a Cr-supplemented diet improved insulin sensitivity and reduced the risk of diarrhoea in milk-fed young calves, but had no or minimal effects on lactose intolerance, antioxidant status, immune response, and growth performance.

Dietary Chromium Picolinate Supplementation Improves Glucose Utilization in Transition Calf by Ameliorating Insulin Response

The decrease in insulin sensitivity during the transition of preruminant calves into ruminant animals is the common denominator. Meanwhile, this adaptation predisposes dairy calves towards various health issues and metabolic disorders that occur in later life. Chromium (Cr) has been shown to potentiate insulin functioning and is thereby helpful in reducing the risk of these metabolic disorders. The aim of this study was to assess the effect of Cr supplementation on the insulin sensitivity and health status in Hariana calves during their transition period. A total of 24 preruminant Hariana calves were randomly allocated into four groups (6 calves per group) for a period of 90 days. Calves either received a basal diet devoid of supplemental Cr (control; Cr_0.0 group) or were supplemented with 0.05 mg (Cr_0.05 group), 0.10 mg (Cr_0.10 group), and 0.15 mg (Cr_0.15 group) of Cr per kg BW^0.75 as Cr-picolinate (Cr-Pic). To determine the effect of Cr supplementation on the insulin response, glucose-insulin-non-esterified fatty acids (NEFAs) kinetics was studied during the intravenous glucose tolerance test (IVGTT) and oral glucose tolerance test (OGTT). A rapid glucose disappearance (p < 0.05) with unaltered insulin kinetics during IVGTT and OLTT indicates greater insulin sensitivity in calves supplemented with 0.10 and 0.15 mg of Cr per kg BW^0.75. Improved insulin sensitivity in the Cr_0.10 and Cr_0.15 groups was further confirmed by higher (p < 0.05) values of the insulin sensitivity check index (QUICKI), revised quantitative insulin sensitivity check index (RQUICKI), and lower (p < 0.05) values of the homeostasis model assessment-insulin resistance (HOMA-IR) during IVGTT. Mean serum non-esterified fatty acids (NEFA_m), and insulin receptor substrate-1 (IRS-1) levels were the highest (p < 0.05) and cortisol concentrations were the lowest (p < 0.05) in the Cr_0.15 groups. Unlike IVGTT, there was no effect of treatment, period, and treatment × period interaction on mean serum glucose and insulin levels during OGTT. However, Cr-supplemented calves had a higher (p < 0.05) glucose clearance rate (_gCR). Serum IRS-1 concentrations during OGTT were also higher (p < 0.05) in the Cr_0.10 and Cr_0.15 groups than in the other groups. Serum Cr levels increased dose dependently and were the highest (p < 0.05) in calves fed a diet supplemented with 0.15 mg Cr per kg BW^0.75. There was no effect of treatment on average daily gain (ADG) and body condition score (BCS) while frequency and duration of diarrhea were lower and fecal score was better in Cr-supplemented calves. The current findings show that Cr supplementation improved glucose utilization and health status in calves during their transition period by improving insulin sensitivity.

Study on osteoinductive activity of biotin film by low-energy electron beam deposition

Biotin film was prepared by low-energy electron beam deposition (LEBD). The molecular structure, chemical composition and micromorphology of the biotin film were investigated by ¹HNMR, FTIR, XPS, AFM and SEM. The results showed the molecular structure of a monolayer of biotin film is fully consistent with the molecular structure of the initial biotin powders. The contact angle test showed that the biotin film exhibit good hydrophilicity. The release kinetics of biotin film was tested by UV-Vis method. It was found that the film was almost completely released in about two weeks. The cell viability of MC3T3-E1 cells on the surface of the biotin film was attaining 100.54 ± 1.7% (P < 0.05), showing excellent biocompatibility and biosafety. Titanium implant with surface of biotin film was implanted into the femoral head of rabbits as experimental group. The animals were euthanized after four weeks. Compared with the control group, mature lamellar bone formation was observed with dense trabecular bone, and the expression of Coll-I, Runx2 and BMP-2 was better. The results showed that the repair effect of bone defect in the experimental group was excellent.

Effects of Betaine-Biotin-Chromium Supplementation and Concentrate to Roughage Ratio on Nutrient Utilization Efficiency in Thai Native Cattle

Simple Summary

Feed additives are attracting considerable interest due to the need to effectively improve the level of production, efficiency, and health of animals. A combination of betaine, biotin, and chromium has been developed to enhance nutrient utilization efficiency. Ideally, the addition of a combination of supplements to livestock feed could improve ruminal fermentation, digestibility and nutrient utilization, nitrogen and energy balance, and metabolism.

Abstract

The objective of this study was to evaluate the effects of supplementation with a feed additive containing a combination of betaine, biotin, and chromium (BBC) and concentrate-to-roughage ratio (C:R ratio) on nutrient digestibility, blood metabolites, ruminal fermentation, nitrogen balance, and energy utilization in Thai native beef cattle. Five Thai feedlot native beef bulls at one year old of age and 87.6 ± 15.7 kg of body weight were assigned in a (2 × 2) + 1 augmented factorial experiment according to a 5 × 5 Latin square design with five periods of 21 days. The two levels of BBC were 3 g/kg DM and 6 g/kg DM, and the two ratios of C:R were 60C:40R and 70C:30R. A C:R ratio of 70C:30R without BBC supplementation was used as a negative control. The cattle were offered feed at 3% BW, which provides sufficient energy and protein to support a weight gain of 500 g/day. The results showed that dry matter intake (DMI) and organic matter intake (OMI) were not different (p > 0.05), but the intake of crude protein (CP) and ether extract (EE) was higher (p < 0.05), whereas neutral detergent fiber (NDF) and acid detergent fiber (ADF) were lower (p < 0.05) in the 70C:30R ratio diets compared to the 60:40R ratio diets. Energy balance and nitrogen balance were not influenced (p > 0.05) by the C:R ratio or the addition of BBC. Rumen pH and ammonia-nitrogen (NH₃-N) did not differ (p > 0.05) among treatments groups. Total volatile fatty acid (VFA) production was higher (p < 0.05) in bulls fed with the 70C:30R ratio diet. The addition of BBC resulted in a lower (p < 0.01) glucose-to-insulin ratio compared to cattle fed with the control diet. Energy and protein utilization efficiency did not differ (p > 0.05) among the experimental treatment groups, which were higher (p > 0.05) than the control group. In conclusion, BBC supplementation showed greater growth performance of cattle compared to the control. BBC supplementation appeared to improve glucose uptake and insulin sensitivity and energy and protein utilization efficiency. Whether BBC supplementation increases glucose production in the liver remains to be determined in future studies.

Effects of chromium supplementation on lipid profile in patients with type 2 diabetes: A systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

The purpose of this study was to determine the influence of chromium supplementation on lipid profile in patients with type 2 diabetes mellitus (T2DM).

METHODS

A systematic search was performed in Scopus, Embase, Web of Science, the Cochrane library and PubMed databases to find randomized controlled trials (RCTs) related to the effect of chromium supplementation on lipid profile in patients with T2DM, up to June 2020. Meta-analyses were performed using the random-effects model, and I² index was used to evaluate heterogeneity.

RESULTS

The primary search yielded 725 publications. 24 RCTs (with 28 effect size) were eligible. Our meta-analysis indicated that chromium supplementation resulted in a significant decrease in serum levels of triglyceride (TG) (MD: -6.54 mg/dl, 95 % CI: -13.08 to -0.00, P = 0.050) and total cholesterol (TC) (WMD: -7.77 mg/dl, 95 % CI: -11.35 to -4.18, P < 0.001). Furthermore, chromium significantly increases high-density lipoprotein (HDL) (WMD: 2.23 mg/dl, 95 % CI: 0.07-4.40, P = 0.043) level. However, chromium supplementation did not have significant effects on low-density lipoprotein (LDL) (WMD: -8.54 mg/dl, 95 % CI: -19.58 to 2.49, P = 0.129) level.

CONCLUSION

Chromium supplementation may significantly improve lipid profile in patients with T2DM by decreasing TG and TC and increasing HDL. However, based on our analysis, chromium failed to affect LDL. It should be noted that the lipid-lowering properties of chromium supplementation were small and may not reach clinical importance.

Whether or Not the Effects of Curcuma longa Supplementation Are Associated with Physical Exercises in T1DM and T2DM: A Systematic Review

Diabetes mellitus is one of the most prevalent chronic diseases in the world; one of its main characteristics is chronic hyperglycemia. Pharmacotherapy and other alternatives such as regular exercise are among the therapeutic methods used to control this pathology and participate in glycemic control, as well as the ingestion of plant extracts with antioxidant effects. Among the different plants used for this purpose, curcumin has potential to be used to attenuate the hyperglycemic condition triggered by diabetes mellitus (DM). Some prior studies suggest that this plant has antioxidant and hypoglycemic potential. This review aims to evaluate the antioxidant and hypoglycemic potential of curcumin supplementation in Type 1 DM (T1DM) and Type 2 DM (T2DM). The search considered articles published between 2010 and 2019 in English and Portuguese, and a theoretical survey of relevant information was conducted in the main databases of scientific publications, including the Virtual Health Library and its indexed databases, PubMed, LILACS (Latin American and Caribbean Literature on Health Sciences-Health Information for Latin America and the Caribbean-BIREME/PAHO/WHO), and Scientific Electronic Library Online (SciELO). The associated use of turmeric and physical exercise has demonstrated antioxidant, anti-inflammatory, and hypoglycemic effects, suggesting that these could be used as potential therapeutic methods to improve the quality of life and survival of diabetic patients.

The Interactive Effect of High Doses of Chromium(III) and Different Iron(III) Levels on the Carbohydrate Status, Lipid Profile, and Selected Biochemical Parameters in Female Wistar Rats

The aim of the study was to evaluate the main and interactive effects of chromium(III) propionate complex (Cr3) supplementation and different iron supply on the carbohydrate metabolism, lipid profile and other selected biochemical parameters of rats. The experiment was carried out in a two-factor design, in which rats were fed a diet with different proportions of Fe(III) and Cr(III) for six weeks. Fifty-four healthy female Wistar rats were divided into nine experimental groups with different Fe(III) levels, i.e. adequate-control group (45 mg/kg)-100% recommended daily dietary dose of Fe for rodents, deficient (5 mg/kg) and oversupply (180 mg/kg-400%). At the same time they were supplemented with Cr(III) of doses 1 (adequate), 50 and 500 mg/kg of diet. The activity and concentrations of most biochemical parameters were measured with standard enzymatic, kinetic, and colorimetric methods. HOMA-IR and QUICKI indexes were calculated according to appropriate formulas. It was found that there was an interactive effect of high Cr(III) doses and different Fe(III) levels in the diet on the carbohydrate metabolism and insulin resistance indexes. The presented results suggested that iron deficient diet fed animals led to insulin resistance; however, an effect is attenuated by Cr(III) supplementation at high doses. There were no significant changes in the rats' lipid profile (except for the high density lipoprotein cholesterol (HDL-C) level) and most of the other biochemical parameters, such as the leptin, aspartate aminotransferase (AST), alanine transaminase (ALT), total protein (TP), creatinine (Crea) and the urea (BUN) concentrations. The study proved that the Cr(III) supplementation, independently and in combination with diversified Fe(III) content in the diet, affected the carbohydrate metabolism and insulin resistance indexes but did not affect lipid profile and most of the other biochemical parameters in healthy rats. The findings proved the role of Fe and Cr(III) and their interactions on disturbances carbohydrates metabolism.

Biotin, coenzyme Q10, and their combination ameliorate aluminium chloride-induced Alzheimer's disease via attenuating neuroinflammation and improving brain insulin signaling

Insulin is important for brain function and neuronal survival. Insulin signaling is initiated by the phosphorylation of insulin receptor substrate-1 (IRS-1) at tyrosine (pTyr) residue. However, IRS-1 is inhibited by phosphorylation at serine (pSer). In Alzheimer's disease (AD), oxidative stress and accumulation of amyloid beta (Aβ) induce neuroinflammation, which augments pSer-IRS-1 and reduces pTyr-IRS-1 disturbing insulin signaling pathway. Coenzyme Q10 (CoQ10) and biotin possess antioxidant and anti-inflammatory properties, and, in this study, their impact on insulin signaling is investigated in an aluminium chloride (AlCl3 ) model of AD. AD was induced by oral administration of AlCl3 (75 mg/kg) for 60 days. Biotin (2 mg/kg), CoQ10 (10 mg/kg), and their combination were supplemented concomitantly with AlCl3 for 60 days. Memory test and histological examination were performed. Brain levels of lipid peroxides, antioxidants (reduced glutathione and superoxide dismutase), inflammatory markers (tumor necrosis factor-α, interleukin-6 [IL-6], IL-1, and nuclear factor κB), and phosphorylated Akt (survival kinase) as well as protein levels of Aβ, IRS-1 (pTyr and pSer), and caspase-3 (apoptotic marker) were determined. AlCl3 resulted in impaired memory, significant increase in Aβ, lipid peroxides, inflammatory markers, caspase-3, and pSer-IRS-1, with significant reduction of the antioxidants, pTyr-IRS-1, and p-Akt reflecting Aβ-induced inflammation and defective insulin signaling. Histological examination revealed focal aggregations of inflammatory cells and neuronal degeneration. The biochemical deviations and histological changes were attenuated by the concomitant treatment with biotin and, to greater extent, with CoQ10 and the combination. In conclusion, biotin and CoQ10 could protect against AD via attenuating inflammatory response and enhancing insulin signaling.

Effects of resistance training and turmeric supplementation on reactive species marker stress in diabetic rats

Background

Type 1 diabetes mellitus (T1DM) is a metabolic disease characterized by hyperglycemia and excessive generation of reactive oxygen species caused by autoimmune destruction of beta-cells in the pancreas. Among the antioxidant compounds, Curcuma longa (CL) has potential antioxidant effects and may improve hyperglycemia in uncontrolled T1DM/TD1, as well as prevent its complications (higher costs for the maintenance of health per patient, functional disability, cardiovascular disease, and metabolic damage). In addition to the use of compounds to attenuate the effects triggered by diabetes, physical exercise is also essential for glycemic control and the maintenance of skeletal muscles. Our objective is to evaluate the effects of CL supplementation associated with moderate- to high-intensity resistance training on the parameters of body weight recovery, glycemic control, reactive species markers, and tissue damage in rats with T1DM/TD1.

Methods

Forty male 3-month-old Wistar rats (200–250 g) with alloxan-induced T1DM were divided into 4 groups (n = 7–10): sedentary diabetics (DC); diabetic rats that underwent a 4-week resistance training protocol (TD); CL-supplemented diabetic rats (200 mg/kg body weight, 3x a week) (SD); and supplemented diabetic rats under the same conditions as above and submitted to training (TSD). Body weight, blood glucose, and the following biochemical markers were analyzed: lipid profile, aspartate aminotransferase (AST), alanine aminotransferase (ALT), uric acid, creatine kinase (CK), lactate dehydrogenase (LDH), and thiobarbituric acid reactive substances (TBARS).

Results

Compared to the DC group, the TD group showed body weight gain (↑7.99%, p = 0.0153) and attenuated glycemia (↓23.14%, p = 0.0008) and total cholesterol (↓31.72%, p ≤ 0.0041) associated with diminished reactive species markers in pancreatic (↓45.53%, p < 0.0001) and cardiac tissues (↓51.85%, p < 0.0001). In addition, compared to DC, TSD promoted body weight recovery (↑15.44%, p ≤ 0.0001); attenuated glycemia (↓42.40%, p ≤ 0.0001), triglycerides (↓39.96%, p ≤ 0.001), and total cholesterol (↓28.61%, p ≤ 0.05); and attenuated the reactive species markers in the serum (↓26.92%, p ≤ 0.01), pancreas (↓46.22%, p ≤ 0.0001), cardiac (↓55.33%, p ≤ 0.001), and skeletal muscle (↓42.27%, p ≤ 0.001) tissues caused by T1DM.

Conclusion

Resistance training associated (and/or not) with the use of Curcuma longa attenuated weight loss, the hypoglycemic and hypolipidemic effects, reactive species markers, and T1DM-induced tissue injury.

Trace Elements, PPARs, and Metabolic Syndrome

Metabolic syndrome (MetS) is a constellation of metabolic derangements, including central obesity, insulin resistance, hypertension, glucose intolerance, and dyslipidemia. The pathogenesis of MetS has been intensively studied, and now many factors are recognized to contribute to the development of MetS. Among these, trace elements influence the structure of proteins, enzymes, and complex carbohydrates, and thus an imbalance in trace elements is an independent risk factor for MetS. The molecular link between trace elements and metabolic homeostasis has been established, and peroxisome proliferator-activated receptors (PPARs) have appeared as key regulators bridging these two elements. This is because on one hand, PPARs are actively involved in various metabolic processes, such as abdominal adiposity and insulin sensitivity, and on the other hand, PPARs sensitively respond to changes in trace elements. For example, an iron overload attenuates hepatic mRNA expression of Ppar-α; zinc supplementation is considered to recover the DNA-binding activity of PPAR-α, which is impaired in steatotic mouse liver; selenium administration downregulates mRNA expression of Ppar-γ, thereby improving lipid metabolism and oxidative status in the liver of high-fat diet (HFD)-fed mice. More importantly, PPARs' expression and activity are under the control of the circadian clock and show a robust 24 h rhythmicity, which might be the reasons for the side effects and the clinical limitations of trace elements targeting PPARs. Taken together, understanding the casual relationships among trace elements, PPARs' actions, and the pathogenesis of MetS is of great importance. Further studies are required to explore the chronopharmacological effects of trace elements on the diurnal oscillation of PPARs and the consequent development of MetS.

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 chromium supplementation on body composition, human and animal health, and insulin and glucose metabolism

PURPOSE OF REVIEW

Chromium(III) has been proposed to have a nutritional or pharmacological role in changing body composition and improving symptoms of insulin resistance, type 2 diabetes, and related conditions although the mode of action of Cr(III) at a molecular level has failed to be elucidated. This review details the current status of studies into Cr(III) supplementation.

RECENT FINDINGS

Clinical trials, meta-analyses and systematic reviews have failed to demonstrate clinically significant effects from Cr(III) supplementation on body composition or symptoms of insulin resistance and related conditions in humans and farm animals. Although new Cr(III) supplements continue to appear in the scientific literature, studies have failed to elucidate the mechanism of chromium action at a molecular level. Conflicting results on a role of transferrin in Cr(III) transport and detoxification have appeared.

SUMMARY

Cr(III) supplementation cannot currently be recommended in humans or farm animals. Further studies are required to probe the mechanism of Cr(III) action in increasing insulin sensitivity and glucose uptake in rodent models of insulin resistance and diabetes, with particular attention being turned to a potential role of transferrin in Cr(III) transport and detoxification.

15-Deoxy-∆-12,14-Prostaglandin J2 (15d-PGJ2), an Endogenous Ligand of PPAR-γ: Function and Mechanism

15-Deoxy-∆-^12,14-prostaglandin J2 (15d-PGJ2), a natural peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, has been explored in some detail over the last 20 years. By triggering the PPAR-γ signalling pathway, it plays many roles and exerts antitumour, anti-inflammatory, antioxidation, antifibrosis, and antiangiogenesis effects. Although many synthetic PPAR-γ receptor agonists have been developed, as an endogenous product of PPAR-γ receptors, 15d-PGJ2 has beneficial characteristics including rapid expression and the ability to contribute to a natural defence mechanism. In this review, we discuss the latest advances in our knowledge of the biological role of 15d-PGJ2 mediated through PPAR-γ. It is important to understand its structure, synthesis, and functional mechanisms to develop preventive agents and limit the progression of associated diseases.