Antihyperglycemic, antihyperlipidemic, and antioxidant effects of Chaenomeles sinensis fruit extract in streptozotocin-induced diabetic rats

Exploring the NRF2/HO-1 and NF-κB Pathways: Spirulina Nanoparticles as a Novel Approach to Combat Diabetic Nephropathy

Arthrospira platensis has been the subject of plentiful studies due to its purported health advantages; nevertheless, additional investigation is required to determine whether several chronic diseases may be treated or avoided with its nanoform. Therefore, we set out to examine A. platensis nanoparticles (SNPs) to protect against kidney impairment caused by Streptozotocin (STZ) in diabetic rats, precisely focusing on its effect and the cellular intracellular pathways involved. Male Wistar rats were assigned into four groups: Group 1 was set as control, comprising the normal rats; group 2 was administered SNPs (0.5 mg/kg BW, once/day) orally for 84 consecutive days; group 3, STZ-diabetic rats were injected with STZ (65 mg/kg BW); and group 4, in which the diabetic rats were treated with SNPs. After inducing diabetes in rats for 84 days, the animals were euthanized. The results disclosed that SNP treatment substantially (P < 0.05) improved the glucose and glycated hemoglobin levels (HbA1c %), insulin, C-peptide, and cystatin C deterioration in diabetic rats. Furthermore, SNP administration significantly lowered (P < 0.05) nitric oxide (NO) and malondialdehyde (MDA) levels in renal tissue and enhanced kidney function metrics, as well as improved the antioxidant capacity of the renal tissue. In addition, oral SNPs overcame the diabetic complications concerning diabetic nephropathy, indicated by downregulation and upregulation of apoptotic and antiapoptotic genes, respectively, along with prominent modulation of the antiangiogenic marker countenance level, improving kidney function. SNP modulated the nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 (NRF2/HO-1) pathways and inhibited the nuclear factor-κB (NF-κB) expression, strengthening the SNP pathways in alleviating diabetic nephropathy. The histopathology results corroborated the obtained biochemical and molecular observations, suggesting the therapeutic potential of SNPs in diabetic nephropathy via mechanisms other than its significant antioxidant and hypoglycemic effects, including modulation of antiangiogenic and inflammatory mediators and the NRF2/HO-1 pathways.

Widely metabolomic combined with transcriptome analysis to build a bioactive compound regulatory network for the fruit growth cycle in Pseudocydonia sinensis

Neglected and underutilised plants such as Pseudocydonia sinensis (Chinese quince) have garnered global interest as invaluable sources of natural bioactive compounds. Herein, a wide-targeted metabolomics-based approach revealed 1199 concurrent metabolites, with further analysis of their fluctuations across with the five stages of fruit growth. The bioactive compounds in Chinese quince primarily comprised sugars and organic acids, flavonoids, and terpenoids. Moreover, 395 metabolites were identified as having medicinal properties and rutin was the most content of them. Transcriptome analysis further provided a molecular basis for the metabolic changes observed during fruit development. By thoroughly analysing metabolite and transcriptome data, we revealed changes in bioactive compounds and related genes throughout fruit development. This study has yielded valuable insights into the ripening process of Chinese quince fruit, presenting substantial implications for industrial applications, particularly in quality control.

Antidepressant-like Effects of Chinese Quince (Chaenomeles sinensis) Fruit Based on In Vivo and Molecular Docking Studies

In this study, we examined the potential antidepressant-like effects of Chinese quince fruit extract (Chaenomeles sinensis fruit extract, CSFE) in an in vivo model induced by repeated injection of corticosterone (CORT)-induced depression. HPLC analysis determined that chlorogenic acid (CGA), neo-chlorogenic acid (neo-CGA), and rutin (RT) compounds were major constituents in CSFE. Male ICR mice (5 weeks old) were orally administered various doses (30, 100, and 300 mg/kg) of CSFE and selegiline (10 mg/kg), a monoamine oxidase B (MAO-B) inhibitor, as a positive control following daily intraperitoneal injections of CORT (40 mg/kg) for 21 days. In our results, mice treated with CSFE exhibited significant improvements in depressive-like behaviors induced by CORT. This was evidenced by reduced immobility times in the tail suspension test and forced swim test, as well as increased step-through latency times in the passive avoidance test. Indeed, mice treated with CSFE also exhibited a significant decrease in anxiety-like behaviors as measured by the elevated plus maze test. Moreover, molecular docking analysis indicated that CGA and neo-CGA from CSFE had stronger binding to the active site of MAO-B. Our results indicate that CSFE has potential antidepressant effects in a mouse model of repeated injections of CORT-induced depression.

Quinces (Cydonia oblonga, Chaenomeles sp., and Pseudocydonia sinensis) as Medicinal Fruits of the Rosaceae Family: Current State of Knowledge on Properties and Use

In recent years, the evaluation of many plant-derived compounds as potential new drugs or functional foods has become an active research topic. The morphological characteristics of quinces of the genera Cydonia sp., Chaenomeles sp., and Pseuocydonia sp. are largely similar, which is why these fruits are often confused. Although they have been appreciated in Asia for centuries as a valuable component of local ethnomedicine, they are less known in Western countries, and scientific knowledge about their health benefits remains fragmentary. This literature review summarizes studies on the content of chemical compounds responsible for the health-promoting and functional properties of the quince fruit. It focuses on the content of carotenoids, vitamins, minerals, and carboxylic acids, although the main emphasis is on the content and diversity of bioactive polyphenols, which are extremely abundant in these fruits. The quince fruits are rich in antioxidants and compounds with proven anti-inflammatory, anticancer, antiallergic, and immunomodulatory effects. Their phytochemicals effectively regulate glycemia and improve the blood lipid profile, suggesting potential antidiabetic and cardioprotective benefits. Analysis of chemical characteristics showed that the Chaenomeles fruits. are underestimated as functional food ingredients. Studies on the molecular effects of their bioactive compounds and species-specific genomic analyses are sorely lacking in the scientific literature.

Phytochemistry and pharmacology of plants in the genus Chaenomeles

Chaenomeles plants belong to the Rosaceae family and include five species, Chaenomeles speciosa (Sweet) Nakai, Chaenomeles sinensis (Thouin) Koehne, Chaenomeles japonica (Thunb.) Lindl, Chaenomeles cathayensis (Hemsl.) Schneid and Chaenomeles thibetica Yu. Chaenomeles plants are found and cultivated in nearly every country worldwide. China serves as both the origin and distribution hub for the plants in the Chaenomeles genus, and all Chaenomeles species except for C. japonica are indigenous to China. Chaenomeles spp. is a type of edible medicinal plant that has been traditionally used in China to treat various ailments, such as rheumatism, cholera, dysentery, enteritis, beriberi, and scurvy. A variety of chemical constituents have been extracted from this genus, including terpenoids, phenolics, flavonoids, phenylpropanoids and their derivatives, benzoic acid derivatives, biphenyls, oxylipins, and alkaloids. The biological activity of some of these constituents has already been evaluated. Pharmacological investigations have demonstrated that the plants in the genus Chaenomeles exhibit anti-inflammatory, analgesic, antioxidant, antihyperglycemic, antihyperlipidemic, gastrointestinal protective, antitumor, immunomodulatory, antibacterial, antiviral, hepatoprotective, neuroprotective and other pharmacological activities. The objective of this review is to provide a comprehensive and up-to-date summary of the available information on the genus Chaenomeles to serve as a valuable reference for further investigations.

Pharmacological Studies on the Antidiabetic, Antioxidant, and Antimicrobial Efficacies of Commiphora myrrha Resin in Streptozotocin-Induced Diabetes in Rats: A Preclinical Study

RESULTS

The aqueous extracts of MAE were phytochemically analyzed, and the results revealed the presence of high concentrations of tannins, sterols, and isoprenoids (terpenoids), while steroids and flavonoids were found in moderate concentrations. The plant extract showed promising inhibition of the growth of gram-positive and gram-negative pathogens. It also showed that MAE has potential antihyperglycemic and antioxidant activities. Microscopic examination of the pancreas showed degenerative changes and atrophy associated with dilatation of the exocrine ducts in the STZ-induced diabetic rats, while the treatment revealed that the Langerhans islets were close to normal without any histopathological alteration.

CONCLUSION

The present results suggested that an aqueous extract of MAE could be considered an efficient antidiabetic, antioxidant, and antimicrobial treatment in the future.

Comparative Metabolomics Study of Chaenomeles speciosa (Sweet) Nakai from Different Geographical Regions

Chaenomeles speciosa (Sweet) Nakai (C. speciosa) is not only a Chinese herbal medicine but also a functional food widely planted in China. Its fruits are used to treat many diseases or can be processed into food products. This study aims to find key metabolic components, distinguish the differences between geographical regions and find more medicinal and edible values of C. speciosa fruits. We used ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) and widely targeted metabolomics analysis to reveal key and differential metabolites. We identified 974 metabolites and screened 548 differential metabolites from 8 regions. We selected significantly high-content differential metabolites to visualize a regional biomarker map. Comparative analysis showed Yunnan had the highest content of total flavonoids, the highest amounts of compounds related to disease resistance and drug targets and the most significant difference from the other regions according to the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform database, a unique platform for studying the systematic pharmacology of Chinese herbal medicine and capturing the relationship between drugs, targets and diseases. We used oral bioavailability (OB) ≥ 30% and drug likeness (DL) ≥ 0.18 as the selection criteria and found 101 key active metabolites, which suggests that C. speciosa fruits were rich in healthy metabolites. These results provide valuable information for the development of C. speciosa.

Beneficial Effect of Thymelaea hirsuta on Pancreatic Islet Degeneration, Renal Fibrosis, and Liver Damages as Demonstrated in Streptozotocin-Induced Diabetic Rat

OBJECTIVE

In Morocco, Thymelaea hirsuta (T. hirsuta) (Thymelaeacea) is a medicinal plant widely used to treat and prevent diabetes. The present study aimed to evaluate the medium-term antidiabetic effect of aqueous extract (AqTh) and ethyl acetate fraction (EaTh) of Th and to investigate their putative protective effect on pancreatic islet degeneration, diabetic nephropathy, and liver damages in streptozotocin (STZ)-diabetic rats.

METHODS

Experimental diabetes in rats was induced by a single intraperitoneal injection of 50 mg/kg of STZ. During the treatment period (4 weeks), 200 mg/kg AqTh and 50 mg/kg EaTh were orally administrated daily to STZ-diabetic rats. A group of parameters including fasting blood glucose, biochemical parameters, and intestinal α-glucosidase inhibition were studied. Furthermore, histological study of the pancreas, kidney, liver, and aorta was also realized.

RESULTS

At the end of the treatment, both AqTh and EaTh had normalized fasting blood glucose to 1.08 and 1.25 g/l, respectively. AqTh has also reduced urinary creatinine and HbAc1. The EaTh showed inhibitory activity against intestinal α-glucosidase, whereas AqTh did not have this inhibitory effect. Furthermore, pancreas hematoxylin and eosin staining showed that AqTh or EaTh prevents pancreatic islet cell degeneration. As the same kidney, Masson's trichrome staining has shown a significant prevention of renal fibrosis in AqTh- or EaTh-treated diabetic rats. On the other hand, liver hematoxylin and eosin staining showed that AqTh and EaTh prevent liver damage.

CONCLUSION

We conclude that medium-term administration of AqTh and EaTh exerts significant antihyperglycemic effect in STZ-diabetic rats possibly through intestinal α-glucosidase inhibition and protection against pancreatic islet cell damage. Moreover, AqTh and EaTh treatment prevent nephropathy and liver complications in STZ-diabetic rats.

The effects of sericin in recovering spermatogenesis and sexual hormone levels in diabetic rats

Sericin-S (a hydrolysate from the silk protein sericin) is a natural antioxidant, which may improve spermatogenesis while having high biological safety, thus potentially useful for the treatment of male infertility. Our objective was to determine the effects of sericin-S on the sperm parameters and sexual hormone levels in a diabetic rat model. Thirty-six adult male rats were randomly divided in two groups, inducing diabetes in one of them by intraperitoneal administration of streptozotocin (STZ; 65 mg/kg). Both groups were randomly assigned to three subgroups, receiving oral gavage of saline, 1% or 2% sericin extract for 60 days. Therefore, the experimental design was a 2 × 3 factorial design of STZ and sericin treatments. One day after the last treatment, the rats were euthanized, weighed, the testes were processed (weigh, volume, and histology), and serum samples were processed for measuring sex hormone levels [testosterone, follicle-stimulating hormone, and luteinizing hormone (LH)]. STZ treatment decreased LH concentration and counts of spermatogonia, spermatocytes, and spermatids. Body and testis weights were significantly (p < 0.05) lower in the control group (non-diabetic saline) compared to the treated groups. In non-diabetic rats, sericin treatments increased (p < 0.05) the number of testicular cells (spermatogonia, spermatocytes, spermatids, Sertoli, and Leydig cells) and sex hormone concentrations. In diabetic rats, administration of sericin significantly (p < 0.05) improved sperm cell number and sex hormones levels. In nutshell, sericin can clearly modify sperm parameters and overall sex hormone function, and could improve spermatogenesis in normal and diabetic rats.

A HPLC fingerprint study on Chaenomelis Fructus

Background

Chaenomelis Fructus is a type of traditional medicine used in China. At present, the quality standard of Chaenomelis Fructus is mainly based on the content of each component as a control index, lacking overall control. To improve the rapid identification of chemical ingredients for Chaenomelis Fructus, a new approach to the construction for Chaenomelis Fructus is presented in this paper.

Methods

The precision, repeatability and stability of the proposed HPLC method were validated in the study. Twenty batches of Chaenomelis Fructus samples from their geographical origin were analyzed by the HPLC method. Common peaks in the chromatograms were adopted to calculate their relative retention time and relative peak area. The chromatographic data were processed by the Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine software (Version 2004 A) for similarity analysis.

Results

The HPLC method demonstrated satisfactory precision, repeatability and stability. The similarities of the 20 Chaenomelis Fructus samples were 0.967, 0.979, 0.965, 0.992, 0.994, 0.988, 0.974, 0.909, 0.993, 0.894, 0.983, 0.976, 0.992, 0.960, 0.990, 0.992, 0.901, 0.815, 0.947, and 0.504, indicating that the similarities of 19 samples showed a similar pattern with the exception of sample 20. Sample S20 could be considered adulterated. This was further confirmed by principal component analysis and hierarchical clustering analysis. The HPLC fingerprints of different Chaenomelis Fructus had obvious differences in area of common peaks, but less differences in the number of common peaks.

Conclusions

The chromatographic fingerprint of Chaenomelis Fructus with high characteristics and specificity can be used as a reference to control its quality, providing a fast quality evaluation tool for distinguishing between the authentic Chaenomelis Fructus and the adulterated products.

Phytochemical and Pharmacological Properties of Chaenomeles speciosa: An Edible Medicinal Chinese Mugua

Chaenomeles plants are adapted to diverse ecological zones particularly the temperate areas of Korea, Japan, and China. In China, Chaenomeles speciosa is mainly planted in Chongqing, Anhui, and Hubei provinces. Most of the studies till date have been focused on the anti-inflammatory activities of C. speciosa fractions. The present study aimed to review the maximum literature reported for the presence of various phytochemicals in C. speciosa. In addition, the pharmacological properties of these chemical compounds of this plant shall also be discussed. The extracts of the various parts of the plant are rich in diversity of antioxidants, organic acids, phenolics, terpenoids, and many different phytochemicals that bear strong anticancer, antioxidant, antiviral, antibacterial properties, anti-inflammation, antihyperlipidemic, antihyperglycemic, and anti-Parkinson properties. C. speciosa fruits have broad scope in industry as well as in medicines. Not only the leaves and fruits of C. speciosa plant, but various other parts including roots, seeds, bark twigs, and flowers all have long history of clinical trials in curing many human ailments. However, the maximum accessible data concerning the chemical compositions and their broad pharmacological properties of C. speciosa plant parts is pretty restricted that make it more appealing for in-depth investigations.

Anti-hyperuricemic and nephroprotective effects of extracts from Chaenomeles sinensis (Thouin) Koehne in hyperuricemic mice

CSF-E possesses potent anti-hyperuricemic through inhibiting XOD activity.

Active compounds, antioxidant activity and α-glucosidase inhibitory activity of different varieties of Chaenomeles fruits

Chaenomeles is an important source for food industry in China, and its planting area is expanding year by year. This study was conducted to evaluate different varieties of Chaenomeles by comparing the chemical compositions, antioxidant activity and α-glucosidase inhibitory activity of peels and fleshes from twelve varieties of Chaenomeles. In the results, peels of Chaenomeles contain more phenolics, flavonoids and triterpenes, and show better antioxidant activity and α-glucosidase inhibitory activity than their fleshes. All varieties of Chaenomeles perform different depend on cultivar and climatic conditions. Oleanolic acid, ursolic acid, protocatechuic acid, rutin, catechin, caffeic acid, syringic acid, epicatechin, hyperin, quercetin, kaempferol and chlorogenic acid are main active compounds in Chaenomeles. Zheng'an, Liufu, Zimugua1, Qijiang and Changjun get Top five scores. This is the first study on the peels and fleshes of twelve varieties of Chaenomeles, and it gives insights into variety selection in the planting and production of Chaenomeles.

Effect of boiling and drying process on chemical composition and antioxidant activity of Chaenomeles speciosa

Chemical composition and antioxidant activity of fresh and boiled Chaenomeles speciosa (CS) slices dried by different drying methods were determined. Data were analyzed by principle component analysis and cluster analysis. All dried boiled CS from dried fresh CS slices form main cluster. The results also demonstrated that both drying methods, freeze drying and hot air drying at 60 °C had good potential in the industrial drying of fresh and boiled CS. Fresh CS dried by hot air drying at 60 °C was more suitable for the industrial production.

Bioactive Triterpenoids from the Twigs of Chaenomeles sinensis

Chaenomeles sinensis has been consumed traditionally for the treatment of throat diseases, diarrhea, inflammatory diseases, and dry beriberi. Repeated chromatography of the CHCl₃-soluble fraction from the 80% MeOH extract of C. sinensis twigs led to the isolation of three new triterpenoids, sinenic acid A (1), 3β-O-cis-feruloyl-2α,19α-dihydroxyurs-12-en-28-oic acid (2), and 3β-O-cis-caffeoylbetulin (3), together with 20 analogues. The chemical structures of 1-3 were determined using diverse NMR techniques and HRMS data analysis, chemical methods, and computational approaches supported by advanced statistics (CP3). All the purified compounds were evaluated not only for their cytotoxicity against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-15) but for their potential neuroprotective effects through induction of nerve growth factor in C6 glioma cells. Their anti-inflammatory effects were also assessed by measuring nitric oxide levels in lipopolysaccharide-insulted murine microglia BV2 cells.

Advantages of the polysaccharides from Gracilaria lemaneiformis over metformin in antidiabetic effects on streptozotocin-induced diabetic mice

In the present study, polysaccharides fromGracilaria lemaneiformis(GLP) were obtained by citric acid extraction, and had a low molecular weight (21.2 kDa) with a high amount of galactose.

Chemical Composition and Bioactivities of Two Common Chaenomeles Fruits in China: Chaenomeles speciosa and Chaenomeles sinensis

Contents of total flavonoids, total phenolics, total triterpenes, total condensed tannin and total saponins in peels, flesh and endocarps of Chaenomeles speciosa (CSP) and Chaenomeles sinensis (CSS) were determined by colorimetric method, while 5 phenolics (vanillic, gallic, chlorogenic, ferulic and p-coumaric acids), 2 triterpenes (oleanolic and ursolic acids), and 3 flavonoids (rutin, catechin and epicatechin) were identified and quantified by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and HPLC, and antioxidant and α-glucosidase inhibitory activities of them also were evaluated as well as their digestive characteristics. In the correlation analysis, total phenolics, vanillic acid, catechin, ursolic acid and oleanolic acid all contribute to DPPH(·) scavenge capacity, gallic acid contributes to total ferric reducing antioxidant power, while total triterpenes, total saponins, chlorogenic acid and ferullic acid contribute to α-glucosidase inhibitory activity. In the principal component analysis, endocarps of CSP and CSS both show better quality than their peels and flesh, respectively. In vitro digestion can increase contents of total flavonoids, total condensed tannin and total saponins, while contents of total phenolics and total triterpenes decreased greatly. Our study would contribute to the full use of discarded parts of the 2 Chaenomeles and be helpful to establish a good foundation for further research of CSP and CSS.

Protective effects of Chaenomeles thibetica extract against carbon tetrachloride-induced damage via the MAPK/Nrf2 pathway

Chaenomeles thibetica extract possesses antioxidant and hepatoprotective effects against carbon tetrachloride-induced damage via the MAPK/Nrf2 pathway.

Lignan Glycosides from the Twigs of Chaenomeles sinensis and Their Biological Activities

Phytochemical investigation of the twigs of Chaenomeles sinensis led to the isolation and identification of six new lignan glycosides, chaenomiside A-F (1-6), along with five known ones (7-11). Their chemical structures were determined by spectroscopic methods, including NMR, MS, ECD, and GC/MS analyses. All the isolated compounds (1-11) were tested for their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide-activated murine microglial cells and the secretion of nerve growth factor (NGF) in a C6 rat glioma cell line. Compound 6 significantly reduced NO levels in the murine microglia BV2 cells with an IC50 value of 21.3 μM, and compounds 1, 3, and 6 were potent stimulants of NGF release with stimulation levels of 151.74 ± 6.77%, 144.31 ± 7.49%, and 167.61 ± 18.5%, respectively.

Hypoglycaemic effect of Berberis vulgaris L. in normal and streptozotocin-induced diabetic rats

OBJECTIVE

To achieve a primary pharmacological screening contained in the aqueous extract of Berberis vulgaris (B. vulgaris) and to examine the hypoglycaemic effect and biochemical parameters of aqueous and saponins extract on groups of rats rendered diabetic by injection of streptozotocin.

METHODS

The phytochemical tests to detect the presence of different compounds were based on the visual observation of color change or formation of precipitate after the addition of specific reagents. Diabetes was induced in rats by intraperitoneal (i.p.) injection of streptozotocin (STZ) at a dose of 65 mg/kg bw. The fasting blood glucose levels were estimated by glucose oxidase-peroxidase reactive strips (Dextrostix, Bayer Diagnostics). Blood samples were taken by cutting the tip of the tail. Serum cholesterol and serum triglycerides were estimated by enzymatic DHBS colorimetric method.

RESULTS

Administration of 62.5 and 25.0 mg/kg of saponins and aqueous extract respectively in normal rats group shows a significant hypoglycemic activity (32.33% and 40.17% respectively) during the first week. However, diabetic group treated with saponin extract produced a maximum fall of 73.1% and 76.03% at day 1 and day 21 compared to the diabetics control. Also, blood glucose levels of the diabetic rats treated with aqueous extract showed decrease of 78.79% on the first day and the effect remains roughly constant during 3 week. Both extracts also declined significantly biochemical parameters (20.77%-49.00%). The control in the loss of body weight was observed in treated diabetic rats as compared to diabetic controls.

CONCLUSIONS

These results demonstrated significant antidiabetic effects and showed that serum cholesterol and serum triglycerides levels were decreased, significantly, consequently this plant might be of value in diabetes treatment.

Indigenous plant medicines for health care: treatment of Diabetes mellitus and hyperlipidemia

Medicinal plants have played an important role in treating and preventing a variety of diseases throughout the world. Metabolic syndrome had become a global epidemic, defined as a cluster of three of five criteria: insulin resistance and glucose intolerance, abdominal obesity, hypertension, low high-density cholesterol, and hypertriglyceridemia. The current review focuses on Indian medicinal plant drugs and plants used in the treatment of diabetes and hyperlipidemia. Though there are various approaches to reduce the ill-effects of diabetes and hyperlipidemia and its secondary complications, plant-based drugs are preferred due to lesser side effects and low cost. The current review focuses on twenty-three medicinal plants used in the treatment of Diabetes mellitus and nine medicinal plants used in the treatment of hyperlipidemia. The wealth of knowledge on medicinal plants points to a great potential for research and the discovery of new drugs to fight diseases, including diabetes and hyperlipidemia.

Dietary Chinese quince polyphenols suppress generation of α-dicarbonyl compounds in diabetic KK-A(y) mice

Many dietary polyphenols can provide health benefits, such as antioxidant and antidiabetic effects, and can down-regulate the progression of glycation (one cause of diabetic complications). Chinese quince (CQ) is rich in polyphenols, especially procyanidins. A few studies have indicated that CQ has an effect on diabetes. In this study, a procyanidin-rich extract was prepared from Chinese quince fruit (CQE), and its effects were investigated and compared with those of green tea extract (GTE) in type 2 diabetes model KK-A(y) mice. Mice were provided one of two high-fat (HF) diets for 4 weeks: a HF diet containing 0.5% CQE or a HF diet containing 0.5% GTE. Blood glucose was suppressed in mice fed CQE and GTE during the experimental period (p < 0.05), although the effect of CQE was weaker than that of GTE. Intake of CQE had no effect on the blood insulin level, whereas GTE decreased the insulin level. Body weight gain was suppressed in mice fed CQE similarly to mice fed GTE (p < 0.05). Hepatic lipid content and α-dicarbonyl compounds in the kidney were reduced in mice fed CQE and GTE (p < 0.05). These results suggest that intake of CQE could moderate type 2 diabetes and diabetic complications.

Effect of HX108-CS supplementation on exercise capacity and lactate accumulation after high-intensity exercise

Background

In the present study, we determined the effects of HX108-CS (mixed extract of Schisandra chinensis and Chaenomeles sinensis) supplementation on lactate accumulation and endurance capacity. Furthermore, we examined CK (creatine kinase), LDH (lactate dehydrogenase) activity to determine whether the HX108-CS affected markers of skeletal muscle injury in vivo and in vitro.

Methods

Exercise capacity was measured by an exhaustive swimming test using ICR mice divided into four groups; one group received distilled water (DW) (Control group, n = 10), and the other groups received three different dosages of HX108-CS (10, 50 and 100 mg/kg, n = 10 per group) solution in water orally. Then, for the time-dependent measurements of blood lactate, CK, and LDH, Sprague–Dawley rats were divided into two groups; one received DW (Control group, n = 10), and the other group received HX108-CS (100 mg/kg, n = 10) solution in the same way as mice. Before the exercise test, the animals were given either DW or HX108-CS for 2 weeks. High-intensity treadmill exercise was performed for 30 minutes. Blood samples were collected and analyzed during and after exercise. For the in vitro experiment, C2C12 cells were treated with HX108-CS to examine its effect on lactate production, CK, and LDH activity.

Results

Blood lactate concentration was significantly lowered immediately after treadmill exercise in HX108-CS group; however, there were no significant differences in activities of CK and LDH between HX108-CS and control during treadmill exercise and recovery phase. Furthermore, treatment with 100 mg/kg of HX108-CS led to a significant increase in the time to exhaustion in swimming test, and concurrently blood lactate concentration was significantly decreased in 50 and 100 mg/kg treated group. Moreover, our results of in vitro experiment showed that HX108-CS suppressed lactate production, CK, and LDH activity in a dose-dependent manner.

Conclusions

These results suggest that supplementation with HX108-CS may enhance exercise capacity by lowering lactate accumulation. This may in part be related to an amelioration of skeletal muscle injury.

Antidiabetic and antiacetylcholinesterase effects of ethyl acetate fraction of Chaenomeles sinensis (Thouin) Koehne fruits in streptozotocin-induced diabetic rats

The present study was intended to examine the effects of the supplementation of active α-glucosidase, α-amylase and lipase inhibitory ethyl acetate (CSE) fraction from the fruits of Chaenomeles sinensis (Thouin) Koehne on blood glucose (BG), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), alanine aminotransferase (ALT), aspartate aminotransaminase (AST), acetylcholinesterase (AChE) and antioxidant levels. The diabetic rats were treated orally with CSE at the doses of 50 and 100 mg/kg bw for 14 days. BG, TC, TG, HDL-C, ALT, AST and AChE levels were significantly reduced; on the other hand antioxidant levels were significantly increased in the treated groups. These observations suggest protective effects of CSE against STZ-induced diabetic dementia model.