Identification of moracin N in mulberry leaf and evaluation of antioxidant activity

Secondary metabolites of mulberry leaves exert anti-lung cancer activity through regulating the PD-L1/PD-1 signaling pathway

Lung cancer ranks the top of malignancies that cause cancer-related deaths worldwide. The leaves of Morus alba L are traditional Chinese medicine widely applied in respiratory diseases. Our previous work has demonstrated the anti-lung cancer effect of secondary metabolites of mulberry leaf, but their mechanism of action has still not fully elucidated. We synthesized Moracin N (MAN)-Probe conjugated with alkyne to label lung cancer cells and identified protein targets by chemical proteomic analysis. MAN and its probe exerted similar growth-inhibitory effect on human lung cancer cells. Chemical proteomic results showed that MAN targeted the programmed death ligand 1 (PD-L1) checkpoint pathway and T cell receptor (TCR) signaling pathway, indicating its immune-regulatory function. Cell-free surface plasmon resonance (SPR) results showed the direct interaction of MAN with PD-L1 protein. Molecular docking analysis demonstrated that MAN bound to E158 residue of PD-L1 protein. MAN downregulated the expression levels of PD-L1 in a time- and dose-dependent manner and disrupted the PD-L1/programmed death 1 (PD-1) binding, including other secondary metabolites of mulberry leaves Guangsangon E (GSE) and Chalcomoracin (CMR). Human peripheral blood mononuclear cells (PBMCs) co-cultured with MAN-treated A549 cells, resulting in the increase of CD8+ GZMB+ T cells and the decrease of CD8+ PD-1+ T cells. It suggested that MAN exerts anti-cancer effect through blocking the PD-L1/PD-1 signaling. In vivo, MAN combined with anti-PD-1 antibody significantly inhibited lung cancer development and metastasis, indicating their synergistic effect. Taken together, secondary metabolites of mulberry leaves target the PD-L1/PD-1 signaling, enhance T cell-mediated immunity and inhibit the tumorigenesis of lung cancer. Their modulatory effect on tumor microenvironment makes them able to enhance the therapeutic efficacy of immune checkpoint inhibitors in lung cancer.

Bioactive compound composition and cellular antioxidant activity of fig (Ficus carica L.)

BACKGROUND

Fig (Ficus carica L.) fruit is consumed worldwide as a functional food. It contains phytochemicals that have been related to health benefits. However, the characteristic chemicals remain unclear. In this work, phytochemicals were prepared from figus by ultrasound-assisted extraction under optimized conditions. The chemical composition of fig fruit and leaves was characterized by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

RESULTS

One hundred and fifty-seven compounds were identified, including 58 flavonoids, 29 coumarins, 19 acids, 15 terpenoids, 11 alkaloids, and 25 other compounds. The mass spectrum (MS) fragmentation pathways of representative chemicals were elucidated. Flavonoid glycosides and prenylated flavonoids were mainly present in fig fruit, whereas coumarins were abundant in leaves. Both fig fruit and leaf extracts showed good cellular antioxidant activity.

CONCLUSION

The full phytochemical profile of fig was revealed by UPLC-MS/MS. Prenylated flavonoids and prenylated coumarins were the characteristic phytochemicals. These data provided useful information for the extensive utilization of fig fruit in functional food. © 2023 Society of Chemical Industry.

New insights of flavonoid glycosidases and their application in food industry

Flavonoids are significant natural nutraceuticals and a key component of dietary supplements. Given that flavonoid glycosides are more plentiful in nature and less beneficial to human health than their aglycone counterparts, they serve as potential precursors for flavonoid production. Glycosidases have shown substantial potential within the food industry, particularly in enhancing the organoleptic properties of juice, wine, and tea. When applied to food resources, glycosidases can amplify their biological activities, thereby improving the performance of functional foods. This review provides up-to-date information on flavonoid glycosidases, including their catalytic mechanisms, biochemical properties, and natural sources, as well as their applications within the food industry. The use of flavonoid glycosidases in improving food quality is also reviewed.

Resveratrol, ε-Viniferin, and Vitisin B from Vine: Comparison of Their In Vitro Antioxidant Activities and Study of Their Interactions

The control of oxidative stress with natural active substances could limit the development of numerous pathologies. Our objective was to study the antiradical effects of resveratrol (RSV), ε-viniferin (VNF), and vitisin B (VB) alone or in combination, and those of a standardized stilbene-enriched vine extract (SSVE). In the DPPH-, FRAP-, and NO-scavenging assays, RSV presented the highest activity with an IC50 of 81.92 ± 9.17, 13.36 ± 0.91, and 200.68 ± 15.40 µM, respectively. All binary combinations resulted in additive interactions in the DPPH- and NO-scavenging assays. In the FRAP assay, a synergic interaction for RSV + VNF, an additive for VNF + VB, and an antagonistic for RSV + VB were observed. The ternary combination of RSV + VNF + VB elicited an additive interaction in the DPPH assay and a synergic interaction in the FRAP- and NO-scavenging assays. There was no significant difference between the antioxidant activity of the SSVE and that of the combination of RSV + VNF. In conclusion, RSV presented the highest effects, followed by VNF and VB. The interactions revealed additive or synergistic effects, depending on the combination of the stilbenes and assay.

Exogenous spraying of 4-chlorophenoxyacetic acid sodium salt promotes growth and flavonoid biosynthesis of mulberry leaves (Morus alba L.)

Mulberry (Morus alba L.) leaves are known as an ideal vegetable with good antioxidant effect, which can bring delicious taste and multiple health benefits. In the present study, the effects of 4-Chlorophenoxyacetic acid sodium salt (4-CPANa) treatment on growth and content of flavonoid compounds in mulberry leaves were investigated. Moreover, the changes in the expression levels of genes involved in flavonoid biosynthetic pathways, and the accumulation of important secondary metabolites including rutin (Rut), chlorogenic acid (ChA), isoquercitrin (IQ) and astragalin (Ast), were investigated in mulberry leaves. The results showed that 4-CPANa treatment could significantly promote the differentiation and growth of mulberry, increased shoot number, bud number, leaf fresh weight and leaf area of mulberry compared with control. Besides, the contents of ChA, Rut, IQ and Ast were significantly increased after 4-CPANa (5 mg/L) treatment. Further analysis revealed that 5 mg/L 4-CPANa strongly induced the expression of flavonoid biosynthesis-related genes including flavonoid 3-O-glucosyltransferase (F3GT) gene, chalcone synthase (CHS) gene, 4-xoumarate-CoA ligase (4CL) and phenylalanine ammonia lyase (PAL) gene. In conclusion, exogenous spraying of 4-CPANa provides a new way to improve the medicinal quality and development of mulberry leaf food with high value.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01339-z.

The bioaccessibility, bioavailability, bioactivity, and prebiotic effects of phenolic compounds from raw and solid-fermented mulberry leaves during in vitro digestion and colonic fermentation

The bioaccessibility and bioactivity of phenolic compounds in mulberry leaves (MLs) relate to the digestion process. This study was aimed at investigating the release of phenolic compounds, as well as the potential bioactivities of raw MLs (UF-MLs) and solid-fermented MLs (F-MLs) during in vitro digestion and colonic fermentation. Antioxidant activities and phenolic compounds released in the digested extracts are shown in decreasing order of location: intestinal > oral > gastric. The bioavailability of total phenolics and flavonoids in F-MLs were 10.14 ± 1.81 % and 6.66 ± 0.55 %, respectively. There was no significant difference in the inhibitory activity of α-glucosidase during gastrointestinal digestion. For colonic fermentation, the highest free radical-scavenging ability of DPPH and ABTS was found at 24 h and 48 h, respectively. The release of phenolic compounds was not significantly different after 48 h of colonic fermentation. LC-MS/MS showed that liquiritigenin, apigenin, chlorogenic acid, and ferulic acid were the major compounds released in the small intestine digestion, and valerenic acid was the primary colonic metabolite. 16S rDNA showed that UF-MLs promoted the growth of Bifidobacterium and F-MLs lowered the Firmicutes-to-Bacteroidetes ratio. Furthermore, F-MLs increased the concentration of acetic acids (25.75 ± 0.86 mM) after 24 h of colonic fermentation. The results of this study indicated that F-MLs exhibit relatively higher phenolic bioaccessibility, antioxidant activities, and SCFA production and are a promising candidate as a health food supplement.

Dual-target affinity analysis and separation of α-amylase and α-glucosidase inhibitors from Morus alba leaves using a magnetic bifunctional immobilized enzyme system

Morus alba leaves are a natural product with great antidiabetic potential. However, the therapeutic efficacy of natural products is usually achieved through the interaction of active compounds with specific targets. Among them, active compounds with multi-target therapeutic functions are more effective than single-target enzymes. In this study, a bienzyme system was constructed by co-immobilizing α-amylase and α-glucosidase onto Fe₃ O₄ for affinity screening of dual-target active components in the complex extract from M. alba leaves. As a result, a potential active compound was selectively screened by ligand fishing, separated by high-speed countercurrent chromatography using a solvent system of ethyl acetate-n-butanol-water (3:2:5, v/v), and identified as rutin. In addition, the result of molecular docking showed that rutin could interact with the active center of α-amylase and α-glucosidase through multiple hydrogen bonds, van der Waals forces, etc. to play an inhibitory role. These results demonstrate the effectiveness of the polydopamine magnetically immobilized bienzyme system for dual-target affinity screening of active substances. This study not only reveals the chemical basis of the antidiabetic activity of M. alba leaves from a dual-target perspective, but also promotes the progress of multitarget affinity screening.

Sericultural By-Products: The Potential for Alternative Therapy in Cancer Drug Design

Major progress has been made in cancer research; however, cancer remains one of the most important health-related burdens. Sericulture importance is no longer limited to the textile industry, but its by-products, such as silk fibroin or mulberry, exhibit great impact in the cancer research area. Fibroin, the pivotal compound that is found in silk, owns superior biocompatibility and biodegradability, representing one of the most important biomaterials. Numerous studies have reported its successful use as a drug delivery system, and it is currently used to develop three-dimensional tumor models that lead to a better understanding of cancer biology and play a great role in the development of novel antitumoral strategies. Moreover, sericin's cytotoxic effect on various tumoral cell lines has been reported, but also, it has been used as a nanocarrier for target therapeutic agents. On the other hand, mulberry compounds include various bioactive elements that are well known for their antitumoral activities, such as polyphenols or anthocyanins. In this review, the latest progress of using sericultural by-products in cancer therapy is discussed by highlighting their notable impact in developing novel effective drug strategies.

The Effect of Hot-Melt Extrusion of Mulberry Leaf on the Number of Active Compounds and Antioxidant Activity

The aim of this study is to compare the functions of the physiologically active compounds of three types of mulberry leaf by cultivar, and to confirm the changes using hot-melt extrusion (HME-ML). The active components of mulberry leaf were analyzed using the HPLC system, and total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity were measured. Among the three varieties, the highest contents of rutin and isoquercetin were detected in Cheongil, of TPC in Cheongol, and of TFC in Cheongil. It was confirmed that this bio-accessibility was increased in HME-ML compared with the control. The DPPH radical scavenging activity of Cheongol showed greater antioxidant properties, and HME showed improvement in the antioxidant properties of all mulberry leaves. These results suggest that the application of HME technology can improve the biological activities of mulberry leaf.

Beneficial Effects of Flaxseed and/or Mulberry Extracts Supplementation in Ovariectomized Wistar Rats

Low endogenous estrogen action causes several injuries. Medicinal plants, such as flaxseed and mulberry, contain substances that have been shown to be effective to the organism. The aim was to verify the effects of flaxseed and/or mulberry extracts on ovariectomized Wistar rats. The animals received supplements of extracts and estrogen or saline by gavage for 60 days and were weighed weekly. Vaginal wash, blood, pituitary, uterus, liver, and kidneys were collected. Phenolic compounds and the antioxidant activity of the extracts, lipid profile, uric acid, liver enzymes, and pituitary weight were measured. Histomorphometric for uterine wall and histopathological analyses for liver and kidney were performed. Flaxseed and mulberry extracts showed great antioxidant activity and large amounts of phenolic compounds. The treatment with extracts had less weight gain, increased pituitary weight, the predominance of vaginal epithelial cells, and reduced TC, LDL-c and lipase activity, similar to estrogen animals. Estrogen or flaxseed + mulberry animals reduced VLDL-c and TAG. HDL-c, uric acid, and liver enzymes did not differ. Estrogen or extracts demonstrated trophic action on the endometrial thickness and have not shown hepatotoxicity or nephrotoxicity. We suggested the beneficial effects of flaxseed and mulberry extract as an alternative to reduce and/or prevent the negative effects caused by low estrogenic action.

Electrochemical Methodologies for Investigating the Antioxidant Potential of Plant and Fruit Extracts: A Review

In recent years, the growing research interests in the applications of plant and fruit extracts (synthetic/stabilization materials for the nanomaterials, medicinal applications, functional foods, and nutraceuticals) have led to the development of new analytical techniques to be utilized for identifying numerous properties of these extracts. One of the main properties essential for the applicability of these plant extracts is the antioxidant capacity (AOC) that is conventionally determined by spectrophotometric techniques. Nowadays, electrochemical methodologies are emerging as alternative tools for quantifying this particular property of the extract. These methodologies address numerous drawbacks of the conventional spectroscopic approach, such as the utilization of expensive and hazardous solvents, extensive sample pre-treatment requirements, long reaction times, low sensitivity, etc. The electrochemical methodologies discussed in this review include cyclic voltammetry (CV), square wave voltammetry (SWV), differential pulse voltammetry (DPV), and chronoamperometry (CAP). This review presents a critical comparison between both the conventional and electrochemical approaches for the quantification of the parameter of AOC and discusses the numerous applications of the obtained bioextracts based on the AOC parameter.

Heterologous biosynthesis of prenylated resveratrol and evaluation of antioxidant activity

Prenylated stilbenoids are good candidates of nutraceuticals presented in food resources. The levels of natural prenylated stilbenoids are usually low. Biotransformation is a promising synthesis strategy to produce novel bioactive compounds. However, information regarding biosynthesis of prenylated stilbenoids is rare. In this work, prenyltransferase and geranyl diphosphate biosynthesispathway were overexpressed in E. coli. Multiple prenyltransferase genes were tested and Ambp1 was found to be effective on resveratrol geranylation. The products were identified by mass spectrometry and nuclear magnetic resonance spectroscopy as 4-C-geranyl resveratrol (1) and 3-O-geranyl resveratrol (2, novel chemical). By optimization of culture conditions, a yield of 36.9% was achieved for the conversion to geranylated resveratrol from resveratrol. These two compounds demonstrated good antioxidant activities with IC₅₀ values of 28.09 μM for 4-C-geranyl resveratrol and 403.88 μM for 3-O-geranyl resveratrol. The results were helpful for developing novel technique to produce prenylated phenolics.

Naturally occurring prenylated stilbenoids: food sources, biosynthesis, applications and health benefits

Prenylated stilbenoids are a unique class of natural phenolic compounds consisting of C6-C2-C6 skeleton with prenyl substitution. They are potential nutraceuticals and dietary supplements presented in some edible plants. Prenylated stilbenoids demonstrate promising health benefits, including antioxidant, anti-cancer, anti-inflammatory, anti-microbial activities. This review reports the structure, bioactivity and potential application of prenylated stilbeniods in food industry. Edible sources of these compounds are compiled and summarized. Structure-activity relationship of prenylated stilbenoids are also highlighted. The biosynthesis strategies of prenylated stilbenoids are reviewed. The findings of these compounds as food preservative, nutraceuticals and food additive are discussed. This paper combines the up-to-date information and gives a full image of prenylated stilbenoids.

Comparative Analysis of the Antioxidant and Antidiabetic Potential of Nelumbo nucifera Gaertn. and Nymphaea lotus L. var. pubescens (Willd.)

Background. Nelumbo nucifera Gaertn. and Nymphaea lotus L. var. pubescens (Willd.) are both aquatic rhizomatous perennial plants mostly found in the tropical region of Nepal, India, Bangladesh, China, and Eastern Asia. Nymphaea pubescens and Nelumbo nucifera plants are famous for their different biological activities such as antidiabetic, antioxidant, hepatoprotective, antidiarrheal, and anti-inflammatory properties. Objective. The present study majorly focused on the determination of in vitro antioxidant and antidiabetic properties of Nelumbo nucifera and Nymphaea pubescens. Methods. In vitro α-glucosidase inhibition was performed using PNPG as a substrate. Antioxidant property of the plant extract was determined by DPPH free radical scavenging assay. The aluminium trichloride method was done for the estimation of total flavonoid content. Likewise, Folin–Ciocalteu reagent was used for determining total phenolic content. Results. The total phenolic content of N. nucifera and N. pubescens was found to be 172.827 ± 0.41 and 194.87 ± 0.93 mg GAE/g, respectively, while the total flavonoid content was reported 17.12 ± 1.04 and 34.59 ± 1.73 mg QE/g, respectively. The IC50 values of the crude extract and its fractions of N. nucifera against the DPPH free radical ranged from 33.46 ± 0.6 to 3.52 ± 0.09 μg/mL, while that of the N. pubescens ranged from 14.30 ± 0.43 to 1.43 ± 0.08 μg/mL. Similarly, for the in vitro α-glucosidase inhibition activity, the IC50 of the crude extract and its fractions of N. nucifera varied from 349.86 ± 2.91 to 29.06 ± 0.24 μg/mL and that of N. pubescens ranged from 224.4 ± 6.85 to 5.29 ± 0.39 μg/mL. Conclusion. Both aquatic plants N. nucifera and N. pubescens show antioxidant properties and can inhibit α-glucosidase in in vitro. Further research is required to identify the inhibiting compounds.

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.

UHPLC-MS/MS Analysis on Flavonoids Composition in Astragalus membranaceus and Their Antioxidant Activity

Astragalus membranaceus is a valuable medicinal plant species widely distributed in Asia. Its root is the main medicinal tissue rich in methoxylated flavonoids. Origin can highly influence the chemical composition and bioactivity. To characterize the principal chemicals influenced by origin and provide more information about their antioxidant profile, the extracts of A. membranaceus roots from four origins were analysed by UHPLC-MS/MS. Thirty-four flavonoids, including thirteen methoxylated flavonoids, fifteen flavonoid glycosides and six flavonols, were identified. By principal component analysis, eighteen identified compounds were considered to be principal compounds. They could be used to differentiate A. membranaceus from Shanxi, Inner Mongolia, Heilongjiang and Gansu. The antioxidant activity was analysed by ORAC assay, DPPH radical scavenging activity assay and cell antioxidant activity assay. 'Inner Mongolia' extract showed the highest antioxidant activity. These results were helpful to understand how origin influenced the quality of A. membranaceus.

Identification of prenylated phenolics in mulberry leaf and their neuroprotective activity

BACKGROUND

Neurodegenerative diseases are becoming increasingly prevalent over the world. Therefore, drug development in this field is urgently required. Neuron impairment leads to the pathogenesis of neurodegenerative diseases, while amelioration of oxidative stress can inhibit the impairment. As a traditional Chinese medicine, mulberry leaf exhibits various pharmacological properties, including neuroprotective activity. But the major components responsible for the neuroprotective activity of mulberry leaf remained unknown. Phytochemicals were potent candidates of neuroprotective drug. Prenylated phenolics are the leading phytochemicals present in mulberry leaf.

PURPOSE

The aim of this study was to investigate the neuroprotective activities and mechanisms of prenylated phenolics.

METHODS

The chemical structure of isolated compounds were elucidated by MS and NMR. UPLC-MS/MS was used to determine the contents of prenylated phenolics in fresh mulberry leaf. Neurotoxicity was induced by erastin in HT22 cells. CCK-8 assay was performed to assess cell viability. ROS production, GSH level and iron release were monitored by using DCFH-DA, monobromobimane, and FeRhoNox™-1, respectively. qRT-PCR and Western blotting assays were performed to assess gene and protein expression, respectively.

RESULTS

Four prenylated phenolics, including isobavachalcone, morachalcone B, moracin N and morachalcone A were isolated and identified from mulberry leaf. Their levels in fresh mulberry leaf were in a decreasing order, moracin N > morachalcone A > morachalcone B > isobavachalcone. Moreover, moracin N showed a good neuroprotective activity with an EC₅₀ < 0.50 µM. The neuroprotective mechanisms of moracin N included inhibition of glutathione depletion, glutathione peroxidase 4 (GPx4) inactivation, reactive oxygen species (ROS) overproduction and iron accumulation, as well as improvement of intracellular antioxidant enzyme activities. Moracin N augmented the transcriptional levels of genes involved in antioxidant defense and glutathione biosynthesis in the early state of ferroptosis induction, and downregulated expression of genes related to iron accumulation and lipid peroxidation.

CONCLUSION

The results confirmed that moracin N was a good ferroptosis inhibitor, which exerted neuroprotective activity through preventing from oxidative stress.

Structure Differences of Water Soluble Polysaccharides in Astragalus membranaceus Induced by Origin and Their Bioactivity

Astragalus membranaceus is a functional food with multiple bioactivities. It presents differentiated health benefits due to origins. Polysaccharides (APS) are the leading bioactive macromolecules of A. membranaceus, which are highly related to its health benefits. However, the effect of origin on the structural characteristics of APSs remains unclear. In this work, polysaccharides from four origins were isolated and identified by NMR. The results showed APSs of four origins had identical monosaccharide composition and glycosidic linkage. Rhamnogalacturonan II pectins and α-(1→4)-glucan were the dominant polysaccharides. However, the level of methyl ester in pectins varied to a large extent. The molecular weight profiles of APSs were also different. Inner Mongolia APS had the largest percentage of 20-40 kDa polysaccharides. Molecular weight and methyl ester level were two important parameters determining the difference of APSs from four origins. These results were helpful to recognize the origin-related quality of A. membranaceus.

Nutritional constituents of mulberry and their potential applications in food and pharmaceuticals: A review

Mulberry is a fast growing deciduous plant found in wide variety of climatic, topographical and soil conditions, and is widely distributed from temperate to subtropical regions. Due to presence of valuable phytochemical constituents, mulberry as a whole plant has been utilized as a functional food since long time. Mulberry fruits are difficult to preserve as they have relatively high water content. Therefore for proper utilization, different value-added products like syrups, squashes, teas, pestil sand köme, pekmez (turkuish by-products), yogurts, jams, jellies, wines, vinegar, breads, biscuits, parathas, and many more are made. In overseas, these value-added products are commercially sold and easily available, though in India, this versatile medicinal plant is still missing its identity at commercial and industrial scale. Leaves of mulberry are economically viable due to their important role in the sericulture industry since ancient times. Mulberries or its extracts exhibit excellent anti-microbial, anti-hyperglycaemic, anti-hyperlipidemic, anti-inflammatory, anti-cancer effects and is used to combat different acute and chronic diseases. Different parts of Morus species like fruits, leaves, twigs, and bark exhibit strong anti-tyrosinase inhibition activity that makes it a suitable candidate in cosmetic industries as a whitening agent. The current review provides a comprehensive discussion concerning the phytochemical constituents, functionality and nutraceutical potential of mulberry and as a common ingredient in various cosmetic products.

Morus alba L. Plant: Bioactive Compounds and Potential as a Functional Food Ingredient

Morus alba L. (M. alba) is a highly adaptable plant that is extensively incorporated in many traditional and Ayurveda medications. Various parts of the plant, such as leaves, fruits, and seeds, possess nutritional and medicinal value. M. alba has abundant phytochemicals, including phenolic acids, flavonoids, flavonols, anthocyanins, macronutrients, vitamins, minerals, and volatile aromatic compounds, indicating its excellent pharmacological abilities. M. alba also contains high nutraceutical values for protein, carbohydrates, fiber, organic acids, vitamins, and minerals, as well as a low lipid value. However, despite its excellent biological properties and nutritional value, M. alba has not been fully considered as a potential functional food ingredient. Therefore, this review reports on the nutrients and bioactive compounds available in M. alba leaves, fruit, and seeds; its nutraceutical properties, functional properties as an ingredient in foodstuffs, and a microencapsulation technique to enhance polyphenol stability. Finally, as scaling up to a bigger production plant is needed to accommodate industrial demand, the study and limitation on an M. alba upscaling process is reviewed.

Prenylated flavonoids in foods and their applications on cancer prevention

Functional foods play an important role in health care and chronic diseases prevention, particularly cancer. Prenylated flavonoids are presented in many food resources. They are recognized as neutraceuticals due to their diverse health benefits. Up to now, more than 1000 prenylated flavonoids have been identified in plants. Their food resources are reviewed in this paper. Due to the good safety and cancer prevention effect of prenylated flavonoids, this paper reviews the cancer prevention activities and mechanisms reported in last decade. The structure-activity relationship is discussed. Due to the limited availability in nature, the heterologously biosynthetic technique of prenylated flavonoids is discussed in this review. Inclusion of dietary prenylated flavonoids into human diet is highly desirable. This paper combines the up-to-date information and give a clear image regarding prenylated flavonoids as neutraceuticals.

The radical scavenging activity of moracins: theoretical insights

Moracins are natural products that have been isolated from different plants such as Artocarpus heterophyllus, Cassia fistula, Morus alba, and Morus mesozygia. Studies showed that moracins may have various advantageous physiological effects such as anticancer, anti-inflammatory, anticholinesterase and particularly antioxidant activities. Most of these bioactivities have not been studied systematically. In this study, the radical scavenging of a typical moracin (moracin M, MM) against HO˙ and HOO˙ radicals was evaluated by thermodynamic and kinetic calculations in the gas phase as well as in water and pentyl ethanoate solvents. It was found that the overall rate constants for the HO˙ radical scavenging in the gas phase and the physiological environments are in the range of 1011 to 1010 M-1 s-1, respectively. For the HOO˙ + MM reaction the rate constants are 4.10 × 107 and 3.80 × 104 M-1 s-1 in the polar and lipid media, respectively. It is important to notice that the single electron transfer pathway of the anion state (MM-O6'-) dominated the HOO˙ radical scavenging in the aqueous solution, whereas in lipid medium the neutral MM exerted its activity by the formal hydrogen transfer mechanism. The HOO˙ radical scavenging of MM is comparable to that of Trolox in lipid medium, whereas it is 315.4 times more active in the polar environment.

A Novel Benzofuran Derivative Moracin N Induces Autophagy and Apoptosis Through ROS Generation in Lung Cancer

Introduction

The leaves of Morus alba L is a traditional Chinese medicine widely applied in lung diseases. Moracin N (MAN), a secondary metabolite extracted form the leaves of Morus alba L, is a potent anticancer agent. But its molecular mechanism remains unveiled.

Objective

In this study, we aimed to examine the effect of MAN on human lung cancer and reveal the underlying molecular mechanism.

Methods

MTT assay was conducted to measure cell viability. Annexin V-FITC/PI staining was used to detect cell apoptosis. Confocal microscope was performed to determine the formation of autophagosomes and autolysosomes. Flow cytometry was performed to quantify cell death. Western blotting was used to determine the related-signaling pathway.

Results

In the present study, we demonstrated for the first time that MAN inhibitd cell proliferation and induced cell apoptosis in human non-small-cell lung carcinoma (NSCLC) cells. We found that MAN treatment dysregulated mitochondrial function and led to mitochondrial apoptosis in A549 and PC9 cells. Meanwhile, MAN enhanced autophagy flux by the increase of autophagosome formation, the fusion of autophagsomes and lysosomes and lysosomal function. Moreover, mTOR signaling pathway, a classical pathway regualting autophagy, was inhibited by MAN in a time- and dose-dependent mannner, resulting in autophagy induction. Interestingly, autophagy inhibition by CQ or Atg5 knockdown attenuated cell apoptosis by MAN, indicating that autophagy serves as cell death. Furthermore, autophagy-mediated cell death by MAN can be blocked by reactive oxygen species (ROS) scavenger NAC, indicating that ROS accumulation is the inducing factor of apoptosis and autophagy. In summary, we revealed the molecular mechanism of MAN against lung cancer through apoptosis and autophagy, suggesting that MAN might be a novel therapeutic agent for NSCLC treatment.

Integrated Transcriptomic and Un-Targeted Metabolomics Analysis Reveals Mulberry Fruit (Morus atropurpurea) in Response to Sclerotiniose Pathogen Ciboria shiraiana Infection

Mulberry sclerotiniose caused by Ciboria shiraiana is a devastating disease of mulberry (Morus alba L.) fruit in Northwest China. At present, no disease-resistant varieties are used in production, as the molecular mechanisms of this disease are not well understood. In this study, to explore new prevention methods and provide direction for molecular breeding, transcriptomic sequencing and un-targeted metabolomics were performed on healthy (CK), early-stage diseased (HB1), and middle-stage diseased (HB2) mulberry fruits. Functional annotation, gene ontology, a Kyoto encyclopedia of genes and genomes (KEGG) analysis, and a Mapman analysis of the differentially expressed genes revealed differential regulation of genes related to plant hormone signal transduction, transcription factors, and phenylpropanoid biosynthesis. A correspondence between the transcript pattern and metabolite profile was observed in the phenylpropanoid biosynthesis pathway. It should be noted that the log2 ratio of eugenol (isoeugenol) in HB1 and HB2 are 85 times and 23 times higher than CK, respectively. Our study shows that phenylpropanoid biosynthesis may play an essential role in response to sclerotiniose pathogen infection and eugenol(isoeugenol) enrichment in mulberry fruit, which may provide a novel method for mulberry sclerotiniose control.

Identification of two novel prenylated flavonoids in mulberry leaf and their bioactivities

Mulberry leaf is a vegetable used in daily diet. It can bring delicious taste and multiple health benefits. However, the chemicals responsible for these health benefits remain unveiled. In this work, two novel prenylated flavonoids were isolated from mulberry leaf. Their structures were identified and named as morachalcone D and morachalcone E. The protective effects of these two compounds were investigated, against endogenous oxidative damage (oxytosis/ferroptosis) induced by glutamate and erastin in HT22 cells. The results revealed that morachalcone D was much more potent in preventing from glutamate- and erastin-induced cell death than morachalcone E. The neuroprotective effect of morachalcone D was related to the prevention of ROS production, glutathione depletion, and iron accumulation. Morachalcone D upregulated the expression of genes involved in antioxidant defense, including GPx4, CAT, SOD2, Nrf2, HMOX1 and SLC7A11. These findings indicated that morachalcone D was responsible for the health benefits of mulberry leaf, and could be a potent neuroprotective agent for use in dietary supplements and functional foods.