Treatment with crocin suppresses diabetic nephropathy progression via modulating TGF-β1 and oxidative stress in an experimental model of pinealectomized diabetic rats

Tanshinone IIA is superior to paricalcitol in ameliorating tubulointerstitial fibrosis through regulation of VDR/Wnt/β-catenin pathway in rats with diabetic nephropathy

Glomerulosclerosis and tubulointerstitial fibrosis (TIF) are closely involved in the development of diabetic nephropathy (DN). Moreover, the development of TIF is closely related to epithelial-to-mesenchymal transition (EMT). Tanshinone IIA (Tan) has various pharmacological effects, especially the anti-fibrotic effect. And it is mainly used in the clinical treatment of cardiovascular diseases. Currently, the protective effect of Tan on DN and its possible mechanism have not been clearly elucidated. Our previous studies illustrated that Tan could improve the EMT of HK-2 cells induced by high glucose by regulating the vitamin D receptor (VDR)/Wnt/β-catenin pathway. Here, we collected demographic information and laboratory results from the National Health and Nutrition Examination Survey (NHANES) database in order to investigate the relationship between VD and DN. Then, we established a DN model and treated DN rats with Tan and paricalcitol (Par) for 6 weeks. We subsequently compared the changes in general condition, renal function, pathological changes, and TIF-related protein expression levels of control rats, DN rats induced by STZ, DN rats with Tan at 5.4 mg/kg, DN rats with Tan at 10.8 mg/kg, and DN rats with Par at 0.054 µg/kg, to explore the effect and mechanism of Tan and Par on DN rats. The results showed that VD had a protective effect against DN in diabetic patients. And we found that Tan had a protective effect on renal fibrosis in DN rats, which was superior to Par in improving the symptoms of "three more and one less," reducing fasting blood glucose level, improving renal index, BUN/SCr, and UACR, reducing histopathological damage of kidney, and improving the expression of fibrosis-related proteins in kidney tissue by regulating VDR/Wnt/β-catenin pathway. Tan was superior to Par in ameliorating tubulointerstitial fibrosis by regulating VDR/Wnt/β-catenin pathway in rats with diabetic nephropathy.

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.

Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins

Crocins are water-soluble apocarotenoids isolated from the flowers of crocus and gardenia. They exhibit various pharmacological effects, including neuroprotection, anti-inflammatory properties, hepatorenal protection, and anticancer activity. They are often used as coloring and seasoning agents. Due to the limited content of crocins in plants and the high cost of chemical synthesis, the supply of crocins is insufficient to meet current demand. The biosynthetic pathways for crocins have been elucidated to date, which allows the heterologous production of these valuable compounds in microorganisms by fermentation. This review article provides a comprehensive overview of the chemistry, pharmacological activity, biosynthetic pathways, and heterologous production of crocins, aiming to lay the foundation for the large-scale production of these valuable natural products by using engineered microbial cell factories.

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.

The protective effect of crocin against testicular toxicity induced by ionizing radiation via AKT/FOXO pathway

Crocin, a pharmacologically active component of Crocus sativus L. (saffron), has been informed to be beneficial in the treatment of stress-related oxidative impairment. In the present study, we examined the protective role of crocin against testicular damage induced by radiation (acute and fractionated) and the alteration of the AKT/FOXO signaling pathway. Male Wister albino rats were exposed to acute dose of 6 Gy and a fractionated dose of gamma radiation (2 Gy every 2 days up to 6 Gy total doses). Rats were pretreated intraperitoneally with crocin in a dose of 50 mg/kg for seven consecutive days prior to exposure to irradiation at a level of 6 Gy and during the fractionated irradiation of rats. Control groups were run concurrently. Ionizing radiation caused changes in the level of oxidative stress biomarkers manifested as elevation of thiobarbituric acid reactive substance, total nitrate/nitrite and reactive oxygen species (ROS) associated with a decrease in catalase as well as in the level of inflammatory parameters (decrease in expression of Nrf2 which was related to a significant increase in expression of NF-κB p65). Irradiation produced cellular damage characterized by an increase in serum lactate dehydrogenase. These findings were aligned with increased expression of the forkhead box O-1 (FOXO-1) and activation of protein kinase B (AKT) pathway. Irradiation of rats led to reduction in serum testosterone level and testicular weights. Pretreatment with the indicated dose of crocin shielded against the changes in all the evaluated parameters. Administration of crocin can be introduced as a novel preclinical approach for regulation of testicular damage induced by radiation; via controlling the ongoing oxidative stress and inflammatory reaction as well as activation FOXO/AKT signaling pathway.

Gardenia (Gardenia jasminoides Ellis) fruit: a critical review of its functional nutrients, processing methods, health-promoting effects, comprehensive application and future tendencies

Gardenia fruit (GF) is the mature fruit of Gardenia jasminoides Ellis, boasting a rich array of nutrients and phytochemicals. Over time, GF has been extensively utilized in both food and medicinal contexts. In recent years, numerous studies have delved into the chemical constituents of GF and their associated pharmacological activities, encompassing its phytochemical composition and health-promoting properties. This review aims to provide a critical and comprehensive summary of GF research, covering nutrient content, extraction technologies, and potential health benefits, offering new avenues for future investigations and highlighting its potential as an innovative food resource. Additionally, the review proposes novel industrial applications for GF, such as utilizing gardenia yellow/red/blue pigments in the food industry and incorporating it with other herbs in traditional Chinese medicine. By addressing current challenges in developing GF-related products, this work provides insights for potential applications in the cosmetics, food, and health products industries. Notably, there is a need for the development of more efficient extraction methods to harness the nutritional components of GF fully. Further research is needed to understand the specific molecular mechanisms underlying its bioactivities. Exploring advanced processing techniques to create innovative GF-derived products will show great promise for the future.

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.

The Effect of Chinese Medicinal Formulas on Biomarkers of Oxidative Stress in STZ-Induced Diabetic Kidney Disease Rats: A Meta-Analysis and Systematic Review

Background

Diabetic kidney disease (DKD), defined broadly as persistent proteinuria with low estimated glomerular filtration rate in patients with diabetes, is a main cause of end-stage renal disease. Excessive production of reactive oxygen species is an important mechanism underlying the pathogenesis of DKD and many antioxidants have been investigated as therapeutic agents. Among them, Chinese medicine antioxidative stress therapies have been widely used to combat DKD, which may offer new insights into therapeutic development of DKD. There are several discrepancies among the efficacy of Western medicine (WM) and Chinese medicinal formula (CMF) action.

Methods

We searched PubMed, Cochrane Library, the Web of Science databases, Embase, and Scopus from inception to December 2021 using relevant keywords and a comprehensive search for randomized controlled trials (RCTs) was performed. Calculating the pooled weighted mean difference (MD) and 95% CI by the method of inverse-variance with a random-effect. All the related statistical analyses were performed using Stata version 15.1 software (Stata Corporation) and Rvman version 5.3 (Nordic Cochrane Center).

Results

A total of 8 articles with the 9 groups including 106 in the model group, 105 in the CMF group, and 99 in the WM group. Pooled data from 8 studies (9 groups) showed a statistical improvement in superoxide dismutase compared with the model group [standardized MD (SMD) = 1.57; 95 CI: 1.16–1.98; P < 0.05] and the WM group (SMD = 0.56; 95 CI: 0.19–0.92; P < 0.05). For glutathione peroxidase (GSH-Px), it was significantly improved in the CMF group vs. the model group and the WM group. For malondialdehyde (MDA), it was significantly reduced in the CMF group (CMF vs. model group: SMD = −1.52; 95 CI: −1.88 −1.17; P < 0.05; CMF vs. WM group: SMD = −0.64; 95 CI: −0.95 −0.33; P < 0.05).

Conclusion

This systematic review and meta-analysis have demonstrated that the therapy of CMF had a notable curative effect on relieving oxidative stress in STZ-induced DKD rats and CMF was significantly more effective than the WM control group. For the clinical application, the results providing confidence and some theoretical reference for DKD via evaluating the efficacy of CMF to a certain extent.

Systematic Review Registration

[PROSPERO], identifier [CRD42022313737].