Unraveling the Roles of Vascular Proteins Using Proteomics.

Vascular bundles play important roles in transporting nutrients, growth signals, amino acids, and proteins between aerial and underground tissues. In order to understand these sophisticated processes, a comprehensive analysis of the roles of the components located in the vascular tissues is required. A great deal of data has been obtained from proteomic analyses of vascular tissues in plants, which mainly aim to identify the proteins moving through the vascular tissues. Here, different aspects of the phloem and xylem proteins are reviewed, including their collection methods, and their main biological roles in growth, and biotic and abiotic stress responses. The study of vascular proteomics shows great potential to contribute to our understanding of the biological mechanisms related to development and defense in plants.

Physiological and Proteomic Responses of Mulberry Trees (Morus alba. L.) to Combined Salt and Drought Stress.

Intensive investigations have been conducted on the effect of sole drought or salinity stress on the growth of plants. However, there is relatively little knowledge on how plants, particularly woody species, respond to a combination of these two stresses although these stresses can simultaneously occur in the field. In this study, mulberry, an economically important resource for traditional medicine, and the sole food of domesticated silkworms was subjected to a combination of salt and drought stress and analyzed by physiological methods and TMT-based proteomics. Stressed mulberry exhibited significant alteration in physiological parameters, including root/shoot ratio, chlorophyll fluorescence, total carbon, and ion reallocation. A total of 577 and 270 differentially expressed proteins (DEPs) were identified from the stressed leaves and roots, respectively. Through KEGG analysis, these DEPs were assigned to multiple pathways, including carbon metabolism, photosynthesis, redox, secondary metabolism, and hormone metabolism. Among these pathways, the sucrose related metabolic pathway was distinctly enriched in both stressed leaves and roots, indicating an important contribution in mulberry under stress condition. The results provide a comprehensive understanding of the adaptive mechanism of mulberry in response to salt and drought stress, which will facilitate further studies on innovations in terms of crop performance.

Protocatechualdehyde Induces S-Phase Arrest and Apoptosis by Stimulating the p27(KIP1)-Cyclin A/D1-CDK2 and Mitochondrial Apoptotic Pathways in HT-29 Cells.

Protocatechualdehyde (PCA) extracted from Phellinus gilvus exhibits anti-cancer activity in human colorectal carcinoma cells (HT-29). However, the underlying mechanisms remain poorly understood. We performed an in vitro study involving MTT, flow cytometry, RT-PCR, and western blot analyses to investigate the effects of PCA treatment on cell proliferation, cell cycle distribution, apoptosis, and expression of several cell cycle-related genes in HT-29 cells. The treatment enhanced S-phase cell cycle and apoptosis in HT-29 cells in a dose-dependent manner. Western blot results showed that PCA treatment decreased the expression levels of cyclin A, cyclin D1, and p27(KIP1) but increased those of cyclin-dependent kinase 2 (CDK2) in HT-29 cells. Furthermore, the expression levels of B-cell lymphoma/leukemia-2 (Bcl-2) and B-cell lymphoma/leukemia-xL (Bcl-xL) were down-regulated, whereas the levels of BH3-interacting domain death agonist (Bid), Bcl-2 homologous antagonist/killer (Bak), and cytosolic cytochrome c were significantly upregulated. Thus, the enzymes caspases-9, -3, -8, and -6 were found to be activated in HT-29 cells with PCA treatment. These results indicate that PCA-induced S-phase cell cycle arrest and apoptosis involve p27(KIP1)-mediated activation of the cyclin-A/D1-Cdk2 signaling pathway and the mitochondrial apoptotic pathway.

Mulberry leaf supplementation inhibits skatole deposition by regulating gut microbiota and upregulating liver cytochrome P450 1A1 expression in finishing pigs.

Skatole, a strong fecal odor substance, is generated through microbial degradation of tryptophan in the animal hindgut. It easily accumulates in adipose tissue and affects meat quality. In this study, the effect of mulberry leaf supplementation on skatole in finishing pigs was studied. In a 35-day trial, 20 finishing pigs (barrows and gilts) were fed with a basal diet or basal diet with 6% mulberry leaves. Growth performance of the pigs (n = 10) was automatically recorded by a performance-testing feeder system and 8 pigs in each treatment were slaughtered and sampled for the remaining tests. Skatole and short-chain fatty acids were detected using HPLC and gas chromatography, respectively. Fecal microbiota were analyzed using 16S rRNA gene sequencing. The metabolomics analysis of feces and serum was performed with UHPLC-MS/MS. The major cytochrome P450 (CYP) enzymes that catalyze skatole degradation in the liver were tested by using RT-PCR and Western blot. Effects of major bioactive compounds in mulberry leaves on the CYP genes were verified in the hepatic cell line HepG2 in an in vitro test (n = 3). In finishing pigs, mulberry leaf supplementation had no significant effect on the average daily gain, average daily feed intake, and feed conversion ratio (P > 0.05), but reduced skatole levels in feces, serum, and backfat (P < 0.05), and increased acetic acid levels in feces (P = 0.027). Mulberry leaf supplementation decreased the relative abundance of the skatole-producing bacteria Megasphaera and Olsenella (P < 0.05). Indole-3-acetic acid, the intermediate that is essential for skatole production, was significantly reduced in feces by mulberry leaf supplementation (P < 0.05) and was positively correlated with skatole content in feces (P = 0.004). In pigs treated with mulberry leaves, liver CYP1A1 expression was increased (P < 0.05) and was negatively correlated with skatole content in backfat (P = 0.045). The in vitro test demonstrated that mulberry leaf polyphenols and polysaccharides could directly stimulate CYP1A1 expression in hepatic cells. These findings suggest that mulberry leaf supplementation reduces skatole production and deposition in finishing pigs by regulating the gut microbiota and promoting skatole degradation in liver.

Development and comprehensive SBSE-GC/Q-TOF-MS analysis optimization, comparison, and evaluation of different mulberry varieties volatile flavor.

Optimization of seven parameters of stir bar sorptive extraction (SBSE) on mulberry volatile components for the first time. A total of 347 volatile components were identified and quantified in 14 mulberry varieties, predominantly encompassing esters, aldehydes, terpenoids, hydrocarbons, ketones, alcohols, heterocyclics, acids, and phenols. Hexanal and (E)-2-hexenal were the dominant volatiles. Furthermore, 79 volatile compounds characterized by odor activity values (OAVs) > 1 were identified, making a significant contribution to the distinctive mulberry flavor. "Green" notes were the most intense, followed by "fatty" and "fruity". Utilizing odor ring charts, the volatile flavor characteristics of the 14 mulberry varieties could be intuitively distinguished. This study not only established a viable methodology for differentiating mulberry varieties but also laid a theoretical foundation for the quality evaluation and variety breeding of mulberry flavor.

Preliminary Comparisons of Tender Shoots and Young Leaves of 12 Mulberry Varieties as Vegetables and Constituents Relevant for Their Potential Use as Functional Food for Blood Sugar Control.

Vegetables are essential for maintaining health and preventing diseases due to their nutrients and functional components. However, vegetables specifically designed for blood sugar control are limited. The mulberry tree (Morus) offers potential as a source of functional vegetables with blood-sugar-lowering properties, mainly attributed to 1-Deoxynojirimycin (DNJ). This study compared the nutritional composition and DNJ content in various edible parts of twelve mulberry tree varieties. Sensory evaluations were also conducted to assess sensory attributes. Interestingly, DNJ was found to show a positive correlation with sensory evaluations. Furthermore, the sugar content, particularly sucrose, was significantly higher in tender shoots than leaves, indicating tender shoots as a preferable choice for development as a functional food for blood sugar control. Finally, VM 19 and VM 22 are considered as good candidates for the mulberry vegetable using varieties after sensory evaluation and combining with the DNJ content. These findings provide valuable insights for future research into vegetable selections for blood sugar management and support the potential commercialization of mulberry leaf vegetables as functional food options.

Identification and Characterization of a Novel Quanzhou Mulberry Virus from Mulberry (Morus alba).

In this study, we discovered a new virus named Quanzhou mulberry virus (QMV), which was identified from the leaves of an ancient mulberry tree. This tree is over 1300 years old and is located at Fujian Kaiyuan Temple, a renowned cultural heritage site in China. We obtained the complete genome sequence of QMV using RNA sequencing followed by rapid amplification of complementary DNA ends (RACE). The QMV genome is 9256 nucleotides (nt) long and encodes five open reading frames (ORFs). Its virion was made of icosahedral particles. Phylogenetic analysis suggests that it belongs to the unclassified Riboviria. An infectious clone for QMV was generated and agroinfiltrated into Nicotiana benthamiana and mulberry, resulting in no visible disease symptoms. However, systemic movement of the virus was only observed in mulberry seedlings, suggesting that it has a host-specific pattern of movement. Our findings provide a valuable reference for further studies on QMV and related viruses, contributing to the understanding of viral evolution and biodiversity in mulberry.

Non-targeted metabonomics and transcriptomics revealed the mechanism of mulberry branch extracts promoting the growth of Sanghuangporus vaninii mycelium.

Sanghuangprous vaninii is a wood-inhabiting fungus, and its mycelium and fruiting body show excellent medicinal values. Mulberry is one of the major hosts of S. vaninii, however, the mechanism of mulberry affecting the growth of S. vaninii has not been reported. In the present study, a mulberry-inhabiting strain of S. vaninii was selected to explore the effects of mulberry branch extracts (MBE) on the growth of the strain. Results showed that MBE could significantly promote the growth of S. vaninii mycelium at the concentration of 0.2 g/l. After 16 days of liquid culture, the dry weight of mycelium in 0.2 g/l MBE medium was higher by three times compared with that in the control. The non-targeted metabonomic analysis of the culture medium at different culture times and concentrations was conducted to find the key components in MBE that promoted the growth of S. vaninii mycelium. Under the different concentrations of MBE culture for 10 and 16 days, 22 shared differential metabolites were identified. Next, in accordance with the peak value trend of these metabolites, HPLC-MS and liquid culture validation, four components derived from MBE (i.e., scopoletin, kynurenic acid, 3,5-dihydroxybenzoic acid and 2,4-dihydroxybenzoic acid) could significantly increase the growth rate of mycelium at the concentration of 2 mg/l. Transcriptomic and qRT-PCR analyzes showed that MBE could upregulate hydrolase-related genes, such as serine-glycine-asparaginate-histidine (SGNH) hydrolase, alpha-amylase, poly-beta-hydroxybutyrate (PHB) depolymerase, glycosyl hydrolase family 61, cerato-platanin protein and Fet3, which might enhance the nutrient absorption ability of S. vaninii. Importantly, MBE could significantly increase the content of harmine, androstenedione and vesamicol, which have been reported to possess various medicinal effects. Results suggested that MBE could be an excellent additive for liquid culture of S. vaninii mycelium, and these hydrolase-related genes also provided candidate genes for improving the nutrient absorption capacity of S. vaninii.

Biological characteristics, bioactive compounds, and antioxidant activities of off-season mulberry fruit.

To understand the yield and quality of off-season mulberry fruits, which are cultivated in open fields from autumn, the biological characteristics, bioactive compounds, and antioxidant activities of them were analyzed. Compared with mulberry fruits in normal season, the fruit length, fruit diameter, single fruit weight, fruit yield per meter strip, and the fruits yield per 667 m2 are significantly lower. The moisture content and juice yield of off-season mulberry fruits are lower than the mulberry fruits in normal season; the pH and soluble solids are higher. The contents of mass fraction of crude protein, total sugar, reducing sugar, total acids, total anthocyanins, and total flavonoids decreased significantly in all batches of off-season mulberry fruits compared with those of normal season. Of off-season mulberry fruits, the contents of glucose, fructose and sucrose, expression, anthocyanin biosynthesis genes, and antioxidant capacity are significantly lower than those in normal season.

Identification of Three Viruses Infecting Mulberry Varieties.

Viruses-mediated genome editing in plants is a powerful strategy to develop plant cultivars with important and novel agricultural traits. Mulberry alba is an important economic tree species that has been cultivated in China for more than 5000 years. So far, only a few viruses have been identified from mulberry trees, and their application potential is largely unknown. Therefore, mining more virus resources from the mulberry tree can pave the way for the establishment of useful engineering tools. In this study, eight old mulberry plants were gathered in seven geographic areas for virome analysis. Based on transcriptome analysis, we discovered three viruses associated with mulberries: Citrus leaf blotch virus isolate mulberry alba 2 (CLBV-ML2), Mulberry-associated virga-like virus (MaVLV), and Mulberry-associated narna-like virus (MaNLV). The genome of CLBV-ML2 was completely sequenced and exhibited high homology with Citriviruses, considered to be members of the genus Citrivirus, while the genomes of MaVLV and MaNLV were nearly completed lacking the 5' and 3' termini sequences. We tentatively consider MaVLV to be members of the family Virgaviridae and MaNLV to be members of the genus Narnavirus based on the results of phylogenetic trees. The infection experiments showed that CLBV-ML2 could be detected in the inoculated seedlings of both N. benthamiana and Morus alba, while MaVLV could only be detected in N. benthamiana. All of the infected seedlings did not show obvious symptoms.

Integrative Analyses of Transcriptomics and Metabolomics in Sex Differentiation of Mulberry Flowers.

Sex determination and sex differentiation of plants are important physiological processes of plant development. Mulberry (Morus indica L.) is an important economic tree being cultivated in sericulture countries, and mulberry leaf is commonly used for sericulture. The transcriptomic and metabolomic differences between the staminate flowers (SFs) and pistillate flowers (PFs) of mulberry were investigated by RNA sequencing and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Overall, we uncovered 4,230 genes and 209 metabolites are significantly differentially expressed between the SFs and PFs of mulberry. The combined transcriptomic and metabolomic analysis revealed these differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) are involved in flavonoid biosynthesis, galactose metabolism, plant-pathogen interaction, and starch and sucrose metabolism, and these detected DEGs and DEMs may be associated with sex differentiation of mulberry through the regulation of the enrichment pathways, such as the MAPK pathway, flavonoid biosynthesis, galactose metabolism, plant-pathogen interaction, and starch and sucrose metabolism. This study will provide a rich source for the analysis of the molecular mechanism of mulberry sex differentiation processes.

Protective effect of sericin peptide against alcohol-induced gastric injury in mice.

BACKGROUND: Sericin peptide (SP) has shown a powerful anti-oxidant property in a host of studies. The present study was designed to investigate the possible protective effects of SP against alcohol-induced gastric lesions in mice and to explore the potential mechanisms. METHODS: Animals were randomly divided into 5 groups: control, alcohol (56%, 14.2 ml/kg), SP-treated mice (0.2, 0.4, 0.8 g/kg). Mice were pretreated with SP before administering alcohol, the concentration of ethanol in serum and urine, the contents of malondialdehyde (MDA), glutathione (GSH) and the glutathione peroxidase (GSH-PX), catalase (CAT) and superoxide dismutase (SOD) activities in the gastric mucosa were measured, subsequently, the pathological evaluation of stomach was also observed. RESULTS: Of the animals pre-treated with SP (0.4, 0.8 g/kg), the concentration of ethanol in serum was significantly decreased, while increased in urine as compared to the alcohol-administered alone animals. Alcohol administration caused severe gastric damage as indicated by markedly increased MDA levels and decreased antioxidants, such as reduced GSH, GSH-PX and SOD in the gastric tissue while the CAT activity was not altered. On SP administration there was a reversal in these values towards normal. Histopathological studies confirmed the beneficial role of SP, which was in accordance with the biochemical parameters. CONCLUSIONS: SP could protect gastric mucosa from alcohol-induced mucosal injury. These gastroprotective effects might be due to increasing 'first-pass metabolism' in the stomach and hastening ethanol elimination directly through the urine. SP might also play an important role in the protection of the structure and function of gastric mitochondria, at least partly based on their anti-oxidant effect.

Hypoglycemic effect of deoxynojirimycin-polysaccharide on high fat diet and streptozotocin-induced diabetic mice via regulation of hepatic glucose metabolism.

Type 2 diabetes mellitus (T2DM) is currently considered a worldwide epidemic and finding effective therapeutic strategies against this disease is highly important. A deoxynojirimycin-polysaccharide mixture (DPM) has previously been shown to exert hypoglycemic effects on alloxan- or streptozotocin (STZ)-induced diabetic mice. The purpose of the present study was to evaluate the therapeutic effects and underlying mechanism(s) of DPM on T2DM induced by high fat diet following low-dose STZ treatment in mice. After daily oral treatment of diabetic mice with DPM (150 mg/kg b.w.) for 90 d, significant decline in blood glucose, pyruvate, triglyceride (TG), aspartate transaminase (AST), alanine transaminase (ALT), creatinine (Cr), lipid peroxide (LPO) and malondialdehyde (MDA) levels as well as evident increases in high density lipoprotein (HDL-c) and hepatic glycogen concentrations were observed. In the first stage, in which DPM was administered for 60 d, blood insulin levels did not undergo significant change but a significant decrease in the HOMA-IR index was detected. By contrast, the HOMA-IR index increased significantly in T2MD controls. In the second stage, in which DPM treatment was continued for another 30 d, insulin levels significantly increased in DPM-treated mice in comparison with T2DM controls. These results indicate that insulin resistance in the pre-diabetic period and the dysfunction of pancreatic ß-cells are ameliorated by DPM treatment. DPM also down-regulated protein levels of insulin receptor (IR) and gluconeogenic enzymes (pyruvate carboxylase, fructose-1, 6-bisphosphatase, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) in peripheral tissues (liver and/or muscle), but enhanced the expressions of insulin in pancreas, lipoprotein lipase (LPL) and glycolysis enzymes (glucokinase, phosphofructokinase, private kinase and pyruvate decarboxylase E1) in the liver. Furthermore, deoxynojirimycin (DNJ) and polysaccharide (P) were found to increase proliferation of hepatic LO-2 cells and scavenging of radicals in vitro. These results support the results of our biochemical analyses and underscore possible mechanisms underlying the protective effects of DPM on STZ-induced damage to the pancreas and the liver. Taken together, our findings suggest that DPM may be developed as an antihyperglycemic agent for the treatment of diabetes mellitus.

Cooperative anti-diabetic effects of deoxynojirimycin-polysaccharide by inhibiting glucose absorption and modulating glucose metabolism in streptozotocin-induced diabetic mice.

We had previously shown that deoxynojirimycin-polysaccharide mixture (DPM) not only decreased blood glucose but also reversed the damage to pancreatic ß-cells in diabetic mice, and that the anti-hyperglycemic efficacy of this combination was better than that of 1-deoxynojirimycin (DNJ) or polysachharide alone. However, the mechanisms behind these effects were not fully understood. The present study aimed to evaluate the therapeutic effects of DPM on streptozotocin (STZ)-induced diabetic symptoms and their potential mechanisms. Diabetic mice were treated with DPM (150 mg/kg body weight) for 90 days and continued to be fed without DPM for an additional 30 days. Strikingly, decrease of blood glucose levels was observed in all DPM treated diabetic mice, which persisted 30 days after cessation of DPM administration. Significant decrease of glycosylated hemoglobin and hepatic pyruvate concentrations, along with marked increase of serum insulin and hepatic glycogen levels were detected in DPM treated diabetic mice. Results of a labeled (13)C6-glucose uptake assay indicated that DPM can restrain glucose absorption. Additionally, DPM down-regulated the mRNA and protein expression of jejunal Na(+)/glucose cotransporter, Na(+)/K(+)-ATPase and glucose transporter 2, and enhanced the activities as well as mRNA and protein levels of hepatic glycolysis enzymes (glucokinase, phosphofructokinase, private kinase and pyruvate decarboxylas E1). Activity and expression of hepatic gluconeogenesis enzymes (phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) were also found to be attenuated in diabetic mice treated with DPM. Purified enzyme activity assays verified that the increased activities of glucose glycolysis enzymes resulted not from their direct activation, but from the relative increase in protein expression. Importantly, our histopathological observations support the results of our biochemical analyses and validate the protective effects of DPM on STZ-induced damage to the pancreas. Thus, DPM has significant potential as a therapeutic agent against diabetes.

Activation of P27kip1-cyclin D1/E-CDK2 pathway by polysaccharide from Phellinus linteus leads to S-phase arrest in HT-29 cells.

Our previous study showed that polysaccharide (P1) from Phellinus linteus exhibits a significant inhibitive activity on human colorectal carcinoma cells (HT-29). However its novel molecular mechanism remains unknown. To obtain insights into P1's mechanism of action, we examined its effects on cell proliferation in vitro and in vivo, cell cycle distribution, apoptosis, autophagy, and expression of several cell cycle interrelated proteins in HT-29 cells. Interestingly, we found that volume and weight of the solid tumor significantly decreased in P1 (200mg/kg)-treated mice compared with the control. However, slightly increased the body weight of the P1 treated tumor-bearing mice, with no significant increased ALT, AST levels in serum and LPO concentration in liver and kidney indicated that P1 has no toxicity to mammals at a dose of 200mg/kg. Furthermore, P1 caused a significantly dose-dependent increase in the S-phase cell cycle, but no apoptosis and autophagy in HT-29 cells. RT-PCR and Western blot results showed significantly down-regulated expressions of cyclin D1, cyclin E, and CDK2, as well as increased expressions of P27kip1 in P1 (100 µg/mL)-treated HT-29 cells. These results suggested that the activation of P27kip1-cyclin D1/E-CDK2 pathway is involved in P1-induced S-phase cell cycle arrest in HT-29 cells.

1-deoxynojirimycin inhibits glucose absorption and accelerates glucose metabolism in streptozotocin-induced diabetic mice.

We investigated the role of 1-deoxynojirimycin (DNJ) on glucose absorption and metabolism in normal and diabetic mice. Oral and intravenous glucose tolerance tests and labeled (13)C6-glucose uptake assays suggested that DNJ inhibited intestinal glucose absorption in intestine. We also showed that DNJ down-regulated intestinal SGLT1, Na(+)/K(+)-ATP and GLUT2 mRNA and protein expression. Pretreatment with DNJ (50 mg/kg) increased the activity, mRNA and protein levels of hepatic glycolysis enzymes (GK, PFK, PK, PDE1) and decreased the expression of gluconeogenesis enzymes (PEPCK, G-6-Pase). Assays of protein expression in hepatic cells and in vitro tests with purified enzymes indicated that the increased activity of glucose glycolysis enzymes was resulted from the relative increase in protein expression, rather than from direct enzyme activation. These results suggest that DNJ inhibits intestinal glucose absorption and accelerates hepatic glucose metabolism by directly regulating the expression of proteins involved in glucose transport systems, glycolysis and gluconeogenesis enzymes.

Draft genome sequence of the mulberry tree Morus notabilis.

Human utilization of the mulberry-silkworm interaction started at least 5,000 years ago and greatly influenced world history through the Silk Road. Complementing the silkworm genome sequence, here we describe the genome of a mulberry species Morus notabilis. In the 330-Mb genome assembly, we identify 128 Mb of repetitive sequences and 29,338 genes, 60.8% of which are supported by transcriptome sequencing. Mulberry gene sequences appear to evolve ~3 times faster than other Rosales, perhaps facilitating the species' spread worldwide. The mulberry tree is among a few eudicots but several Rosales that have not preserved genome duplications in more than 100 million years; however, a neopolyploid series found in the mulberry tree and several others suggest that new duplications may confer benefits. Five predicted mulberry miRNAs are found in the haemolymph and silk glands of the silkworm, suggesting interactions at molecular levels in the plant-herbivore relationship. The identification and analyses of mulberry genes involved in diversifying selection, resistance and protease inhibitor expressed in the laticifers will accelerate the improvement of mulberry plants.

Hybrid of 1-deoxynojirimycin and polysaccharide from mulberry leaves treat diabetes mellitus by activating PDX-1/insulin-1 signaling pathway and regulating the expression of glucokinase, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase in alloxan-induced diabetic mice.

ETHNOPHARMACOLOGICAL RELEVANCE: 1-Deoxynojirimycin (DNJ) discovered from mulberry trees has been reported to be a potent inhibitor of intestinal α-glycosidases (sucrase, maltase, glucoamylase), and many polysaccharides were useful in protecting against alloxan-induced pancreatic islets damage through their scavenging ability. This study was aimed to evaluate the therapeutic effect and potential mechanism(s) of the hybrid of DNJ and polysaccharide (HDP) from mulberry leaves on alloxan-induced diabetic mice. MATERIALS AND METHODS: Daily oral treatment with HDP (150 mg/kg body weight) to diabetic mice for 12 weeks, body weight and blood glucose were determined every week, oral glucose tolerance test was performed after 4 and 8 weeks, biochemical values were measured using assay kits and gene expressions were investigated by RT-PCR. RESULTS: A significant decline in blood glucose, glycosylated hemoglobin, triglyceride, aspartate transaminase and alanine transaminase levels and an evident increase in body weight, plasma insulin level and high density lipoprotein were observed in HDP treated diabetic mice. The polysaccharide (P1) showed a significant scavenging hydroxyl radicals and superoxide anion radical effects in vitro, which indicated that P1 could protect alloxan-induced pancreatic islets from damage by scavenging the free radicals and repaired the destroyed pancreatic ß-cells. Pharmacokinetics assay showed that DNJ could be absorbed from the gastrointestinal mucosa and diffused rapidly into the liver, resulted in postprandial blood glucose decrease and alleviated the toxicity caused by sustained supra-physiological glucose to pancreatic ß-cells. RT-PCR results indicated that HDP could modulate the hepatic glucose metabolism and gluconeogenesis by up/down-regulating the expression of rate-limiting enzymes (glucokinase, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) in liver and up-regulating the pancreatic and duodenal homeobox factor-1 (PDX-1), insulin-1 and insulin-2 expressions in pancreas. CONCLUSION: These findings suggested that HDP has complimentary potency to develop an antihyperglycemic agent for treatment of diabetes mellitus.