Polyhydroxylated alkaloids isolated from mulberry trees (Morusalba L.) and silkworms (Bombyx mori L.)

Two new phenolic constituents from the root bark of Morus alba L. and their cardioprotective activity

A new biphenyl-furocoumarin, named morescoumarin A (1), and a new prenylated flavanone, named morflavanone A (2) were isolated from the root bark of Morus alba L., together with four known compounds (3-6). Their structures were determined by extensive spectroscopic analyses and comparison with literature data. The cardioprotective effects of these compounds against doxorubicin-induced cell death were evaluated by MTT method.

Phenolic constituents from the root bark of Morus alba L. and their cardioprotective activity in vitro

A flavanone C-glycoside, steppogenin-5'-C-β-D-glucopyranoside, six prenylated 2-arylbenzofuran derivatives, moracin O-3″-O-β-D-glucopyranoside, moracin O-3'-O-β-D-xylopyranoside, moracin P-2″-O-β-D-glucopyranoside, moracin P-3'-O-β-D-glucopyranoside, moracin P-3'-O-α-L-arabinopyranoside and moracin P-3'-O-[β-D-glucopyranosyl-(1 → 2)]-α-L-arabinopyranoside, two phenolic acids, 2,4-dihydroxy-5-(4-hydroxybenzyl) benzoic acid and 2,4-dihydroxy-5-(3,4-dihydroxybenzyl) benzoic acid, as well as three known compounds, moracinoside C, moracin O, and moracin P were isolated from the root bark of Morus alba L. Their structures were ascertained on the basis of spectroscopic evidence. The protective effects of the compounds against doxorubicin-induced cardiomyopathy in H9c2 cells was investigated in vitro. Of all of the isolated compounds, moracin P-3'-O-β-D-glucopyranoside, moracin O and moracin P had a strong protective influence against doxorubicin-induced cell death with EC₅₀ values of 9.5 ± 2.6, 4.5 ± 1.3, and 8.8 ± 2.4 μM, respectively.

Viruses of insects reared for food and feed

The use of insects as food for humans or as feed for animals is an alternative for the increasing high demand for meat and has various environmental and social advantages over the traditional intensive production of livestock. Mass rearing of insects, under insect farming conditions or even in industrial settings, can be the key for a change in the way natural resources are utilized in order to produce meat, animal protein and a list of other valuable animal products. However, because insect mass rearing technology is relatively new, little is known about the different factors that determine the quality and yield of the production process. Obtaining such knowledge is crucial for the success of insect-based product development. One of the issues that is likely to compromise the success of insect rearing is the outbreak of insect diseases. In particular, viral diseases can be devastating for the productivity and the quality of mass rearing systems. Prevention and management of viral diseases imply the understanding of the different factors that interact in insect mass rearing. This publication provides an overview of the known viruses in insects most commonly reared for food and feed. Nowadays with large-scale sequencing techniques, new viruses are rapidly being discovered. We discuss factors affecting the emergence of viruses in mass rearing systems, along with virus transmission routes. Finally we provide an overview of the wide range of measures available to prevent and manage virus outbreaks in mass rearing systems, ranging from simple sanitation methods to highly sophisticated methods including RNAi and transgenics.

Anti-HSV Activity of Kuwanon X from Mulberry Leaves with Genes Expression Inhibitory and HSV-1 Induced NF-κB Deactivated Properties

Six stilbene derivatives isolated from Mulberry leaves including Kuwanon X, Mulberrofuran C, Mulberrofuran G, Moracin C, Moracin M 3'-O-b-glucopyranoside and Moracin M were found to have antiviral effects against herpes simplex virus type 1 and 2 (HSV-1 and HSV-2) at different potencies except for Mulberrofuran G. Kuwanon X exhibited the greatest activity against HSV-1 15577 and clinical strains and HSV-2 strain 333 with IC₅₀ values of 2.2, 1.5 and 2.5 µg/mL, respectively. Further study revealed that Kuwanon X did not inactivate cell-free HSV-1 particles, but inhibited cellular adsorption and penetration of HSV-1 viral particles. Following viral penetration, Kuwanon X reduced the expression of HSV-1 IE and L genes, and decreased the synthesis of HSV-1 DNA. Furthermore, it was demonstrated that Kuwanon X inhibited the HSV-1-induced nuclear factor (NF)-κB activation through blocking the nuclear translocation and DNA binding of NF-κB. These results suggest that Kuwanon X exerts anti-HSV activity through multiple modes and could be a potential candidate for the therapy of HSV infection.

1-Deoxynojirimycin: Occurrence, Extraction, Chemistry, Oral Pharmacokinetics, Biological Activities and In Silico Target Fishing

1-Deoxynojirimycin (DNJ, C₆H13NO₄, 163.17 g/mol), an alkaloid azasugar or iminosugar, is a biologically active natural compound that exists in mulberry leaves and Commelina communis (dayflower) as well as from several bacterial strains such as Bacillus and Streptomyces species. Deoxynojirimycin possesses antihyperglycemic, anti-obesity, and antiviral features. Therefore, the aim of this detailed review article is to summarize the existing knowledge on occurrence, extraction, purification, determination, chemistry, and bioactivities of DNJ, so that researchers may use it to explore future perspectives of research on DNJ. Moreover, possible molecular targets of DNJ will also be investigated using suitable in silico approach.

Effect of Wheat Flour Noodles with Bombyx mori Powder on Glycemic Response in Healthy Subjects

Recent trial results suggest that the consumption of a low glycemic index (GI) diet is beneficial in the prevention of high blood glucose levels. Identifying active hypoglycemic substances in ordinary foods could be a significant benefit to the management of blood glucose. It has been hypothesized that noodles with Bombyx mori powder are a low GI food. We evaluated GI and changes in postprandial glucose levels following consumption of those noodles and compared them with those following consumption of plain wheat flour noodles (control) and glucose (reference) in healthy subjects. Thirteen males (age: 34.2±4.5 years, body mass index: 23.2±1.1 kg/m2) consumed 75 g carbohydrate portions of glucose and the 2 kinds of noodle after an overnight fast. Capillary blood was measured at time 0 (fasting), 15, 30, 45, 60, 90, 120, and 180 min from the start of each food intake. The GI values were calculated by taking the ratio of the incremental area under the blood glucose response curve (IAUC) for the noodles and glucose. There was a significant difference in postprandial glucose concentrations at 30 and 45 min between the control noodles and the noodles with Bombyx mori powder: the IAUC and GI for the noodles with Bombyx mori powder were significantly lower than those for glucose and plain wheat flour noodles. The wheat flour noodles with Bombyx mori powder could help prevent an increase in postprandial glucose response and possibly provide an alternative to other carbohydrate staple foods for glycemic management.

Effects of high hydrostatic pressure and thermal processing on bioactive compounds, antioxidant activity, and volatile profile of mulberry juice

The aim of this study was to investigate the effects of high hydrostatic pressure and thermal processing on microbiological quality, bioactive compounds, antioxidant activity, and volatile profile of mulberry juice. High hydrostatic pressure processing at 500 MPa for 10 min reduced the total viable count from 4.38 log cfu/ml to nondetectable level and completely inactivated yeasts and molds in raw mulberry juice, ensuring the microbiological safety as thermal processing at 85 ℃ for 15 min. High hydrostatic pressure processing maintained significantly (p < 0.05) higher contents of total phenolic, total flavonoid and resveratrol, and antioxidant activity of mulberry juice than thermal processing. The main volatile compounds of mulberry juice were aldehydes, alcohols, and ketones. High hydrostatic pressure processing enhanced the volatile compound concentrations of mulberry juice while thermal processing reduced them in comparison with the control. These results suggested that high hydrostatic pressure processing could be an alternative to conventional thermal processing for production of high-quality mulberry juice.

Fabrication of Apigenin loaded gellan gum-chitosan hydrogels (GGCH-HGs) for effective diabetic wound healing

The Apigenin (APN) was isolated from ethanolic extract of M. alba leaves and screened by in-vivo wound models (Diabetic and Dead space) in rats. Apigenin loaded hydrogel (HGs) was prepared using gellan gum-chitosan (GGCH) with PEG as a cross linker and characterized for various parameter like AFM, swelling property, entrapment efficiency and drug release. Further performance of hydrogel was evaluated by wound healing activity tested against wound contraction, collagen content, dried granuloma weights and antioxidant activity. The percent entrapment efficiency of optimized hydrogel found to be 87.15±1.20. APN loaded GGCH-HGs were able to release 96.11% APN in 24h. The level of superoxide dismutase (SOD) and catalase were found increased significantly in granuloma tissue of APN treated group. APN GGCH-HGs found higher wound healing effect in diabetic as well as normal wound tissues with significant antioxidant activity. Results proven the utility of prepared hydrogel (APN loaded GGCH-HGs) seems to be highly suitable for wound healing due to its unique properties of biocompatibility, biodegradability, moist nature and antioxidant effectiveness.

Identification and characterization of Lateral Organ Boundaries Domain genes in mulberry, Morus notabilis

Genes from the plant specific Lateral Organ Boundaries Domain (LBD) family encode transcriptional regulators that have a variety of functions in various physiological and developmental processes. In the present study, 31 LBD genes were identified in the mulberry genome. The genome features of all MnLBD genes and phylogenetic studies with Arabidopsis LBD protein sequences, accompanied by the expression analysis of each of the Morus LBD genes provide insights into the functional prediction of mulberry LBDs. The genome-wide surveys of the current mulberry genome have resulted in the identification of catalogs of MnLBD genes that may function in the development of leaf, root, and secondary metabolism in Morus sp.

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We identified and characterized 31 LBD genes in Morus.

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We analyzed the expression and phylogeny relationship with Arabidopsis of the Morus LBD genes for function prediction.

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Morus LBD genes might implicate in variety of functions especially in lateral organ development and secondary metabolism.

1-Deoxynojirimycin Alleviates Liver Injury and Improves Hepatic Glucose Metabolism in db/db Mice

The present study investigated the effect of 1-Deoxynojirimycin (DNJ) on liver injury and hepatic glucose metabolism in db/db mice. Mice were divided into five groups: normal control, db/db control, DNJ-20 (DNJ 20 mg·kg⁻¹·day⁻¹), DNJ-40 (DNJ 40 mg·kg⁻¹·day⁻¹) and DNJ-80 (DNJ 80 mg·kg⁻¹·day⁻¹). All doses were treated intravenously by tail vein for four weeks. DNJ was observed to significantly reduce the levels of serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and liver TG, as well as activities of serum alanine aminotransferase (ALT), and aspartate transaminase (AST); DNJ also alleviated macrovesicular steatosis and decreased tumor necrosis factor α (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6) levels in liver tissue. Furthermore, DNJ treatment significantly increased hepatic glycogen content, the activities of hexokinase (HK), pyruvate kinase (PK) in liver tissue, and decreased the activities of glucose-6-phosphatase (G6Pase), glycogen phosphorylase (GP), and phosphoenolpyruvate carboxykinase (PEPCK). Moreover, DNJ increased the phosphorylation of phosphatidylinositol 3 kinase (PI3K) on p85, protein kinase B (PKB) on Ser473, glycogen synthase kinase 3β (GSK-3β) on Ser9, and inhibited phosphorylation of glycogen synthase (GS) on Ser645 in liver tissue of db/db mice. These results demonstrate that DNJ can increase hepatic insulin sensitivity via strengthening of the insulin-stimulated PKB/GSK-3β signal pathway and by modulating glucose metabolic enzymes in db/db mice. Moreover, DNJ also can improve lipid homeostasis and attenuate hepatic steatosis in db/db mice.

Enhanced anti-immobility effects of Sanggenon G isolated from the root bark of Morus alba combined with the α2-antagonist yohimbine in the rat forced swim test

In this study, we aimed to determine whether Sanggenon G, an active compound isolated from the root bark of Morus alba, exhibited enhanced anti-immobility activity with the addition of the α2-antagonist yohimbine in rats subjected to forced swim test (FST)-induced depression. Fluoxetine (a selective serotonin reuptake inhibitor) treatment in rats reduced the immobility time, and pretreatment with yohimbine significantly enhanced the antidepressant-like behavior of fluoxetine at 5, 10 and 20 mg/kg. Similarly, Sanggenon G significantly decreased the immobility time, reducing immobility by a maximum of 43.9 % when treated at a dose of 20 mg/kg. Furthermore, pretreatment with yohimbine significantly enhanced the antidepressant-like behavior of Sanggenon G at 5 and 10 mg/kg. Our findings suggest that the antidepressant-like effect of Sanggenon G could be facilitated by concomitant use of the α2-antagonist. Further studies are needed to evaluate the potential of Sanggenon G as an alternative therapeutic approach for the treatment of depression.

Pressurized liquid extraction of Aglaonema sp. iminosugars: Chemical composition, bioactivity, cell viability and thermal stability

Pressurized liquid extraction of Aglaonema sp. iminosugars has been optimized. A single cycle under optimal conditions (80mg, 100°C, 2min) was enough to extract ⩾96% of most iminosugars. Further incubation with Saccharomyces cerevisiae for 5h removed coextracted interfering low molecular weight carbohydrates from extracts of different Aglaonema cultivars. A complete characterization of these extracts was carried out by gas chromatography-mass spectrometry: three iminosugars were tentatively identified for the first time; α-homonojirimycin and 2,5-dideoxy-2,5-imino-d-mannitol were the major iminosugars determined. α-Glucosidase inhibition activity, cell viability and thermal stability of Aglaonema extracts were also evaluated. Extracts with IC50 for α-glucosidase activity in the 0.010-0.079mgmL(-1) range showed no decrease of Caco-2 cell viability at concentrations lower than 125μgmL(-1) and were stable at 50°C for 30days. These results highlight the potential of Aglaonema extracts as a source of bioactives to be used as functional ingredients.

Identification and Determination of the Polyhydroxylated Alkaloids Compounds with α-Glucosidase Inhibitor Activity in Mulberry Leaves of Different Origins

Mulberry leaves have commonly been utilized in China as a herbal medicine for the treatment of diabetes for thousands of years. To evaluate the quality, an ultra-high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC-Q-TOF/MS) method was developed for identification of polyhydroxylated alkaloids with α-glucosidase inhibitor activity in mulberry leaf. As a result, five alkaloid compounds were identified or tentatively characterized. Among them, the compound 1-deoxynojirimycin (DNJ) was selected as the most typical and active chemical marker and quantified using an improved high performance liquid chromatography (HPLC) normal phase coupled with evaporative light scattering detector (ELSD) method. The developed method was fully validated in terms of linearity, sensitivity, precision and repeatability, as well as recovery, and subsequently applied to evaluate twenty-nine batches of mulberry leaves from different collections. From the analytical data it was discovered that the average content of DNJ is 1.53 mg/g, while the total contents of DNJ in the 29 mulberry leaf sample ranged from 0.20 to 3.88 mg/g, which suggested remarkable differences, although it reached the highest levels in early August. These data may provide an important reference for the quality of mulberry leaves used as herbal medicine for the treatment of diabetes or as a material to obtain the DNJ of α-glucosidase inhibitor or as a functional food.

Inhibition of α-glucosidase activity by N-deoxynojirimycin analogs in several insect phloem sap feeders

Secondary metabolites and synthetic iminosugars that structurally resemble monosaccharides are potent inhibitors of α-glucosidase activity. The enzyme is core in cleaving sucrose in phloem feeding insects and it also plays a crucial role of reducing osmotic stress via the formation of oligosaccharides. Inhibition of hydrolysis by iminosugars should result in nutritional deficiencies and/or disruption of normal osmoregulation. Deoxynojirimycin (DNJ) and 2 N-alkylated analogs [N-butyl DNJ (NB-DNJ) and N-nonyl DNJ (NN-DNJ)] were the major iminosugars used throughout the study. The extensive experiments conducted with α-glucosidase of the whitefly Bemisia tabaci indicated the competitive nature of inhibition and that the hydrophilic DNJ is a potent inhibitor in comparison to the more hydrophobic NB-DNJ and NN-DNJ compounds. The same inhibitory pattern was observed with the psyllid Cacopsylla bidens α-glucosidase. In contrast to the above pattern, enzymes of the aphids, Myzus persicae and Aphis gossypii were more sensitive to the hydrophobic iminosugars as compared to DNJ. In vivo experiments in which adult B. tabaci were fed dietary iminosugars, show that the hydrophilic DNJ was far less toxic than the lipophilic NB-DNJ and NN-DNJ. It is proposed that this pattern is attributed to the better accessibility of the hydrophobic NN-DNJ to the α-glucosidase membrane-bound compartment in the midgut. Based on the inhibitory effects of certain polyhydroxy N-alkylated iminosugars, α-glucosidase of phloem feeding hemipterans could serve as an attractive target site for developing novel pest control agents.

Anti-tumor effect of morusin from the branch bark of cultivated mulberry in Bel-7402 cells via the MAPK pathway

In this experiment, the morusin separated from the branch bark of cultivated mulberry, an edible medicinal plant, is used to study the inhibition of morusin in the human hepatocellular carcinoma cell line Bel-7402.

1-Deoxynojirimycin Alleviates Insulin Resistance via Activation of Insulin Signaling PI3K/AKT Pathway in Skeletal Muscle of db/db Mice

1-Deoxynojirimycin (DNJ) is widely used for the treatment of diabetes mellitus as an inhibitor of intestinal α-glucosidase. However, there are few reports about its effect on insulin sensitivity improvement. The aim of the present study was to investigate whether DNJ decreased hyperglycemia by improving insulin sensitivity. An economical method was established to prepare large amounts of DNJ. Then, db/db mice were treated with DNJ intravenously (20, 40 and 80 mg·kg(-1)·day(-1)) for four weeks. Blood glucose and biochemical analyses were conducted to evaluate the therapeutic effects on hyperglycemia and the related molecular mechanisms in skeletal muscle were explored. DNJ significantly reduced body weight, blood glucose and serum insulin levels. DNJ treatment also improved glucose tolerance and insulin tolerance. Moreover, although expressions of total protein kinase B (AKT), phosphatidylinositol 3 kinase (PI3K), insulin receptor beta (IR-β), insulin receptor substrate-1 (IRS1) and glucose transporter 4 (GLUT4) in skeletal muscle were not affected, GLUT4 translocation and phosphorylation of Ser473-AKT, p85-PI3K, Tyr1361-IR-β and Tyr612-IRS1 were significantly increased by DNJ treatment. These results indicate that DNJ significantly improved insulin sensitivity via activating insulin signaling PI3K/AKT pathway in skeletal muscle of db/db mice.

Mulberry 1-Deoxynojirimycin Inhibits Adipogenesis by Repression of the ERK/PPARγ Signaling Pathway in Porcine Intramuscular Adipocytes

Intramuscular fat (IMF), which is modulated by adipogenensis of intramuscular adipocytes, plays a key role in pork quality associated with marbling, juiceness, and flavor. However, the regulatory mechanism of 1-deoxynojirimycin (DNJ) on adipogenesis is still unknown. Here, we found that both DNJ (2.0, 3.0, 4.0, 5.0, and 6.0 μM) and rosiglitazone (RSG; 0.1, 0.2, 0.3, 0.4, and 0.5 mM) had no effect on cell viability. Moreover, 4 μM DNJ significantly inhibited adipogenesis, whereas 0.4 mM RSG increased lipogenesis of porcine intramuscular adipocytes. Interestingly, DNJ sharply inhibited phosphorylation of extracellular regulated protein kinases 1/2 (ERK1/2), but did not change phosphorylation of AKT (protein kinase B) in intramuscular adipocytes. We further found that the inhibitory adipogenesis of DNJ was attenuated by RSG via up-regulation of PPARγ. On the basis of the above findings, we suggest that DNJ inhibited adipogenesis through the ERK/PPARγ signaling pathway in porcine intramuscular adipocytes.

A 1H-NMR Based Study on Hemolymph Metabolomics in Eri Silkworm after Oral Administration of 1-Deoxynojirimycin

We aimed to investigate whether 1-deoxynojirimycin (DNJ) modulates glycometabolism and has toxicity in Eri silkworm (Samia cynthia ricini, Saturniidae). In this paper, hemolymph metabolites were used to explore metabolic changes after oral administration of DNJ or mulberry latex and to characterize the biological function of DNJ at the metabolic and systemic levels. Hemolymph samples were collected from fourth-instar larvae of Eri silkworm and ex-vivo high-resolution 1H nuclear magnetic resonance (NMR) spectra were acquired from the collected hemolymph samples. Then the obtained spectra were analyzed by principal component analysis (PCA) and independent-samples t-test. Metabolic pattern recognition analysis of hemolymph samples indicated that the groups of 0.25% DNJ, latex, and the mixture of 0.5% DNJ and latex (1:1) were significantly different from the control group. Moreover, compared to the control group, the groups of 0.25% DNJ, latex, and the mixture of 0.5% DNJ and latex (1:1) showed the decreased levels of citrate, succinate, fumarate, malate, and glutamine in hemolymph, the groups of 0.25% DNJ and the mixture of 0.5% DNJ and latex (1:1) showed the increased levels of trehalose and lactate. In addition, mulberry leaves exude latex was highly toxic to Eri silkworm because rich unidentified high-molecular-weight factor (s) acted as toxic substances. In our results, latex caused 20 deaths among 50 fourth-instar larvae of Eri silkmoth, but DNJ or the mixture did not caused death. All these results suggest that DNJ has a positive impact on the reverse glycometabolism by modulating glycometabolism and inhibiting glucogenesis and energy metabolism. DNJ is a secure substance as a single-ingredient antidiabetic medicine due to its nontoxicity and bioactivity.

A novel sucrose hydrolase from the bombycoid silkworms Bombyx mori, Trilocha varians, and Samia cynthia ricini with a substrate specificity for sucrose

Although membrane-associated sucrase activity has been detected in the midgut of various lepidopteran species, it has not yet been identified and characterized at the molecular level. In the present study, we identified a novel sucrose hydrolase (SUH) gene from the following three bombycoid silkworms: Bombyx mori, Trilocha varians, and Samia cynthia ricini and named them BmSuh, TvSuh, and ScSuh, respectively. The EST dataset showed that BmSuh is one of the major glycoside hydrolase genes in the larval midgut of B. mori. These genes were almost exclusively expressed in the larval midgut in all three species, mainly at the feeding stage. SUHs are classified into the glycoside hydrolase family 13 and show significant homology to insect maltases. Enzymatic assays revealed that recombinant SUHs were distinct from conventional maltases and exhibited substrate specificity for sucrose. The recombinant BmSUH was less sensitive to sugar-mimic alkaloids than TvSUH and ScSUH, which may explain the reason why the sucrase activity in the B. mori midgut was less affected by the sugar-mimic alkaloids derived from mulberry.

Therapeutic phytogenic compounds for obesity and diabetes

Natural compounds have been used to develop drugs for many decades. Vast diversities and minimum side effects make natural compounds a good source for drug development. However, the composition and concentrations of natural compounds can vary. Despite this inconsistency, half of the Food and Drug Administration (FDA)-approved pharmaceuticals are natural compounds or their derivatives. Therefore, it is essential to continuously investigate natural compounds as sources of new pharmaceuticals. This review provides comprehensive information and analysis on natural compounds from plants (phytogenic compounds) that may serve as anti-obesity and/or anti-diabetes therapeutics. Our growing understanding and further exploration of the mechanisms of action of the phytogenic compounds may afford opportunities for development of therapeutic interventions in metabolic diseases.

Mulberry leaf extract improves postprandial glucose response in prediabetic subjects: a randomized, double-blind placebo-controlled trial

This study was a randomized, double-blind placebo-controlled trial to assess the efficacy of 4 weeks of mulberry leaf aqueous extract (MLAE) supplementation (5 g/day) for postprandial glycemic control in 36 subjects with impaired fasting glucose (IFG) tolerance. Postprandial responses in the glucose, insulin, and C-peptide levels were measured after a carbohydrate load both at baseline and after 4 weeks of MLAE supplementation. The postprandial glycemic response was attenuated in the MLAE group after the treatment period, particularly 30 and 60 min after loading (P=.003 and 0.0325 for glucose, P=.0005 and .0350 for insulin, and P=.0151 and .0864 for C-peptide). Additionally, the incremental area under the curve for insulin was significantly lower in the MLAE group than in the placebo group (P=.0207). Four weeks of MLAE supplementation improved postprandial glycemic control in individuals with IFG tolerance.

The use of plants in the traditional management of diabetes in Nigeria: pharmacological and toxicological considerations

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system.

MATERIALS AND METHODS

Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. 'Diabetes' and 'Nigeria' were used as keywords for the primary searches; and then 'Plant name - accepted or synonyms', 'Constituents', 'Drug interaction' and/or 'Toxicity' for the secondary searches.

RESULTS

The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants. Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs.

CONCLUSION

This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb-drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided.

Analysis and characterisation of phytochemicals in mulberry (Morus alba L.) fruits grown in Vojvodina, North Serbia

In this study, the polyphenolic profile of 11 Morus alba fruits grown in the Vojvodina region was investigated. Ultra high performance liquid chromatography (UHPLC) coupled with Linear Trap Quadrupole and OrbiTrap mass analyzer, and UHPLC coupled with a diode array detector and a triple-quadrupole mass spectrometer were used for the identification and quantification of the polyphenols, respectively. A total of 14 hydroxycinnamic acid esters, 13 flavonol glycosides, and 14 anthocyanins were identified in the extracts with different distributions and contents according to the sampling. The total phenolic content ranged from 43.84 to 326.29 mg GAE/100g frozen fruit. The radical scavenging capacity (50.18-86.79%), metal chelating ability (0.21-8.15%), ferric ion reducing power (0.03-38.45 μM ascorbic acid) and superoxide anion radical scavenging activity (16.53-62.83%) were assessed. The findings indicated that mulberry polyphenolics may act as potent superoxide anion radical scavengers and reducing agents.

Improved 1-Deoxynojirimycin (DNJ) production in mulberry leaves fermented by microorganism

DNJ, an inhibitor of α-glucosidase, is used to suppress the elevation of postprandial hyperglycemia. In this study, we focus on screening an appropriate microorganism for performing fermentation to improve DNJ content in mulberry leaf. Results showed that Ganoderma lucidum was selected from 8 species and shown to be the most effective in improvement of DNJ production from mulberry leaves through fermentation. Based on single factor and three factor influence level tests by following the Plackett-Burman design, the optimum extraction yield was analyzed by response surface methodology (RSM). The extracted DNJ was determined by reverse-phase high performance liquid chromatograph equipped with fluorescence detector (HPLC-FD). The results of RSM showed that the optimal condition for mulberry fermentation was defined as pH 6.97, potassium nitrate content 0.81% and inoculums volume 2 mL. The extraction efficiency reached to 0.548% in maximum which is 2.74 fold of those in mulberry leaf.

Neuroprotective effects of berry fruits on neurodegenerative diseases

Recent clinical research has demonstrated that berry fruits can prevent age-related neurodegenerative diseases and improve motor and cognitive functions. The berry fruits are also capable of modulating signaling pathways involved in inflammation, cell survival, neurotransmission and enhancing neuroplasticity. The neuroprotective effects of berry fruits on neurodegenerative diseases are related to phytochemicals such as anthocyanin, caffeic acid, catechin, quercetin, kaempferol and tannin. In this review, we made an attempt to clearly describe the beneficial effects of various types of berries as promising neuroprotective agents.

Antidepressant-like effects of the ethyl acetate soluble fraction of the root bark of Morus alba on the immobility behavior of rats in the forced swim test

In this study, the antidepressant-like effects of Morus alba fractions in rats were investigated in the forced swim test (FST). Male Wistar rats (9-week-old) were administered orally the M. alba ethyl acetate (EtOAc 30 and 100 mg/kg) and M. alba n-butanol fractions (n-BuOH 30 and 100 mg/kg) every day for 7 consecutive days. On day 7, 1 h after the final administration of the fractions, the rats were exposed to the FST. M. alba EtOAc fraction at the dose of 100 mg/kg induced a decrease in immobility behavior (p < 0.01) with a concomitant increase in both climbing (p < 0.05) and swimming (p < 0.05) behaviors when compared with the control group, and M. alba EtOAc fraction at the dose of 100 mg/kg decreased the hypothalamic-pituitary-adrenal (HPA) axis response to the stress, as indicated by an attenuated corticosterone response and decreased c-fos immunoreactivity in the hippocampal and hypothalamic paraventricular nucleus (PVN) region. These findings demonstrated that M. alba EtOAc fraction have beneficial effects on depressive behaviors and restore both altered c-fos expression and HPA activity.

Response surface optimized extraction of 1-deoxynojirimycin from mulberry leaves (Morus alba L.) and preparative separation with resins

In the present study, the extraction technology and preparative separation of 1-deoxynojirimycin from mulberry leaves were systematically investigated. Four extraction parameters (ethanol concentration, extraction temperature, extraction time and ratio of solvent to sample) were explored by response surface methodology (RSM). The results indicated that the maximal yield of 1-deoxynojirimycin was achieved with an ethanol concentration of 55%, extraction temperature of 80 °C, extraction time of 1.2 h and ratio of solvent to sample of 12:1. The extraction yield under these optimum conditions was found to be 256 mg/100 g dry mulberry leaves. A column packed with a selected resin was used to perform dynamic adsorption and desorption tests to optimize the separation process. The results show that the preparative separation of 1-deoxynojirimycin from mulberry leaves can be easily and effectively done by adopting 732 resin. In conclusion, 732 resin is the most appropriate for the separation of 1-deoxynojirimycin from other components in mulberry leaves extracts, and its adsorption behavior can be described with Langmuir isotherms and a two-step adsorption kinetics model. The recovery and purity of 1-deoxynojirimycin in the final product were 90.51% and 15.3%, respectively.

Morus alba L. suppresses the development of atopic dermatitis induced by the house dust mite in NC/Nga mice

BACKGROUND

Morus alba, a medicinal plant in Asia, has been used traditionally to treat diabetes mellitus and hypoglycemia. However, the effects of M. alba extract (MAE) on atopic dermatitis have not been verified scientifically. We investigated the effects of MAE on atopic dermatitis through in vitro and in vivo experiments.

METHODS

We evaluated the effects of MAE on the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in RAW 264.7, as well as thymus and activation-regulated chemokine (TARC/CCL17) in HaCaT cells. In an in vivo experiment, atopic dermatitis was induced by topical application of house dust mites for four weeks, and the protective effects of MAE were investigated by measuring the severity of the skin reaction on the back and ears, the plasma levels of immunoglobulin E (IgE) and histamine, and histopathological changes in the skin on the back and ears.

RESULTS

MAE suppressed the production of NO and PGE2 in RAW 264.7 cells, as well as TARC in HaCaT cells, in a dose-dependent manner. MAE treatment of NC/Nga mice reduced the severity of dermatitis and the plasma levels of IgE and histamine. MAE also reduced the histological manifestations of atopic dermatitis-like skin lesions such as erosion, hyperplasia of the epidermis and dermis, and inflammatory cell infiltration in the skin on the back and ears.

CONCLUSION

Our results suggest that MAE has potent inhibitory effects on atopic dermatitis-like lesion and may be a beneficial natural resource for the treatment of atopic dermatitis.

Natural product and natural product derived drugs in clinical trials

The 25 Natural Product (NP)-derived drugs launched since 2008 and the 100 NP-derived compounds and 33 Antibody Drug Conjugates (ADCs) in clinical trials or in registration at the end of 2013 are reviewed.

Evaluation of general toxicity and genotoxicity of the silkworm extract powder

The silkworm extract powder contain 1-deoxynojirimycin (DNJ), a potent α-glycosidase inhibitor, has therapeutic potency against diabetes mellitus. Therefore, natural products containing DNJ from mulberry leaves and silkworm are consumed as health functional food. The present study was performed to evaluate the safety of the silkworm extract powder, a health food which containing the DNJ. The repeated toxicity studies and gentic toxicity studies of the silkworm extract powder were performed to obtain the data for new functional food approval in MFDS. The safety was evaluated by a single-dose oral toxicity study and a 90 day repeated-dose oral toxicity study in Sprague-Dawley rats. The silkworm extract powder was also evaluated for its mutagenic potential in a battery of genetic toxicity test: in vitro bacterial reverse mutation assay, in vitro chromosomal aberration test, and in vivo mouse bone marrow micronucleus assay. The results of the genetic toxicology assays were negative in all of the assays. The approximate lethal dose in single oral dose toxicity study was considered to be higher than 5000 mg/kg in rats. In the 90 day study, the dose levels were wet at 0, 500, 1000, 2000 mg/kg/day, and 10 animals/sex/dose were treated with oral gavage. The parameters that were monitored were clinical signs, body weights, food and water consumptions, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, organ weights, and histopathological examination. No adverse effects were observed after the 90 day administration of the silkworm extract powder. The No-Observed-Adverse-Effect-Level (NOAEL) of silkworm extract powder in the 90 day study was 2000 mg/kg/day in both sexes, and no target organ was identified.

Fatty Acid Composition of Adipose Tissues in Obese Mice and SD Rats Fed with Isaria sinclairii Powder

Isaria sinclairii (Cicada Dongchunghacho) was studied as a potential crude natural food in powdered form. The role of tissue fatty acids in relation to the anti-obesity effects of I. sinclairii (IS) was examined by feeding the powder to SD rats ad libitum at 0, 1.25, 2.5, 5 and 10% (calculated about 8 g/kg) of the feed for a period of 3 months and 6 months. The fatty acid composition profile as indicated GC-MS, showed significantly slight dose-dependent increases in the levels of unsaturated fatty acids, particularly, arachidonic acid (C20: 4n6) , oleic acid, linoleic acid, eicosadienoic acid, eicosapentaenoic acid (EPA) (C20: 5) concentration in the the ad libitum IS-fed groups compared to the control group in SD abdominal fat over 6 month period. Over viewing of the SD and Ob mice treated Isaria sinclairii powder; there were increases in the single (mono) unsaturated fatty acids ratio but decreases in polyunsaturated fatty acid. In IS-fed groups in proportion to the treatment period, this Dongchunghacho also induced an increase in the level of same result of unsaturated fatty acid in C57BL/6 obese (ob/ob) mice over a 6-month period treatment compared to those given 10% dry mulberry leaf powder (ML) or silkworm powder mixed with the standard diet.