Nelumbo nucifera Gaertn leaves extract inhibits the angiogenesis and metastasis of breast cancer cells by downregulation connective tissue growth factor (CTGF) mediated PI3K/AKT/ERK signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Nelumbo nucifera Gaertn (Nymphaeaceae) has been recognized as a medicinal plant, which was distributed throughout the Asia. The aqueous extract of Nelumbo nucifera leaves extract (NLE) has various biologically active components such as polyphenols, flavonoids, oligomeric procyanidines. However, the role of NLE in breast cancer therapy is poorly understood.

THE AIM OF THIS STUDY

The purpose of this study was to identify the hypothesis that NLE can suppress tumor angiogenesis and metastasis through CTGF (connective tissue growth factor), which has been implicated in tumor angiogenesis and progression in breast cancer MDA-MB-231 cells.

RESULTS

We examined the effects of NLE on angiogenesis in the chicken chorioallantoic membrane (CAM) model. The data showed that NLE could reduce the chorionic plexus at day 17 in CAM and the duration of this inhibition was dose-dependent. In Xenograft model, NLE treatment significantly reduced tumor weight and CD31 (capillary density) over control, respectively. We examined the role of angiogenesis involved restructuring of endothelium using human umbilical vein endothelial cell (HUVEC) in Matrigel angiogenesis model. The results indicated that vascular-like structure formation was further blocked by NLE treatment. Moreover, knockdown of CTGF expression markedly reduced the expression of MMP2 as well as VEGF, and attenuated PI3K-AKT-ERK activation, indication that these signaling pathways are crucial in mediating CTGF function.

CONCLUSION

The present results suggest that NLE might be useful for treatment in therapy-resistance triple negative breast cancer.

Neferine induces autophagy of human ovarian cancer cells via p38 MAPK/ JNK activation

Ovarian cancer is the most lethal gynecological malignancy. Patients usually have poor prognosis because of late diagnosis, relapse, and chemoresistance. It is pressing to seek novel agent for the treatment of ovarian cancer. Neferine is a bisbenzylisoquinoline alkaloid isolated from the embryos of lotus (Nelumbo nucifera). In this study, we investigated the antitumor effect of neferine on ovarian cancer cells. We found that neferine exhibited growth-inhibitory effect on human ovarian cancer cells, whereas showing less cytotoxic to non-malignant fallopian tube epithelial cells. Furthermore, we demonstrated that neferine induced autophagy and inactivated the mTOR pathway. Finally, we found that both p38 MAPK and JNK signaling pathways were activated by neferine treatment and contributed to the induction of autophagy in ovarian cancer cells. In conclusion, our findings showed that neferine induced autophagy of human ovarian cancer cells via p38 MAPK/JNK activation. Neferine may be explored as a promising antitumoral agent in ovarian cancer.

Changes in physicochemical properties related to the texture of lotus rhizomes subjected to heat blanching and calcium immersion

Pretreatments such as low temperature blanching and/or calcium soaking affect the cooked texture of vegetal food. In the work, lotus rhizomes (Nelumbo nucifera Gaertn.) were pretreated using the following 4 treatments, blanching at 40°C, blanching at 90°C, soaking in 0.5% CaCl2, and blanching at 40°C followed by immersion in 0.5% CaCl2. Subsequently, the cell wall material of pretreated samples was isolated and fractioned to identify changes in the degree of esterification (DE) and monosaccharide content of each section, and the texture of the lotus rhizomes in different pre-treatments was determined after thermal processing with different time. The results showed that the greatest hardness was obtained after blanching at 40°C in CaCl2, possibly attributing to the formation of a pectate calcium network, which maintains the integrity of cell walls. Furthermore, the content of galactose, rhamnose and arabinose decreased due to the breakage of sugar backbones and subsequent damage to cell walls. Our results may provide a reference for lotus rhizome processing.

Analysis of Isoquinoline Alkaloid Composition and Wound-Induced Variation in Nelumbo Using HPLC-MS/MS

Alkaloids are the most relevant bioactive components in lotus, a traditional herb in Asia, but little is known about their qualitative and quantitative distributions. Here, we report on the alkaloid composition in various lotus organs. Lotus laminae and embryos are rich in isoquinoline alkaloids, whereas petioles and rhizomes contain trace amounts of alkaloids. Wide variation of alkaloid accumulation in lamina and embryo was observed among screened genotypes. In laminae, alkaloid accumulation increases during early developmental stages, reaches the highest level at full size stage, and then decreases slightly during senescence. Vegetative and embryogenic tissues accumulate mainly aporphine-type and bisbenzylisoquinoline-type alkaloids, respectively. Bisbenzylisoquinoline-type alkaloids may be synthesized mainly in lamina and then transported into embryo via latex through phloem translocation. In addition, mechanical wounding was shown to induce significant accumulation of specific alkaloids in lotus leaves.

Iron-Chelating and Anti-Hemolytic Properties of Ethanolic Extract of Lotus (Nelumbonucifera Gaertn) Leaves

BACKGROUND

Iron overload is the major consequence of blood transfusion in β-thalassemia patients. Redox iron plays a critical role in the formation of reactive oxygen species and subsequently leads to oxidative stress damage in many cells, especially red blood cells and hepatocytes. Iron deposition in hepatocytes is associated with fibrosis and cirrhosis. Polyphenolic compounds found in natural products are interesting iron chelators and antioxidants.

OBJECTIVE

This study aims to evaluate the iron-chelating properties and free-radical scavenging activities of lotus leaf extract in iron-loaded HepG2 cells.

MATERIAL AND METHOD

Lotus (Nelumbonucifera Gaertn) leaves were extracted with 80% (v/v) ethanol. The extract was examined for free-radical scavenging activity by using 2, 2-diphenyl-1-picrylhydrazyl assay (DPPH assay); iron-binding and anti-hemolytic activities using spectrophotometrical method. Iron-depriving activity of the extract was determined in iron loaded human hepatocellular (HepG2) cells using fluorescence technique.

RESULTS

The lotus extract showed antioxidant and anti-hemolytic activities in a concentration-dependent manner. Furthermore, it was able to bind iron rapidly and was saturated within 10 minute. With 24-hour treatment, this extract dose dependently decreased the level of labile iron pool in iron loaded HepG2 cells.

CONCLUSION

Lotus leaf extract had strong antioxidant activities, iron chelating properties on iron loaded HepG2 cells and anti-hemolytic activity.

Positive Modulation of Pink Nelumbo nucifera Flowers on Memory Impairment, Brain Damage, and Biochemical Profiles in Restraint Rats

Due to the crucial role of oxidative stress in the stress-induced memory deficit, the benefit of substance possessing antioxidant effect is focused. Since no data are available, we aimed to determine the effect of Nelumbo nucifera flowers extract on spatial memory and hippocampal damage in stressed rats. Male Wistar rats, weighing 250-350 g, were orally given N. nucifera extract at doses of 10, 10, and 200 mg·kg(-1) 45 minutes before the exposure to 12-hour restraint stress. The spatial memory and serum corticosterone were assessed at 7 and 14 days of study period. At the end of study, acetylcholinesterase (AChE), monoamine oxidase type A and monoamine oxidase type B (MAO-A and MAO-B), oxidative stress status, neuron density, and Ki67 expression in hippocampus were also assessed. The results showed that N. nucifera extract decreased memory deficit and brain damage, serum corticosterone, oxidative stress status, AChE, and MAO-A and MAO-B activities but increased neuron density and Ki67 expression in hippocampus. These suggested that the improved oxidative stress status, adult neurogenesis, and cholinergic and monoaminergic functions might be responsible for the protective effect against stress-related brain damage and dysfunction of the extract. Therefore, N. nucifera extract is the potential neuroprotective and memory enhancing agent. However, further researches are still required.

Isoliensinine, a Bioactive Alkaloid Derived from Embryos of Nelumbo nucifera, Induces Hepatocellular Carcinoma Cell Apoptosis through Suppression of NF-κB Signaling

Isoliensinine (isolie) is an alkaloid produced by the edible plant Nelumbo nucifera. Here, we unveiled that isolie was able to provoke HepG2, Huh-7, and H22 hepatocellular carcinoma (HCC) cell apoptosis. Isolie decreased NF-κB activity and constitutive phosphorylation of NF-κB p65 subunit at Ser536 in HCC cells. Overexpression of p65 Ser536 phosphorylation mimics abrogated isolie-mediated HCC cell apoptosis. Furthermore, intraperitoneal injection of isolie inhibited the growth of Huh-7 xenografts in nude mice. Additionally, isolie given by both intraperitoneal injection and gavage diminished the proliferation of transplanted H22 cells in Kunming mice. Reduced tumor growth in vivo was associated with inhibited p65 phosphorylation at Ser536 and declined NF-κB activity in tumor tissues. Finally, we revealed that isolie was bioavailable in the blood of mice and exhibited no detectable toxic effects on tumor-bearing mice. Our data provided strong evidence for the anti-HCC effect of isolie.

[Study on chemical constituents in stems of Nelumbo nucifera by UPLC-ESI/Q-TOF-MS/MS]

This paper employed UPLC-Electrospray Ionization /Quadrupole-Time of Flight-Mass /Mass Spectrometry( UPLC-ESI/Q-TOF-MS/MS) to analyze the chemical constituents in the stems of Nelumbo nucifera. The stems of N. nucifera were extracted with 75% methanol, and we applied an Agilent Zorbax SB-Aq column (2.1 mm x 100 mm, 1.8 μm) to UPLC analysis with water methanol-water( containing 0.05% formic acid) in gradient as mobile phase. The eluates were then detected by ESI-Q-TOF-MS/MS. Results indicated that 22 benzylisoquinoline alkaloids were indendified. Among them, one alkaloid may be a new compound and a component was found in the Lotus for the first time. We fully identify the composition of the Lotus stems for the first time, Which could provides theoretical foundation for further study and utilization of the medicinal resources.

[Study on content determination of alkaloids and HPLC fingerprint of "Jianlian" Nelumbinis Plumula]

This study is to determine the content of three alkaloids and establish the HPLC fingerprint of "Jianlian" Nelumbinis Plumula. The HPLC method of content determination was as follows: Thermo C18 (4. 6 mm x 250 mm, 5 μm) was conducted with acetonitrile-sodium dodecyl sulfonate solution-acetic acid (56: 43: 1) at a flow rate of 1.0 mL x min(-1). The monitoring wavelength was set at 282 nm and the column temperature was 35 degrees C. The method of HPLC fingerprint was as follows: Agilent ZORBAX SB-Aq C18 (4.6 mm x 250 mm, 5 μm) was conducted with gradient elution of methanol and water at a flow rate of 0.8 mL x min(-1), the monitoring wavelength was set at 282 nm and the column temperature was 35 degrees C. Similarities evaluation and hierarchical clustering analysis were applied to demonstrate the variability of 12 batches of "Jianlian" Nelumbinis Plumula samples. The results demonstrated that 11 batches showed good similarity on chemical constituents. The method could well display the chemical information of "Jianlian" Nelumbinis Plumula. It was simple, reliable and could be used for the chemical quality control of "Jianlian" Nelumbinis Plumula.

Proteomic and Epigenetic Analyses of Lotus (Nelumbo nucifera) Petals Between Red and White cultivars

Lotus is a vital aquatic ornamental plant with different flower colors. To explore the flower coloration mechanism in lotus, the constituents and contents of pigments in two lotus cultivars with red and white flowers were analyzed. Although flavones and flavonols were detected in both cultivars, anthocyanins could only be detected in the red cultivar. A comparative proteomics analysis on the flower petals between these two cultivars was conducted. A total of 88 differentially expressed proteins were identified with 36 more abundant and 52 less abundant in the red than in the white cultivar. Among them, four enzymes involved in the anthocyanin pathway were identified, i.e. flavanone 3-hydroxylase, anthocyanidin synthase, anthocyanidin 3-O-glucosyltransferase and glutathione S-transferase. Analysis of the expression patterns of anthocyanin biosynthetic genes indicated that the anthocyanindin synthase (ANS) gene might be the critical gene determining anthocyanin biosynthesis and accumulation in lotus flower. Further analysis showed that different methylation intensities on the promoter sequence of the ANS gene might result in the different flower coloration in the red and white cultivar. This study provides new insights into the mechanism of flower coloration in lotus, and may be helpful in its breeding and germplasm enhancement.

Human Ether-à-go-go Related Gene (hERG) Channel Blocking Aporphine Alkaloids from Lotus Leaves and Their Quantitative Analysis in Dietary Weight Loss Supplements

Blockage of the human ether-à-go-go related gene (hERG) channel can result in life-threatening ventricular tachyarrhythmia. In an in vitro screening of herbal materials for hERG blockers using an automated two-microelectrode voltage clamp assay on Xenopus oocytes, an alkaloid fraction of Nelumbo nucifera Gaertn. (lotus) leaves induced ∼50% of hERG current inhibition at 100 μg/mL. Chromatographic separation resulted in the isolation and identification of (-)-asimilobine, 1, nuciferine, 2, O-nornuciferine, 3, N-nornuciferine, 4, and liensinine, 5. In agreement with in silico predicted ligand-target interactions, 2, 3, and 4 revealed distinct in vitro hERG blockages measured in HEK293 cells with IC50 values of 2.89, 7.91, and 9.75 μM, respectively. Because lotus leaf dietary weight loss supplements are becoming increasingly popular, the identified hERG-blocking alkaloids were quantitated in five commercially available products. Results showed pronounced differences in the content of hERG-blocking alkaloids ranging up to 992 μg (2) in the daily recommended dose.

Analysis of Flavonoids in Lotus (Nelumbo nucifera) Leaves and Their Antioxidant Activity Using Macroporous Resin Chromatography Coupled with LC-MS/MS and Antioxidant Biochemical Assays

Lotus (Nelumbo nucifera) leaves, a traditional Chinese medicinal herb, are rich in flavonoids. In an effort to thoroughly analyze their flavonoid components, macroporous resin chromatography coupled with HPLC-MS/MS was employed to simultaneously enrich and identify flavonoids from lotus leaves. Flavonoids extracted from lotus leaves were selectively enriched in the macroporous resin column, eluted subsequently as fraction II, and successively subjected to analysis with the HPLC-MS/MS and bioactivity assays. Altogether, fourteen flavonoids were identified, four of which were identified from lotus leaves for the first time, including quercetin 3-O-rhamnopyranosyl-(1→2)-glucopyranoside, quercetin 3-O-arabinoside, diosmetin 7-O-hexose, and isorhamnetin 3-O-arabino- pyranosyl-(1→2)-glucopyranoside. Further bioactivity assays revealed that these flavonoids from lotus leaves possess strong antioxidant activity, and demonstrate very good potential to be explored as food supplements or even pharmaceutical products to improve human health.

Nuciferine, extracted from Nelumbo nucifera Gaertn, inhibits tumor-promoting effect of nicotine involving Wnt/β-catenin signaling in non-small cell lung cancer

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of Nelumbo nucifera Gaertn are recorded in the earliest written documentation of traditional Chinese medicinal as "Ben Cao Gang Mu", a medicinal herb for blood clotting, dysentery and dizziness. Recently, nuciferine (NF), one of N. nucifera Gaertn leaf extracts has been shown to possess several pharmacological properties, including anti-viral and anti-cancer. The aim of this study is to investigate the underlying molecular mechanism of the anti-cancer activity of NF in NSCLC progression induced by nicotine

MATERIALS AND METHODS

The effect of NF on proliferation of A549 (human lung adenocarcinoma epithelial cell line) pretreated with or without nicotine was detected by tumor cell proliferation assay. TOP-Flash reporter assay was applied to investigate the activity of Wnt/β-catenin signaling in tumor cells in the presence of NF and/or nicotine. Apoptosis was measured using a FITC-Annexin V and PI detection kit by flow cytometry. In addition, mRNA or protein expression levels were respectively tested by quantitative RT-PCR or western blot. In vivo experiments, tumor samples were fixed in formalin and embedded in paraffin for additional analyses by immunohistochemistry and TUNEL staining.

RESULTS

NF significantly inhibited the proliferation of NSCLC cells in the presence of nicotine, suppressed the activity of Wnt/β-catenin signaling, enhanced the stabilization of Axin, and induced apoptosis. NF down-regulated the expression levels of β-catenin and its downstream targets including c-myc, cyclin D and VEGF-A. NF also decreased the ratio of Bcl-2/Bax, which may explain the pro-apoptosis effect of NF. In tumor xenograft nude mice, NF not only inhibited the growth of non-small cell lung cancer (NSCLC) cells, but also remarkably alleviated the injury induced by nicotine in liver function.

CONCLUSIONS

NF has the remarkable effect to inhibit nicotine-induced NSCLC progression, which was due to its ability to reduce the activity of Wnt/β-catenin signaling. Thus, the work stated here emphasizes the importance of this traditional medicine and presents a potential novel alternative to NSCLC prevention and therapy.

The role of bio-inspired hierarchical structures in wetting

Superhydrophobicity facilitates the development of self-cleaning, anti-biofouling, and anti-corrosion surfaces. The leaves of the lotus (Nelumbo nucifera) and taro (Colocasia esculenta) plants are well known for their self-cleaning properties. A hierarchical structure comprising papillae epidermal cells superimposed with epicuticular wax crystalloids of varying shapes, sizes, and orientations is an important aspect of the surface of these plant leaves. We fabricated two types of hierarchical structures biomimicking the surface topography of the lotus leaf. The hierarchical patterns successfully demonstrated the superhydrophobic state in comparison with nano and micro patterns. We used the finite element method (FEM) to simulate and understand the wetting process. The FEM simulations showed good correlation with the experimental results. FEM was helpful in understanding the wetting of enormously complex biological surfaces with relative ease, and it qualifies as a potential tool for designing superhydrophobic surfaces. Using the FEM framework, we further designed surfaces to optimize the order of the shapes in hierarchy. The results showed that the superhydrophobic surface with the lowest wetted area was obtained by placing shapes with smaller geometric angles at the top of the hierarchy. This arrangement of shapes provides the optimum combination of superhydrophobicity and surface integrity. This observation explains why the hierarchical structure of many superhydrophobic leaves follows this order. We also investigated the complex hierarchical structure of Salvinia minima. Owing to its remarkable ability to entrap air and pin the contact line, it exhibits superhydrophobicity along with the much-required Cassie state. These properties of Salvinia minima make it an excellent candidate for developing omniphobic surfaces.

Anti-angiogenic effect of Nelumbo nucifera leaf extracts in human umbilical vein endothelial cells with antioxidant potential

Nelumbo nucifera Gaertn (Nymphaeaceae) has long been used as a traditional herb in Chinese, Japanese, Indian, and Korean medicinal practices since prehistoric times and flourishes today as the primary form of medicine. This study reports for the first time the potent ability of N. nucifera leaf extracts to inhibit vascular endothelial growth factor (VEGF)-induced angiogenesis in vitro and in vivo, as well as their antioxidant efficacy in various scavenging models and an analysis of their chemical composition. In vivo anti-angiogenic activity was evaluated in a chick chorioallantoic membrane (CAM) model using fertilized chicken eggs, in human umbilical vein endothelial cells (HUVECs) by using cell viability, cell proliferation and tube formation assays, and by determining intracellular reactive oxygen species (ROS) in vitro. The antioxidant efficacy of N. nucifera leaf extracts was determined in various scavenging models, including total phenolic and flavonoid content. The chemical composition of N. nucifera leaf extracts was determined by GC-MS analysis, which revealed the presence of different phytochemicals. The IC₅₀ values for the DPPH radical scavenging activities of water and methanol extracts were found to be 1699.47 and 514.36 μg ml⁻¹, and their total phenolic and flavonoid contents were 85.01 ± 2.32 and 147.63 ± 2.23 mg GAE g dry mass⁻¹ and 35.38 ± 1.32 and 41.86 ± 1.07 mg QA g dry mass⁻¹, respectively. N. nucifera leaf extracts (10–100 μg ml⁻¹) exhibited significant dose-dependent inhibition of VEGF-induced angiogenesis, as well as VEGF-induced proliferation and tube formation in HUVECs. In this study, N. nucifera leaf extracts displayed potent antioxidant and inhibitory effects on VEGF-induced angiogenesis. N. nucifera exerted an inhibitory effect on VEGF-induced proliferation and tube formation, as well as CAM angiogenesis in vivo. Moreover, N. nucifera leaf extracts significantly blocked VEGF-induced ROS production in HUVECs, confirming their possible anti-angiogenic mechanism.

Lipase ligands in Nelumbo nucifera leaves and study of their binding mechanism

Lotus (Nelumbo nucifera) leaves have been widely used in weight-loss foods to prevent obesity in China. In this work, a facile procedure based on ligand fishing was developed to isolate and identify lipase inhibitors present in lotus leaves. Highly stable and active lipase-Fe3O4 superparamagnetic nanoparticle conjugates (LMNPs) were prepared and used as baits. Two flavonoids in lotus leaf extract were found to bind to the baits and were identified as quercetin-3-O-β-d-arabinopyranosyl-(1→2)- β-d-galactopyranoside (1) and quercetin-3-O-β-d-glucuronide (4) based on electrospray ionization-mass spectrometric analyses. Their 50% inhibitory concentrations on lipase (IC50) were 52.9 ± 3.2 and 17.1 ± 1.5 μg/mL, respectively. In addition, they were found to significantly quench the fluorescence of lipase, suggesting their strong affinities with this enzyme, which was further evidenced by molecular docking. Ligand fishing based on LMNPs shows great power for fast screening and identification of lipase inhibitors present in edible and medicinal plants.

Antioxidant and anticancer aporphine alkaloids from the leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena

Fifteen compounds were extracted and purified from the leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena. These compounds include liriodenine (1), lysicamine (2), (-)-anonaine (3), (-)-asimilobine (4), (-)-caaverine (5), (-)-N-methylasimilobine (6), (-)-nuciferine (7), (-)-nornuciferine (8), (-)-roemerine (9), 7-hydroxydehydronuciferine (10) cepharadione B (11), β-sitostenone (12), stigmasta-4,22-dien-3-one (13) and two chlorophylls: pheophytin-a (14) and aristophyll-C (15). The anti-oxidation activity of the compounds was examined by antiradical scavenging, metal chelating and ferric reducing power assays. The results have shown that these compounds have antioxidative activity. The study has also examined the antiproliferation activity of the isolated compounds against human melanoma, prostate and gastric cancer cells. The results shown that 7-hydroxydehydronuciferine (10) significantly inhibited the proliferation of melanoma, prostate and gastric cancer cells. Together, these findings suggest that leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena are a good resource for obtaining the biologically active substances with antioxidant properties.

Ultra-performance LC separation and quadrupole time-of-flight MS identification of major alkaloids in Plumula Nelumbinis

INTRODUCTION

As an essential medicine and tea source in many countries, Plumula Nelumbinis potentially exerts its major biological activities through its alkaloids. However, the activities of Plumula Nelumbinis are not fully understood due to the lack of studies on its chemical components.

OBJECTIVE

To establish an ultra-performance liquid chromatography combined with diode-array detector (UPLC/DAD) method, coupled to an electrospray ionisation with quadrupole time-of-flight mass spectrometry (ESI/QTOF/MS) method, for the separation and identification of Plumula Nelumbinis alkaloids.

METHODS

The eluant from an UPLC separation of an ethanol extract of Plumula Nelumbinis was directly infused into an ESI/QTOF/MS system. Both positive and negative ion modes of ESI with low and high collision energy (CE) were used to obtain sufficient MS information.

RESULTS

Twenty-one alkaloids were tentatively identified based on their chromatographic characteristics, UV spectra, exact mass, MS fragments and literature reports. They consist of six bis-1-benzyltetrahydroisoquinoline, eleven benzyltetrahydroisoquinoline (including two glycoalkaloids and two quaternary ammoniums), two aporphine, one proaporphine and one indole alkaloids. Eleven were identified in Plumula Nelumbinis for the first time and seven were first reported in Nelumbo nucifera Gaertn. Five compounds, namely norcoclaurine-4'-O-glucoside, norcoclaurine-6-O-glucoside, isolotusine, 6-demethyl-4-demethylN-methylcoclaurine and N-norisoliensinine, were characterised and proposed as new compounds.

CONCLUSION

The established UPLC/DAD - ESI/QTOF/MS method is efficient for systematic identification of the alkaloids in Plumula Nelumbinis extract.

[Studies on flavonoids from stems of Nelumbo nucifera Gaertn and their cytotoxic activities]

This research is to investigate study the flavonoids from stems of Nelumbo nucifera and the cytotoxic activities of iso- lated compounds. The constituents were separated by column chromatography,and their structures were elucidated by spectroscopic data analyses. The isolated compounds were evaluated for cytoxic activities by MTT method. Twelve compounds were isolated and identified as rhamnazin-3-O-beta-D-glucopyranoside (1), luteolin-3', 4'-dimethylether-7-O-beta-D-glucoside (2), kaempferol-3-O-beta-D-xylopyranosyl-(1-->2)-O-beta-D-glucopyranoside (3), quercetin-3,3'-di-O-beta-D-glucopyranoside (4), 1, 8-dihydroxy-3,7-dimethoxyxanthone (5), isorhamnetin-3-O-beta-D-glucopyranoside(6) , kaempferol(7), isorhamnetin (8), quercetin(9), astragalin(10), hyperoside (11) and 1-hy- droxy-3,7,8-trimethoxyxanthone(12). All compounds were isolated from stems of this plant for the first time, and compounds 1-5 were firstly isolated from the family nelumbonaceae. Compounds 24 and 6 showed significant cytotoxic activities against BEL-7402 carcinoma cell lines at a concentration of 1 x 10(-5) mol x L(-1) with the inhibitory rate of 67.36%, 53.25%, 57.78%, 60.13% and 52.11%, respectively.

The mixture of different parts of Nelumbo nucifera and two bioactive components inhibited tyrosinase activity and melanogenesis

Melanin is the pigment responsible for the color of the eyes, hair, and skin in humans. Tyrosinase is well known to be the key enzyme in melanin biosynthesis. JKTM-12 is composed of the flowers, roots, seeds, and receptacles of Nelumbo nucifera (lotus). In this study, JKTM-12 was investigated for its inhibitory effects on tyrosinase activity and melanin biosynthesis in B16F10 melanoma cells. Moreover, two main bioactive compounds (hyperoside and astragalin) were found from the receptacles of N. nucifera, which are used as the main material of JKTM-12. JKTM-12 was shown to inhibit tyrosinase activity and melanin biosynthesis in alpha-melanocyte-stimulating hormone-stimulated B16F10 melanoma cells. Hyperoside and astragalin, which are the main bioactive compounds of JKTM-12, not only inhibited tyrosinase activity and melanogenesis but also tyrosinase-related protein 1 and tyrosinase-related protein 2 mRNA expression without cytotoxicity at various experiment doses (0.1, 1, and 10 μg/ml). These results suggest that JKTM-12 has the potential for skin whitening with hyperoside and astragalin as the main bioactive compounds.

Comparative analysis of antioxidant activity and functional components of the ethanol extract of lotus (Nelumbo nucifera) from various growing regions

The variations in antioxidant activity and concentration of functional components in the ethanol extracts of lotus seeds and rhizomes based on the growing region and dryness were investigated. Free radical scavenging activity, total phenolic and flavonoid content, and concentration of several specific flavonoids and alkaloids in the ethanol extracts of lotus were measured. Antioxidant activity and its correlative total phenolic content varied characteristically depending on the growing region and dryness. High-perfomance liquid chromatography analysis showed that the ethanol extracts of lotus seeds from Vietnam (Ho Chi Minh City), raw rhizomes from Korea (Siheung), and dried rhizomes from Japan (Nigata) had the greatest specific flavonoid content. The ethanol extracts of seeds from China (Hubei), raw rhizomes from Japan (Nigata), and dried rhizomes from Korea (Siheung) had the greatest specific alkaloid content. Astragaline, rutin, isoquercetin, nuciferine, dauricine, isoliensinine, and neferine were identified in lotus rhizomes for the first time in this study.

Evaluation of in vitro aldose reductase inhibitory potential of alkaloidal fractions of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera

BACKGROUND

Aldose reductase is primarily involved in development of long-term diabetic complications due to increased polyol pathway activity. The synthetic aldose reductase inhibitors are not very successful clinically. Therefore, the natural sources may be exploited for safer and effective aldose reductase inhibitors.

METHODS

In the present study, the aldose reductase inhibitory potential of hydroalcoholic and alkaloidal extracts of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera was evaluated. The hydroalcoholic and alkaloidal extracts of the selected plants were prepared. The different concentrations of hydroalcoholic and alkaloidal extracts of these plants were evaluated for their goat lens aldose reductase inhibitory activity using dl-glyceraldehyde as substrate. The aldose reductase inhibitory potential of extracts was assessed in terms of their IC50 value.

RESULTS

Amongst the hydroalcoholic extracts, the highest aldose reductase inhibitory activity was shown by P. nigrum (IC50 value 35.64±2.7 μg/mL) followed by M. koenigii (IC50 value 45.67±2.57 μg/mL), A. mexicana (IC50 value 56.66±1.30 μg/mL), and N. nucifera (IC50 value 59.78±1.32 μg/mL). Among the alkaloidal extracts, highest inhibitory activity was shown by A. mexicana (IC50 value 25.67±1.25 μg/mL), followed by N. nucifera (IC50 value 28.82±1.85 μg/mL), P. nigrum (IC50 value 30.21±1.63 μg/mL), and M. koenigii (IC50 value 35.66±1.64 μg/mL).

CONCLUSIONS

It may be concluded that the alkaloidal extracts of these plants possess potent aldose reductase inhibitory activity and may be therapeutically exploited in diabetes-related complications associated with increased activity of aldose reductase.

Identification and characterization of potent CYP2D6 inhibitors in lotus leaves

ETHNOPHARMACOLOGICAL RELEVANCE

The herb of lotus (Nelumbo nucifera) leaves is a commonly used traditional Chinese herbal medicine that is utilized for the treatment of sunstroke, to assuage thirst, and to cure both diarrhea and fever in China. Modern pharmacological studies have demonstrated that the herb exhibits various pharmacological effects, such as anti-hyperlipidemia, anti-obesity, anti-oxidant, anti-HIV, anti-microbial, and anti-hypoglycemic activities. Currently, the herb is becoming more popular in China as a "tea drink" or as a main ingredient of some herbal formulations, which implies that the herb and/or its products are now more likely to be concurrently administered with conventional medicines for losing body weight and reducing blood lipids. However, its potential inhibitory effect on human cytochrome P450 (CYP) has not been systemically investigated to date. The present study was performed to assess the potential inhibitory effects of lotus leaf alcoholic extract (LAE), its major fractions, and its main compounds on five CYP isoenzymes (CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4) in vitro.

MATERIAL AND METHODS

Five probe substrates were incubated with human liver microsomes in the presence or absence of the LAE, the alkaloid fraction (AF), the flavonoid fraction (FF), or the individual aporphine alkaloids, namely, nuciferine (NF), N-nornuciferine (N-NF), and 2-hydroxy-1-methoxyaporphine (HMA). After the incubation, the relative metabolites of the substrates were analyzed using LC-MS/MS.

RESULTS

The results showed that the LAE strongly inhibited CYP2D6 with an IC50 value of 12.05µg/mL and weakly inhibited other isoenzymes. In addition, FF was found to weakly inhibit CYP2D6, whereas AF exerted a markedly higher inhibitory effect on CYP2D6 activity with an IC50 value of 0.96µg/mL. The three aporphine alkaloids isolated from the AF (NF, N-NF, and HMA) significantly inhibited CYP2D6 with IC50 values of 3.78, 3.76, and 3.15µM, respectively. Their Lineweaver-Burk plots and Dixon plots showed that NF, N-NF, and HMA competitively inhibited CYP2D6 activity with Ki values of 1.88, 2.34, and 1.56µM, respectively.

CONCLUSION

The study revealed that the alkaloid compounds in lotus leaves exert a potent inhibitory effect on CYP2D6 isoenzyme. The possible drug interactions of the leaves and their preparations with conventional medicines should thus be taken into account.

Anthelmintic activities of aporphine from Nelumbo nucifera Gaertn. cv. Rosa-plena against Hymenolepis nana

Nelumbo nucifera Gaertn. cv. Rosa-plena (Nelumbonaceae), commonly known as lotus, is a perennial aquatic plant grown and consumed throughout Asia. All parts of N. nucifera have been used for various medicinal purposes in oriental medicine. From the leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena (an aquatic plant), liriodenine (1), lysicamine (2), (−)-anonaine (3), (-)-asimilobine (4), (-)-caaverine (5), (-)-N-methylasimilobine (6), (-)-nuciferine (7), (-)-nornuciferine (8), (-)-roemerine (9), 7-hydroxydehydronuciferine (10) and cepharadione B (11) were isolated and identification and anthelmintic activities of aporphine was evaluated against Anisakis simplex and Hymenolepis nana. This study found that the above constituents killed H. nana or reduced their spontaneous movements (oscillation/peristalsis). However, the above constituents at various concentrations demonstrated no larvicidal effect or ability to halt spontaneous parasite movement for 72 h against A. simplex, respectively. In addition, according to an assay of cestocidal activity against H. nana and nematocidal activity against A. simplex, we found that the above compounds showed greater lethal efficacy on H. nana than against A. simplex. Further investigation showed that these above constituents have effects against peroxyl radicals under cestocidal effect. Together, these findings suggest that these constituents of Nelumbo nucifera Gaertn. cv. Rosa-plena might be used as anthelmintic agents against H. nana.

Neferine, an alkaloid from lotus seed embryo, inhibits human lung cancer cell growth by MAPK activation and cell cycle arrest

Neferine is the major bisbenzylisoquinoline alkaloid isolated from the seed embryo of a traditional medicinal plant Nelumbo nucifera (Lotus). Epidemiological studies have revealed the therapeutic potential of lotus seed embryo. Although several mechanisms have been proposed, a clear anticancer action mechanism of neferine on lung cancer cells is still not known. Lung cancer is the most common cause of cancer death in the world, and the patients with advanced stage of nonsmall lung cancer require adjunct chemotherapy after surgical resection for the eradication of cancer cells. In this study, the effects of neferine were evaluated and characterized in A549 cells. Neferine induced apoptosis in a dose-dependent manner with the hypergeneration of reactive oxygen species, activation of MAPKs, lipid peroxidation, depletion of cellular antioxidant pool, loss of mitochondrial membrane potential, and intracellular calcium accumulation. Furthermore, neferine treatment leads to the inhibition of nuclear factor kappaB and Bcl2, upregulation of Bax and Bad, release of cytochrome C, activation of caspase cascade, and DNA fragmentation. In addition, neferine could induce p53 and its effector protein p21 and downregulation of cell cycle regulatory protein cyclin D1 thereby inducing G1 cell cycle arrest. These results suggest a novel function of neferine as an apoptosis inducer in lung cancer cells.