Effect of crocin on the insulin resistance and lipid profile of streptozotocin-induced diabetic rats

Potential therapeutic effects of crocin

Crocin, a natural bioactive compound derived from saffron (Crocus sativus) and other Crocus genera, has gained significant attention recently due to its potential therapeutic properties. The multifaceted nature of crocin's biological effects has piqued the interest of researchers and health enthusiasts, prompting further investigations into its mechanisms of action and therapeutic applications. This review article comprehensively explores the emerging evidence supporting crocin's role as a promising ally in protecting against metabolic disorders. The review covers the molecular mechanisms underlying crocin's beneficial effects and highlights its potential applications in preventing and treating diverse pathological conditions. Understanding the mechanisms through which crocin exerts its protective effects could advance scientific knowledge and offer potential avenues for developing novel therapeutic interventions. As we uncover the potential of crocin as a valuable ally in the fight against disorders, it becomes evident that nature's palette holds remarkable solutions for enhancing our health.

Modulating effects of crocin on lipids and lipoproteins: Mechanisms and potential benefits

Dyslipidemia poses a significant risk to cardiovascular health in both diabetic and non-diabetic individuals. Therefore, it is crucial to normalize lipid homeostasis in order to prevent or minimize complications associated with dyslipidemia. However, pharmacological interventions for controlling lipid metabolism often come with adverse effects. As an alternative, utilizing herbal-based agents, which typically have fewer side effects, holds promise. Crocin, a naturally occurring nutraceutical, has been shown to impact various intracellular pathways, reduce oxidative stress, and alleviate inflammatory processes. Recent evidence suggests that crocin may also confer lipid-related benefits and potentially contribute to the normalization of lipid homeostasis. However, the specific advantages and the cellular pathways involved are not yet well understood. In this review, we present the latest findings regarding the lipid benefits of crocin, which could be instrumental in preventing or reducing disorders associated with dyslipidemia. Additionally, we explore the potential cellular mechanisms and pathways that mediate these lipid benefits.

Effect of saffron supplementation on the glycemic outcomes in diabetes: a systematic review and meta-analysis

Aim

This meta-analysis was conducted to investigate the impact of saffron supplementation on the glycemic outcomes in patients with diabetes.

Methods

Eight electronic databases were systematically searched from inception to March 31, 2023. RCTs of patients with diabetes receiving saffron compared with placebo which reported glycemic control outcomes were identified. WMD and 95% CIs were pooled using fixed-effects or random-effects models, depending on the significance of heterogeneity.

Results

Out of the 837 citations screened, ten RCTs were included in the systematic review and meta-analysis. A total of 562 participants were enrolled, with 292 assigned to the intervention group and 270 to the control group. Saffron was administered at a dose of 5 mg/day to 1 g/day. Compared with placebo, saffron supplementation significantly reduced FPG (WMD = -8.42 mg/dL; 95% CI: -13.37, -3.47; p = 0.001) and HbA1c (WMD = -0.22%; 95% CI: -0.33, -0.10; p < 0.001). However, there was no significant effect on insulin levels, QUICKI and HOMA-IR.

Conclusion

Saffron is effective for patients with diabetes in terms of FPG and HbA1c, therefore, it appears to be a promising adjuvant for the glycemic control of DM. However, the overall methodological quality of the identified studies is heterogeneous, limiting the interpretation of the benefit of saffron in diabetes. More long-term follow-up, well-designed and large-scale clinical trials are warranted to draw definitive conclusions.

Systematic review registration

The protocol of review was registered in International Prospective Register of Systematic Reviews (PROSPERO) (ID: CRD42023426353).

Oral supplementation with crocin (a constituent of saffron) in subjects with cigarette smoking: a clinical trial

Smoking is one of the main causes of death in the world. Cigarette use is related with various components of metabolic syndrome (e.g., insulin resistance, raised blood pressure, dyslipidemia, oxidative stress, inflammation state) and psychiatric disorders. This study was conducted to determine the effect of crocin (Cro) supplementation on nicotine dependence, anxiety, depression, and metabolic indices in smokers. A total of 50 smokers were selected and randomly categorized into two groups (crocin and placebo). The intervention group received crocin (30 mg per day; n = 25) and placebo (containing Avicel; n = 25) once a day. The primary (nicotine dependence, depression, and anxiety inventory) and secondary (metabolic indices) outcomes were assessed at the start of the intervention and after the 3 months. Multiple linear regression models were used to assess the treatment effects on the outcomes adjusting for confounding variables. The primary outcome results such as nicotine dependence, depression, and anxiety inventory did not have a significant difference among the intervention groups (P > 0.05). Also in the secondary outcomes, fasting plasma glucose (FPG), insulin, and homeostasis model of assessment-insulin resistance (HOMA-IR) levels did indicate a significant difference by Cro intervention (β - 3.27 mg/dL; 95% CI, - 5.23, - 1.31; P = 0.002; β - 0.76 μIU/mL; 95% CI, - 1.38, - 0.15; P = 0.01; β - 0.18; 95% CI, - 0.29, - 0.07; P = 0.002), respectively. There were also significant reductions in serum levels of high-sensitivity C-reactive protein (hs-CRP) (β - 0.72 mg/L; 95% CI, - 1.37, - 0.07; P = 0.03), compared with the placebo. Cro intake may have favorable effects on the level of FPG, insulin, HOMA-IR, and hs-CRP in smokers. However, due to the small sample size and limited scientific reports on smokers, further studies are necessary. ClinicalTrial.gov Identifier: IRCT20170420033551N11.

Effect of crocin and treadmill exercise on oxidative stress and heart damage in diabetic rats

Diabetes increases the production of free radicals and inflammatory agents in the heart tissue and alters the expression of genes associated with the induction of apoptosis. Considering the importance of common cardiovascular disorders in diabetes, this study investigated the effect of eight weeks of aerobic exercise and crocin use, as well as tissue damage and oxidative stress caused by diabetes in the hearts of adult rats. Streptozotocin 50 mg/kg was injected as a single dose intraperitoneally to cause the diabetes. After 72 hours, a glucometer monitored blood glucose levels, and blood glucose above 250 mg/dl was considered diabetes. Continuous treadmill exercise was performed for eight weeks by placing the animal on the treadmill. Next, the animals were anesthetized, and samples were taken from the hearts and frozen in liquid nitrogen. Then, superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) were measured in the cardiac tissue. Finally, the hearts of half of the animals were immediately immersed in a formalin solution for histological changes. According to our findings, diabetes increased lipid peroxidation, characterized by increased MDA levels in the control diabetes group and decreased SOD and GPx levels (P <0.05). It also changes the balance of expression of genes associated with apoptosis control, increased Bcl-2-associated X (Bax) expression, and decreased Bcl-2 expression (P <0.05). Also, we observed the induction of apoptosis in cardiac tissue. Using eight weeks of continuous exercise and administration of crocin significantly reduced blood sugar levels and lipid peroxidation and increased the activity of antioxidant enzymes and Bcl-2 gene expression compared to the diabetes control group. In addition, continuous exercise and crocin improved the oxidative stress parameters in the control group. This study showed that diabetes could cause oxidative stress and heart dysfunction. Moreover, simultaneously and separately, aerobic exercise with a treadmill and crocin administration can reduce these disorders and prevent apoptosis in the heart tissue.

Identification of Crocetin as a Dual Agonist of GPR40 and GPR120 Responsible for the Antidiabetic Effect of Saffron

Crocin, a glycoside of crocetin, has been known as the principal component responsible for saffron's antidiabetic, anticancer, and anti-inflammatory effects. Crocetin, originating from the hydrolytic cleavage of crocin in biological systems, was subjected to ligand-based virtual screening in this investigation. Subsequent biochemical analysis unveiled crocetin, not crocin, as a novel dual GPR40 and GPR120 agonist, demonstrating a marked preference for GPR40 and GPR120 over peroxisome proliferator-activated receptors (PPAR)γ. This compound notably enhanced insulin and GLP-1 secretion from pancreatic β-cells and intestinal neuroendocrine cells, respectively, presenting a dual mechanism of action in glucose-lowering effects. Docking simulations showed that crocetin emulates the binding characteristics of natural ligands through hydrogen bonds and hydrophobic interactions, whereas crocin's hindered fit within the binding pocket is attributed to steric constraints. Collectively, for the first time, this study unveils crocetin as the true active component of saffron, functioning as a GPR40/120 agonist with potential implications in antidiabetic interventions.

Evaluation of Crocin Content and In Vitro Antioxidant and Anti-Glycation Activity of Different Saffron Extracts

Crocin, a glycoside carotenoid that exhibits several health benefits, is mainly obtained from saffron (Crocus sativus L.), whose quality and content of phytochemicals can be strongly affected by environmental conditions. Therefore, in this work, the crocin content and in vitro antioxidant activity of saffron extracts obtained from three different varieties (Greek, Sicilian, and Iranian saffron) were assessed. Crocin content in saffron extracts was quantified via ultra-performance liquid chromatography coupled with mass spectrometry. The antioxidant activity of saffron extracts was evaluated using the oxygen radical absorbance capacity (ORAC) assay and nitric oxide (NO) radical scavenging test. The Maillard reaction was used to assess anti-glycation activity. Although the Sicilian and Iranian saffron extracts contained higher amounts of crocin (128 ± 6 ng/mL and 126 ± 4 ng/mL, respectively) compared to the Greek extracts (111 ± 2 ng/mL), ORAC values (50.9 ± 0.5) and % NO inhibition (35.2 ± 0.2) were higher for the Greek variety, which displayed a total phenolic content about two-fold greater than that of the other two extracts. Sicilian and Greek saffron had similar anti-glycation activities, while Iranian saffron was less effective. These results suggest that the antioxidant activity of saffron extracts could be ascribed to their naturally occurring complex mixture of phytochemicals, deserving further investigation as supplements to prevent pathological conditions induced by radical species.

Antioxidant and anti-inflammatory potential of crocin on the doxorubicin mediated hepatotoxicity in Wistar rats

Doxorubicin (DXR) is widely used in cancer treatment. However, it has not yet been possible to prevent the side effects of DXR. The aim of this study was to investigate the hepatoprotective effect of crocin against DXR used in cancer treatment. For this reason; forty Wistar rats (male-250-300 g) were allocated into four groups (n = 10/group): Control, Crocin, DXR and DXR+Crocin. Control and Crocin groups were administered saline and crocin (40 mg/kg, i.p) for 15 days, respectively. DXR group, cumulative dose 12 mg/kg DXR, was administered for 12 days via 48 h intervals in six injections (2 mg/kg each, i.p). DXR+Crocin group, crocin (40 mg/kg-i.p) was administered for 15 days, and DXR was given as in the DXR group. The results revealed that serum liver markers (alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) increased significantly after DXR administration but recovered after crocin therapy. In addition, lipid peroxidation (MDA), and inflammatory cytokine (TNF-α) increased after DXR application and the antioxidative defense system (GSH, SOD, CAT) significantly decreased and re-achieved by crocin treatment. Our results conclude that crocin treatment was related to ameliorated hepatocellular architecture and reduced hepatic oxidative stress and inflammation in rats with DXR-induced hepatotoxicity.

Crocin improves the renal autophagy in rat experimental membranous nephropathy via regulating the SIRT1/Nrf2/HO-1 signaling pathway

Membranous nephropathy (MN) is a glomerular disease. Crocin is isolated from saffron and gardenia. Its antioxidant, anti-inflammatory, anti-hyperlipidemic, anti-atherosclerotic, anti-tumor, free-radical scavenging and neuroprotective activities have been well established. We investigated the biological functions of crocin and its related mechanisms in MN. We established an experimental passive Heymann nephritis (PHN) rat model induced by anti-Fx1A antiserum. The rats were divided into sham, sham + crocin, PHN, PHN + crocin, and PHN + enalapril groups. Blood samples and kidneys of rats were collected for estimation of biochemical parameters in serum and oxidative stress indicators in kidney tissues. Histopathological changes of renal tissues were evaluated by hematoxylin and eosin, periodic acid-Schiff (PAS) and Masson staining. The podocyte number was estimated by immunohistochemistry staining of Wilms tumor type 1 (WT1). The deposition of rat anti-rabbit IgG antibodies, complement C3 and C5b-9 was detected by immunofluorescence staining. Western blotting was performed to measure the levels of Sirtuin 1 (Sirt1), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1) and apoptosis-related proteins. The total cholesterol, triglycerides, creatinine, blood urea nitrogen, urine volume and urine albumin of PMN rats were significantly reduced by crocin. Additionally, crocin attenuated the renal histopathological changes. Moreover, the oxidative stress damage and podocyte loss and immune injury were relieved by crocin in PHN rats. Mechanistically, crocin administration activated the Sirt1/Nrf2/HO-1 pathways. The results provide a scientific basis that crocin could alleviate MN by inhibiting immune injury and podocyte damage through activating the Sirt1/Nrf2/HO-1 pathways.

Effects of Aqueous Saffron Extract on Glucoregulation as Well as Hepatic Agt and TNF-α Gene Expression in Rats Subjected to Sub-Chronic Stress

Background

Stress and saffron seem to affect glucoregulation mechanisms and insulin resistance in different ways. Impacts of the aqueous saffron extract were investigated on serum glucose levels, serum insulin levels, the homeostatic model assessment of β-cell function (HOMA-B), the homeostatic model assessment of insulin resistance (HOMA-IR), adrenal weight, and hepatic gene expression of angiotensinogen (Agt) and tumor necrosis factor-α (TNF-α) in rats under sub-chronic stress.

Materials and Methods

Forty-two male rats were divided into six groups: control, restraint stress (6h/day for seven days), saffron (30 and 60 mg/kg) treatments for seven days, and post-stress saffron (30 and 60 mg/kg) treatments for seven days. The serum glucose and insulin levels, hepatic gene expressions of Agt and TNF-α, HOMA-IR, HOMA-B, and adrenal gland weight were measured.

Results

One-week recovery following sub-chronic stress led to non-significant hyperglycemia, hyperinsulinemia, and insulin resistance. The hepatic Agt and TNF-α mRNA levels increased significantly in this group. Saffron administration led to enhanced hepatic Agt mRNA in the non-stressed subjects. In addition, serum glucose levels, insulin resistance, and hepatic Agt gene expression significantly increased in stress-saffron groups. The hepatic TNF-α gene expression was reduced only in the stress-saffron 60 group.

Conclusion

Saffron treatment after sub-chronic stress not only did not improve glucose tolerance but also enhanced insulin resistance. It indicated the interaction of saffron and sub-chronic stress to promote renin-angiotensin system activity. In addition, the saffron treatment decreased TNF-α gene expression after sub-chronic stress. The synergistic stimulating effect of saffron and sub-chronic stress on gene expression of hepatic Agt led to insulin resistance and hyperglycemia.

Inhibition of notch signalling and mesangial expansion by combined glucagon like peptide-1 agonist and crocin therapy in animal model of diabetic nephropathy

Diabetic nephropathy (DN) is one of the devastating complications in diabetes mellitus (DM). Glucagon-like peptide-1 (GLP-1) is one of the incretins secreted from L cells in the intestine. Crocin (a carotenoid component of saffron) has antioxidants properties. We investigated the renal effects of Exendin-4 as a GLP-1 agonist and Crocin in DN.Thirty male rats were divided into five groups: control, type II DM, type II DM + Exendin-4, type II DM + Crocin ‏ and type II DM + Exendine-4 + Crocin. At the end of the experimental period, systolic and diastolic blood pressures were measured, and GFR was calculated. Blood and urine samples were collected for biochemical analysis. Tissue samples were collected from the kidney for histological examination and biochemical measurements of protein expression.Treatment with GLP-1 agonist or Crocin caused a significant improvement in renal function. Better results were achieved with simultaneous administration of both drugs with inhibition of notch signalling pathway and the related proteins.

Effect of crocin and losartan on biochemical parameters and genes expression of FRMD3 and BMP7 in diabetic rats

BACKGROUND

Diabetes is a multifactorial and growing disease, one of the severe complications of which is diabetic nephropathy (DN), which is the most common cause of chronic renal failure. FERM domain containing 3 (FRMD3) is responsible for maintaining the shape and integrity of nephron cells, and bone morphogenetic protein 7 (BMP7) helps maintain function and reduce kidney damage. This study aimed to evaluate the effect of crocin and losartan on biochemical parameters and the expression of FRMD3 and BMP7 genes in streptozotocin (STZ)-induced diabetic rats.

METHODS

Forty male Wistar rats were randomly divided into five experimental groups as healthy, diabetic control (D), crocin, losartan, and diabetic rats treated with losartan-crocin (n = 8). A single dose of STZ (50 mg/kg intraperitoneally injection) was used to induce diabetes. Four weeks after induction of diabetes, rats received crocin (50 mg/kg) and losartan (25 mg/kg) daily for four weeks orally. Rats were sacrificed at the end of the intervention, and blood samples were taken to determine serum levels of glucose, urea, creatinine (Cr), malondialdehyde (MDA), and thiol. Real-time polymerase chain reaction (PCR) was used to assess the expression of the FRMD3 and BMP7 genes in the kidney samples.

RESULTS

Diabetes induction increased serum levels of glucose, Cr, urea, MDA, and thiol, but decreased BMP7 and FRMD3 genes expression. Treatment with crocin and losartan decreased these biochemical parameters and increased the expression of the BMP7 and FRMD3 genes.

DISCUSSION

Crocin may be a promising therapeutic agent for preventing and improving diabetes-related kidney disease due to its antidiabetic and antioxidant properties.

The effect of saffron (Crocus sativus L.) on glycemia, lipid profile, and antioxidant status in patients with type-2 diabetes mellitus: A randomized placebo-controlled trial

In the current study, we aimed to investigate the effect of saffron supplementation on glycemic status, lipid profile, atherogenic indices, and oxidative status in patients with type-2 diabetes (T2DM). In a randomized, double-blind controlled trial, 70 patients were randomly allocated into two groups (n = 35, each) and received 100 mg/day of saffron or placebo for eight weeks. Dietary intake, weight, body mass index (BMI), waist and hip circumferences (WC and HC), waist to hip ratio (WHR), fasting blood sugar (FBS), hemoglobin A1c (HbA1c), insulin, and Homeostatic model assessment for insulin resistance (HOMA-IR), lipid profile, atherogenic indices, oxidative status, and liver enzymes were determined before and after the intervention. At the end of the eighth week, saffron intervention could significantly reduce FBS (7.57%), lipid profile (except high-density lipoprotein cholesterol [HDL-C]), atherogenic indices, and liver enzymes (p < .05). Moreover, saffron could improve oxidative status (nitric oxide [NO] and malondialdehyde [MDA] reduced by 26.29% and 16.35%, respectively). Catalase (CAT) concentration remained unchanged. Saffron supplementation may alleviate T2DM by improving glycemic status, lipid profile, liver enzymes, and oxidative status. Further investigation is necessary to assess possible side effects and confirm the positive effect of saffron as a complementary therapy in clinical recommendations for T2DM.

Isorhamnetin Reduces Glucose Level, Inflammation, and Oxidative Stress in High-Fat Diet/Streptozotocin Diabetic Mice Model

Background: Isorhamnetin is a flavonoid that is found in medical plants. Several studies showed that isorhamnetin has anti-inflammatory and anti-obesity effects. This study aims to investigate the anti-diabetic effects of isorhamnetin in a high-fat diet and Streptozotocin-(HFD/STZ)-induced mice model of type 2 diabetes. Materials and Methods: Mice were fed with HFD followed by two consecutive low doses of STZ (40 mg/kg). HFD/STZ diabetic mice were treated orally with isorhamnetin (10 mg/kg) or (200 mg/kg) metformin for 10 days before sacrificing the mice and collecting plasma and soleus muscle for further analysis. Results: Isorhamnetin reduced the elevated levels of serum glucose compared to the vehicle control group (p < 0.001). Isorhamnetin abrogated the increase in serum insulin in the treated diabetic group compared to the vehicle control mice (p < 0.001). The homeostasis model assessment of insulin resistance (HOMA-IR) was decreased in diabetic mice treated with isorhamnetin compared to the vehicle controls. Fasting glucose level was significantly lower in diabetic mice treated with isorhamnetin during the intraperitoneal glucose tolerance test (IPGTT) (p < 0.001). The skeletal muscle protein contents of GLUT4 and p-AMPK-α were upregulated following treatment with isorhamnetin (p > 0.01). LDL, triglyceride, and cholesterol were reduced in diabetic mice treated with isorhamnetin compared to vehicle control (p < 0.001). Isorhamnetin reduced MDA, and IL-6 levels (p < 0.001), increased GSH levels (p < 0.001), and reduced GSSG levels (p < 0.05) in diabetic mice compared to vehicle control. Conclusions: Isorhamnetin ameliorates insulin resistance, oxidative stress, and inflammation. Isorhamnetin could represent a promising therapeutic agent to treat T2D.

The landscape of potential health benefits of carotenoids as natural supportive therapeutics in protecting against Coronavirus infection

The Coronavirus Disease-2019 (COVID-19) pandemic urges researching possibilities for prevention and management of the effects of the virus. Carotenoids are natural phytochemicals of anti-oxidant, anti-inflammatory and immunomodulatory properties and may exert potential in aiding in combatting the pandemic. This review presents the direct and indirect evidence of the health benefits of carotenoids and derivatives based on in vitro and in vivo studies, human clinical trials and epidemiological studies and proposes possible mechanisms of action via which carotenoids may have the capacity to protect against COVID-19 effects. The current evidence provides a rationale for considering carotenoids as natural supportive nutrients via antioxidant activities, including scavenging lipid-soluble radicals, reducing hypoxia-associated superoxide by activating antioxidant enzymes, or suppressing enzymes that produce reactive oxygen species (ROS). Carotenoids may regulate COVID-19 induced over-production of pro-inflammatory cytokines, chemokines, pro-inflammatory enzymes and adhesion molecules by nuclear factor kappa B (NF-κB), renin-angiotensin-aldosterone system (RAS) and interleukins-6- Janus kinase-signal transducer and activator of transcription (IL-6-JAK/STAT) pathways and suppress the polarization of pro-inflammatory M1 macrophage. Moreover, carotenoids may modulate the peroxisome proliferator-activated receptors γ by acting as agonists to alleviate COVID-19 symptoms. They also may potentially block the cellular receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), human angiotensin-converting enzyme 2 (ACE2). These activities may reduce the severity of COVID-19 and flu-like diseases. Thus, carotenoid supplementation may aid in combatting the pandemic, as well as seasonal flu. However, further in vitro, in vivo and in particular long-term clinical trials in COVID-19 patients are needed to evaluate this hypothesis.

A review of the anti-diabetic potential of saffron

Diabetes mellitus is one of the most prevalent metabolic disorders that affect people of all genders, ages, and races. Medicinal herbs have gained attention from researchers and have been widely investigated for their antidiabetic potential. Saffron (Crocus sativus L.) and its main constituents, that is, crocin and crocetin, are natural carotenoid compounds, widely known to possess a wide spectrum of properties and induce pleiotropic anti-inflammatory, anti-oxidative, and neuro-protective effects. An increasing number of experimental, animal and human studies have investigated the effects and mechanism of action of these compounds and their potential therapeutic use in the treatment of diabetes. This narrative review presents the key findings of published clinical studies that examined the effects of saffron and/or its constituents in the context of diabetes mellitus. Moreover, an overview of the proposed underlying mechanisms mediating these effects, the medicinal applications of saffron, and the new findings regarding its effect on diabetes and various cellular and molecular mechanisms of action will be debated.

Mechanistic insights on the effect of crocin, an active ingredient of saffron, on atherosclerosis in apolipoprotein E knockout mice

BACKGROUND

We investigated the effect of crocin treatment on atherosclerosis and serum lipids in apolipoprotein E knockout (ApoE-/-) mice, focusing on the expression of endothelial nitric oxide synthase (eNOS) and hypoxia-induced factor-1 alpha (HIF-1α).

METHODS

Sixty-two animals were divided into two groups and randomly allocated to crocin (100 mg/kg/day) in drinking water or no crocin. All mice were maintained on standard chow diet containing 5% fat. Crocin was initiated at the 16th week of age and continued for 16 additional weeks. At 32 weeks of age, after blood sampling for plasma lipid determination and euthanasia, proximal aorta was removed and 3 μm sections were used to measure the atherosclerotic area and determine the expression of eNOS and HIF-1α by immunohistochemistry.

RESULTS

Each group consisted of 31 animals (17 males and 14 females in each group). Crocin significantly reduced the atherosclerotic area (mm2 ± SEM) in treated mice compared to controls, both in males (0.0798 ± 0.017 vs. 0.1918 ± 0.028, P < 0.002, respectively) and females (0.0986 ± 0.023 vs. 0.1765 ± 0.025, P < 0.03, respectively). eNOS expression was significantly increased in crocin-treated mice compared to controls, both in males (2.77 ± 0.24 vs. 1.50 ± 0.34, P=0.004, respectively) and females (3.41 ± 0.37 vs. 1.16 ± 0.44, P=0.003, respectively). HIF-1α expression was significantly decreased in crocin-treated mice compared to controls, both in males (21.25 ± 2.14 vs. 156.5 ± 6.67, P < 0.001, respectively) and females (35.3 ± 7.20 vs. 113.3 ± 9.0, P < 0.01, respectively). No difference was noticed in total, low- and high-density lipoprotein cholesterol between treated and control mice.

CONCLUSION

Crocin reduces atherosclerosis possibly by modulation of eNOS and HIF-1α expression in ApoE-/- mice without affecting plasma cholesterol.

The effect of saffron supplementation on glycemic parameters: An overview of systematic reviews

Due to the widespread use of herbal medicine and evidence pointing to the health benefits of saffron supplementation, this review was performed to evaluate the effects of saffron supplementation on glycemic parameters and lipid profiles based on previous reviews. Relevant articles were retrieved from various databases, which included PubMed, Scopus, ProQuest, Web of Science, Embase, and Cochrane until 2020, with no date restrictions. The quality of the included reviews was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) checklist. Finally, of 877 obtained articles, eight reviews meeting the inclusion criteria were included for analysis. Among the eight included reviews, seven articles were meta-analyses. In addition, one review had an average quality while seven had a good quality. A narrative description of the included reviews was performed, while a network meta-analysis was not conducted. A brief review of the results was reported according to the weighted mean difference and mean difference. Seven included reviews assessed the effects of saffron or crocin supplementation on glycemic parameters, and six examined these effects on lipid profile parameters. Almost half of the articles reported significant effects of these supplements on glycemic parameters and lipid profiles. Taken together, results suggest that saffron supplementation may improve glycemic and lipid profile parameters; however, further high-quality studies are needed to confirm the clinical efficacy of saffron on glycemic parameters and lipid profiles.

Metabolic impact of saffron and crocin: an updated systematic and meta-analysis of randomised clinical trials

The present systematic and meta-analysis study was designed to show the protective impact of saffron and crocin supplementation on hyperlipidaemia and hyperglycaemia in randomised and clinical trials (RCTs). A pooled analysis using a model for random-effects showed that HDL-C levels were 0.21 fold higher in the saffron and 0.01 fold higher in the crocin group than placebo. LDL-C levels in the saffron group reduced by 0.51 and 0.04 fold in the crocin group versus the placebo. Moreover, TC levels in the saffron group were 0.19 lower and 0.11 fold lower in crocin group than in the placebo group. TG level in saffron group was 0.04 lower and 0.02 fold lower in crocin than the control group. The blood glucose levels did not significantly differ from the control group. This study suggests that saffron and crocin may modulate the serum lipid profile in patient with metabolic disorders.

Hypoglycemic and hepatoprotective effects in adult zebrafish (Danio rerio) of fisetinidol isolated from Bauhinia pentandra: In vivo and in silico assays

Diabetes mellitus is a chronic metabolic disorder that has been increasing drastically around the worldwide. It is important to emphasize that although many drugs are commercially available to treat diabetes, many of them have shown a number of adverse effects. Therefore, search for new antidiabetic agents is of great interest, and natural products, especially those obtained from plants sources, may be an alternative to available drugs. This study reports the in vivo and in silico evaluation of the hypoglycemic activity of fisetinidol. The conformational analysis confirmed that the fisetinidol compound possesses two valleys in the potential energy curve, showing a stable conformer on the global minimum of the PES defined by the dihedral angle θ (C6-C7-O-H) at 179.9°, whose energy is equal to zero. In addition, fisetinidol has shown promise in glycemic control and oxidative stress caused by hyperglycemia induced by high sucrose concentration, causing hypoglycemic and hepatoprotective effects in adult zebrafish. ADMET studies showed that fisetinidol has high passive permeability, low clearance and low toxic risk by ingestion, and computational studies demonstrated that fisetinidol complexes in the same region as metformin and α-acarbose, which constitutes a strong indication that fisetinidol has the same inhibitory mechanisms of α-acarbose and metformin.Communicated by Ramaswamy H. Sarma.

Animal models of diabetic microvascular complications: Relevance to clinical features

Diabetes has become more common in recent years worldwide, and this growth is projected to continue in the future. The primary concern with diabetes is developing various complications, which significantly contribute to the disease's mortality and morbidity. Over time, the condition progresses from the pre-diabetic to the diabetic stage and then to the development of complications. Years and enormous resources are required to evaluate pharmacological interventions to prevent or delay the progression of disease or complications in humans. Appropriate screening models are required to gain a better understanding of both pathogenesis and potential therapeutic agents. Different species of animals are used to evaluate the pharmacological potentials and study the pathogenesis of the disease. Animal models are essential for research because they represent most of the structural, functional, and biochemical characteristics of human diseases. An ideal screening model should mimic the pathogenesis of the disease with identifiable characteristics. A thorough understanding of animal models is required for the experimental design to select an appropriate model. Each animal model has certain advantages and limitations. The present manuscript describes the animal models and their diagnostic characteristics to evaluate microvascular diabetic complications.

Therapeutic role of Azadirachta indica leaves ethanolic extract against diabetic nephropathy in rats neonatally induced by streptozotocin

Diabetic nephropathy (DN) is manifested by chronic loss of renal function due to damage of glomeruli and renal tubules. Therefore, this study is mainly designed to evaluate the therapeutic role of Azadiracta indica (neem) leaves extract as a novel approach for treatment of DN in rats neonatally induced by streptozotocin (STZ). For this study, 40 offspring were selected after parturition and categorized into four groups (n = 10). Group1: control group, group 2: neem leaves extract supplemented group, group 3: diabetic group that injected with a single dose of STZ and group 4: diabetic group treated with neem extract. The results revealed deleterious histological and ultrstructural changes in the renal tissues of diabetic rats. Such changes included atrophied glomeruli, dilated renal cortical tubules and scattered hemorrhage spots, thickening of glomerular basement membrane, expansion of mesangial matrix and pyknotic podocyte. Additionally, the proximal convoluted tubule and distal tubule showed cytoplasmic vacuolation, vacuolated mitochondria, scattered lipid droplets, lost microvilli and disrupted basal lamina and basal infoldings. Moreover, significant decreased levels of serum antioxidants (SOD&CAT) and significant increased levels of serum MDA, urea and creatinine were noticed in diabetic rats. Neem leaves extract successfully alleviated the histological and ultrastructural as well as biochemical changes induced by diabetes.

The cardiovascular-protective properties of saffron and its potential pharmaceutical applications: A critical appraisal of the literature

Saffron, the dried stigma of Crocus sativus L., is used in traditional medicine for its healing properties and the treatment of various pathological conditions. The present literature review aimed to summarize and evaluate the preclinical and clinical data regarding the protective effects and mechanisms of saffron and its main components (crocin, crocetin, safranal) on cardiovascular risk factors and diseases. Many in vitro and animal studies have been conducted implicating antioxidant, hypolipidemic, anti-diabetic, and antiinflammatory impact of saffron and its constituents. Notably, there is evidence of direct atherosclerosis regression and stabilization in valid atherosclerosis-prone animal models. However, current clinical trials have shown mostly weak effects of saffron and its constituents on cardiovascular risk factors: (a) Modest lowering of fasting blood glucose, without significant reduction of HbA1c in type 2 diabetic patients, (b) moderate/controversial hypolipidemic effects, (c) negligible hypotensive effect, and (d) inconsistent modification of metabolic syndrome parameters. There are important drawbacks in clinical trial design, including the absence of pharmacokinetic/pharmacodynamic tests, the wide variance of doses and cohorts' characteristics, the small number of patients, the short duration. Therefore, large, properly designed, high-quality clinical trials, focusing on specific conditions are required to evaluate the biological/pharmacological activities and firmly establish the clinical efficacy of saffron and its possible therapeutic uses in cardiovascular diseases.

Saffron improves life and sleep quality, glycaemic status, lipid profile and liver function in diabetic patients: A double-blind, placebo-controlled, randomised clinical trial

BACKGROUND

Type 2 diabetes (T2D) is a metabolic disorder that is related to hyperglycaemia, hyperlipidaemia and liver dysfunction and has detrimental effects on a patient's mental health. Hence, the current study investigated the effects of saffron supplementation on dietary intake, anthropometric measures, mood, sleep quality and metabolic biomarkers in overweight/obese patients with T2D.

METHODS

In a double-blind, randomised controlled trial, 70 overweight/obese patients with T2D were randomly allocated to two groups and received 100 mg/day saffron or placebo for 8 weeks. Participants completed the Beck depression inventory-II (BDI-II), Hurlbert index of sexual desire (HISD), Pittsburgh Sleep Quality Index (PSQI) and Diabetes-specific Quality-of-Life Brief Clinical Inventory questionnaires (DQOL-BCI). Dietary intake, anthropometric measures, fasting plasma glucose (FPG), haemoglobin A1C (HbA1C), insulin, lipid profile and liver enzymes were determined at baseline and the end of the study.

RESULTS

At the end of the eighth week, saffron supplementation significantly decreased FPG, triglyceride (TG), insulin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (P < .001). Moreover, significant improvements in BDI-II scores and total quality of life were observed in the intervention group (P < .001). The saffron group showed more significant improvements in PSQI scores than the placebo group, such that at the post-intervention analysis, only the saffron group achieved a "good" sleep band. At this relatively high dose, saffron supplementation improved glycaemic status, lipid profile and liver enzyme measures in patients with T2D while also improving sleep and overall quality of life.

CONCLUSION

Our results indicate that saffron notably reduced hyperglycaemia and hyperlipidaemia and improved liver function in patients with T2D in an 8-week randomised clinical trial. Saffron also significantly improved depression, sleep quality and overall quality of life in diabetic patients. However, further investigation is necessary to confirm whether saffron is an effective complementary therapy for T2D.

Therapeutic potential of active components of saffron in post-surgical adhesion band formation

BACKGROUND

Abdominal adhesions are common and often develop after abdominal surgery. There are currently no useful targeted pharmacotherapies for adhesive disease. Saffron and its active constituents, Crocin and Crocetin, are wildly used in traditional medicine for alleviating the severity of inflammatory or malignant disease.

PURPOSE

The aim of this study was to investigate the therapeutic potential of the pharmacological active component of saffron in attenuating the formation of post-operative adhesion bands using different administration methods in a murine model.

MATERIAL METHOD

saffron extract (100 mg/kg), Crocin (100 mg/kg), and Crocetin (100 mg/kg) were administered intraperitoneally and by gavage in various groups of male Wistar rat post-surgery. Also three groups were first treated intra-peritoneally by saffron extract, Crocin, and Crocetin (100 mg/kg) for 10 days and then had surgery. At the end of the experiments, animals sacrificed for biological assessment.

RESULT

A hydro-alcoholic extract of saffron and crocin but not crocetin potently reduced the adhesion band frequency in treatment and pre-treatment groups in the mice given intra-peritoneal (i.p) injections. Following the saffron or crocin administration, histological evaluation and quantitative analysis represented less inflammatory cell infiltration and less collagen composition, compared to control group. Moreover, the oxidative stress was significantly reduced in treatment groups.

CONCLUSION

These findings suggest that a hydro-alcoholic extract of saffron or its active compound, crocin, is a potentially novel therapeutic strategy for the prevention of adhesions formation and might be used as beneficial anti-inflammatory or anti-fibrosis agents in clinical trials.

TAXONOMY

Abdominal surgeries/post-surgical adhesions.

Protective Effects of Crocin Against Hepatic Damages in D-galactose Aging Model in Rats

Aging is a progressive process which is associated with liver dysfunction and it is due to oxidative stress, inflammation, and cell apoptosis. Long-term D-galactose (D-gal) administration is able to develop an aging model in animals. Crocin as a major active ingredient in saffron has shown anti-inflammatory and hepatoprotective effects via its antioxidant capacity. Thus, the aim of the present study was the assessment of crocin effects on hepatic and metabolic disorders induced by D-gal in rats. Aging model was induced in rats by 56-day administration of D-gal (400 mg/kg/day subcutaneously). Protective effects of different doses of crocin (7.5, 15 and 30 mg/kg/day) in concomitant with D-gal administration were evaluated. Malondialdehyde (MDA) and reduced glutathione (GSH) amounts were measured by means of their reaction, respectively, with thiobarbituric acid and 5,5'-Dithiobis (2-nitrobenzoic acid) (DTNB) under a specific condition. Cyclooxygenase-2 (COX-2), β-galactosidase, induced nitric oxide synthase (iNOS), and carboxymethyllysine (CML) levels were determined by western blotting method. Additionally, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were measured in serum. D-gal administration significantly elevated ALT, AST, ALP levels, which were markedly inhibited by crocin administration. Crocin suppressed the overgeneration of lipid peroxidation products such as MDA. iNOS was elevated by D-gal administration and was returned to the normal extent by crocin. Therefore, Crocin as a powerful antioxidant and radical scavenger, totally exhibited hepatoprotective effects against D-gal-induced toxicity in rats.

Crocin attenuates oxidative stress and inflammation in myocardial infarction induced by isoprenaline via PPARγ activation in diabetic rats

Background and purpose

Hyperglycemia induced oxidative stress and inflammation lead to development of diabetic cardiomyopathy. Diabetic patients are more at risk for myocardial infarction than non-diabetics. The current study has investigated the involvement of PPARγ activation in effects of crocin as a natural carotenoid against cardiac infarction in diabetic rats.

Materials and methods

Diabetes was induced in male Wistar rats by streptozotocin injection (55 mg/kg, i.p) 15 min after the administration of nicotinamide (110 mg/kg). Then saline, crocin (40 mg/kg, orally) and GW9662 (1 mg/kg, as PPARγ antagonist) were injected for 4 weeks. Isoprenaline was administrated on the 27th and 28th days to induce infarction. Cardiac injury markers, antioxidant enzymes content, blood glucose level, lipid profile, pro and anti-inflammatory cytokines, and PPARγ gene expression were measured.

Results

GSH, CAT content, CK-MB isoenzyme, LDH level, IL-10 and PPARγ gene expression in myocardial tissue were decreased in diabetic rats receiving isoprenaline and inflammatory cytokines TNFα and IL-6 and also plasma lipids were increased. Crocin administration significantly ameliorated inflammatory cytokines levels, CK-MB, and LDH contents and also it could enhance antioxidant capacity and PPARγ expression. However, GW9662 administration reversed the effects of crocin.

Conclusion

Overexpression of PPARγ in crocin treated rats and inhibition of crocin effects by GW9662 reflected the potential involvement of PPARγ pathway in the protective effects of crocin.

Graphical abstract

The Combination Effect of Voluntary Exercise and Crocin on Angiogenic miRNAs in High-Fat Diet/Low-Dose STZ-Induced Type2 Diabetes in Rats: miR-126 and miR-210

Background: As one of the major complications of diabetes, cardiovascular disease might result in early death in people with diabetes. miR-126 and 210 expressions undergo alterations in cardiac disease and cause heart failure. Methods: Animals were divided into the 5 groups of control (Con), diabetes (Dia), diabeticcrocin (Dia-Cro), diabetic-voluntary exercise (Dia-Exe), and diabetic-crocin-voluntary exercise (Dia-Cro-Exe). Type 2 diabetes was induced by the use of a high-fat diet (4 weeks) and injection of streptozotocin (STZ) (i.p, 35 mg/kg). Animals received crocin orally (50 mg/kg), and voluntary exercise was performed alone or together for 8 weeks. QRT–PCR method was used to determine the levels of miR-210 and miR-126 in cardiac tissue. Results: The levels of miR-210 and miR-126 in the cardiac tissue augmented in both the crocin and voluntary exercise groups in comparison with the non-treated group (p<0.001). The use of combination therapy with exercise and crocin magnified their effects on miR-210 and miR-126 levels (p<0.001). Moreover, MiR-210 levels were lower in the crocin group compared to the exercise group (p<0.001). Conclusion: The results indicated that voluntary exercise combined with crocin might provide a novel therapeutic plan for cardiovascular disease through increasing miR-210 and miR-126 expression.

Crocins from Crocus sativus L. in the Management of Hyperglycemia. In Vivo Evidence from Zebrafish

Diabetes mellitus is a disease characterized by persistent high blood glucose levels and accompanied by impaired metabolic pathways. In this study, we used zebrafish to investigate the effect of crocins isolated from Crocus sativus L., on the control of glucose levels and pancreatic β-cells. Embryos were exposed to an aqueous solution of crocins and whole embryo glucose levels were measured at 48 h post-treatment. We showed that the application of crocins reduces zebrafish embryo glucose levels and enhances insulin expression. We also examined whether crocins are implicated in the metabolic pathway of gluconeogenesis. We showed that following a single application of crocins and glucose level reduction, the expression of phosphoenolpyruvate carboxykinase1 (pck1), a key gene involved in glucose metabolism, is increased. We propose a putative role for the crocins in glucose metabolism and insulin management.

The effect of crocin supplementation on lipid concentrations and fasting blood glucose: A systematic review and meta-analysis and meta-regression of randomized controlled trials

OBJECTIVE

This meta-analysis aimed to assess the effects of crocin supplementation on fasting blood glucose (FBG) and lipid profile levels in clinical trial studies.

DESIGN

A systematic literature search was performed in PubMed, Scopus, Embase, Web of Science, and the Cochrane Library databases for clinical trials published from the beginning up to November 2019. Of the 547 papers identified from all searched databases, eight eligible studies with nine effect sizes have all needed criteria for inclusion in this meta-analysis.

RESULTS

Results of the pooled random-effect size analysis showed just a significant decreasing effect of crocin supplementation on FBG (WMD: -6.52 mg/l, 95 % CI, -11.96, -1.08; p = 0.019) and TC (WMD: -4.64 mg/l, 95 % CI, -8.19, -1.09; p = 0.010). Crocin supplements did not have any significant effect on serum TG (p = 0.144) levels, LDL-C (p = 0.161), and HDL-C (p = 0.872) levels. Results showed that crocin supplementation could beneficially have effect on TG level only when trial duration less than 12 weeks and LDL-C levels in trials that used high dose intervention and trials that conducted on subjects with metabolic disorders. However, crocin supplementation did not significantly change FBG in trials that used low dose intervention. Meta-regression analysis indicated a linear relationship between the duration of intervention and significant change in FBG (p = 0.019).

CONCLUSION

Results of this systematic review and meta-analysis study have shown that crocin supplementation can decrease significantly FBS and TC without any beneficial effects on TG, LDL-C, and HDL-C levels.

The effect of crocin supplementation on glycemic control, insulin resistance and active AMPK levels in patients with type 2 diabetes: a pilot study

BACKGROUND

Crocin as a carotenoid exerts anti-oxidant, anti-inflammatory, anti-cancer, neuroprotective and cardioprotective effects. Besides, the increasing prevalence of diabetes mellitus and its allied complications, and also patients' desire to use natural products for treating their diseases, led to the design of this study to evaluate the efficacy of crocin on glycemic control, insulin resistance and active adenosine monophosphate-activated protein kinase (AMPK) levels in patients with type-2 diabetes (T2D).

METHODS

In this clinical trial with a parallel-group design, 50 patients with T2D received either 15-mg crocin or placebo, twice daily, for 12 weeks. Anthropometric measurements, dietary intake, physical activity, blood pressure, glucose homeostasis parameters, active form of AMPK were assessed at the beginning and at the end of the study.

RESULTS

Compared with the placebo group, crocin improved fasting glucose level (P = 0.015), hemoglobin A1c (P = 0.045), plasma insulin level (P = 0.046), insulin resistance (P = 0.001), and insulin sensitivity (P = 0.001). Based on the within group analysis, crocin led to significant improvement in plasma levels of glucose, insulin, hemoglobin A1c, systolic blood pressure, insulin resistance and insulin sensitivity. The active form of AMPK did not change within and between groups after intervention.

CONCLUSIONS

The findings indicate that crocin supplementation can improve glycemic control and insulin resistance in patients with T2D. Further studies are needed to confirm these findings.Trial Registration This study has been registered at Clinicaltrial.gov with registration number NCT04163757.

Impact of Crocus Sativus L. on Metabolic Profile in Patients with Diabetes Mellitus or Metabolic Syndrome: A Systematic Review

Background: Experimental studies demonstrated a positive effect of administration of Crocus sativus L. (saffron) and its bioactive ingredients on metabolic profile through their antioxidant capacity. Purpose: To determine if the use of saffron in humans is beneficial to patients with diabetes mellitus (DM) or metabolic syndrome (MS). Methods: This systematic review includes 14 randomized control trials that investigated the impact of saffron administration and its bioactive ingredient crocin on the metabolic profile of patients with DM, MS, prediabetes, and coronary artery disease. We documented the following clinical outcomes: fasting blood glucose (FBG), glycated haemoglobin (HbA1c), total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, systolic, and diastolic blood pressure. Results: Eight studies examined the efficacy of saffron in patients with DM, four with the metabolic syndrome, one with prediabetes and one with coronary artery disease. A favorable effect on FBG was observed. The results regarding blood lipids and blood pressure were inconclusive in the current review. Conclusions: According to the available limited evidence, saffron may have a favorable effect on FBG. Many of the studies in the reviewed literature are of poor quality, and more research is needed in this direction to confirm and establish the above findings.

The Hypoglycemic and Renal Protection Properties of Crocin via Oxidative Stress-Regulated NF-κB Signaling in db/db Mice

Background

As the main ingredient of Crocus sativus L. (Iridaceae) extract, crocin- I (CR) has been reported to show various pharmacological activities. The aim of this study was to investigate the hypoglycemic and renal protection properties of CR in db/db mice.

Methods

Eight-week-old db/db mice were treated with metformin (Met) (100 mg/kg) and CR (50 mg/kg) for eight weeks.

Results

CR treatment showed hypoglycemic functions indicated by reduced bodyweight, food and water intake, plasma glucose, and serum levels of glycated hemoglobin A1c. Additionally, the CR group showed increased serum levels of insulin and pyruvate kinase, hypolipidemic functions indicated by the suppressed levels of total cholesterol and triglyceride, and enhanced levels of high-density lipoprotein cholesterol, which are also indicators of hypoglycemic functions. The renal protection function of CR was demonstrated by its protection of renal structures and its regulation of potential indicators of nephropathy. The anti-oxidation and anti-inflammation effects of CR were verified by enzyme-linked immunosorbent assay. In the kidneys of db/db mice, CR decreased the expression of phospho-IκBα and phospho-nuclear factor-κB (NF-κB), whereas it enhanced the expression of nuclear respiratory factor 2, manganese superoxide dismutase 1, heme oxygenase-1, and catalase.

Conclusions

The anti-diabetic and anti-diabetic nephritic effects of CR were related to its modulation of oxidative stress-mediated NF-κB signaling.

Possible Antidiabetic and Antioxidative Activity of Hydro-Methanolic Extract of Musa balbisiana (Colla) Flower in Streptozotocin-Induced Diabetic Male Albino Wistar Strain Rat: A Genomic Approach

The aim of the investigation was to search out the possible corrective effect of hydro-methanolic extract:: 3:2 of Musa balbisiana flower on streptozotocin (STZ)-induced diabetic male rat. In this concern, glycemic profile, oxidative stress profile, lipid profile, and toxicity profile were studied where a genomic approach has been taken to explain the mechanism of action of the said extract for such recovery. Such enzyme kinetics domain and genomic domain of concerned profile were not covered till now to explore the mechanism of diabetes management by this plant part. As hexokinase is one of the important enzymes of glycolysis and glycogenesis, and GLUT-4 an important transporter of glucose in skeletal muscle, liver and adipose tissue these genes have been selected here. For focusing the status of apoptosis in hepatic tissue, an important organ for carbohydrate metabolism, Bax and Bcl-2 gene expression were included, which are the novelty of this study. The hydro-methanolic extract was administered orally at the dose of 10 mg/100 g body weight for 28 days to diabetic rats. Abovementioned extract exhibited a significant recovery in parameters like fasting blood glucose; serum insulin; glycated hemoglobin; antioxidative enzymes in hepatic and renal tissue; and carbohydrate metabolic enzymes in hepatic and skeleto-muscular tissue along with proappoptotic gene Bax and antiappoptotic gene Bcl-2, glycemic genes like Hex-I, and GLUT-4 in hepatic tissue of STZ-induced diabetic rat. This investigation demonstrated the potentiality of hydro-methanolic extract (3:2) of M. balbisiana flower for correction of diabetes and diabetes-induced oxidative stress.

Crocin prevents metabolic syndrome in rats via enhancing PPAR-gamma and AMPK

Metabolic syndrome (Mets) is a major health hazard. The syndrome is strongly linked to cardiovascular disease. The objective of the current study was to address whether or not crocin could protect against experimentally-induced MetS in rats as well as the possible underlying mechanisms. Animals were allocated into 4 groups. The first one served as control and was kept on regular food pellets and drinking water. The other three groups were subjected to experimental MetS. Induction of MetS was achieved by keeping rats on food pellets containing 3% NaCl; and drinking water enriched with 10% fructose. The first and second groups were daily gavaged with saline. The third and fourth groups were daily administered crocin 5 and 10 mg/kg, respectively. The treatment continued for 12 consecutive weeks. Crocin significantly reduced body weight gain and adiposity index as compared to MetS group. Also, crocin protected against the occurrence of hyperglycemia and insulin resistance as indicated by controlled values of HOMA-IR. Crocin protected against MetS-induced dyslipidemia as well as the rise blood pressure. These beneficial effects were accompanied by enhanced serum levels of PPARγ & AMPK and inhibited serum levels of IL-6 and TNF-α. In conclusion, crocin protects against experimentally-induced MetS. This can be attributed, at least partly, to activation of PPARγ and AMPK as well as inhibiting inflammation.

Lansoprazole enhances the antidiabetic effect of dapagliflozin in fortified diet-fed streptozotocin-treated diabetic rats

Dapagliflozin (DAPA) is used for treating type 2 diabetes, whereas lansoprazole (LPZ) is used as a traditional antiulcer drug. The present study investigated the possible antidiabetic effects of LPZ on fortified diet-fed streptozotocin (FDF/STZ)-induced insulin-resistant diabetic rats. On the basis of the current results, it can be concluded that LPZ could be used as an add-on drug along with the conventional treatment for T2D as it showed beneficial effects in the current experimental model of insulin resistance.

Animal Models of Diabetes-Associated Renal Injury

Diabetic nephropathy (DN) is the main factor leading to end-stage renal disease (ESRD) and subsequent morbidity and mortality. Importantly, the prevalence of DN is continuously increasing in developed countries. Many rodent models of type 1 and type 2 diabetes have been established to elucidate the pathogenesis of diabetes and examine novel therapies against DN. These models are developed by chemical, surgical, genetic, drug, and diet/nutrition interventions or combination of two or more methods. The main characteristics of DN including a decrease in renal function, albuminuria and mesangiolysis, mesangial expansion, and nodular glomerulosclerosis should be exhibited by an animal model of DN. However, a rodent model possessing all of the abovementioned features of human DN has not yet been developed. Furthermore, mice of different genetic backgrounds and strains show different levels of susceptibility to DN with respect to albuminuria and development of glomerular and tubulointerstitial lesions. Therefore, the type of diabetes, development of nephropathy, duration of the study, cost of maintaining and breeding, and animals' mortality rate are important factors that might be affected by the type of DN model. In this review, we discuss the pros and cons of different rodent models of diabetes that are being used to study DN.

The effect of endurance training with crocin consumption on the levels of MFN2 and DRP1 gene expression and glucose and insulin indices in the muscle tissue of diabetic rats

This study aimed to investigate the effect of crocin consumption, high-intensity interval training (HIIT), and low-intensity continuous training (LICT) and their interactive effect on the gene expression of Mfn2 and Drp1 in the skeletal muscle and serum glucose and insulin indices in high-fat diet (HFD) and streptozotocin (STZ)-induced diabetic rats. Fifty-six adult rats were divided into eight groups of seven subjects: crocin consumption, HIIT, LICT, HIIT with crocin, LICT with crocin, diabetic control, healthy control, and sham (placebo). At the end of the course (5 months), metabolic indices were measured. Moreover, the Mfn2 and Drp1 gene expression levels in all groups were measured using RT-PCR. The statistical analysis showed that in the exercise training (HIIT and LICT) and the crocin consumption groups, the glucose and insulin indices significantly improved (p = .005). Moreover, in these groups, the levels of gene expression of Mfn2 and Drp1 significantly increased and decreased, respectively (p = .001). Exercise training and crocin consumption appear to, either in combination or individually, have a beneficial effect on mitochondrial dynamics and diabetes by improving the mitochondrial fusion and fission indices (Mfn2 and Drp1), and by modifying the insulin resistance index and glucose homeostasis. PRACTICAL APPLICATIONS: Mfn2 and Drp1, as the main regulators of the mitochondrial fusion and fission, play an important role in maintaining mitochondrial dynamics and type 2 diabetes. Thus, the regulation of mitochondrial dynamics is an intricate process that retains the balance between mitochondrial fission and fusion, and any disturbance in this balance can lead to mitochondrial-associated diseases including insulin resistance and T2D. There is evidence that herbal antioxidants Including crocin and exercise training help improve the mitochondrial activity and insulin sensitivity in T2D. Considering the importance of the two Drp1 and Mfn1 genes in the mitochondrial dynamic pathway and coding the proteins that play a key role in relation to T2D, this study primarily examined the interactive effects of endurance training (HIIT and LICT) along with crocin consumption on the expression the genes mentioned above; the results obtained in this study can provide a new approach to the treatment of HFD + STZ-induced diabetic rats.

The effect of crocetin supplementation on markers of atherogenic risk in patients with coronary artery disease: a pilot, randomized, double-blind, placebo-controlled clinical trial

BACKGROUND AND PURPOSE

Molecular mechanisms of atherogenesis are considered to be emerging therapeutic targets for atherosclerosis prevention. Cell and animal studies have shown that crocetin can decelerate atherogenesis. However, the anti-atherogenic properties of crocetin in humans are still ambiguous.

METHODS AND RESULTS

Fifty clinically diagnosed CAD patients were randomly divided into two parallel groups, crocetin and placebo, who received one capsule of crocetin (10 mg) and placebo per day, respectively, for two months. Serum circulating homocysteine (Hcy) [-1.09 (-1.64 to -0.54) μM, P = 0.001], heart-type fatty acid binding protein (h-FABP) [-2.07 (-2.72 to -1.43) ng mL^-1, P = 0.001], intercellular adhesion molecule 1 [-14.92 (-21.92 to -7.92) ng mL^-1, P = 0.001], vascular cell adhesion molecule 1 [-18.61 (-29.73 to -7.49) ng mL^-1, P = 0.002], and monocyte chemoattractant protein 1 [-4.67 (-6.50 to -2.83) pg mL^-1, P = 0.001] decreased significantly after the trial in the crocetin group, while high-density lipoprotein (HDL) significantly increased [+4.21 (0.68 to 7.73) mg mL^-1, P = 0.021]. Also, systolic [-0.21 (-0.32 to -0.10) mmHg, P = 0.001] and diastolic [-0.20 (-0.34 to -0.07) mmHg, P = 0.004] blood pressures decreased significantly in the crocetin group. Nevertheless, clinically significant percentage changes were only observed in Hcy (-15.25 ± 3.15, μM), HDL (-10.70 ± 5.06, mg dL^-1), and h-FABP (-21.10 ± 3.09, ng mL^-1) in the crocetin group. Furthermore, the relative increase in the gene expressions of sirtuin1 and AMP-activated protein kinase and a decrease in the lectin-type oxidized LDL receptor 1 and nuclear factor-kappa B expression in isolated peripheral blood mononuclear cells in the crocetin group were significant at the end of the trial in comparison with the placebo.

CONCLUSION

As the first human study, we showed the ability of crocetin to alter the expression of atherogenic genes and endothelial cell adhesion molecules in CAD patients. It appears that crocetin could be considered as a promising anti-atherogenic candidate for future studies.

Crocin treatment decreased pancreatic atrophy, LOX-1 and RAGE mRNA expression of pancreas tissue in cholesterol-fed and streptozotocin-induced diabetic rats

Objective

Oxidative stress in diabetic mellitus is a consequence of oxidative stress, which plays a critical role in the pathogenesis of diabetic tissue damage. Receptors for advanced glycation end products and for oxidized low-density lipoproteins (LDL) have critical contribution in oxidative tissue damage. The present study investigated whether anti-diabetic effects of Crocin via modulation of mRNA expression of RAGE and LOX-1 receptors in diabetic rats.

Methods

In the current study, high-fat cholesterol (HFC) and streptozotocin (40 mg/kg) used to induce type II diabetes. Experimental groups as follows: (Group 1: control); (Group 2: control treatment [Crocin]); (Group 3: DM [STZ]); (Group 4: DM treatment [STZ + Crocin]); (Group 5; DM + HFC [STZ + HFC]); (Group 6; DM + HFC treatment [STZ + HFC + Crocin]). Crocin (20 mg/kg/day, i.p.) administered in treatment groups for 60 days. Serum glucose and cholesterol levels evaluated on days 5, 30 and 60 after induction of DM. Pancreatic tissue from all group removed on day 60 for histological and RT-PCR analysis.

Results

Application of Crocin significantly decreased serum cholesterol levels on day 60 after induction of DM in diabetic + HFC rats. Moreover, Crocin significantly decreased serum glucose levels on days 30 and 60 both in diabetic and diabetic + HFC rats. Crocin partially prevented the atrophic effects of STZ on both exocrine and endocrine parts of pancreas. Additionally, Crocin significantly decreased LOX-1 and RAGE mRNA expression OF pancreas in diabetic rats.

Conclusion

The current study suggested that Crocin suppressed atrophic change of the pancreas by decrease of LOX-1 and RAGE mRNA expression in diabetic rats.