Enhancement of Neuroprotection of Mulberry Leaves (Morus alba L.) Prepared by the Anaerobic Treatment against Ischemic Damage

Mulberry leaves juice attenuates arsenic-induced neurobehavioral and hepatic disorders in mice

Arsenic (As) poisoning has caused an environmental catastrophe in Bangladesh as millions of people are exposed to As-contaminated drinking water. Chronic As-exposure causes depression, memory impairment, and liver injury in experimental animals. This study was carried out to assess the protective effect of mulberry leaves juice (Mul) against As-induced neurobehavioral and hepatic dysfunctions in Swiss albino mice. As-exposed mice spent significantly reduced time in open arms and increased time spent in closed arms in the elevated plus maze (EPM) test, whereas they took significantly longer time to find the hidden platform in the Morris water maze (MWM) test and spent significantly less time in the desired quadrant when compared to the control mice. A significant reduction in serum BChE activity, an indicator of As-induced neurotoxicity-associated behavioral changes, was noted in As-exposed mice compared to control mice. Supplementation of Mul to As-exposed mice significantly increased serum BChE activity, increased the time spent in open arms and reduced time latency to find the hidden platform, and stayed more time in the target quadrant in EPM and MWM tests, respectively, compared to As-exposed-only mice. Also, a significantly reduced activity of BChE, AChE, SOD, and GSH in brain, and elevated ALP, AST, and ALT activities in serum were noted in As-exposed mice when compared to control mice. Mul supplementation significantly restored the activity of these enzymes and also recovered As-induced alterations in hepatic tissue in As-exposed mice. In conclusion, this study suggested that mulberry leaves juice attenuates As-induced neurobehavioral and hepatic dysfunction in mice.

Phytochemistry, bioactivities and future prospects of mulberry leaves: A review

Mulberry leaves (MLs) have been used traditionally to raise silkworms and as herbs and herbal drinks. In vitro and in vivo studies as well as some clinical trials provide some evidence of health benefits, mostly for ML extracts. ML extracts showed antioxidant, hypoglycemic, anticholesterol (affecting lipid metabolism), antiobesity, anti-inflammatory, anticancer activities, and so on. These might be linked to strong antioxidant activities, inhibition of α-glucosidase and α-amylase, reduction of foam cell formation, inhibition of fat formation, decrease of NF-κB activity, and the promotion or induction of apoptosis. Phenolic constituents, especially flavonoids, phenolic acids and alkaloids, are likely to contribute to the reported effects. The phytochemistry and pharmacology of MLs confer the traditional and current uses as medicine, food, fodder, and cosmetics. This paper reviews the economic value, chemical composition and pharmacology of MLs to provide a reference for the development and utilization of MLs.

Effect of Morus alba leaf extract dose on lipid oxidation, microbiological stability, and sensory evaluation of functional liver pâtés during refrigerated storage

Mulberry (Morus alba L.), and above all the extract from the leaves of this plant, is a natural medicine that has been used in traditional medicine for hundreds of years. Mulberry leaves contains polyphenol compounds: flavonoids, coumarins, numerous phenolic acids, as well as terpenes and steroids. The antioxidant effect of these compounds may be beneficial to the fat fraction of meat products, thereby increasing their functional qualities. The aim of the study was to evaluate the effectiveness of the use of mulberry water leaf extract, as an additive limiting adverse fat changes and affecting the functionality in model liver pâtés. Pork pâtés were prepared by replacing 20% of animal fat with rapeseed oil (RO), and water extract of mulberry leaves was added in the proportion of 0.2%, 0.6% and 1.0%. It has been shown that the addition of mulberry leaf extract delayed the appearance of primary and secondary fat oxidation products. The most effective antioxidant effect during 15-day storage was observed in the sample with the addition of 0.6% and 1.0% water mulberry leaf extract. These samples also showed inhibiting activity against angiotensin-converting enzymes and cholinesterase's. During storage, the tested pâtés had a high sensory quality with unchanged microbiological quality. Mulberry leaf extract can be an interesting addition to the production of fat meat products, delaying adverse changes in the lipid fraction and increasing the functionality of products.

Pharmacological Activities for Morus alba L., Focusing on the Immunostimulatory Property from the Fruit Aqueous Extract

Depending on the extraction method, numerous compounds that have specific pharmacological effects can be obtained from M. alba L. There is a growing scientific interest in health problems related to aging. Efforts to develop safe immune-enhancing pharmaceuticals are increasing. This review aims to summarize and critically discuss the immunity enhancement effects and pharmaceutical efficacy of M. alba L. extracts. The scientific database search was conducted using Google Scholar, Web of Science, and PubMed until May 2021. Additional articles were identified and obtained from references in the retrieved articles. Ethanol or methanol extraction of various parts of M. alba L. identified a large amount of phenols and flavonoids, which are effective for immunosuppression, antioxidants, and cardiovascular diseases, and are antibacterial, and anticancer. Water extraction of M. alba L. enhanced the innate immune response based on immune cell activation. A polysaccharide and an alkaloid related to increased macrophage activity were isolated from M. alba L. fruit extracts. M. alba L. fruit water extracts primarily induced the production of pro-inflammatory substances, in model organisms, via TLR4 in immune cells. Water extracts have been shown to be effective in pathogen defense and tumor suppression by enhancing macrophage activity. Based on our literature review on the bioactivity of M. alba L. fruit extracts, particularly in relation to their immunity enhancement activity, we anticipate that M. alba-derived pharmaceuticals will have excellent potential in future medical research.

Albanin A, Derived from the Root Bark of Morus alba L., Depresses Glutamate Release in the Rat Cerebrocortical Nerve Terminals via Ca2+/Calmodulin/Adenylate Cyclase 1 Suppression

Decreasing synaptic release of glutamate may counteract glutamate excitotoxicity in many neurological diseases. In this study, we investigated the effect of albanin A, a constituent in the root bark of Morus alba L., on the release of glutamate in rat cerebral cortex nerve endings (synaptosomes). We found that albanin A at 5-30μM suppressed 4-aminopyridine (4-AP)-induced release of glutamate. This phenomenon was abolished by extracellular calcium removal or by vesicular transporter inhibition, and was associated with a decrease in intrasynaptosomal Ca²⁺ levels. However, albanin A had no effect on the synaptosomal membrane potential. The inhibition of N- and P/Q-type Ca²⁺ channels, calmodulin, adenylate cyclase (AC), and protein kinase A, abolished the effect of albanin A on the glutamate release evoked by 4-AP. Moreover, the albanin A-mediated inhibition of glutamate release was prevented by the Ca²⁺/calmodulin-stimulated AC1 inhibitor. Western blot showed that AC1, but not AC8, was presented in the synaptosomes, and albanin A reduced 4-AP-induced increases in synaptosomal cyclic adenosine monophosphate content. In addition, albanin A pretreatment substantially attenuated neuronal damage in a rat model of kainic acid-induced glutamate excitotoxicity. Our data reveal that albanin A suppresses glutamate release by decreasing Ca²⁺/calmodulin/AC1 activation in synaptosomes and exerts neuroprotective effect in vivo.

Effects of Mulberry on The Central Nervous System: A Literature Review

Background

Mulberry, including several species belonging to genus Morus, has been widely used as a traditional medicine for a long time. Extracts and active components of mulberry have many positive neurological and biological effects and can become potential candidates in the search for new drugs for neurological disorders.

Objectives

We aimed to systematically review the medical literature for evidence of mulberry effects on the central nervous system.

Methods

We conducted a systematic search in nine databases. We included all in vivo studies investigating the effect of mulberry on the central nervous system with no restrictions.

Results

We finally included 47 articles for quality synthesis. Our findings showed that mulberry and its components possessed an antioxidant effect, showed a reduction in the cerebral infarct volume after stroke. They also improved the cognitive function, learning process, and reduced memory impairment in many animal models. M. alba and its extracts ameliorated Parkinson's disease-like behaviors, limited the complications of diabetes mellitus on the central nervous system, possessed anti-convulsant, anti-depressive, and anxiolytic effects.

Conclusion

Mulberry species proved beneficial to many neurological functions in animal models. The active ingredients of each species, especially M. alba, should be deeper studied for screening potential candidates for future treatments.

Morus alba leaf extract mediates neuroprotection against glyphosate-induced toxicity and biochemical alterations in the brain

Recent studies demonstrate that glyphosate exposure is associated with oxidative stress and some neurological disorders such as Parkinson's pathology. Therefore, phytochemicals, in particular phenolic compounds, have attracted increasing attention as potential agents for neuroprotection. In the present study, we investigate the impact of glyphosate on the rat brain following i.p. injection and the possible molecular target of neuroprotective activity of the phenolic fraction from Morus alba leaf extract (MALE) and its ability to reduce oxidative damage in the brain. Wistar rats from 180 to 240 g were i.p. treated with a single dose of glyphosate (100 mg kg-1 b.w.) or MALE (100 μg mL-1 kg-1 b.w.) for 2 weeks. Brain homogenates were used to evaluate neurotoxicity induced by the pesticide. For this, biochemical parameters were measured. Data shows that MALE regulated oxidative stress and counteracted glyphosate-induced deleterious effects and oxidative damage in the brain, as it abrogated LDH, protein carbonyls, and malonyldialdehyde. MALE also appears to be able to scavenge H2O2 levels, maintain iron and Ca2+ homeostasis, and increase SOD activity. Thus, in vivo results showed that mulberry leaf extract is a potent protector against glyphosate-induced toxicity, and its protective effect could result from synergism or antagonism between the various bioactive phenolic compounds in the acetonic fraction from M. alba leaf extract.

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.

Coumarins with α-glucosidase and α-amylase inhibitory activities from the flower of Edgeworthia gardneri

The flower of Edgeworthia gardneri is consumed in beverages in Tibet and has potential health benefits for diabetes. As a part of our continuous studies on dietary supplements for diabetes, two monomers, five dimers and one trimer of coumarins were isolated from the flowers of E. gardneri. One dimer was a new compound (1) and its structure was determined by spectroscopic methods, including multiple NMR techniques and mass spectrometry. The inhibitory activities of all coumarins against α-amylase and α-glucosidase were evaluated. Compound 4 displayed potent inhibitory effect on both α-amylase and α-glucosidase, with an IC50 of 90 and 86μg/mL, respectively. The IC50 of compound 3 against α-glucosidase was 18.7μg/mL, and its inhibition mode was noncompetitive. Based on the fluorescence analysis, the binding constant and the number of binding sites of compound 3 were calculated as 2.05×10(5) and 1.24, respectively. Furthermore, the interaction between compound 3 and α-glucosidase was a spontaneous process that was driven mainly by hydrophobic force. This study could facilitate the utilization of E gardneri as functional food ingredient.

Antidepressant-Like Effects of Sanggenon G, Isolated from the Root Bark of Morus alba, in Rats: Involvement of the Serotonergic System

The root bark of Morus alba is commonly used as an alternative medicine due to its numerous health benefits in humans. However, the antidepressant effects of various active components from M. alba have not been fully elucidated. In this study, we aimed to determine whether sanggenon G, an active compound isolated from the root bark of M. alba, exhibited antidepressant-like activity in rats subjected to forced swim test (FST)-induced depression. Acute treatment of rats with sanggenon G (30 mg/kg, intraperitoneally (i.p.)) significantly reduced immobility time and increased swimming time without any significant change in climbing. Rats treated with sanggenon G also exhibited a decrease in the limbic hypothalamic-pituitary-adrenal (HPA) axis response to the FST, as indicated by attenuation of the corticosterone response and decreased c-Fos immunoreactivity in the hypothalamic paraventricular nucleus (PVN). In addition, the antidepressant-like effects of sanggenon G were significantly inhibited by WAY100635 (1 mg/kg, i.p.; a selective 5-hydroxytryptamine1A (5-HT1A) receptor antagonist), but not SCH23390 (0.05 mg/kg, i.p.; a dopamine D1 receptor antagonist). Our findings suggested that the antidepressant-like effects of sanggenon G were mediated by an interaction with the serotonergic system. Further studies are needed to evaluate the potential of sanggenon G as an alternative therapeutic approach for the treatment of depression.

Oxyresveratrol abrogates oxidative stress by activating ERK-Nrf2 pathway in the liver

Oxyresveratrol is a polyphenolic phytoalexin produced by plants as an antioxidant. This study investigated the hepatoprotective effects of oxyresveratrol as well as its underlying mechanism of action. Here, we evaluated the protective effects of oxyresveratrol against tert-butyl hydroperoxide (tBHP)-induced severe oxidative stress in HepG2 cells as well as acute liver injury caused by carbon tetrachloride (CCl4) in mice. tBHP-induced reactive oxygen species production and cell death in hepatocytes were blocked by oxyresveratrol, as indicated by MTT, TUNEL, and FACS analyses. Moreover, pretreatment with oxyresveratrol increased nuclear translocation and transactivation of NF-E2-related factor 2 (Nrf2), as assessed by antioxidant response element reporter gene expression and immunofluorescence staining, and transactivated expression of both hemeoxygenase-1 and glutamate-cysteine ligase catalytic subunit. More importantly, oxyresveratrol induced phosphorylation of Nrf2 mediated through activation of extracellular signal-regulated kinase 1/2 (ERK1/2). Further, ERK inhibitors such as PD98059 and U0126 blocked phosphorylation of Nrf2 as well as the protective effect of oxyresveratrol in mitochondria. In mice, oral administration of oxyresveratrol significantly prevented hepatocyte degeneration, inflammatory cell infiltration, as well as elevation of plasma markers such as ALT and AST induced by CCl4 injection. In conclusion, this study confirmed that oxyresveratrol protected hepatocytes against oxidative stress and mitochondrial dysfunction, which might be associated with activation of Nrf2.

Mulberry extracts alleviate aβ 25-35-induced injury and change the gene expression profile in PC12 cells

Mulberry, which contained high amounts of anthocyanins, has been used in traditional Chinese medicine. Mulberry fruit extracts (ME) have demonstrated the antioxidant activity and neuroprotection. The study was to investigate the neuroprotective efficacy of ME against β-amyloid 25–35- (Aβ_25–35-) induced PC12 cells injury. Cells preincubated with or without ME (200 μg/mL) for 24 h were treated with Aβ_25–35 (20 μmol/L) for another 24 h. Cell viability was assessed by MTT, gene expression profiles were examined by cDNA microarrays, and RT-PCR were used to confirm the results of microarray assays. ME pretreatment was found to neutralize the cytotoxicity and prevent Aβ_25–35-induced cells injury. Analyses of gene expression profile revealed that genes involving cell adhesion, peptidase activity, cytokine activity, ion binding activity, and angiogenesis regulation were significantly modulated by ME pretreatment. Among those genes, Apaf1, Bace2, and Plcb4 were enriched in the “Alzheimer's disease-reference pathway” and downregulated after ME intervention. RT-PCR results showed that ME preincubation could significantly inhibit Aβ_25–35 increased mRNA levels of these three genes. Overall, ME pretreatment could substantially alleviate PC12 cells injury and downregulate expression of AD-related genes, such as Apaf1, Bace2, and Plcb4. This study has a great nutrigenomics interest and brings new and important light in the field of AD intervention.

A sensitive LC-MS/MS method for simultaneous determination of six flavonoids in rat plasma: application to a pharmacokinetic study of total flavonoids from mulberry leaves

A simple and sensitive LC-MS/MS method has been developed and validated for the determination of rutin, isoquercitrin, astragalin, quercetin, kaempferol and isorhamnetin in rat plasma using naringin as the internal standard (IS). The plasma samples were pretreated and extracted by liquid-liquid extraction. Chromatographic separation was accomplished on a C18 column with a 10 min gradient elution using acetonitrile and 0.1% formic acid aqueous solution as mobile phase at a flow rate of 0.3 mL min(-1). A tandem mass spectrometric detection was conducted using multiple reaction monitoring (MRM) via an electrospray ionization (ESI) source and operating in the negative ionization mode. The lower limit of quantitation (LLOQ) of each analyte was lower than 1 ng mL(-1). Intra-day and inter-day precisions were less than 11.9%. The relative errors of accuracy were in the range of -9.2% to 6.1%. The mean recoveries of flavonoids and IS were higher than 53.8%. The proposed method was further applied to investigate the pharmacokinetics of all analytes after a single oral administration of total flavonoids from mulberry leaves to rats.

Morus alba and active compound oxyresveratrol exert anti-inflammatory activity via inhibition of leukocyte migration involving MEK/ERK signaling

BACKGROUND

Morus alba has long been used in traditional Chinese medicine to treat inflammatory diseases; however, the scientific basis for such usage and the mechanism of action are not well understood. This study investigated the action of M. alba on leukocyte migration, one key step in inflammation.

METHODS

Gas chromatography-mass spectrometry (GC-MS) and cluster analyses of supercritical CO2 extracts of three Morus species were performed for chemotaxonomy-aided plant authentication. Phytochemistry and CXCR4-mediated chemotaxis assays were used to characterize the chemical and biological properties of M. alba and its active compound, oxyresveratrol. fluorescence-activated cell sorting (FACS) and Western blot analyses were conducted to determine the mode of action of oxyresveratrol.

RESULTS

Chemotaxonomy was used to help authenticate M. alba. Chemotaxis-based isolation identified oxyresveratrol as an active component in M. alba. Phytochemical and chemotaxis assays showed that the crude extract, ethyl acetate fraction and oxyresveratrol from M. alba suppressed cell migration of Jurkat T cells in response to SDF-1. Mechanistic study indicated that oxyresveratrol diminished CXCR4-mediated T-cell migration via inhibition of the MEK/ERK signaling cascade.

CONCLUSIONS

A combination of GC-MS and cluster analysis techniques are applicable for authentication of the Morus species. Anti-inflammatory benefits of M. alba and its active compound, oxyresveratrol, may involve the inhibition of CXCR-4-mediated chemotaxis and MEK/ERK pathway in T and other immune cells.

A comparative study on the antioxidant activity of methanolic extracts from different parts of Morus alba L. (Moraceae)

Background

Antioxidants play an important role to protect damage caused by oxidative stress (OS). Plants having phenolic contents are reported to possess antioxidant properties. The present study was designed to investigate the antioxidant properties and phenolic contents (total phenols, flavonoids, flavonols and proanthrocyanidins) of methanolic extracts from Morus alba (locally named as Tut and commonly known as white mulberry) stem barks (TSB), root bark (TRB), leaves (TL) and fruits (TF) to make a statistical correlation between phenolic contents and antioxidant potential.

Methods

The antioxidant activities and phenolic contents of methanolic extractives were evaluated by in vitro standard method using spectrophotometer. The antioxidant activities were determined by total antioxidant capacity, DPPH (1,1-diphenyl-2-picrylhydrazine) radical scavenging assay, hydroxyl radical scavenging assay, ferrous reducing antioxidant capacity and lipid peroxidation inhibition assay methods.

Results

Among the extracts, TSB showed the highest antioxidant activity followed by TRB, TF and TL. Based on DPPH and hydroxyl radical scavenging activity, the TSB extract was the most effective one with IC₅₀ 37.75 and 58.90 μg/mL, followed by TRB, TF and TL with IC₅₀ 40.20 and 102.03; 175.01 and 114.63 and 220.23 and 234.63 μg/mL, respectively. The TSB extract had the most potent inhibitory activity against lipid peroxidation with IC₅₀ 145.31 μg/mL. In addition, the reducing capacity on ferrous ion was in the following order: TSB > TRB > TL > TF. The content of phenolics, flavonoids, flavonols and proanthocyanidins of TSB was found to be higher than other extractives.

Conclusion

The results indicate high correlation and regression (p-value <0 .001) between phenolic contents and antioxidant potentials of the extracts, hence the Tut plant could serve as effective free radical inhibitor or scavenger which may be a good candidate for pharmaceutical plant-based products. However, further exploration is necessary for effective use in both modern and traditional system of medicines.

Effect of mulberry silage supplementation during late fattening stage of Hanwoo (Bos taurus coreanae) steer on antioxidative enzyme activity within the longissimus muscle

This study was conducted to determine the possible application of mulberry silage as a functional feed in the feeding management of Hanwoo, Korean native cattle, for high quality beef production. Twenty Hanwoo steers in the last stage of fattening were randomly assigned to two groups with (MSS) or without (Control) supplemental mulberry silage. The Control group was fed on a standard total mixed commercial ration, while the MSS group was fed on a total mixed commercial ration formulated with mulberry silage at the rate of 10%, fresh matter basis, for 30 days. The mulberry silage contained active ingredients such as 1-deoxynojirimycin, γ-aminobutyric acid, and phenol compounds. In the present study, the oxidative stress biomarkers such as glutathione, superoxide dismutase, glutathione peroxidase, catalase, and glutathione-S-transferase were improved in the MSS group compared with the Control group. Electron spin resonance assays showed that 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was significantly elevated by 75.5% in the MSS group (P < 0.001). Moreover, the MSS group exhibited stronger scavenging activity against hydroxyl radicals, superoxide radicals, and alkyl radicals, and the radical scavenging activity occurred in a dose-dependent manner. Findings from the present study suggest that mulberry silage may be useful as a functional feed by improving the antioxidant activity against various reactive radicals for beef cattle.

Inhibitory effect of 2-arylbenzofurans from the Mori Cortex Radicis (Moraceae) on oxygen glucose deprivation (OGD)-induced cell death of SH-SY5Y cells

Three known 2-arylbenzofurans, moracin P (1), moracin O (2) and mulberrofuran Q (3) were isolated from the MeOH extract of the Mori Cortex Radicis. These compounds 1-3 enhanced cell viability in dose-dependent manner against oxygen-glucose deprivation (OGD)-induced cell death in neuroblastoma SH-SY5Y cells, which was measured by MTT reduction assay. (EC(50) values of 10.4, 12.6, and 15.9 μM, respectively). In addition, the compounds 1-3 were examined for their inhibitory effect on OGD-induced ROS production by FACS analysis. We observed these compounds reduced ROS production in OGD-induced cell death (IC(50) values of 1.9, 0.3 and 12.1 μM, respectively). Consequently, reactive oxygen species (ROS) were overexpressed in OGD-induced cells and all three compounds reduced ROS induced by OGD in dosedependent manner. Taken together, compounds 1-3 might protect neuronal cell death against the oxidative stress induced by OGD, though further studies in vitro and in vivo models are necessary.

Morus bombycis Koidzumi extract suppresses collagen-induced arthritis by inhibiting the activation of nuclear factor-κB and activator protein-1 in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Morus bombycis Koidzumi is widely distributed in Asia. In Korea, it has been used in traditional medicine because of its apparent anti-inflammatory, antioxidant, and hepatoprotective properties.

AIM OF THE STUDY

Although the extract of Morus bombycis Koidzumi (MB) has long since been used as a traditional anti-inflammatory medicine in Korea, its effect on arthritis remains unknown. We aimed to investigate the anti-arthritis activity of MB and the mechanism underlying it.

MATERIALS AND METHODS

The anti-arthritis activity of MB was assessed by using mouse models of type II collagen-induced arthritis (CIA). The clinical arthritis index and histopathological changes were evaluated in mice. Reverse transcriptase-polymerase chain reaction (RT-PCR), electrophoretic mobility shift assay (EMSA), and other biologic approaches were used for measuring the effect of MB on arthritis and understanding the underlying mechanism.

RESULTS

MB significantly decreased the clinical arthritis index in CIA mice; this was confirmed by examining histological changes in joints. Infiltration of immune cells, synovial hyperplasia, cartilage destruction, and bone erosion in the hind paw were largely suppressed by MB. The mRNA levels of matrix metalloproteinase (MMP)-1/MMP-3, inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6), and chemokines (macrophage inflammatory protein (MIP)-1, monocyte chemoattractant protein (MCP)-1, RANTES) were significantly suppressed by MB in a dose-dependent manner. The number of osteoclasts in the hind tibia was also significantly decreased. With regard to the mechanism, MB suppressed the activation of nuclear factor (NF)-κB and activator protein (AP)-1 in CIA mice.

CONCLUSIONS

MB produced an anti-arthritis effect in CIA mice by inhibiting the production of critical inflammatory mediators and osteoclasts through the downregulation of NF-κB and AP-1.

Effect of Morus alba L. (mulberry) leaves on anxiety in mice

Objective:

The aim of the present work is to evaluate the anxiolytic effect of a methanolic extract of Morus alba L. leaves in mice.

Materials and Methods:

The hole-board test, elevated plus-maze paradigm, open field test, and light/dark paradigm were used to assess the anxiolytic activity of the methanolic extract of M. alba L. Morus alba extract (50, 100, and 200 mg/kg, i.p.) and diazepam (1 mg/kg, i.p.) were administered 30 min before the tests.

Results:

The results showed that the methanolic extract of M. alba significantly increased the number and duration of head poking in the hole-board test. In the elevated plus-maze, the extract significantly increased the exploration of the open arm in similar way to that of diazepam. At a dose of 200 mg/kg i.p. the extract significantly increased both the time spent in and the entries into the open arm by mice. Further, in the open field test, the extract significantly increased rearing, assisted rearing, and number of squares traversed, all of which are demonstrations of exploratory behavior. In the light/dark paradigm, the extract produced significant increase in time spent in the lighted box as compared to vehicle. The spontaneous locomotor activity count, measured using an actophotometer, was significantly decreased in animals pretreated with M. alba extract, indicating a remarkable sedative effect of the plant.

Conclusion:

The results of the present study suggest that a methanolic extract of M. alba leaves may possess an anxiolytic effect.

Anti-dopaminergic effect of the methanolic extract of Morus alba L. leaves

Objective:

To evaluate the effect of methanolic extract of Morus alba L. leaves on dopaminergic function.

Materials and Methods:

The effect of the methanolic extract of Morus alba L. leaves was evaluated on haloperidol and metoclopramide induced catalepsy, foot shock-induced aggression, amphetamine-induced stereotyped behavior and phenobarbitone induced sleeping in mice. In each of these tests, the extract was administered in doses of 50, 100 and 200 mg/kg, i.p., 30 min before performing the test in mice. Further, the inhibitory effect of the extract on dopamine was studied using isolated rat vas deferens.

Results:

The extract produced significant dose dependent potentiation of haloperidol (1 mg/kg, i.p.) and metoclopramide (20 mg/kg, i.p.) induced catalepsy in mice. The extract significantly reduced number of fights and increased latency to fights in foot shock-induced aggression; it also decreased amphetamine (1 mg/kg, i.p.) induced stereotyped behavior in a dose dependent manner. The sleeping time induced by phenobarbitone (50 mg/kg, i.p.) too was prolonged. The extract inhibited contractions produced by dopamine on isolated rat vas deferens.

Conclusion:

The results suggest that the methanolic extract of Morus alba L. possesses antidopaminergic activity. Further neurochemical investigation can explore the mechanism of action of the plant drug with respect to antidopaminergic functions and help to establish the plant as an antipsychotic agent.

Protective effect of Morus alba leaves on haloperidol-induced orofacial dyskinesia and oxidative stress

Long-term treatment with haloperidol, a typical neuroleptic, induces neurodegeneration caused by excitotoxicity and oxidative stress, which play an important role in the development of orofacial dyskinesia. In the present investigation, an attempt has been made to examine the effect of a concomitant treatment of methanol extract of Morus alba Linn. (Moraceae) leaves (100-300 mg/kg, i.p.) and haloperidol (1 mg/kg, i.p.) on an animal model of tardive dyskinesia. Rats were treated for 21 days with haloperidol and Morus alba extract; vacuous chewing movements and tongue protrusions were counted. The extract attenuated the increase in vacuous chewing movements and tongue protrusions induced by haloperidol, which were quantified on day 22. The extract showed a marked effect on behavioral parameters altered by haloperidol treatment. Similar treatment with extract attenuated haloperidol-induced lipid peroxidation and nitrite and normalized superoxide dismutase, catalase, and protein in comparison to the control group. The results suggest a protective effect of Morus alba extract against haloperidol-induced orofacial dyskinesia and oxidative stress.

Inhibitory effects on mushroom tyrosinase by flavones from the stem barks of Morus lhou (S.) Koidz

Five flavones displaying tyrosinase inhibitory activity were isolated from the stem barks of Morus lhou (S.) Koidz., a cultivated edible plant. The isolated compounds were identified as mormin (1), cyclomorusin (2), morusin (3), kuwanon C (4), and norartocarpetin (5). Mormin (1) was characterized as a new flavone possesing a 3-hydroxymethyl-2-butenyl at C-3. The inhibitory potencies of these flavonoids toward monophenolase activity of mushroom tyrosinase were investigated. The IC50 values of compounds 1-5 for monophenolase activity were determined to be 0.088, 0.092, 0.250, 0.135 mM, and 1.2 microM, respectively. Mormin (1), cyclomorusin (2), kuwanon C (4) and norartocarpetin (5) exhibited competitive inhibition characteristics. Interestingly norartocarpetin (5) showed a time-dependent inhibition against oxidation of L-tyrosine: it also operated under the enzyme isomerization model (k5 = 0.8424 min(-1), k6 = 0.0576 min(-1), K(app)(i) = 1.354 microM).

Mulberry leaf ameliorates the expression profile of adipocytokines by inhibiting oxidative stress in white adipose tissue in db/db mice

Previous study showed that mulberry (Morus Alba L.) leaf (ML) ameliorates atherosclerosis in apoE(-/-) mice. Although the adipocytokine dysregulation is an important risk factor for atherosclerotic cardiovascular disease, the effect of ML on metabolic disorders related to adipocytokine dysregulation and inflammation has not been studied. Therefore, we studied the effects of ML in metabolic disorders and examined the mechanisms by which ML ameliorates metabolic disorders in db/db mice. We treated db/db mice with ML, pioglitazone, or both for 12 weeks and found that ML decreased blood glucose and plasma triglyceride. Co-treatment with ML and pioglitazone showed additive effects compared with pioglitazone. Moreover, their co-treatment attenuated the body weight increase observed under the pioglitazone treatment. ML treatment also increased the expression of adiponectin, and decreased the expression of TNF-alpha, MCP-1, and macrophage markers in white adipose tissue (WAT). Furthermore, ML decreased lipid peroxides and the expression of NADPH oxidase subunits in WAT and liver. Their co-treatment enhanced these effects. Thus, ML ameliorates adipocytokine dysregulation at least in part through inhibiting oxidative stress in WAT of db/db mice, and that ML may be a basis for a pharmaceutical for the treatment of the metabolic syndrome as well as reducing adverse effects of pioglitazone.

Localization of mucilaginous polysaccharides in mulberry leaves

Mulberry tree leaves were shown to have mucilaginous polysaccharides. The extracted water-soluble mucilage was separated into three fractions via a cetylpyridinum chloride complex and purified by anion-exchange chromatography. Five acidic polysaccharides were separated from these fractions, one of which was a major polysaccharide (Mp-3) that was structurally analyzed and used for antibody preparation. The Mp-3 polysaccharide contained rhamnose, galactose, glucose, galacturonic acid, and glucuronic acid in a molar ratio of 1 : 0.2 : 0.5 : 2.3 : 1.5 as constituent monosaccharides. Methylation and gas chromatography-mass spectrometry analysis indicated that the polysaccharide was a rhamnogalacturonan mainly consisting of 1,2,3-linked rhamnose residues, 1,3,4- and 1,4-linked uronic acid residues, and terminal uronic acid residues. Its molecular weight was estimated to be 5.5 x 10(5). Immunohistological observation revealed that the Mp-3 polysaccharide is specifically localized in inner epidermal cells situated in adaxial leaves, and electron microscopy showed that its subcellular location is between the plasma membrane and the cell wall. In young leaves, numerous secretory vesicles were present in a shrunken cytoplasm that was surrounded by fibers. In mature leaves, more than 20% of total epidermal cells were these inner cells in which polysaccharide deposition was significantly increased. The deposits appeared as a rounded electron-dense mass throughout the inner cells by electron microscopy.

Mulberry leaves protect rat tissues from immobilization stress-induced inflammation

The ability of the antioxidants in the mulberry leaves to protect Sprague-Dawley rats from injuries caused by immobilization stress was studied as an indicator of the tissue bioavailability of antioxidants. Nitrite level, lipid peroxidation and total antioxidant activity (TAA) in the plasma and tissues were measured. There were hypertrophy of the adrenal glands and kidneys, significant increased levels of nitrite in the plasma and adrenal glands, elevated thiobarbituric acid reactive substances (TBARS) in the plasma, kidneys and spleen, and a reduction of TAA in the plasma, liver, adrenal glands, kidneys and spleen of the immobilized rats. Antioxidants in the mulberry leaf extract suppressed the increase of nitrite and TBARS. Adrenal glands appeared to be the target organ of the antioxidants in the leaf extract. The low dose mulberry antioxidants were more effective than pure rutin (4 mg/day) to protect the cells against inflammation and peroxidation induced by stress.

The Effects of Chronic Treatment with Morus bombycis KOIDZUMI in Spontaneously Hypertensive Rats

The present study was performed to evaluate the antihypertensive effects of Morus bombycis KOIDZUMI (MK) in spontaneously hypertensive rats (SHRs). In addition, the effects on vascular responses and cardiac functions were also investigated. In isolated rat aortic preparations, the 100% ethanol extract of MK exhibited a potent vascular relaxant effect with IC(50) value of 3.9 microg/ml, and this vasorelaxant effect was completely abolished by pretreatment of the aortic tissues with N(G)-nitro-L-arginine methyl ester or the denudation of endothelial layer. In isolated rat hearts, the MK extract significantly reduced cardiac functions such as left ventricular developed pressure and heart rate. In an antihypertensive study in SHRs, long-term administration with MK extracts (10, 30, 100 mg/kg) for 42 d dose-dependently decreased systolic blood pressure (approximately 20 mmHg). In SHRs, MK extract enhanced the aortic relaxation to acetylcholine and sodium nitroprusside after 42 d of treatment. In addition, lipid peroxidation and DNA damage in liver of SHRs were also attenuated by long-term treatment with MK extract. These results suggest that chronic treatment with MK extract exerts an antihypertensive effect in SHRs, and its direct vasorelaxant, negative inotropic actions, and anti-oxidant properties may contribute to reduce the elevated blood pressure.