Narcissus tazetta lectin shows strong inhibitory effects against respiratory syncytial virus, influenza A (H1N1, H3N2, H5N1) and B viruses.

A mannose-binding lectin (Narcissus tazetta lectin [NTL]) with potent antiviral activity was isolated and purified from the bulbs of the Chinese daffodil Narcissus tazetta var. chinensis, using ion exchange chromatography on diethylaminoethyl (DEAE)-cellulose, affinity chromatography on mannose-agarose and fast protein liquid chromatography (FPLC)-gel filtration on Superose 12. The purified lectin was shown to have an apparent molecular mass of 26 kDa by gel filtration and 13 kDa by SDS-PAGE, indicating that it is probably a dimer with two identical subunits.

Isolation, characterization, molecular cloning and modeling of a new lipid transfer protein with antiviral and antiproliferative activities from Narcissus tazetta.

A fetuin-binding peptide with a molecular mass of about 9kDa (designated NTP) was isolated and purified from the bulbs of Chinese daffodil, Narcissus tazetta var. chinensis L., by gel filtration and high-performance liquid chromatography, after removing the mannose-binding proteins by mannose-agarose column.

Antiviral and anti-proliferative glycoproteins from the rhizome of Smilax glabra Roxb (Liliaceae).

The glycoproteins possessing antiviral and anti-proliferative activities were isolated from the Chinese medicinal herb Smilax glabra (known as tufuling), by extraction with 0.2 M NaCl, ammonium sulfate precipitation, fetuin-agarose affinity chromatography and gel filtration. The molecular mass of the fetuin-binding glycoprotein (designated SGPF2) was estimated to be about 58 kDa, with a major protein subunit of 26 kDa.

The plant mannose-binding lectin NTL preserves cord blood haematopoietic stem/progenitor cells in long-term culture and enhances their ex vivo expansion.

Ex vivo expansion of haematopoietic stem and progenitor cells in cytokine combinations is effective in promoting differentiation and proliferation of multilineage progenitor cells, but often results in reduction of self-renewable stem cells. This study investigated the effect of a mannose-binding lectin, NTL, purified from Narcissus tazetta var. chinensis, on prolonged maintenance and expansion of cord blood CD34+ cells.

Antiviral triterpenoids from the medicinal plant Schefflera heptaphylla.

Schefflera heptaphylla (L.) Frodin is a principal ingredient of an herbal tea formulation widely used for the treatment of common cold in southern China. An extract of the long leafstalk of the compound leaf of S.

Antiviral flavans from the leaves of Pithecellobium clypearia.

Two new antiviral flavan derivatives were isolated from a methanol extract of leaves of Pithecellobium clypearia as guided by antiviral assays. The structures were characterized, by spectroscopic analyses, as 7-O-galloyltricetifavan (1) and 7,4'-di-O-galloyltricetifavan (2). Cytopathic effect (CPE) reduction assay showed that both compounds 1 and 2 possess antiviral activity against respiratory syncytial virus (RSV), with 50% inhibition concentration (IC(50)) values of 5 and 10 microg/mL, respectively; influenza A (H1N1) virus, with IC(50) values of 15.

Antimicrobial activities of cinnamon oil and cinnamaldehyde from the Chinese medicinal herb Cinnamomum cassia Blume.

Both Cinnamomum verum J.S. Presl.

Antiviral activities of purified compounds from Youngia japonica (L.) DC (Asteraceae, Compositae).

The ethanol extract of a biannual medicinal herb, Youngia japonica (commonly known as Oriental hawk's beard) was reported previously to have potent antiviral activity against respiratory syncytial virus (RSV) cultured in HEp-2 cells. Three anti-microbial agents, namely 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, and luteolin-7-O-glucoside were subsequently purified and chemically characterized from the ethanol extract of Youngia japonica. The two dicaffeoylquinic acids exhibited prominent anti-RSV with 50% inhibitory concentration (IC50) of 0.

Purification and characterization of non-specific lipid transfer proteins from the leaves of Pandanus amaryllifolius (Pandanaceae).

Two proteins were isolated from the saline extract of mature leaves of Pandanus amaryllifolius, using affinity chromatography on fetuin-agarose and Affi-gel Blue gel, anion exchange chromatography as well as gel filtration. The proteins were demonstrated as non-glycoproteins, with molecular mass of 18 and 13 kDa, respectively, comprising of peptide subunits from 6.5 to 9 kDa in the forms of heterodimer and homodimer.

Antiviral activities of medicinal herbs traditionally used in southern mainland China.

The aqueous extracts from 21 medicinal herbs traditionally used in southern mainland China were screened for antiviral activities against human herpes simplex virus type 1 (HSV-1) and human respiratory syncytial virus (RSV) using a cytopathic effect (CPE) reduction assay. Three extracts from Agrimonia pilosa, Pithecellobium clypearia and Punica granatum, respectively, showed anti-HSV-1 activity, which was possibly contributed by the polyphenolic compounds in the herbal extracts. Six of the extracts, from Blumea laciniata, Elephantopus scaber, Laggera pterodonta, Mussaenda pubescens, Schefflera octophylla and Scutellaria indica, respectively, exhibited anti-RSV activity with 50% inhibition (IC50) concentrations ranging from 12.

New mannose-binding lectin isolated from the rhizome of Sarsaparilla Smilax glabra Roxb. (Liliaceae).

A new mannose-binding lectin, designated SGM2, was isolated from the rhizome of a Chinese medicinal herb Smilax glabra (also known as sarsaparilla in general) by saline extraction, ammonium sulfate precipitation and fractionation, and affinity chromatography on fetuin- and mannose-agarose. SGM2 is shown to have a molecular mass of 37 kDa on gel filtration and 12.5 kDa on SDS-PAGE, indicating that it is a trimeric protein composed of three identical subunits.

Anticancer and antiviral activities of Youngia japonica (L.) DC (Asteraceae, Compositae).

Aqueous and ethanol extracts of Youngia japonica (also known as Oriental hawksbeard) were tested in vitro for anti-tumor activity against three cell lines, human promyelocytic leukaemia (HL-60), human myelogenous leukaemia (chronic K-562) and mouse Sarcoma 180 (S-180), and for antiviral activity against respiratory syncytial virus (RSV), influenza A virus (Flu A) and herpes simplex virus type 1 (HSV-1) by cytopathic effect (CPE) reduction assay. Hot water extract of Youngia japonica inhibited cell proliferation and growth of all cancer cell lines to various extent. K-562 cells were the most sensitive to the extract whereas S-180 cells were the least.

Purification and characterization of a new antiviral protein from the leaves of Pandanus amaryllifolius (Pandanaceae).

A lectin, designated Pandanin, was isolated from the saline extract of the leaves of Pandanus amaryllifolius, using ammonium sulfate precipitation, affinity chromatography on mannose-agarose and molecular size exclusion by gel filtration. Pandanin is an unglycosylated protein with a molecular mass of 8.0 kDa both after gel filtration and on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it is a single polypeptide chain.

Gene expression of immunomodulatory cytokines induced by Narcissus tazetta lectin in the mouse.

The immunomodulation of Narcissus tazetta lectin (NTL) on the induction of gene expression of cytokines in the mouse was studied using specific cytokine primers, total RNA isolated from mouse splenocytes and macrophages, and reverse transcription-polymerase chain reaction (RT-PCR). For comparison, a fungal antimitogenic lectin from Agaricus bisporus (ABL) was used to test and compare the acute (kinetic) induction of cytokine gene expression. NTL was able to induce the expression of IL-1beta, TNF-alpha, and immunoreactive nitric oxide synthase (NOS) in both splenocytes and macrophages in vivo after 10-day consecutive peritoneal injections of 5 mg NTL x kg(-1) x day(-1) in the mouse.

Isolation and characterization of a bioactive mannose-binding protein from the Chinese chive Allium tuberosum.

A mannose-binding protein was isolated from two different cultivars of the Chinese chive Allium tuberosum by extraction with 0.2 M NaCl, ammonium sulfate precipitation, and affinity chromatography on mannose agarose and fetuin agarose. It exhibited hemagglutinating activity toward rabbit erythrocytes.