Isolation of a small chitinase-like antifungal protein from Panax notoginseng (sanchi ginseng) roots

Panax notoginseng-microbiota interactions: From plant cultivation to medicinal application

BACKGROUND

Microbiomes and their host plants are closely linked with each other; for example, the microbiome affects plant growth, fitness, nutrient uptake, stress tolerance and pathogen resistance, whereas the host plant supports the photosynthetically carbon-rich nutrition of the microbiome. The importance of the microbiome in plant‒soil ecosystems is unquestioned and has expanded to influence the medicinal application of some herbal plants via the gut microbiota.

PURPOSE

Herbal plant-microbiome interactions may provide novel knowledge to enhance the robustness of herbal plant crop performance and medicinal applications, which requires a systematic review and preceding discussion.

STUDY DESIGN AND METHODS

The interactions between Panax notoginseng and microorganisms (from soil to host) were reviewed from the literature. The terms "Panax notoginseng" and "microbiota" were used in combination with the keywords "microbiota/microbes", "bacteria/bacterium" or "fungi/fungus" or "endophyte", as well as our targeted bioactive phytochemicals, including saponins and ginsenosides.

RESULT

Our study focuses on the famous medicinal herb Panax notoginseng F. H. Chen and proposes that the microbiota is a crucial participant not only in the cultivation of this herbal plant but also in its medicinal application. We also summarize and discuss how these plant‒microbe co-associations shape the assembly of plant-related microbiomes and produce bioactive phytochemicals, as well as influence beneficial herbal traits, such as herbal plant health and pharmacology. In addition, we also highlight future directions.

CONCLUSION

The rhizosphere and endophytic microbiome of Panax notoginseng are indirectly or directly involved in plant health, biomass production, and the synthesis/biotransformation of plant secondary metabolites. Harnessing the microbiome to improve the quality of traditional Chinese medicine and improve the value of medicinal plants for human health is highly promising.

Bioactive Proteins in Panax notoginseng Roots and Other Panax Species

The genus Panax consists of a group of prized medicinal herbs. Major members of the Panax genus include P. ginseng, P. notoginseng, P. quinquefolius, and P. vietnamensis. They possess various bioactive constituents such as ginsenosides, saponins, polysaccharides and proteins. Many of them were reported to show beneficial effects on human health. Ginsenosides and saponins of ginsengs caught the sight of most researchers. Precise investigations revealed their roles on improvement of the functioning of the nervous system, cardiovascular system, and other functions. In contrast, our knowledge of the bioactive Panax proteins is relatively limited. A number of proteins from P. ginseng, the most valuable member of Panax species, have been investigated and proved to be beneficial to our body. Meanwhile, a few bioactive P. notoginseng proteins, such as ribonucleases and antifungal proteins, have been characterized and reported. We summarize herein the proteins present in P. notoginseng that have been identified, and try to compare them with those from other Panax species with a similar structure or bioactivity, and conclude whether the proteins in P. notoginseng have any distinctive features.

Characterization and immunostimulating effects on murine peritoneal macrophages of a novel protein isolated from Panax quinquefolius L

ETHNOPHARMACOLOGICAL RELEVANCE

Panax quinquefolius L. has been used as a proverbial tonic in oriental countries for hundreds of years. It is used as a traditional medicinal herb to nourish vitality.

AIM OF THE STUDY

The purpose of our study was to inquiry the activation effects on murine peritoneal macrophages of a novel protein separated from the roots of Panax quinquefolius L.

MATERIALS AND METHODS

In our work, a novel protein of the roots of American ginseng (AGNP) was separated and purified from the roots of Panax quinquefolius L. The characteristic was investigated with SDS-PAGE, high pressure gel filtration chromatography (HPGFC) and matrix-assisted laser desorption ionization/time-of-flight mass (MALDI-TOF-MS) spectrometry method. The method of neutral red was carried out to investigate the phagocytosis of peritoneal macrophages. And Griess method and colorimetry were executed to detect the level of nitric oxide and iNOS activity respectively. Tumor necrosis factor-α and interleukin-6 were analyzed by enzyme linked immunosorbent assay (ELISA).

RESULTS

Our results demonstrated that the subunit molecular weight of AGNP determined by SDS-PAGE was 15kD and the content of proteins determined by Bradford assay was 2.31mg/mL. The molecular weight of the AGNP was15, 114Da both of electrophoresis and MS purity. And the result of HPGFC showed that the molecular weight of AGNP was 31,086Da, Immunological studied indicated that AGNP could conspicuously increase phagocytosis of macrophages, facilitate the nitric oxide production, Tumor necrosis factor-α and interleukin-6 production. What is more, AGNP dose-dependently stimulated NO formation through the up-regulation of iNOS activity.

CONCLUSIONS

In conclusion, AGNP had good immunoregulatory effects supporting the traditional claims and may provide a valuable therapeutic strategy to promoting immune function and metabolism.

Two new fatty acids esters were detected in ginseng stems by the application of azoxystrobin and the increasing of antioxidant enzyme activity and ginsenosides content

Panax ginseng C.A. Meyer is a valuable herb in China that has also gained popularity in the West because of its pharmacological properties. The constituents isolated and characterized in ginseng stems include ginsenosides, fatty acids, amino acids, volatile oils, and polysaccharides. In this study, the effects of fungicide azoxystrobin applied on antioxidant enzyme activity and ginsenosides content in ginseng stems was studied by using Panax ginseng C. A. Mey. cv. (the cultivar of Ermaya) under natural environmental conditions. The azoxystrobin formulation (25% SC) was sprayed three times on ginseng plants at different doses (150ga.i./ha and 225ga.i./ha), respectively. Two new fatty acids esters (ethyl linoleate and methyl linolenate) were firstly detected in ginseng stems by the application of azoxystrobin as foliar spray. The results indicated that activities of enzymatic antioxidants, the content of ginsenosides and two new fatty acids esters in ginseng stems in azoxystrobin-treated plants were increased. Azoxystrobin treatments to ginseng plants at all growth stages suggest that the azoxystrobin-induced delay of senescence is due to an enhanced antioxidant enzyme activity protecting the plants from harmful active oxygen species (AOS). The activity of superoxide dismutase (SOD) in azoxystrobin-treated plants was about 1-3 times higher than that in untreated plants. And the effects was more significant (P=0.05) when azoxystrobin was applied at dose of 225ga.i./ha. This work suggests that azoxystrobin plays an important role in delaying of senescence by changing physiological and biochemical indicators and increasing ginsenosides content in ginseng stems.

Traditional uses, botany, phytochemistry, pharmacology and toxicology of Panax notoginseng (Burk.) F.H. Chen: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Panax notoginseng (Burk.) F.H. Chen is a widely used traditional Chinese medicine known as Sanqi or Tianqi in China. This plant, which is distributed primarily in the southwest of China, has wide-ranging pharmacological effects and can be used to treat cardiovascular diseases, pain, inflammation and trauma as well as internal and external bleeding due to injury.

AIMS OF THE REVIEW

This paper provides up-to-date information on investigations of this plant, including its botany, ethnopharmacology, phytochemistry, pharmacology and toxicology. The possible uses and perspectives for future investigation of this plant are also discussed.

MATERIALS AND METHODS

The relevant information on Panax notoginseng (Burk.) F.H. Chen was collected from numerous resources, including classic books about Chinese herbal medicine, and scientific databases, including Pubmed, SciFinder, ACS, Ebsco, Elsevier, Taylor, Wiley and CNKI.

RESULTS

More than 200 chemical compounds have been isolated from Panax notoginseng (Burk.) F.H. Chen, including saponins, flavonoids and cyclopeptides. The plant has pharmacological effects on the cardiovascular system, immune system as well as anti-inflammatory, anti-atherosclerotic, haemostatic and anti-tumour activities, etc.

CONCLUSIONS

Panax notoginseng is a valuable traditional Chinese medical herb with multiple pharmacological effects. This review summarizes the botany, ethnopharmacology, phytochemistry, pharmacology and toxicology of P. notoginseng, and presents the constituents and their corresponding chemical structures found in P. notoginseng comprehensively for the first time. Future research into its phytochemistry of bio-active components should be performed by using bioactivity-guided isolation strategies. Further work on elucidation of the structure-function relationship among saponins, understanding of multi-target network pharmacology of P. notoginseng, as well as developing its new clinical usage and comprehensive utilize will enhance the therapeutic potentials of P. notoginseng.

Purification and characterization of a novel chitinase from Trichosanthes dioica seed with antifungal activity

Chitinases are a group of enzymes that show differences in their molecular structure, substrate specificity, and catalytic mechanism and widely found in organisms like bacteria, yeasts, fungi, arthropods actinomycetes, plants and humans. A novel chitinase enzyme (designated as TDSC) was purified from Trichosanthes dioica seed with a molecular mass of 39±1 kDa in the presence and absence of β-mercaptoethanol. The enzyme was a glycoprotein in nature containing 8% neutral sugar. The N-terminal sequence was determined to be EINGGGA which did not match with other proteins. Amino acid analysis performed by LC-MS revealed that the protein was rich in leucine. The enzyme was stable at a wide range of pH (5.0-11.0) and temperature (30-90 °C). Chitinase activity was little bit inhibited in the presence of chelating agent EDTA (ethylenediaminetetraaceticacid), urea and Ca(2+). A strong fluorescence quenching effect was found when dithiothreitol and sodium dodecyl sulfate were added to the enzyme. TDSC showed antifungal activity against Aspergillus niger and Trichoderma sp. as tested by MTT assay and disc diffusion method.

Plant antifungal proteins and their applications in agriculture

Fungi are far more complex organisms than viruses or bacteria and can develop numerous diseases in plants that cause loss of a substantial portion of the crop every year. Plants have developed various mechanisms to defend themselves against these fungi which include the production of low-molecular-weight secondary metabolites and proteins and peptides with antifungal activity. In this review, families of plant antifungal proteins (AFPs) including defensins, lectins, and several others will be summarized. Moreover, the application of AFPs in agriculture will also be analyzed.

Structural and functional evolution of chitinase-like proteins from plants

The plant genome contains a large number of sequences that encode catalytically inactive chitinases referred to as chitinase-like proteins (CLPs). Although CLPs share high sequence and structural homology with chitinases of glycosyl hydrolase 18 (TIM barrel domain) and 19 families, they may lack the binding/catalytic activity. Molecular genetic analysis revealed that gene duplication events followed by mutation in the existing chitinase gene have resulted in the loss of activity. The evidences show that adaptive functional diversification of the CLPs has been achieved through alterations in the flexible regions than in the rigid structural elements. The CLPs plays an important role in the defense response against pathogenic attack, biotic and abiotic stress. They are also involved in the growth and developmental processes of plants. Since the physiological roles of CLPs are similar to chitinase, such mutations have led to plurifunctional enzymes. The biochemical and structural characterization of the CLPs is essential for understanding their roles and to develop potential utility in biotechnological industries. This review sheds light on the structure-function evolution of CLPs from chitinases.

Anti-fatigue effects of proteins isolated from Panax quinquefolium

ETHNOPHARMACOLOGICAL RELEVANCE

American ginseng (Panax quinquefolium) is an obligate shade perennial plant that belongs to Araliaceae ginseng species, and is native to eastern USA and Canada. Ginseng proteins are reported to have several pharmaceutical properties. However, such properties of American ginseng proteins (AGP) have seldom been reported. Also, anti-fatigue properties of AGP have not been studied. Therefore, we examined the anti-fatigue effects of AGP in mice.

MATERIALS AND METHODS

The molecular weight and protein contents of AGP were determined by SDS-PAGE, while the amino acid composition was analyzed by HPLC. The mice were divided into four groups. The control group was administered distilled water by gavage every day for 28 days. The other groups, designated as AGP treatment groups, were administered 125, 250 and 500 mg/kg of body weight, respectively of AGP by gavage every day for 28 days. Anti-fatigue activity was estimated using forced swimming test, and biochemical indices were determined using available kits.

RESULTS

The subunit molecular weight of AGP ranged from 8-66 kD and the protein content measured by Bradford assay was 1.86 mg/mL. The forced swimming time of low, intermediate and high groups were found to be longer as compared to the control group. AGP significantly decreased blood lactate (BLA) and serum urea nitrogen (SUN) levels, and increased hepatic glycogen (GLU) level. Additionally, AGP lowered malondialdehyde (MDA) content and increased the levels of glutathione peroxidase (GPx) and superoxide dismutase (SOD).

CONCLUSION

AGP shows anti-fatigue activity in mice, as measured by the physiological indices for fatigue.

Neuroprotective effect of Panax notoginseng plysaccharides against focal cerebral ischemia reperfusion injury in rats

Our present study was conducted to investigate whether Panax notoginseng plysaccharides (PNPS) exerted a neuroprotective effect against focal cerebral ischemia/reperfusion (I/R) injury in rats. Before mice were subjected to middle cerebral artery occlusion (MCAO) for 2 h and reperfusion for 22 h, PNPS at the doses of 50, 100, and 200 mg/kg was administered once a day intragastrically for continuous 7 days. Oral administration of PNPS could significantly reduce the severity of neurological deficits, infarct volumes, cerebral edema, and neuronal death caused by MCAO in rats. Moreover, in the presence of PNPS, the Bcl-2/Bax ratio increased, but the level of cleaved caspase-3 reduced. Thus, these finding suggested that suppressing apoptosis through increasing Bcl-2/Bax ratio and evoking caspase-3 cascade should be potential mechanism by which PNPS exerts its neuroprotective function against focal cerebral I/R injury.

A novel aspartic protease with HIV-1 reverse transcriptase inhibitory activity from fresh fruiting bodies of the wild mushroom Xylaria hypoxylon

A novel aspartic protease with HIV-1 RT inhibitory activity was isolated and characterized from fruiting bodies of the wild mushroom Xylaria hypoxylon. The purification protocol comprised distilled water homogenization and extraction step, three ion exchange chromatographic steps (on DEAE-cellulose, Q-Sepharose, and CM-cellulose in succession), and final purification was by FPLC on Superdex 75. The protease was adsorbed on all the three ion exchangers. It was a monomeric protein with a molecular mass of 43 kDa as estimated by SDS-PAGE and FPLC. Its N-terminal amino acid sequence was HYTELLSQVV, which exhibited no sequence homology to other proteases reported. The activity of the protease was adversely affected by Pepstatin A, indicating that it is an aspartic protease. The protease activity was maximal or nearly so in the pH range 6–8 and in the temperature range 35–60°C. The purified enzyme exhibited HIV-1 RT inhibitory activity with an IC₅₀ value of 8.3 μM, but was devoid of antifungal, ribonuclease, and hemagglutinating activities.

An antifungal peptide from Phaseolus vulgaris cv. brown kidney bean

A 5.4-kDa antifungal peptide, with an N-terminal sequence highly homologous to defensins and inhibitory activity against Mycosphaerella arachidicola (IC(50)= 3 μM), Setospaeria turcica and Bipolaris maydis, was isolated from the seeds of Phaseolus vulgaris cv. brown kidney bean. The peptide was purified by employing a protocol that entailed adsorption on Affi-gel blue gel and Mono S and finally gel filtration on Superdex 75. The antifungal activity of the peptide against M. arachidicola was stable in the pH range 3-12 and in the temperature range 0°C to 80°C. There was a slight reduction of the antifungal activity at pH 2 and 13, and the activity was indiscernible at pH 0, 1, and 14. The activity at 90°C and 100°C was slightly diminished. Deposition of Congo red at the hyphal tips of M. arachidicola was induced by the peptide indicating inhibition of hyphal growth. The lack of antiproliferative activity of brown kidney bean antifungal peptide toward tumor cells, in contrast to the presence of such activity of other antifungal peptides, indicates that different domains are responsible for the antifungal and antiproliferative activities.

Potent cryoprotective activity of cold and CO2-regulated cherimoya (Annona cherimola) endochitinase

A cryoprotective chitinase (BChi14) was isolated and purified from the mesocarp of CO(2)-treated cherimoya fruit (Annona cherimola Mill.) stored at chilling temperature by anion exchange and chromatofocusing chromatography. This hydrolase was characterized as an endochitinase with a M(r) of 14.31 kDa and a pI of 8.26, belonging to the family 19 of glycosyl hydrolases (GH19). While it was stable over a wide pH range and active in a broad acidic pH range, it had an optimum pH of 7.0. Its optimum temperature was low, 35 degrees C, and it retained about 30% of its maximum activity at 5 degrees C. Moreover, BChi14 was relatively heat unstable and its activity was progressively lost at temperatures above 50 degrees C. Kinetic studies revealed many similarities with other plant endochitinases. However, BChi14 had high k(cat) (6.93 s(-1)) value for the fluorogenic substrate 4-MU-(GlcNAc)(3), reflecting its great catalytic efficiency. Moreover, a thermodynamic characterization revealed that the purified enzyme displayed a high k(cat) at 37 and 5 degrees C, and a low E(a) (11.32 kJ mol(-1)). In vitro functional studies indicated that BChi14 had no effect on the inhibition of Botrytis cinerea hyphal growth and no antifreeze activity, as shown by the thermal hysteresis analysis using differential scanning calorimetry. However, the purified endochitinase showed very strong cryoprotective activity against freeze-thaw inactivation of lactate dehydrogenase. The PD(50) was 12.5 times higher than that of the cryoprotective protein BSA, and 2 or 3 orders of magnitude greater than sucrose, comparable with that of most cryoactive plant dehydrins. These results, together with the consolidated microstructure and the integrity of CO(2)-treated mesocarp tissue, indicate that BChi14 is functionally implicated in the mechanisms underlying chilling tolerance activated by high CO(2) concentrations.

First report of an antifungal amidase from Peltophorum pterocarpum. [corrected]

A 60 kDa antifungal amidase was purified from Peltophorum pterocarpum [corrected] seeds using an isolation procedure that entailed ion-exchange chromatography on Q-Sepharose, ion-exchange chromatography on DEAE-cellulose and FPLC-gel filtration on Superdex 75. Unlike most other antifungal proteins isolated previously, it was adsorbed on Q-Sepharose and DEAE-cellulose. The isolated protein, designated as peltopterin, exhibited an N-terminal amino acid sequence closely resembling those of amidases. It exhibited amidase activity and digested iodoacetamide with an optimum pH and temperature at pH 9 and 50 degrees C, respectively. It also hydrolyzed acrylamide and urea. It impeded mycelial growth in Rhizotonia solani with an IC(50) of 0.65 microm. Chitin deposition at hyphal tips in R. solani was observed by staining with Congo red after incubation with peltopterin. Its antifungal activity was stable throughout pH 0-14 and 25-100 degrees C. It potently inhibited HIV-1 reverse transcriptase with an IC(50) of 27 nm.

Brassiparin, an antifungal peptide from Brassica parachinensis seeds

Aims:  To isolate and characterize an antifungal peptide from the seeds of Brassica parachinensis L.H.Bailey.

Methods and Results:  An antifungal peptide designated as brassiparin was isolated. It exhibited a molecular mass of 5716 Da. It potently inhibited mycelial growth in a number of fungal species including Fusarium oxysporum, Helminthosporium maydis, Mycosphaerella arachidicola and Valsa mali. The antifungal activity of brassiparin toward M. arachidicola exhibited pronounced thermostability and pH stability. It inhibited proliferation of hepatoma (HepG2) and breast cancer (MCF7) cells and the activity of HIV‐1 reverse transcriptase. Its N‐terminal sequence differed from those of antifungal proteins which have been reported to date.

Conclusions:  Brassiparin can be purified by using a protocol involving ion exchange chromatography, affinity chromatography and gel filtration. It manifests potent, thermostable and pH‐stable antifungal activity. It demonstrates antiproliferative activity toward tumour cells, and inhibitory activity toward HIV‐1 reverse transcriptase. Thus, brassiparin is a defense protein.

Significance and Impact of the Study:  Brassiparin represents one of the few antifungal proteins reported to date from Brassica species. Its antifungal activity has pronounced pH stability and thermostability. Brassiparin exhibits other exploitable activities such as antiproliferative activity toward hepatoma and breast cancer cells and inhibitory activity toward HIV‐reverse transcriptase.

Campesin, a thermostable antifungal peptide with highly potent antipathogenic activities

An 9.4-kDa antifungal peptide designated as campesin was isolated from seeds of the cabbage Brassica campestris. The isolation procedure involved affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Q-Sepharose and Mono S, and gel filtration on Superdex 75 and Superdex Peptide. The peptide was adsorbed on the first three chromatographic media. It exerted an inhibitory action on mycelial growth including Fusarium oxysporum and Mycosphaerella arachidicola, with an IC(50) of 5.1 microM and 4.4 microM, respectively. The peptide was characterized by remarkable thermostability and pH stability. It inhibited proliferation of HepG2 and MCF cancer cells with an IC(50) of 6.4 microM and 1.8 microM, and the activity of HIV-1 reverse transcriptase with an IC(50) of 3.2 microM. It demonstrated lysolecithin binding activity.

Purification and characterization of a novel antifungal protein from Bacillus subtilis strain B29

An antifungal protein was isolated from a culture of Bacillus subtilis strain B29. The isolation procedure comprised ion exchange chromatography on diethylaminoethyl (DEAE)-52 cellulose and gel filtration chromatography on Bio-Gel P-100. The protein was absorbed on DEAE-cellulose and Bio-Gel P-100. The purified antifungal fraction was designated as B29I, with a molecular mass of 42.3 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), pI value 5.69 by isoelectric focusing (IEF)-PAGE, and 97.81% purity by high performance liquid chromatography (HPLC). B29I exhibited inhibitory activity on mycelial growth in Fusarium oxysporum, Rhizoctonia solani, Fusarium moniliforme, and Sclerotinia sclerotiorum. The 50% inhibitory concentrations (IC(50)) of its antifungal activity toward Fusarium oxysporum and Rhizoctonia solani were 45 and 112 micromol/L, respectively. B29I also demonstrated an inhibitory effect on conidial spore germination of Fusarium oxysporum and suppression of germ-tube elongation, and induced distortion, tumescence, and rupture of a portion of the germinated spores.

A novel and exploitable antifungal peptide from kale (Brassica alboglabra) seeds

The aim of this study was to purify and characterize antifungal peptides from kale seeds in view of the paucity of information on antifungal peptides from the family Brassicaceae, and to compare its characteristics with those of published Brassica antifungal peptides. A 5907-Da antifungal peptide was isolated from kale seeds. The isolation procedure comprised affinity chromatography on Affi-gel blue gel, ion exchange chromatography on SP-Sepharose and Mono S, and gel filtration on Superdex Peptide. The peptide was adsorbed on the first three chromatographic media. It inhibited mycelial growth in a number of fungal species including Fusarium oxysporum, Helminthosporium maydis, Mycosphaerella arachidicola and Valsa mali, with an IC(50) of 4.3microM, 2.1microM, 2.4microM, and 0.15microM, respectively and exhibited pronounced thermostability and pH stability. It inhibited proliferation of hepatoma (HepG2) and breast cancer (MCF7) cells with an IC(50) of 2.7microM and 3.4microM, and the activity of HIV-1 reverse transcriptase with an IC(50) of 4.9microM. Its N-terminal sequence differed from those of antifungal proteins which have been reported to date.

A relatively stable antifungal peptide from buckwheat seeds with antiproliferative activity toward cancer cells

An antifungal peptide with a molecular mass of approximately 4 kDa was isolated from buckwheat seeds by using ion-exchange chromatography on SP-Sepharose and Q-Sepharose, and gel filtration on Superdex peptide. The peptide was adsorbed on SP-Sepharose in 10 mM NH(4)OAc buffer (pH 4.5) and on Q-Sepharose in 10 mM NH(4)HCO(3) buffer (pH 9.4), and appeared to be highly purified after these two steps. It inhibited mycelial growth in Fusarium oxysporum and Mycosphaerella arachidicola with an IC(50) of 35 and 40 microM, respectively. Its antifungal activity was stable between 0 and 70 degrees C, and between pH 1.0/2.0 and 13. It inhibited proliferation of Hep G2 (hepatoma) cells, L1210 (leukemia) cells, breast cancer (MCF-7) cells, and liver embryonic WRL 68 cells with an IC(50) of 33, 4, 25, and 37 microM, respectively. On the other hand, the peptide was unable to evoke a mitogenic response from splenocytes or induce nitric oxide production by macrophages. It inhibited HIV-1 reverse transcriptase with an IC(50) of 5.5 microM.

Expression of chitinase in Adenanthera pavonina seedlings

Chitinases (EC 3.2.1.14) are hydrolytic enzymes found in different organisms. In plants, they have been described in different tissues and organs, including seeds. This study was triggered by the isolation of a 30-kDa thermostable chitinase from Adenanthera pavonina L. seeds. The enzyme was submitted to N-terminal amino acid sequencing, and the analysis revealed a high degree of homology with class III chitinases. Bidimensional electrophoresis of the 30-kDa band showed the presence of three isoforms with pIs of 5.2, 5.5 and 5.8. A chitinase was also found in exudates released from the same seeds, which was seen to be immunorelated to the above 30-kDa protein. It was also submitted to N-terminal amino acid sequencing and seen as highly homologous to class III chitinases. In addition, the expression of chitinases during A. pavonina L. seed germination and seedling development was investigated. Seeds were allowed to germinate in the absence of light for approximately 5 days and were grown, for different times, in the absence or presence of light. After each seedling developmental time, samples of exudates, roots and cotyledonary leaves were collected and submitted to protein extraction. The presence of proteins immunorelated to the 30-kDa chitinase was detected in all analyzed samples. Further analyses showed that light significantly interfered with the chitinase expression in some organs. The tissue and subcellular chitinase location in seedling roots was also investigated, and it was majorly localized in the cell wall and in the intercellular spaces of the root hair zone.

Pharmacological activity of sanchi ginseng (Panax notoginseng)

The pharmacological activity and constituents of the sanchi ginseng Panax notoginseng have been reviewed. The bulk of pharmacological findings have been based on the saponins or steryl glycosides, although polysaccharides with immunopotentiating activity, proteins with antifungal, ribonuclease and xylanase activity, and a triacylglycerol (trilinolein) with antioxidant activity have been reported. Protective actions against cerebral ischaemia, beneficial effects on the cardiovascular system, and haemostatic, antioxidant, hypolipidaemic, hepatoprotective, renoprotective and estrogen-like activities have been described. Various methods for authentication of P. notoginseng are available.

Plant-derived antifungal proteins and peptides

Plants produce potent constitutive and induced antifungal compounds to complement the structural barriers to microbial infection. Approximately 250 000 – 500 000 plant species exist, but only a few of these have been investigated for antimicrobial activity. Nevertheless, a wide spectrum of compound classes have been purified and found to have antifungal properties. The commercial potential of effective plant-produced antifungal compounds remains largely unexplored. This review article presents examples of these compounds and discusses their properties.Key words: antifungal, peptides, phytopathogenic, plants, proteins.

An antifungal protein from flageolet beans

A protein with antifungal and hemagglutinating activities was isolated from dried flageolet beans (Phaseolus vulgaris cv. 'Flageolet Bean'). The protein was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel blue gel and CM-cellulose. The protein demonstrated antifungal activity against Mycophaerella arachidicola with an IC50 of 9.8 microM, but was inactive toward Fusarium oxysporum and Botrytis cinerea. Its hemagglutinating activity could not be inhibited by a variety of the sugars tested. The activity was stable up to 60 degrees C. At 70 degrees C, 75% of the hemagglutinating activity remained while no activity was discernible at and above 100 degrees C. The hemagglutinating activity was stable in the presence of a variety of monovalent, divalent and trivalent chlorides, and also when the ambient pH changed from 3 to 12. It did not exert any mitogenic activity on mouse splenocytes in vitro. Neither did it inhibit HIV-1 reverse transcriptase. It inhibited [3H-methyl]-thymidine incorporation into leukemia L1210 cells with an IC50 of about 4 microM.

An antifungal peptide from the coconut

A chromatographic procedure consisting of ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-cellulose, and gel filtration by fast performance liquid chromatography on Supedex 75 was utilized to isolate a 10 kDa antifungal peptide from coconut flesh. The peptide was unadsorbed on DEAE-cellulose, but adsorbed on Affi-gel blue gel and CM-cellulose. It displayed antifungal activity against Fusarium oxysporum, Mycosphaerella arachidicola and Physalospora piricola. The IC50 values of its inhibitory activities on mycelial growth in M. arachidicola and HIV-1 reverse transcriptase activity were respectively 1.2 and 52.5 microM.

Sesquin, a potent defensin-like antimicrobial peptide from ground beans with inhibitory activities toward tumor cells and HIV-1 reverse transcriptase

An antifungal peptide with a molecular mass around 7 kDa and an N-terminal sequence highly homologous to defensin was isolated from ground beans (Vigna sesquipedalis cv. 'Ground Bean'). The peptide was adsorbed on Affi-gel blue gel and on Mono S. It exerted an antifungal action on Botrytis cinerea, Fusarium oxysporum and Mycosphaerella arachidicola; and an antibacterial action on Escherichia coli B, Proteus vulgaris, Mycobacterium phlei and Bacillus megaterium. The antimicrobial activity was inhibited in presence of the 5 mM CaCl2 and MgCl2, but no inhibition was observed in 5 mM NaCl. The peptide exerted antiproliferative activity toward breast cancer (MCF-7) cells and leukemia M1 cells, this activity could not be inhibited by the ions mentioned above. It also exhibited some inhibitory activity toward human immunodeficiency virus-type 1 reverse transcriptase.

Characterization of cell wall polysaccharides from the medicinal plant Panax notoginseng

Panax notoginseng is a commonly used medicinal plant in south-western China. Recent studies indicate that wall polysaccharides are responsible for some of the immunostimulatory activity. Fractionation of the P. notoginseng root powder alcohol insoluble residue (AIR) and its compositional analysis enabled us to deduce the polysaccharide and protein composition of the root cell walls. P. notoginseng walls are composed primarily of polysaccharide (approximately 97% w/w) and some protein. The polysaccharides include pectic polysaccharides (neutral Type I 4-galactan (21%), arabinan (5%), acidic rhamnogalacturonan I (RG I, 2%) and homogalacturonan (HGA, 24%), non-cellulosic polysaccharides (heteroxylan, 3%), xyloglucan (XG, 3%) and heteromannan (1%)) and cellulose (24%). The root AIR also contains Type II AG/AGPs (5% w/w) typically associated with the plasma membrane and extracellular matrix. Thus, P. notoginseng roots contain polysaccharides typical of Type I primary cell walls but are distinguished by their very high levels of Type I 4-galactans and low levels of XGs. The major amino acids in the AIR were Leu (14 mol%), Asx (16 mol%), Glx (10 mol%), Ala (9 mol%), Thr (9 mol%) and Val (9 mol%).

Phaseococcin, an antifungal protein with antiproliferative and anti-HIV-1 reverse transcriptase activities from small scarlet runner beans

From the seeds of small scarlet runner beans (Phaseolus coccineus 'Minor'), an antifungal protein with an N-terminal sequence homologous to those of defensins was isolated. The antifungal protein bound to Affi-gel blue gel and Mono S but it did not bind to DEAE-cellulose. It was further purified by gel filtration on a Superdex peptide column. It exhibited a molecular mass of 5422 Da as determined by mass spectrometry. The protein, designated as phaseococcin, suppressed mycelial growth in a number of fungi including Botrytis cinerea, Coprinus comatus, Fusarium oxysporum, Mycosphaerella arachidicola, Physalospora piricola, and Rhizoctonia solani. It also inhibited proliferation in several Bacillus species and the leukemia cell lines HL60 and L1210 and curtailed the activity of HIV-1 reverse transcriptase. It did not affect proliferation of mouse splenocytes and neither did it inhibit protein synthesis in a cell-free rabbit reticulocyte lysate system.Key words: antifungal proteins, runner beans, antiproliferative.

Agrocybin, an antifungal peptide from the edible mushroom Agrocybe cylindracea

An antifungal peptide with a molecular mass of 9 kDa was isolated from fresh fruiting bodies of the mushroom Agrocybe cylindracea. The isolation procedure comprised ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography by fast protein liquid chromatography (FPLC) on Mono S, and FPLC-gel filtration on a Superdex 75 column. The antifungal peptide, designated as agrocybin, was unadsorbed on DEAE-cellulose, and adsorbed on Affi-gel blue gel and Mono S. Agrocybin exerted antifungal activity against several fungal species but lacked inhibitory activity against bacteria when tested up to 300 microM. The activity of HIV-1 reverse transcriptase was attenuated in the presence of agrocybin. It exhibited weaker mitogenic activity than Con A on isolated murine splenocytes, but was devoid of antiproliferative activity on Hep G2 (hepatoma) cells when tested at 110 microM.

Coccinin, an antifungal peptide with antiproliferative and HIV-1 reverse transcriptase inhibitory activities from large scarlet runner beans

An antifungal peptide, designated coccinin, with a molecular mass of 7kDa and an N-terminal sequence resembling those of defensins, was purified from the seeds of large scarlet runner beans (Phaseolus coccineus cv. 'Major'). The peptide isolated was unadsorbed on DEAE-cellulose, and adsorbed on Affi-gel blue gel and Mono S. The peptide excerted antifungal activity on a number of fungal species including Botrytis cinerea, Coprinus comatus, Fusarium oxysporum, Mycosphaerella arachidicola, Physalospora piricola, and Rhizoctonia solani. It also inhibited proliferation in the leukemia cell lines HL60 and L1210, and reduced the activity of HIV-1 reverse transcriptase. However, it did not affect proliferation of mouse splenocytes.

Antifungal proteins and peptides of leguminous and non-leguminous origins

Antifungal proteins and peptides, as their names imply, serve a protective function against fungal invasion. They are produced by a multitude of organisms including leguminous flowering plants, non-leguminous flowering plants, gymnosperms, fungi, bacteria, insects and mammals. The intent of the present review is to focus on the structural and functional characteristics of leguminous, as well as non-leguminous, antifungal proteins and peptides. A spectacular diversity of amino acid sequences has been reported. Some of the antifungal proteins and peptides are classified, based on their structures and/or functions, into groups including chitinases, glucanases, thaumatin-like proteins, thionins, and cyclophilin-like proteins. Some of the well-known proteins such as lectins, ribosome inactivating proteins, ribonucleases, deoxyribonucleases, peroxidases, and protease inhibitors exhibit antifungal activity. Different antifungal proteins may demonstrate different fungal specificities. The mechanisms of antifungal action of only some antifungal proteins including thaumatin-like proteins and chitinases have been elucidated.

Eryngin, a novel antifungal peptide from fruiting bodies of the edible mushroom Pleurotus eryngii

An antifungal peptide with a molecular mass of 10k Da was isolated from fruiting bodies of the mushroom Pleurotus eryngii. The peptide, designated as eryngin, inhibited mycelial growth in Fusarium oxysporum and Mycosphaerella arachidicola. It was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and S-Sepharose. Its N-terminal sequence demonstrated some similarity to the antifungal protein from the mushroom Lyophyllum shimeiji and little resemblance to thaumatin and thaumatin-like proteins.

Lentin, a novel and potent antifungal protein from shitake mushroom with inhibitory effects on activity of human immunodeficiency virus-1 reverse transcriptase and proliferation of leukemia cells

From the fruiting bodies of the edible mushroom Lentinus edodes, a novel protein designated lentin with potent antifungal activity was isolated. Lentin was unadsorbed on DEAE-cellulose, and adsorbed on Affi-gel blue gel and Mono S. The N-terminal sequence of lentin manifested similarity to endoglucanase. Lentin, which had a molecular mass of 27.5 kDa, inhibited mycelial growth in a variety of fungal species including Physalospora piricola, Botrytis cinerea and Mycosphaerella arachidicola. Lentin also exerted an inhibitory activity on HIV-1 reverse transcriptase and proliferation of leukemia cells.

Purification of castamollin, a novel antifungal protein from Chinese chestnuts

A novel antifungal protein, designated castamollin, was isolated from Chinese chestnut (Castanea mollisima) seeds with a procedure involving ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-Sepharose and FPLC-gel filtration on Superdex 75. Castamollin possessed a novel N-terminal sequence demonstrating little similarity to N-terminal sequences of Castanea sativa chitinase. Castamollin exhibited a molecular mass of 37kDa in gel filtration and SDS-PAGE. It inhibited the activity of human immunodeficiency virus-1 reverse transcriptase with an IC(50) of 7microM and translation in a cell-free rabbit reticulocyte lysate system with an IC(50) of 2.7microM. Castamollin displayed antifungal activity against Botrytis cinerea, Mycosphaerella arachidicola, Physalospora piricola, and Coprinus comatus but was devoid of lectin activity.

Effects of Panax notoginseng saponins on myocardial Gsalpha mRNA expression and ATPase activity after severe scald in rats

The aim of this study was to investigate the changes of myocardial Gsalpha mRNA expression and ATPase and the effects of Panax notoginseng saponins (PNS) on that after burns in rats. Wistar rats were exposed to a 95 degrees C water bath for 10s to produce 30% TBSA skin-full-thickness scalds. Myocardial Gsalpha mRNA level, cAMP content and adenyl cyclase (AC) activities were determined with dot blotting hybridization, radioimmunoassay and indirect method, respectively. The ATPase activities in plasma membrane of cardiomyocytes and erythrocytes were measured colorimetrically. At 3, 6, 9 hours after scalds, the myocardial Gsalpha mRNA expression decreased significantly (P<0.01). PNS (100, 200 mg kg(-1), i.p.) markedly increased these levels (P<0.01). The elevation was correlated significantly with PNS dose (r=0.95, P<0.05). At 3, 6, 9, 12, 24, 48 hour after the scalds, the myocardial cAMP content and AC basal activity was reduced significantly. PNS (100, 200 mg kg(-1), i.p.) increased cAMP content and enhanced AC activity markedly in comparison with the 3rd hour postburn group. The activities of (Ca(2+)-Mg(2+))-ATPase and (Na(+)-K(+))-ATPase in plasma membrane of myocardial cells and red blood cells in scald group were significantly lower than those in the normal control group (P<0.01). PNS (100 mg kg(-1), i.p.) improved these indexes significantly after scalds (P<0.01 or 0.05). These data suggested that the effects of PNS on myocardium in burned rats involved its action to increase myocardial Gsalpha mRNA expression and AC activity, cAMP content as well as ATPase activities.

Gymnin, a potent defensin-like antifungal peptide from the Yunnan bean (Gymnocladus chinensis Baill)

From the seeds of the Yunnan bean, we purified an antifungal peptide using affinity chromatography on Affi-gel blue gel, FPLC-ion exchange chromatography on Mono S, and FPLC-gel filtration on Superdex 75. The antifungal peptide was adsorbed on Affi-gel blue gel at pH 7.8 and Mono S at pH 4.5. It exhibited a molecular mass of 6.5 kDa in both gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its N-terminal sequence closely resembled defensin-related peptides. The peptide exerted antifungal activity toward the fungal species Fusarium oxysporum and Mycosphaerella arachidicola, with an IC50 of 2 microM for the former fungus and 10 microM for the latter. It manifested a weaker mitogenic activity toward murine splenocytes than Concanavalin A. It also displayed antiproliferative activity on a murine leukemia (L1210), a hepatoma (HepG2), and a murine leukemia (M1) cell line. It inhibited human immunodeficiency virus-1 reverse transcriptase with an IC50 of 200 microM.

Cicerarin, a novel antifungal peptide from the green chickpea

A peptide designated cicerarin, with an N-terminal amino acid sequence VKSTGRADDDLAVKTKYLPP dissimilar from known proteins and peptides and a molecular mass of 8kDa, was isolated from seeds of the green chickpea Cicer arietinum cv green chickpea. Cicerarin was isolated with a procedure that involved ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, and gel filtration by fast protein liquid chromatography on Superdex 75. Cicerarin was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel in 10mM Tris-HCl buffer (pH 7.3). Cicerarin exerted antifungal activity against Botrytis cinerea, Mycosphaerella arachidicola, and Physalospora piricola. The antifungal activity was preserved after exposure to 100 degrees C for 15min.

Cicerin and arietin, novel chickpea peptides with different antifungal potencies

Two antifungal peptides with novel N-terminal sequences, designated cicerin and arietin were isolated from seeds of the chickpea (Cicer arietinum), respectively. Both peptides were adsorbed on Affi-gel blue gel and CM-Sepharose and exhibited a molecular weight of approximately 8.2 and 5.6 kDa, respectively. Arietin was more strongly adsorbed on CM-Sepharose than cicerin and manifested a higher translation-inhibiting activity in a rabbit reticulocyte lysate system and a higher antifungal potency toward Mycosphaerella arachidicola, Fusarium oxysporum and Botrytis cinerea. Both were devoid of mitogenic and anti-HIV-1 reverse transcriptase activities.