Effect of crocin on antioxidant gene expression, fibrinolytic parameters, redox status and blood biochemistry in nicotinamide-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.

Antidiabetic and antioxidant potential of Crocin in high-fat diet plus streptozotocin-induced type-2 diabetic rats

OBJECTIVES

Crocin, the principal water-soluble active constituent of saffron, possesses numerous pharmacological activities. The present investigation examined the potential antidiabetic and antioxidant characteristics of Crocin in rats with type-2 diabetes by administering it orally and intraperitoneally (i.p.).

METHODS

After 2 weeks of a high-fat diet, streptozotocin (STZ) (i.p., 40 mg/kg) was administered to male adult rats to induce type-2 diabetes mellitus. Body weight and fasting blood glucose (FBG) were measured on days zero, weeks 1, and 2. At the end of 2 weeks of drug administration in their respective groups, fasting insulin and glucose levels were estimated, and insulin resistance (HOMA-IR) was determined. Intraperitoneal glucose (IPGTT) and insulin tolerance tests (ITT) were carried out. Histopathological investigation and biochemical parameters were estimated in pancreatic tissues.

RESULTS

The Crocin (100 mg/kg) treatment has significantly improved body weight, abatement of FBG, fasting insulin, and HOMA-IR. Likewise, Crocin treatment significantly improved the glucose and insulin challenges. We observed a significantly marked elevation in endogenous antioxidant enzymes in Crocin-treated groups. Similarly, Crocin treatment reversed the histopathological changes and restored the normal integrity and function of the pancreas.

CONCLUSION

The overall finding indicates that intraperitoneal administration of Crocin demonstrated better control of glycemic level and body weight. Further, it has improved insulin levels in the serum and potentiated antioxidant properties.

Crocin protects against endoplasmic reticulum stress-related tubular injury in diabetic nephropathy via the activation of the PI3K/AKT/Nrf2 pathway

Objectives

Diabetic nephropathy (DN) is the main cause of end-stage renal disease, but the current treatment is not satisfactory. Crocin is a major bioactive compound of saffron with antioxidant and anti-endoplasmic reticulum stress (ERS) abilities used to treat diabetes. This study specifically investigated whether crocin has a regulatory role in renal injury in DN.

Materials and Methods

The experiment was divided into control, (db/m mice), model (db/db mice), and experimental groups (db/db mice were intraperitoneally injected with 40 mg/kg crocin). Renal function-related indicators (Scr, BUN, FBG, UP, TG, TC, ALT, and AST) and oxidative stress-related indicators (ROS, MDA, GSH, SOD, and CAT) were assessed. The pathological changes of renal tissues were confirmed by HE, Masson, PAS, and TUNEL staining. The levels of ERS-related proteins (GRP78 and CHOP), apoptosis-related proteins, and PI3K/AKT and Nrf2 pathways-related proteins in renal tissue were detected.

Results

In db/db mice, renal function-related indicators, apoptotic cells of renal tissues, the contents of ROS and MDA as well as the expressions of CHOP, GRP78, and Bax were increased, the degree of renal tissue damage was aggravated, while the contents of GSH, SOD, and CAT, as well as the protein levels of Nrf2, PARP, anti-apoptotic proteins (Mcl-1, Bcl-2, Bcl-xl) were decreased compared to the db/m mice. However, crocin treatment reversed the above-mentioned situation. The expressions of the PI3K/AKT and Nrf2 pathways-related proteins were also activated by crocin.

Conclusion

Crocin inhibited oxidative stress and ERS-induced kidney injury in db/db mice by activating the PI3K/AKT and Nrf2 pathways.

Saffron as a promising therapy for diabetes and Alzheimer's disease: mechanistic insights

The prevalence of both Alzheimer's disease (AD) and diabetes mellitus is increasing with the societies' aging and has become an essential social concern worldwide. Accumulation of amyloid plaques and neurofibrillary tangles (NFTs) of tau proteins in the brain are hallmarks of AD. Diabetes is an underlying risk factor for AD. Insulin resistance has been proposed to be involved in amyloid-beta (Aβ) aggregation in the brain. It seems that diabetic conditions can result in AD pathology by setting off a cascade of processes, including inflammation, mitochondrial dysfunction, and ROS and advanced glycation end products (AGEs) synthesis. Due to the several side effects of chemical drugs and their high cost, using herbal medicine has recently attracted attention for the treatment of diabetes and AD. Saffron and its active ingredients have been used for its anti-inflammatory, anti-oxidant, anti-diabetic, and anti-AD properties. Therefore, in the present review paper, we take account of the clinical, in vivo and in vitro evidence regarding the anti-diabetic and anti-AD effects of saffron and discuss the preventive or postponing properties of saffron or its components on AD development via its anti-diabetic effects.

Neuroprotective effects of crocin and crocin-loaded niosomes against the paraquat-induced oxidative brain damage in rats

Paraquat (PQ) is a nonselective herbicide that induces oxidative reactions and multiple-organ failure on exposure. Crocin, a carotenoid obtained from saffron, has demonstrated many therapeutic effects against neural conditions because of its antioxidant properties. In this study, 30 male Wistar rats were divided into 6 groups to evaluate the protective effects of crocin and crocin-loaded niosomes (NC) against PQ in the brain. The levels of total antioxidant capacity (TAC), lipid peroxidation (LPO), total thiol groups (TTG), superoxide dismutase (SOD), and catalase (CAT) activity were measured as the markers of redox status. Histopathological changes in the CA1 region of the hippocampus were evaluated by cresyl violet staining. Results indicated that both crocin and NC were able to attenuate the adverse effects of PQ at the histopathological level, which was following the changes in LPO (P < 0.0001), TAC (P < 0.01), and TTG (P < 0.05) level. The activity of CAT (P < 0.01) and SOD (P < 0.01) could be restored either by crocin or NC. Also, results indicated that nanoformulation of crocin in niosomes appears to be more promising. In conclusion, both crocin and NC showed favourable effects of PQ in the brain of rats, and were determined to be excellent agents to prevent acute toxicities of PQ. Furthermore, these two compounds can be known to provide neuroprotection.

The Nicotinamide/Streptozotocin Rodent Model of Type 2 Diabetes: Renal Pathophysiology and Redox Imbalance Features

Diabetic nephropathy (DN) is a common complication of diabetes mellitus. While there has been a great advance in our understanding of the pathogenesis of DN, no effective managements of this chronic kidney disease are currently available. Therefore, continuing to elucidate the underlying biochemical and molecular mechanisms of DN remains a constant need. In this regard, animal models of diabetes are indispensable tools. This review article highlights a widely used rodent model of non-obese type 2 diabetes induced by nicotinamide (NA) and streptozotocin (STZ). The mechanism underlying diabetes induction by combining the two chemicals involves blunting the toxic effect of STZ by NA so that only a percentage of β cells are destroyed and the remaining viable β cells can still respond to glucose stimulation. This NA-STZ animal model, as a platform for the testing of numerous antidiabetic and renoprotective materials, is also discussed. In comparison with other type 2 diabetic animal models, such as high-fat-diet/STZ models and genetically engineered rodent models, the NA-STZ model is non-obese and is less time-consuming and less expensive to create. Given that this unique model mimics certain pathological features of human DN, this model should continue to find its applications in the field of diabetes research.

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.

Effect of Total Suspended Particulate Matter in the Air on Inflammation Factors and Apoptotic Markers in Diabetic Rats: The Protective Effect of Insulin and Crocin

Background

The effect of total suspended particulate matter (TSP) was investigated on the expression of inflammatory and apoptotic factors in diabetic rats, and the effect of crocin and insulin was examined on these factors.

Methods

Fifty-four adult male wistar rats were divided into nine experimental groups: control group, crocin group (received crocin, 50 mg/kg), diabetic group (received a single dose of alloxan at 120 mg/kg, IP), TSP group (5 mg/kg TSP instilled intratracheally), diabetic-crocin group (received crocin at 50 mg/kg after the induction of diabetes by alloxan (120 mg/kg)), diabetic-insulin group (received regular insulin (5 U/kg), crocin-TSP group (received crocin at 50 mg/kg, IP, and then 5 mg/kg TSP was instilled intratracheally), diabetic-TSP-insulin group (after receiving alloxan (120 mg/kg) and instilling TSP (5 mg/kg, intratracheally), a single dose (5 U/kg) of regular insulin), and diabetic-TSP-crocin group (after receiving alloxan (120 mg/kg) and instilling TSP (5 mg/kg, intratracheally), a single dose of crocin (50 mg/kg, IP)). Quantitative real-time PCR was performed to measure the expression of the mRNAs of apoptotic (Bax and Bcl2) and inflammatory mediators (TNFα, COX2, iNOS/eNOS) in Wistar rats.

Results

In diabetic and TSP groups the inflammatory factors and BAX/Bcl2 ratio significantly increased compared to the control group. In diabetic-TSP-insulin and diabetic-TSP-crocin, a significant decrease was observed in the rate of inflammatory factors and BAX/Bcl2 ratio.

Conclusion

The results suggested that diabetes and exposure to TSP increase the rate of apoptosis and inflammation, and also demonstrated the anti-apoptotic and anti-inflammation role of insulin and crocin.

The effect of Crocin on TFAM and PGC-1α expression and Catalase and Superoxide dismutase activities following cholestasis-induced neuroinflammation in the striatum of male Wistar rats

Bile secretion is a physiological function that is disrupted following Bile Duct Ligation (BDL) and induces cholestasis. Cholestasis is a bile flow reduction that induces apoptosis, oxidative stress, and inflammation, and alters the expression of genes. Evidence shows the relationship between cholestasis and neuroinflammation. Cholestasis via attenuating mitochondrial biogenesis and anti-oxidant activity can induce neuroinflammation and apoptosis. Mitochondrial transcriptional factor A (TFAM) and Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) are involved in mitochondrial biogenesis, and TFAM, PGC-1α, Catalase (CAT), and Superoxide dismutase (SOD) have a role in upregulating antioxidant pathways. On the other hand, many studies have shown the neuroprotective effects of Crocin, the water-soluble carotenoid of Saffron (Crocus sativus L.). In this study, we aimed to investigate the effect of Crocin on the level of TFAM, PGC-1α, CAT, and SOD following cholestasis-induced neuroinflammation in the rat's striatum. Cholestasis was induced by BDL surgery and administration of Crocin was intraperitoneal, at the dose of 30 mg/kg every day, 24 h after BDL surgery up to thirty days. The results showed that TFAM, PGC-1α, and SOD were decreased following cholestasis; while, CAT was increased. In addition, Crocin restored the effects of cholestasis on the level of TFAM, PGC-1α, and SOD. In conclusion, Crocin may have improvement effects on cholestasis-induced neuroinflammation in the rat's striatum.

A novel combined bioactivity / chemoactivity holistic approach for the evaluation of dietary supplements

There is increasing evidence that the excessive generation of free radicals in the human body plays a major role in the pathophysiology and development of various diseases, closely associated with oxidative damage. In this frame, the consumption of antioxidant nutrients through food or dietary supplements may prevent from the harmful effects of free radicals on human cells. This work proposes a holistic approach consisting of distinct methodologies, suitable to evaluate the antioxidant and chemoprotective activity of three novel dietary supplements, each one containing active substances with complementary properties. In the first step, this approach includes in vitro studies to evaluate the antioxidant activity of the dietary supplements by measuring the parameters of free radical scavenging capacity, of reducing power activity, as well as, their ability to protect biomolecules from oxidation. Furthermore, the evaluation of their antimutagenic and antigenotoxic effects is also presented. SubsequentlySub, the specific effects of the dietary supplements were examined in three cancer cell lines (HepG2, HeLa, MKN45), by measuring redox biomarkers such as glutathione, reactive oxygen species and thiobarbituric acid reactive substances, using flow cytometry and spectrophotometry. Our results indicate that all the dietary supplements exhibit high antioxidant, antimutagenic, antigenotoxic and lipid protective activity. The most prominent result is their capability to induce oxidative damage on cancer cells via the critical decrease of the levels of their intracellular glutathione, as well as the increase of ROS and lipid peroxidation levels after the administration of non-cytotoxic concentrations. We suggest that the proposed methodology could constitute a valuable tool for the characterization of dietary supplements based on their chemical and functional properties.

Resveratrol, curcumin and gallic acid attenuate glyoxal-induced damage to rat renal cells

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RES, CUR and GA protected renal cells from GO–induced cells death.

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RES, CUR and GA reduced formation of ROS.

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RES, CUR and GA diminished lipid peroxidation products.

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RES, CUR and GA repressed GO-induced mitochondrial membrane potential collapse.

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RES, CUR and GA decreased lysosomal membrane leakage in GO-treated cells.

Glyoxal (GO), a by-product of glucose auto-oxidation, is involved in the glycation of proteins/ lipids and formation of advanced glycation (AGE) and lipoxidation (ALE) end products. AGE/ALE were shown to contribute to diabetic complications development/progression such as nephropathy. Diabetic nephropathy progression has an oxidative nature. Given the antioxidant effects of polyphenols, potential protective effects of resveratrol, curcumin and gallic acid, in rat renal cells treated with GO, were evaluated in the present work. According to our results, incubation of GO with the cells reduced their viability and led to membrane lysis, reactive oxygen species (ROS) formation, lipid peroxidation, mitochondrial membrane potential collapse, and lysosomal membrane leakage. These findings were prevented by pre-treatment with resveratrol, curcumin and gallic acid. Mitochondrial and lysosomal toxic interactions appear to worsen oxidative stress/cytotoxicity produced by GO. Resveratrol, curcumin and gallic acid inhibited ROS formation and attenuated GO-induced renal cell death.

Apigenin-Loaded Solid Lipid Nanoparticle Attenuates Diabetic Nephropathy Induced by Streptozotocin Nicotinamide Through Nrf2/HO-1/NF-kB Signalling Pathway

Background

Apigenin is known to have a broad-spectrum efficacy in oxidative stress and conditions due to inflammation, although weak absorption, fast metabolic rate and a fast elimination (systemic) limit the pharmacological efficacy of this drug. Hence, we propose the usage of highly bioavailable Apigenin-solid lipid nanoparticles (SLNPs) to recognize such limitations. The defensive function of Apigenin-SLNPs on renal damage induced by streptozotocin (STZ) in animals was studied.

Materials and Methods

We initially injected the rats with 35 mg kg⁻¹ streptozocin intraperitoneally, and after 7 days, the rats were then injected 150 mg kg⁻¹ of metformin intragastrically followed by a once-daily intragastric dose of Apigenin-SLNP (25 or 50 mg kg⁻¹) for a continuous period of 30 days. We then measured the level of insulin and blood glucose, superoxide dismutase, catalase and malondialdehyde in the tissues of the kidney. We also observed messenger-RNA expression of Interleukin-1β, Interleukin-6 and Tumor Necrosis Factor-alpha in renal tissue through RT-PCR technique. Moreover, H&E staining and Western blotting observed the histopathological variations and protein expression of nuclear factor erythroid 2-related factor 2/heme oxygenase/Nuclear Factor-κB signaling pathway, respectively.

Results

An enhancement in the expressing of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 and a suppression in the expression of Nuclear Factor-κB occurred due to Apigenin-SLNPs treatment, which was a result of the protective mechanism of Apigenin-SLNPs which is because of not only its anti-inflammatory function (by inhibition of release of inflammatory factors) but also their anti-oxidant activity (through reduction of lipid peroxidation production).

Conclusion

We found that a protective effect on diabetic nephropathy was shown due to Apigenin-SLNPs, in rats induced with streptozocin maybe through the pathway of nuclear factor erythroid 2-related factor 2/heme oxygenase-1/Nuclear Factor-κB.