Chrysin Reduces Oxidative Stress but Does Not Affect Polyol Pathway in the Lenses of Type 1 Diabetic Rats

Chrysin attenuates epithelial prostatic hyperplasia in the ventral prostate of spontaneously hypertensive rats

The aim of this study was to evaluate the effects of chrysin on the ventral prostate of spontaneously hypertensive rats (SHR). Ten-week-old male Wistar and SHR rats received 100 mg/kg/day of chrysin (TW and TSHR) or 200 µL/day of the dilution vehicle (CW and CSHR) for 70 days. After the treatment, the animals were euthanized and the prostates were dissected out, fixed, and processed for further morphological, immunohistochemical, and biochemical analyses. Blood was collected for serological analysis. Chrysin did not interfere with the blood pressure. Morphologically, the epithelial height increased in TW and decreased in TSHR. Stereology showed an increase in the epithelial and stromal relative frequency, and a decrease in the lumen of TW, whereas the epithelium in TSHR was reduced. Normal alveoli decreased, and hyperplastic alveoli had an increment in TW, whereas in TSHR normal alveoli increased and intense hyperplasia decreased. The secretion area was reduced in TW. Immunohistochemical analysis showed a smaller number of PCNA-positive cells in TW. Finally, the biochemical analysis showed a reduction in malondialdehyde, carbonylated proteins, superoxide dismutase, and catalase in TW and TSHR. We concluded that the chrysin effect is dependent on the context in which this flavonoid is employed. In normal conditions, the anabolic potential of the chrysin was favored, disrupting the morphology of the prostate. However, when used in animals predisposed to develop hyperplasia, this flavonoid attenuates the hyperplastic status, improving the morphology of the gland.

Hypothyroidism is a causal determinant of age-related cataract risk in European population: a Mendelian randomization study

Objective

To determine whether there is a causal relationship between thyroid dysfunction and the risk of age-related cataract (ARC) in the European population.

Design

A two-sample Mendelian randomization (MR) study.

Methods

Hypothyroidism, hyperthyroidism, free thyroxine (fT4), and thyrotropin (TSH) were selected as exposures. The single nucleotide polymorphisms (SNP) of hypothyroidism and hyperthyroidism were obtained from the genome-wide association studies (GWAS) of the IEU database, including 337,159 subjects. Data for fT4 and TSH (72,167 subjects) were extracted from the ThyroidOmics Consortium. ARC was used as the outcome. The SNPs associated with ARC were selected from a GWAS of 216,362 individuals in the FinnGen database. The main method used was the inverse variance-weighted method, together with four complementary methods. Sensitivity analyses were performed using Cochran's Q test, MR-PRESSO, MR-Egger regression and leave-one-out test. MR pleiotropy was used to test for pleiotropy. MR Steiger test was used to test for the directionality.

Results

Two-sample MR analysis revealed a positive association between genetically predicted hypothyroidism and risk of ARC (OR = 2.501, 95% CI: 1.325-4.720; P = 0.004). Hyperthyroidism, circulating fT4 and TSH levels did not have a significant causal effect on ARC (P > 0.05). The results were robust and reliable, and no horizontal pleiotropy was found after sensitivity analyses. In the MR Steiger test, we found no reverse causal effects of hypothyroidism on the ARC (P <0.001).

Conclusions

Our study provides strong evidence that hypothyroidism is a causal determinant of ARC risk.

Investigation of the antioxidant effect of Chrysin in an experimental cataract model created in chick embryos

PURPOSE

Cataract, which occurs as a result of lens opacification, is one of the most common causes of vision loss. In the literature, deterioration of the antioxidant system due to the increase in reactive oxygen species and oxidant levels is shown among the causes of cataract formation. The aim of this study was to investigate the antioxidant effect of chrysin on steroid-induced cataract development in an experimental chick embryo model using morphological, histological and biochemical parameters.

METHODS

Within the scope of the study, 150 specific pathogen free (SPF) fertilized eggs were used. Eggs were divided into 6 groups as control (group 1), corn oil (group 2), hydrocortisone hemisuccinate sodium (HC) (group 3), low dose chrysin (group 4), medium dose chrysin (group 5) and high dose chrysin (group 6). On the 15th day of incubation, Chrysin and HC were applicated to the air sac of the eggs with Hamilton and/or insulin injector. On day 17, the chick embryos were removed from the eggs and the bulbus oculi of the embryos were dissected. Lenses of 9 embryos were used for morpholigical cataract grading in each group, lens of 8 embryos for biochemical analysis and intact eyes of 7 embryos for histological evaluation (TUNEL method).

RESULTS

No opacity was observed in any of the lenses in Group 1 and 2. Cataract was observed in all lenses in Group 3. The mean opacity grades in group 3 were statistically significantly higher when compared to group 1 and 2 (p<0.05). The difference between group 6 and group 3 was statistically significant (p<0.05). GSH and TAS levels in the lenses were statistically significantly decreased compared to the control group due to HC application (p<0.05). It was determined that the decreased GSH and TAS levels in the lenses increased in relation to the Chrysin application doses. The increased levels of MDA, TOS, caspase 3 and caspase 9 in the HC group decreased significantly depending to the chrysin doses (p<0.05). In addition, while the rate of apoptotic cells determined by the TUNEL method was statistically significantly higher in the HC administered group than in the control group (p<0.05), it was statistically significantly decreased in the chrysin-administered groups, in relation to the dose of chrysin (p<0.05).

CONCLUSIONS

We think that anti-cataract effect of crhysin may be due to the antioxidant and antiapoptotic properties of chrysin. However, more research is needed to clarify the anti-cataract effects of chrysin.

Synthesis and characterization of novel acyl hydrazones derived from vanillin as potential aldose reductase inhibitors

In the polyol pathway, aldose reductase (AR) catalyzes the formation of sorbitol from glucose. In order to detoxify some dangerous aldehydes, AR is essential. However, due to the effects of the active polyol pathway, AR overexpression in the hyperglycemic state leads to microvascular and macrovascular diabetic problems. As a result, AR inhibition has been recognized as a potential treatment for issues linked to diabetes and has been studied by numerous researchers worldwide. In the present study, a series of acyl hydrazones were obtained from the reaction of vanillin derivatized with acyl groups and phenolic Mannich bases with hydrazides containing pharmacological groups such as morpholine, piperazine, and tetrahydroisoquinoline. The resulting 21 novel acyl hydrazone compounds were investigated as an inhibitor of the AR enzyme. All the novel acyl hydrazones derived from vanillin demonstrated activity in nanomolar levels as AR inhibitors with IC50 and KI values in the range of 94.21 ± 2.33 to 430.00 ± 2.33 nM and 49.22 ± 3.64 to 897.20 ± 43.63 nM, respectively. Compounds 11c and 10b against AR enzyme activity were identified as highly potent inhibitors and showed 17.38 and 10.78-fold more effectiveness than standard drug epalrestat. The synthesized molecules' absorption, distribution, metabolism, and excretion (ADME) effects were also assessed. The probable-binding mechanisms of these inhibitors against AR were investigated using molecular-docking simulations.

Chrysin loaded nanovesicles ameliorated diabetic peripheral neuropathy. Role of NGF/AKT/GSK-3β pathway

Diabetic peripheral neuropathy (DPN) is a common diabetic complication. Chrysin (CHY) has many biological properties but poor oral bioavailability. This study investigates the effect of CHY and CHY-loaded nanovesicles (CHY-NVs) on streptozotocin (STZ)-induced DPN in rats. CHY-NVs were prepared by using film hydration method. The formula with the best entrapment efficiency%, lowest particle size, highest zeta potential, and highest in vitro CHY released profile was selected, characterized by Differential scanning calorimetry, Fourier transformation infrared spectroscopy analysis, and examined by Transmission electron microscope. Acute toxicity test, pharmacokinetic study and experimental model of diabetes mellitus were performed on the selected formulation. Wistar rats were considered diabetic by administration of a single intraperitoneal dose of STZ (50 mg/kg). 48 h after STZ administration, hyperglycemic rats were randomly assigned into four groups, one group of untreated hyperglycemic rats and the other three groups received daily oral doses of unloaded NVs, CHY-NVs (25 mg/kg), and CHY-NVs (50 mg/kg), respectively for 21 days. Moreover, five additional groups of healthy rats received: distilled water (control), free CHY, unloaded NVs, and CHY-NVs respectively for 21 days. CHY and CHY-NVs maintained body weight and reduced STZ-induced behavioral changes in rotarod, hind paw cold allodynia, tail cold allodynia, tail flick, and hot plate tests. CHY and CHY-NVs lowered blood glucose, glycated hemoglobin, elevated serum reduced glutathione (GSH), and reduced plasma malondialdehyde (MDA) levels. CHY-NVs elevated phosphatidylinositol 3-kinase (Pi3k), phosphorylated protein kinase B (p-AKT), and reduced nuclear factor kappa B (NF-κB), interleukin-6 (IL-6) in sciatic nerve homogenate. CHY and CHY-NVs increased nerve growth factor (NGF) and decreased glycogen synthase kinase-3β (GSK-3β) gene expressions in the sciatic nerve. In conclusion, CHY and CHY-NVs ameliorated STZ-induced DPN behavioral and histopathological changes via attenuating hyperglycemia, exerting anti-oxidant, anti-inflammatory effects, activating NGF/p-AKT/GSK-3β pathway, and its anti-apoptotic effect. The best pharmacokinetic profile and therapeutic effect was observed in rats treated with CHY-loaded NVs.

Improved Chrysin Production by a Combination of Fermentation Factors and Elicitation from Chaetomium globosum

Flavonoids encompass a heterogeneous group of secondary metabolites with exceptional health benefits. Chrysin, a natural dihydroxyflavone, possesses numerous bioactive properties, such as anticancer, antioxidative, antidiabetic, anti-inflammatory, etc. However, using traditional sources of chrysin involves extracting honey from plants, which is non-scalable, unsustainable, and depends on several factors, including geography, climatic conditions, and the season, which limits its production at a larger scale. Recently, microbial production of desirable metabolites has garnered attention due to the cost-effectiveness, easy scale-up, sustainability, and low emission of waste. We previously reported for the first time the chrysin-producing marine endophytic fungus Chaetomium globosum, associated with a marine green alga. To extend our understanding of chrysin biosynthesis in C. globosum, in the present study, we have assessed the presence of flavonoid pathway intermediates in C. globosum extracts using LC-MS/MS. The presence of several key metabolites, such as dihydrokaempferol, chalcone, galangin, baicalein, chrysin, p-Coumaroyl-CoA, and p-Cinnamoyl-CoA, indicates the role of flavonoid biosynthesis machinery in the marine fungus. Further, we have aimed to enhance the production of chrysin with three different strategies: (1) optimizing the fermentation parameters, namely, growth medium, incubation time, pH, and temperature; (2) feeding key flavonoid pathway intermediates, i.e., phenylalanine and cinnamic acid; (3) elicitation with biotic elicitors, such as polysaccharide, yeast extract, and abiotic elicitors that include UV radiation, salinity, and metal stress. The combined effect of the optimized parameters resulted in a 97-fold increase in the chrysin yield, resulting in a fungal cell factory. This work reports the first approach for enhanced production of chrysin and can serve as a template for flavonoid production enhancement using marine endophytic fungi.

Dietary Dried Jujube Fruit Powder (DJFP) Supplementation Improves Growth Performance, Antioxidant Stability, and Meat Composition in Broilers

Nowadays, broiler production is faced with great challenges due to intensive culture modes, and chickens are more susceptible to oxidative stress. Consequently, synthetic antioxidants have been used to reduce this process, but their use has shown potential health risks. Thus, the use of natural ingredients has been suggested as a strategy to prevent oxidative stress. This study investigated how dietary dried jujube fruit powder (DJFP) supplementation influences the growth performance, antioxidant stability, meat composition, and nutritional quality of Cobb broilers. A total of 360 unsexed broilers (1-day-old) were randomly assigned to treatments that varied in DJFP levels: a basal diet without DJFP (control) and diets supplemented with 50 g/kg DJFP (P1), 100 g/kg DJFP (P2), and 150 g/kg DJFP (P3), with 9 replicates per treatment (90 broilers/treatment or 10 broilers/replicate). The results demonstrated improvement in the growth performance of broilers in terms of body weight (BW), body weight gain (WG), average daily body weight gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) following dietary DJFP supplementation. In addition, the antioxidant stabilities in the DJFP-treated broilers were improved and inhibited the production of lipid oxidation products compared with the control, with those in the P2 group showing the most marked effect. Moreover, dietary DJFP supplementation significantly increased (p < 0.05) the activity of antioxidant enzymes in broilers. Furthermore, the breast meat of the broilers displayed an increased protein content with a simultaneous reduction in the fat content after DJFP treatment (p < 0.05). Essential amino acid levels were higher in the DJFP-supplemented groups (p < 0.05). The sum of saturated fatty acids was lower, and that of monounsaturated fatty acids (MUFAs) and the polyunsaturated fatty acid/saturated fatty acid ratio (PUFA/SFA) were higher in the DJFP-supplemented groups (p < 0.05). Together, these results indicate that up to 100 g/kg of dietary DJFP supplementation can enhance the growth performance and antioxidant capacity, meat composition, and amino acid and fatty acid composition in broiler breast meat. In conclusion, dietary DJFP supplementation is a healthy alternative to the use of synthetic antioxidants in broiler production, especially in regions rich in jujube resources.

Suppression of cisplatin-induced ovarian injury in rats by chrysin: an experimental study

The aim of this study was to investigate the potential therapeutic efficacy of chrysin (CHS) against ovotoxicity caused by intraperitoneal administration of cisplatin (CDDP) in rats. In this experimental study, 24 female rats were randomly divided into four groups: control, CHS (2 mg/kg), CDDP (5 mg/kg) and CDDP (5 mg/kg) + CHS (2 mg/kg). The levels of malondialdehyde (MDA), total oxidant status (TOS), total antioxidant status (TAS), superoxide dismutase (SOD), interleukin-6 (IL-6) and myeloperoxidase (MPO) were determined in the ovarian tissues using spectrophotometric methods. In addition, the ovarian samples were evaluated histopathologically by hematoxylin&eosin staining. The results revealed that the levels of MDA, TOS, IL-6 and MPO significantly increased by CDDP administration compared with control group (p < 0.05). Also, it was found that CDDP significantly decreased TAS and SOD levels (p < 0.05). CHS ameliorated CDDP-induced the increased levels of MDA, TOS, IL-6, MPO and increased the levels of TAS and SOD significantly (p < 0.05). Histological findings also supported the therapeutic effect of CHS against CDDP-induced ovarian damage parameters. In conclusion, our results showed that CHS exhibits a therapeutic effect against CDDP-induced ovotoxicity and therefore the use of CHS after chemotherapy may improve the side effets of CDDP. IMPACT STATEMENTWhat is already known about this subject? Cisplatin (CDDP) is an effective and widely used chemotherapeutic agent to treat various malignancies, but its therapeutic use is limited due to dose-related tissue toxicity. Chrysin (CHS), a natural flavone, exhibits various beneficial activities, including antioxidant, anti-inflammatory and anticancer. There are increasing evidences in the literature that CHS reduces the toxicity of various chemotherapeutic agents, such as CDDP, doxorubicin and cyclophosphamide, in colon, kidney and liver tissues through its antioxidant and anti-inflammatory potential.What do the results of this study add? This study demonstrated that CHS can abolish CDDP-induced in vivo ovarian injury by decreasing MDA, TOS, IL-6 and MPO levels and increasing SOD and TAS levels through its antioxidant and anti-inflammatory potential.What are the implications of these findings for clinical practice and/or further research? This study revealed the therapeutic potential of CHS against CDDP-induced acute ovotoxicity, for the first time. Further pre-clinical studies are necessary to prove the beneficial effect of CHS on the prevention of CDDP-induced ovarian toxicity.

Chrysin-Loaded Chitosan Nanoparticle-Mediated Neuroprotection in Aβ1-42-Induced Neurodegenerative Conditions in Zebrafish

Amyloid β plaques and neurofibrillary tangles are the characteristic features of Alzheimer's disease (AD). Plaques of amyloid β play a pivotal role in affecting cognitive functions and memory. Alzheimer's disease is a progressive neurodegenerative disease and is one of the leading causes of dementia worldwide. Several treatment strategies focusing on the amyloid cascade have been implemented to treat AD. The blood-brain barrier (BBB) poses the main obstructive barrier by refraining drugs from penetrating the brain. Nanotechnology is a promising research field for brain drug delivery using nanosized particles. Zebrafish is emerging as a model of interest to elaborate on brain targeting and nanotechnology-based therapeutics for neurodegenerative diseases. In the current study, we have synthesized and characterized chrysin-loaded chitosan nanoparticles (Chr-Chi NPs) and evaluated them for neuroprotection against amyloid-β-induced toxicity. We find that treatment with Chr-Chi NPs helps to retain memory, cognition, and synaptic connections, which are otherwise compromised due to Aβ_1-42 toxicity. The NPs further help in reducing aggregates of amyloid β, thus decreasing neuronal death and generation of reactive oxygen species (ROS). Taken together, our study brings to light a novel strategy for treating AD by a combined action on the neurons and amyloid aggregates mediated by chrysin and chitosan, respectively. Chr-Chi NPs, therefore, have the potential to provide a beneficial combinatorial treatment strategy for AD.

Silymarin from Milk Thistle Fruits Counteracts Selected Pathological Changes in the Lenses of Type 1 Diabetic Rats

Diabetes is a metabolic disease affecting many tissues and organs. The main etiological factor for diabetic complications is hyperglycemia and subsequent pathologies, such as oxidative stress. One of the organs susceptible to the development of diabetic complications is the eye with all of its elements, including the lens. The aim of this study was to evaluate the effect of silymarin, an extract obtained from milk thistle fruit husks, on the oxidative stress markers in the lenses of type 1 diabetic rats. The study was performed on male rats in which type 1 diabetes was induced with 60 mg/kg streptozotocin injection. Diabetic animals were treated via an intragastric tube with silymarin at 50 and 100 mg/kg doses for four weeks. Multiple oxidative stress and polyol pathway-related parameters were measured in the lenses, and auxiliary biochemical tests in the serum were conducted. Diabetes induced severe pathological changes both in the lenses and the serum, and silymarin counteracted several of them. Nevertheless, the qualitative analyses encompassing all tested parameters indicate that silymarin slightly improved the overall state of diabetic animals. Upon the obtained results, it can be concluded that silymarin reveals a faint positive effect on the lenses in type 1 diabetic rats.

Effect of Chrysin on Endoplasmic Reticulum Stress in a Rat Model of Testicular Torsion

BACKGROUND

The purpose of this study was to evaluate the possible therapeutic effect of chrysin (CHS) on testicular torsion/detorsion (T/D) injury in vivo through the mechanisms of oxidative stress and endoplasmic reticulum stress (ERS).

METHODS

Eighteen male rats were divided into three groups of six subjects in each group: control, T/D and T/D + CHS (100 mg/kg). To evaluate the degree of oxidative stress, tissue malondialdehyde (MDA), total oxidant status (TOS) and total antioxidant status (TAS) levels were determined using colorimetric methods, while tissue superoxide dismutase (SOD) levels were determined using an ELISA kit. To evaluate the degree of ERS, tissue glucose regulatory protein 78 (GRP78), activating transcription factor 6 (ATF6) and C/EBP homologous protein (CHOP) levels were determined using ELISA kits. Johnsen's testicle scoring system was used for histological evaluation.

RESULTS

In the T/D group, it is determined that statistically significant decreasing in the levels of TAS, SOD and Johnsen score, and increasing in TOS, MDA, GRP78, ATF6 and CHOP levels compared to control group (p < 0.05). CHS administration statistically significantly restored this T/D-induced damage (p < 0.05).

CONCLUSION

This is the first study to show that CHS prevent T/D-induced testicular damage through its ERS inhibitor activity. More comprehensive studies are needed to understand the underlying mechanisms.

Supplemental data for this article is available online at https://doi.org/10.1080/08941939.2021.2015489 .

Restoration and stabilization of acrylamide-induced DNA, mitochondrial damages and oxidative stress by chrysin in human lymphocyte

BACKGROUND

Acrylamide (AA) is a water-soluble toxic chemical that is considered one of the most important food contaminants. Furthermore, AA is considered a major public health risk.

METHODS

This study was designed to evaluate the effects of AA on cytotoxicity, oxidative damage and genotoxicity in human lymphocytes and also to evaluate the protective effects of the chrysin (CH). Lymphocytes after isolation from the blood were treated with AA (50 µM), AA (50 µM) plus CH (10, 25, 50 µM) and CH (50 µM), and parameters such as cell viability, mitochondrial and lysosomal damage, as well as oxidative damage to DNA were examined.

RESULTS

The results showed that CH was able to reduce cytotoxicity, reactive oxygen species (ROS) levels, lipid peroxidation (LPO) level, collapse in mitochondrial membrane potential (MMP) and oxidative damage of DNA caused by AA in human lymphocytes. Also, co-treatment of the AA-exposed human lymphocytes with CH increases the glutathione (GSH) levels.

CONCLUSION

Results suggest that CH (10, 25, 50 µM) shows a protective role in AA-induced cytotoxicity, oxidative stress, mitochondrial damage and DNA oxidative damage.

Anti-Inflammatory and Anti-Hyperuricemic Effects of Chrysin on a High Fructose Corn Syrup-Induced Hyperuricemia Rat Model via the Amelioration of Urate Transporters and Inhibition of NLRP3 Inflammasome Signaling Pathway

Hyperuricemia is the main cause of gout and involved in the occurrence of many other diseases such as hyperlipidemia and hypertension correlated with metabolic disorders. Chrysin is a flavonoid compound found naturally in honey, propolis, and mushrooms and has anti-inflammatory and antioxidant effects. However, its mechanism of action is not clear yet. This study investigated the mechanism of chrysin’s anti-hyperuricemic effect in hyperuricemia-induced rats fed with high-fructose corn syrup. Orally administrated chrysin for 28 consecutive days effectively decreased uric acid by inhibiting the activity of xanthine oxidase (XO) in the liver. Moreover, chrysin markedly downregulated the protein expression of uric acid transporter 1 (URAT1) and glucose transporter type 9 (GLUT9) and upregulated the protein expression of organic anion transporter 1 (OAT1) and human ATP-binding cassette subfamily G-2 (ABCG2). In addition, chrysin showed prominent anti-oxidative and inflammatory effects as the malondialdehyde (MDA) and interleukin 1 beta (IL-1β) concentration was reduced in both rat kidney and serum, which aligned with the inhibition of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome signaling pathway activation. Collectively, our results strongly suggest that chrysin exhibits potent anti-hyperuricemic and anti-inflammatory effects that may yield new adjuvant treatments for gout.

Broad-Spectrum Preclinical Antitumor Activity of Chrysin: Current Trends and Future Perspectives

Pharmacological profile of phytochemicals has attracted much attention to their use in disease therapy. Since cancer is a major problem for public health with high mortality and morbidity worldwide, experiments have focused on revealing the anti-tumor activity of natural products. Flavonoids comprise a large family of natural products with different categories. Chrysin is a hydroxylated flavonoid belonging to the flavone category. Chrysin has demonstrated great potential in treating different disorders, due to possessing biological and therapeutic activities, such as antioxidant, anti-inflammatory, hepatoprotective, neuroprotective, etc. Over recent years, the anti-tumor activity of chrysin has been investigated, and in the present review, we provide a mechanistic discussion of the inhibitory effect of chrysin on proliferation and invasion of different cancer cells. Molecular pathways, such as Notch1, microRNAs, signal transducer and activator of transcription 3 (STAT3), nuclear factor-kappaB (NF-κB), PI3K/Akt, MAPK, etc., as targets of chrysin are discussed. The efficiency of chrysin in promoting anti-tumor activity of chemotherapeutic agents and suppressing drug resistance is described. Moreover, poor bioavailability, as one of the drawbacks of chrysin, is improved using various nanocarriers, such as micelles, polymeric nanoparticles, etc. This updated review will provide a direction for further studies in evaluating the anti-tumor activity of chrysin.

Effect of Berberine on Glycation, Aldose Reductase Activity, and Oxidative Stress in the Lenses of Streptozotocin-Induced Diabetic Rats In Vivo-A Preliminary Study

Diabetes mellitus affects the eye lens, leading to cataract formation by glycation, osmotic stress, and oxidative stress. Berberine, an isoquinoline alkaloid, is a natural compound that has been reported to counteract all these pathological processes in various tissues and organs. The goal of this study was to evaluate whether berberine administered at a dose of 50 mg/kg by oral gavage for 28 days to rats with streptozotocin-induced diabetes reveals such effects on the biochemical parameters in the lenses. For this purpose, the following lenticular parameters were studied: concentrations of soluble protein, non-protein sulfhydryl groups (NPSH), advanced oxidation protein products (AOPP), advanced glycation end-products (AGEs), thiobarbituric acid reactive substances (TBARS), and activities of aldose reductase (AR), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Diabetes induced unfavorable changes in the majority of the examined parameters. The administration of berberine resulted in an increased soluble protein level, decreased activity of AR, and lowered AOPP and AGEs levels. The results suggest that berberine administered orally positively affects the lenses of diabetic rats, and should be further examined with regard to its anticataract potential.

Antinociceptive effect of chrysin in diabetic neuropathy and formalin-induced pain models

Chrysin, a natural flavonoid, is the main ingredient of many medicinal plants, which shows potent pharmacological properties. In the present study, the antinociceptive effects of chrysin were examined in ICR mice. Chrysin orally administered at the doses of from 10 to 100 mg/kg exerted the reductions of formalin-induced pain behaviors observed during the second phase in the formalin test in a dose-dependent manner. In addition, the antinociceptive effect of chrysin was further characterized in streptozotocin-induced diabetic neuropathy model. Oral administration chrysin caused reversals of decreased pain threshold observed in diabetic-induced peripheral neuropathy model. Intraperitoneally (i.p.) pretreatment with naloxone (a classic opioid receptor antagonist), but not yohimbine (an antagonist of α2-adrenergic receptors) or methysergide (an antagonist of serotonergic receptors), effectively reversed chrysin-induced antinociceptive effect in the formalin test. Moreover, chrysin caused a reduction of formalin-induced up-regulated spinal p-CREB level, which was also reversed by i.t. pretreated naloxone. Finally, chrysin also suppressed the increase of the spinal p-CREB level induced by diabetic neuropathy. Our results suggest that chrysin shows an antinociceptive property in formalin-induced pain and diabetic neuropathy models. In addition, spinal opioid receptors and CREB protein appear to mediate chrysin-induced antinociception in the formalin-induced pain model.