Lotus leaf flavonoids induce apoptosis of human lung cancer A549 cells through the ROS/p38 MAPK pathway.

BACKGROUND: Leaves of the natural plant lotus are used in traditional Chinese medicine and tea production. They are rich in flavonoids. METHODS: In this study, lotus leaf flavonoids (LLF) were applied to human lung cancer A549 cells and human small cell lung cancer cells H446 in vitro to verify the effect of LLF on apoptosis in these cells through the ROS/p38 MAPK pathway. RESULTS: LLF had no toxic effect on normal cells at concentrations up to 500 µg/mL, but could significantly inhibit the proliferation of A549 cells and H446 cells. Flow cytometry showed that LLF could induce growth in A549 cells. We also found that LLF could increase ROS and MDA levels, and decrease SOD activity in A549 cells. Furthermore, qRT-PCR and western blot analyses showed that LLF could upregulate the expression of p38 MAPK (p-p38 MAPK), caspase-3, caspase-9, cleaved caspase-3, cleaved caspase-9 and Bax and downregulate the expression of Cu/Zn SOD, CAT, Nrf2, NQO1, HO-1, and Bcl-2 in A549 cells. Results of HPLC showed that LLF mainly contain five active substances: kaempferitrin, hyperoside, astragalin, phloridzin, and quercetin. The apoptosis-inducing effect of LLF on A549 cells came from these naturally active compounds. CONCLUSIONS: We have shown in this study that LLF is a bioactive substance that can induce apoptosis in A549 cells in vitro, and merits further research and development.

Lotus leaf flavonoids induce apoptosis of human lung cancer A549 cells through the ROS/p38 MAPK pathway

BACKGROUND: Leaves of the natural plant lotus are used in traditional Chinese medicine and tea production. They are rich in flavonoids. METHODS: In this study, lotus leaf flavonoids (LLF) were applied to human lung cancer A549 cells and human small cell lung cancer cells H446 in vitro to verify the effect of LLF on apoptosis in these cells through the ROS/p38 MAPK pathway. RESULTS: LLF had no toxic effect on normal cells at concentrations up to 500 µg/mL, but could significantly inhibit the proliferation of A549 cells and H446 cells. Flow cytometry showed that LLF could induce growth in A549 cells. We also found that LLF could increase ROS and MDA levels, and decrease SOD activity in A549 cells. Furthermore, qRT-PCR and western blot analyses showed that LLF could upregulate the expression of p38 MAPK (p-p38 MAPK), caspase-3, caspase-9, cleaved caspase-3, cleaved caspase-9 and Bax and downregulate the expression of Cu/Zn SOD, CAT, Nrf2, NQO1, HO-1, and Bcl-2 in A549 cells. Results of HPLC showed that LLF mainly contain five active substances: kaemp-feritrin, hyperoside, astragalin, phloridzin, and quercetin. The apoptosis-inducing effect of LLF on A549 cells came from these naturally active compounds. CONCLUSIONS: We have shown in this study that LLF is a bioactive substance that can induce apoptosis in A549 cells in vitro, and merits further research and development.

Understanding the roles of Lys33 and Arg45 in the binding-site stability of LjLTP10, an LTP related to drought stress in Lotus japonicus.

In Lotus japonicus, as in most plants, long-chain fatty acids are important components of cuticular wax, one of the principal functions of which is to act as a barrier to water loss in response to drought stress. It is thought that lipid transfer proteins (LTPs) are involved in the process of cuticle formation. We previously described LjLTP10 as an LTP involved in cuticle formation during acclimation response to drought stress in L. japonicus. The structural model of LjLTP10 had two residues (K33 and R45) in the hydrophobic cavity, although the role of these residues was unclear. In the present work, we investigated the molecular mechanism involved in the transport of lipid precursors in L. japonicus and clarified the importance of the residues K33 and R45. First, in silico site-directed mutagenesis studies were carried out on the LjLTP10 structure. Structural analysis showed that LjLTP10 mutants possess similar structures but their hydrophobic cavities are somewhat different. Unfavorable energies for the interactions of the mutant proteins with different ligands were found by molecular docking and molecular dynamics simulations. We also examined the contributions of energetic parameters to the free energy of the protein-ligand complex using the MM-GBSA method. Results showed that the different complexes present similar, favorable van der Waals interactions, whereas electrostatic interactions were not favored in the mutant structures. Our study indicates that the residues K33 and R45 play a crucial role in maintaining the binding pocket structure required for lipid transport.

Inhibitory effect of lotus seedpod oligomeric procyanidins on advanced glycation end product formation in a lactose-lysine model system

Background Industrial food processing induces protein glycation modifications and toxic advanced glycation end products (AGEs) which affect human health. Therefore, it is of interest to monitor AGEs in food processing. The present study was carried out to investigate the influence of lotus seedpod oligomeric procyanidin (LSOPC) concentrations, solution pH value and metal ions on AGE formation by heat treatment of lactose-lysine model solutions. Ne-(carboxymethyl) lysine (CML), as one of the common AGEs was also determined by HPLC-MS/MS in this experiment. Results The results showed that LSOPC can inhibit the formation of AGEs effectively at higher concentrations, lower temperature, and it can reverse the promotion function of metal ions because of its high inhibition activity. Also, LSOPC can inhibit CML formation in the Maillard reaction as well. Conclusion These results indicated that LSOPC could be used as functional food ingredients to inhibit AGE formation.

Phytochemical profile and antimicrobial properties of Lotus spp. (Fabaceae).

The phytochemical profile and antimicrobial activity of cultivar (cv.) extracts of Lotus uliginosus (cvs. Trojan and Serrano), L. tenuis (cv. Larrañaga) and L. corniculatus (cv. São Gabriel) were investigated. The phytochemical analysis revealed tannins, coumarins and flavonoids in all extracts, with variations among cultivars, showing genotypic variability. By High Performance Liquid Chromatographic method, the cvs. Larrañaga and São Gabriel showed the highest percentage of catechin and epicatechin, respectively, and presented rutin, which was not detected in the other ones. These genotypes showed antifungal activity but not antibacterial one. The cv. Larrañaga inhibited the mycelia growth of Alternaria sp. and Fusarium graminearum while the cv. São Gabriel was active only against Alternaria sp. The cultivars showed the greatest amounts of secondary metabolites and demonstrated significant activity against filamentous fungi. The results provide a direction for further research about pharmacological use of Lotus spp.

Lotus corniculatus regulates the inflammation induced by bradykinin in a murine model of pleurisy.

This study evaluated the anti-inflammatory efficacy of the crude extract (CE), the fractions derived from hexane (HEX), ethyl acetate (AcOEt), n-butanol (BuOH), and aqueous (Aq) and isolated compounds (oleanolic acid or kaempferitrin) obtained from the aerial parts of Lotus corniculatus var. São Gabriel in mice with bradykinin-induced pleurisy. Swiss mice were used for the In Vivo experiments. Inflammatory parameters [leukocytes; exudate concentrations; myeloperoxidase and adenosine-deaminase activities, and nitric oxide and interleukin-17 levels] were evaluated 4 h after pleurisy induction. The crude extract of Lotus corniculatus, its derived fractions, and isolated compounds inhibited leukocytes and the exudate. This inhibitory effect was associated with decreased of myeloperoxidase and adenosine-deaminase activities, nitric oxide products, and IL-17A levels. Lotus corniculatus presented important anti-inflammatory action by inhibiting leukocyte influx and exudate concentrations. This effect was directly related to the inhibition of nitric oxide and interleukinin17 levels. Oleanolic acid and kaempferitrin can account for these anti-inflammatory effects.

Antiplatelet activity of white and pink Nelumbo nucifera Gaertn flowers / Atividade antiplaquetária de flores Nelumbo nucifera Gaertn branco e rosa

Nelumbo nucifera Gaertn (Nelumbonaceae) a plant used in Ayurvedic medicine (common name: lotus), is a perennial, large and rhizomatous aquatic herb most prevalent in South India. Preliminary phytochemical screening of both white and pink Nelumbo nucifera flowers revealed the presence of phytochemical constituents (flavonoids, alkaloids, phenols etc,). Hence, an attempt has been made to screen the effect of Nelumbo nucifera flowers (both types) on platelet aggregation. The antiplatelet activity of hydroethanolic extract of both types of flowers was studied using platelet-rich plasma in different concentrations (100-500µg/ml). Both white and pink Nelumbo nucifera flower extracts showed dose-dependent effective antiplatelet activity with maximum activity at 500µg/ml concentration; prevention of platelet aggregation was 50 percent of that achieved with standard aspirin. Furthermore, the antiplatelet activity of white flowers was relatively high (p<0.05; ANOVA) compared to pink flowers. In conclusion, these observations suggest that both varieties of Nelumbo nucifera flower extracts exert different levels of inhibitory action on platelets in vitro (secretion and platelet aggregation suppression) due to differences in phytochemical content (alkaloids, flavonoids, phenols, tannins, phytosteroids, glycosides and saponins).

Nelumbo nucifera Gaertn (Nelumbonaceae, planta utilizada na medicina Ayurvédica, é erva aquática rizomatosa grande, predominante no sul da Índia. A triagem fitoquímica preliminar das flores brancas e cor-de-rosa de Nelumbo nucifera revelou a presença de constituintes fitoquímicos (flavonoides, alcaloides, fenóis etc). Assim, tentou-se a triagem do efeito das flores de Nelumbo nucifera de ambos os tipos na agregação plaquetária. A atividade antiplaquetária dos extratos hidroetanólico de ambos os tipos de flores foi estudada, utilizando-se plasma rico em plaquetas em duas diferentes concentrações (100 - 500 µg/mL). Tanto os extratos das flores brancas quanto daquelas de cor-de-rosa mostraram atividade antiplaquetária dose-dependente, com o máximo na concentração de 500 µg/mL. A prevenção da agregação plaquetária foi 50 por cento daquela alcançada com o padrão de ácido acetilsalicílico. Além disso, a atividade antiplaquetária das flores brancas foi, relativamente, alta (p<0,05; ANOVA), comparativamente às flores cor-de-rosa. Estas observações sugerem que ambas as variedades de extratos de flores de Nelumbo nucifera exercem diferentes níveis de ação inibitória nas plaquetas in vitro (supressão da secreção e da agregação plaquetária) devido a diferentes constituintes fitoquímicos (alcaloides, flavonoides, fenóis, taninos, fitoesteróides, glicosídeos e saponinas).

Aspectos químicos do gênero Lotus L. com ênfase em metabólitos secundários / Chemistry aspects of Lotus L. genus with emphasis in secondary metabolites

Objetivou-se caracterizar Lotus corniculatus (cvs. São Gabriel e ARS 2620), L. uliginosus (cv. Maku) e L. subbiflorus (cv. El Rincón) quanto ao perfil fitoquímico, mediante a determinação dos teores de proteína bruta (PB), fibra em detergente ácido (FDA) e neutro (FDN), fenóis totais (FT), taninos totais (TT), taninos condensados (TC) e bioensaio. As espécies foram cultivadas em vasos com substrato fértil e colhidas aos 258 dias de idade. Apenas na cv. São Gabriel foi testada a presença de flavonóides, comparando com amostras coletadas no campo. Os teores de PB e FDN não variaram entre as espécies, e foram de 13,2 a 17,6% para PB e de 53,5 e 65,1% para FDN. Os teores de FDA variaram entre as espécies, com 34,7% (S. Gabriel), 31,4% (ARS 2620), 43,2% (Maku) e 41,7% (El Rincón). Foram identificados flavonóides do tipo rutina e vitexina na cv. São Gabriel. Os teores de TC e FT foram respectivamente: cv. São Gabriel: 1,99 e 2,88 g/kg; ARS 2620: 0,05 e 1,70 kg/kg; Maku: 0,34 e 2,50 g/kg; El Rincón: 1,67 e 1,27 g/kg. Na presença de polietilenoglicol (PEG) ocorreu maior produção de gás. O baixo teor de taninos indica a necessidade de investigação para verificar a interação genótipo x ambiente.

Aimed to characterize Lotus corniculatus (cvs. São Gabriel and ARS 2620), L. uliginosus (cv. Maku) and L. subbiflorus (cv. El Rincón) on the phytochemical profile, by determining the levels of crude protein (CP), acid detergent fiber (ADF) and neutral (NDF), total phenolics (FT), total tannins (TT), tannins condensed (TC) and bioassay. The species were grown in pots filled with fertile substrate and harvested at 258 days of age. In cv. São Gabriel was also evaluated the presence of flavonoids, with samples of plants harvested in the field. The CP and NDF did not differ between species, and were 13.2 to 17.6% for CP and 53.5 and 65.1% for NDF. The ADF varied among species, with 34.7% (São Gabriel), 31.4% (ARS 2620), 43.2% (Maku) and 41.7% (El Rincón). There were identified flavonoids like rutin and vitexin in cv. São Gabriel. The levels of CT and FT were: cv. São Gabriel: 1.99 and 2.88 g/kg; ARS 2620: 0.05 and 1.70 kg/kg: Maku 0.34 and 2.50 g/kg: El Rincón: 1.67 and 1.27 g/kg. In the presence of polyethylene glycol (PEG) was higher gas production. The low tannin content indicates the need for research to verify the genotype x environment.

Crystallization and preliminary X-ray diffraction analysis of an anti-H(O) lectin from Lotus tetragonolobus seeds.

The seed lectin from Lotus tetragonolobus (LTA) has been crystallized. The best crystals grew over several days and were obtained using the vapour-diffusion method at a constant temperature of 293 K. A complete structural data set was collected at 2.00 angstroms resolution using a synchrotron-radiation source. LTA crystals were found to be monoclinic, belonging to space group P2(1), with unit-cell parameters a = 68.89, b = 65.83, c = 102.53 angstroms, alpha = gamma = 90, beta = 92 degrees. Molecular replacement yielded a solution with a correlation coefficient and R factor of 34.4 and 51.6%, respectively. Preliminary analysis of the molecular-replacement solution indicates a new quaternary association in the LTA structure. Crystallographic refinement is under way.