Phosphodiesterase 5 and Arginase Inhibitory Activities of the Extracts from Some Members of Nelumbonaceae and Nymphaeaceae Families.

The objectives of this study were (1) to investigate the effect of extracts from some plants in the families Nelumbonaceae and Nymphaeaceae on phosphodiesterase 5 (PDE5) and arginase, which have been used in erectile dysfunction treatment, and (2) to isolate and identify the compounds responsible for such activities. The characterization and quantitative analysis of flavonoid constituents in the active extracts were performed by HPLC. Thirty-seven ethanolic extracts from different parts of plants in the genus Nymphaea and Victoria of Nymphaeaceae and genus Nelumbo of Nelumbonaceae were screened for PDE5 and arginase inhibitory activities. The ethanolic extracts of the receptacles and pollens of Nelumbo nucifera Gaertn., petals of Nymphaea cyanea Roxb. ex G.Don, Nymphaea stellata Willd., and Victoria amazonica (Poepp.) Sowerby and the petals and receptacles of Nymphaea pubescens Willd. showed IC50 values on PDE5 of less than 25 µg/mL while none of the extracts showed effects on arginase. The most active extract, N. pubescens petal extract, was fractionated to isolate and identify the PDE5 inhibitors. The results showed that six flavonoid constituents including quercetin 3'-O-ß-xylopyranoside (1), quercetin 3-methyl ether 3'-O-ß-xylopyranoside (2), quercetin (3), 3-O-methylquercetin (4), kaempferol (5) and 3-O-methylkaempferol (6) inhibited PDE5 with IC50 values at the micromolar level.

Far infrared-assisted removal of extraction solvent for capillary electrophoretic determination of the bioactive constituents in Plumula Nelumbinis.

Far infrared radiation was employed in the rapid removal of the solvents in the extracts of Plumula Nelumbinis and standard mixture solutions to prevent the interference of the solvent peaks toward their capillary electrophoretic measurements. The sample solutions in small vials were exposed to far infrared ray at 60°C for 3 min to remove solvent. The dried samples in the vials were each dissolved into running buffer with the aid of ultrasonication for capillary electrophoresis analysis. The far infrared-assisted solvent removal approach was sucessfully applied in the rapid determination of neferine, liensinine, isoliensinine, rutin and hyperoside in Plumula Nelumbinis. The five analytes could be well separated within 12 min in a 40 cm long fused silica capillary at a separation voltage of 12 kV in a 50 mM borate buffer (pH 9.2). The results indicated that the interferences of the solvent peaks in the capillary electropherograms of the herbal drugs were eliminated completely.

Phytochemical analysis and antimicrobial activity of aqueous and methanolic extracts of the flowers of Nelumbium speciosum.

In present investigation aqueous and methanolic extracts of Nelumbium speciosum flowers were screened for phytochemical constituents and antibacterial activity to ascertain their traditional use. Antimicrobial activity of both extracts was tested by Kirby-Bauer disc diffusion method against four Gram positive strains, viz. Staphylococcus aureus (ATCC25923), Streptococcus agalactiae (13813), Bacillus subtilis (ATCC 6633), Staphylococcus epidermidis (ATCC 12228) and four Gram negative bacterial strains Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 27853), Proteus mirabilis (12453) and Klebsiella pneumoniae (10031). Phytochemical analysis showed the presence of tannins, saponins and alkaloids in both extracts while flavonoids and steroids were present only in methanolic extract. Methanolic extract of Nelumbium speciosum flower showed concentration dependent antibacterial activity against all tested strains with maximum zone of inhibition (17.3±0.3mm) against P. aeruginosa. Aqueous extract showed concentration dependent activity against S. aureus, E. coli, B. subtilis and S. epidermidis with maximum antibacterial activity against E. coli (14.3±0.3mm). MIC of methanolic and aqueous extracts was in the range of 0.015-0.251 and 0.0625-0.251 mg/mL, respectively. Results showed that methanolic extract of Nelumbium speciosum exhibits superior antibacterial activity than aqueous extract.

Pharmacokinetics, tissue distribution, bioavailability, and excretion of nuciferine, an alkaloid from lotus, in rats by LC/MS/MS.

OBJECTIVE: In order to characterize the pharmacokinetics, tissue distribution, bioavailability, and excretion of nuciferine, a reliable gradient LC/MS/MS-based method was developed and validated. METHODS: Sprague-Dawley rats were intravenously injected with a bolus of nuciferine (0.2 mg/kg) and orally given a single dose of nuciferine (10.0 mg/kg). Blood samples were withdrawn via the ocular vein at specific times. Organs, including the liver, kidney, brain, lung, heart, and spleen, were collected at specific times after oral administration of 10.0 mg/kg nuciferine. The plasma and tissue samples were assayed by LC/MS/MS. RESULTS: The results indicated that nuciferine had rapid distribution and poor absorption into systemic circulation. The value of absolute bioavailability was only 1.9 ± 0.8% after administration of 10.0 mg/kg nuciferine by oral and administration of 0.2 mg/kg nuciferine intravenously (IV) to rats. The AUC0→4 h values in tissues were in the order of kidney > lung > spleen > liver > brain > heart. The majority of excretion of nuciferine (50.7%) was excreted through kidneys with parent drug after oral administration without liver metabolism. CONCLUSION: This study may provide a meaningful basis for clinical application of such a bioactive compound of herbal medicines.

Enantioselective accumulation of chiral polychlorinated biphenyls in lotus plant (Nelumbonucifera spp.).

Enantioselective accumulation of chiral polychlorinated biphenyls (PCBs) 91, 95, 136, 149, 176 and 183 was investigated in lotus plants (Nelumbonucifera spp.) exposed to these chemicals via spiked sediment, to determine uptake and possible biotransformation for aquatic phytoremediation purposes. The concentrations of most PCBs were greatest in roots at 60 d (19.6 ± 1.51-70.6 ± 6.14 µg kg(-1)), but were greatest in stems and leaves at 120 d (25.3 ± 6.14-95.5 ± 19.4 µg kg(-1) and 17.4 ± 4.41-70.4 ± 10.4 µg kg(-1), respectively). Total amounts were greatest at 120 d and significantly higher in roots than those in stems and in leaves (1,457 ± 220-5,852 ± 735 ng, 237 ± 47.1-902 ± 184 ng and 202 ± 60.3-802 ± 90.2 ng, respectively), but represented less than 0.51% of the total mass of PCBs added to sediments, indicating that lotus plants were unlikely to remove appreciable amounts of PCBs from contaminated sediments. Racemic PCB residues in sediment indicate no enantioselective biodegradation by sedimentary microbial consortia over the entire experiment. Preferential accumulation of the (-)-enantiomers of PCBs 91, 95 and 136 were observed in roots, stems and leaves, but non-enantioselective accumulation was observed for PCBs 149, 176 and 183. These results indicate that aquatic plants can accumulate PCBs enantioselectively via root uptake, possibly by biotransformation within plant tissues as observed for terrestrial plants. This is also the first report to identify optical rotation of the atropisomers of PCBs 91 and 95.