Today, Hypericum perforatum L. is probably one of the best-characterized medicinal plants, and hyperforin is its best-characterized constituent. Extracts from H. perforatum are widely used as antidepressants;however, ...Today, Hypericum perforatum L. is probably one of the best-characterized medicinal plants, and hyperforin is its best-characterized constituent. Extracts from H. perforatum are widely used as antidepressants;however, less attention has been given to other properties of hyperforin, such as antitumor, fungicidal, antiviral and antibacterial action, or its possible use as a substance with immunomodulation properties. The present study summarizes results that describe the influence of hyperforin as an immunomodulation agent on phagocytosis and the breakdown of Escherichia coli by human polymorphonuclear neutrophils (PMNs). Hyperforin at 1 - 100 μg/mL concentrations was found to have a major influence on phagocytosis and the breakdown of E. coli by PMNs in vitro. A 100 μg/mL solution of hyperforin increased the uptake of non-opsonized E. coli almost 50-fold, and the uptake of IgG-opsonized E. coli more than threefold;on the other hand, the uptake of serum-opsonized bacteria was reduced to approximately 60% of that of the control. Hyperforin seems to bind to both PMNs and E. coli and acts like an opsonin. The elimination of remnants of IgG-opsonized E. coli from the PMNs was stimulated by hyperforin, while the elimination of remnants from non-op-so nized and serum-opsonized material was unaffected by the drug. Hyperforin exhibited clear immunomodulation ability as a phagocytosisstimulating agent. Hyperforin is probably inactive against human immunodeficiency virus (HIV) and most Gram-negative bacteria. However, it can protect acquired immunodeficiency syndrome (AIDS) patients and other immunocompromised patients by its antibacterial activity against Gram-positive bacteria and by enhancement of phagocytosis of Gram-positive and Gram-negative bacteria;some Gram-negative bacteria, such as Neisseria, are sensitive to hyperforin. Hyperforin has the ability to penetrate the blood-brain barrier (BBB) and blood-testis barrier (BTB) and is a valuable antibacterial agent against meningitis and gonorrhea. These properties of hyperforin are important for an antibiotic with immunomodulation activity in the struggle against the growing mortality in AIDS patients as a result of opportunistic bacteria, as recently shown by Bekondi et al. (2006, Int. J. Infect. Dis. 10, 387-395). It could also help to combat primary and opportunistic pathogens associated with meningitis in adults' relation to HIV serostatus.展开更多
Hypericum perforatum is a perennial medicinal plant known as ＂St. John＇s wort＂ in Western Europe and has been used in the treatment of several diseases for centuries. In the present study, morphologic, phenologic a...Hypericum perforatum is a perennial medicinal plant known as ＂St. John＇s wort＂ in Western Europe and has been used in the treatment of several diseases for centuries. In the present study, morphologic, phenologic and population variability in pseudohypericin and hyperforin concentrations among H. perforatum populations from Northern Turkey was investigated for the first time. The aerial parts of H. perforatum plants representing a total of 30 individuals were collected at full flowering from 10 sites of Northern Turkey to search the regional variation in the secondary metabolite concentrations. For morphologic and phenologic sampling, plants from one site were gathered in five phenological stages： vegetative, floral budding, full flowering, fresh fruiting and mature fruiting. The plant materials were air-dried at room temperature and subsequently assayed for chemical concentrations by high performance liquid chromatography. Secondary metabolite concentrations ranged from traces to 2.94mg/g dry weight （DW） for pseudohypericin and traces -6.29mg/g DW for hyperforin. The differences in the secondary metabolite concentrations among populations of H. perforatum were found to be significant. The populations varied greatly in hyperforin concentrations, whereas they produced a similar amount of pseudohypericin. Concentrations of both secondary metabolites in all tissues increased with advancing of plant development and higher accumulation levels were reached at flowering. Among different tissues, full opened flowers were found to be superior to stems, leaves and the other reproductive parts with regard to pseudohypericin and hyperforin accumulations. The present findings might be useful to optimize the processing methodology of wild-harvested plant material and obtain increased concentrations of these secondary metabolites.展开更多
文摘Today, Hypericum perforatum L. is probably one of the best-characterized medicinal plants, and hyperforin is its best-characterized constituent. Extracts from H. perforatum are widely used as antidepressants;however, less attention has been given to other properties of hyperforin, such as antitumor, fungicidal, antiviral and antibacterial action, or its possible use as a substance with immunomodulation properties. The present study summarizes results that describe the influence of hyperforin as an immunomodulation agent on phagocytosis and the breakdown of Escherichia coli by human polymorphonuclear neutrophils (PMNs). Hyperforin at 1 - 100 μg/mL concentrations was found to have a major influence on phagocytosis and the breakdown of E. coli by PMNs in vitro. A 100 μg/mL solution of hyperforin increased the uptake of non-opsonized E. coli almost 50-fold, and the uptake of IgG-opsonized E. coli more than threefold;on the other hand, the uptake of serum-opsonized bacteria was reduced to approximately 60% of that of the control. Hyperforin seems to bind to both PMNs and E. coli and acts like an opsonin. The elimination of remnants of IgG-opsonized E. coli from the PMNs was stimulated by hyperforin, while the elimination of remnants from non-op-so nized and serum-opsonized material was unaffected by the drug. Hyperforin exhibited clear immunomodulation ability as a phagocytosisstimulating agent. Hyperforin is probably inactive against human immunodeficiency virus (HIV) and most Gram-negative bacteria. However, it can protect acquired immunodeficiency syndrome (AIDS) patients and other immunocompromised patients by its antibacterial activity against Gram-positive bacteria and by enhancement of phagocytosis of Gram-positive and Gram-negative bacteria;some Gram-negative bacteria, such as Neisseria, are sensitive to hyperforin. Hyperforin has the ability to penetrate the blood-brain barrier (BBB) and blood-testis barrier (BTB) and is a valuable antibacterial agent against meningitis and gonorrhea. These properties of hyperforin are important for an antibiotic with immunomodulation activity in the struggle against the growing mortality in AIDS patients as a result of opportunistic bacteria, as recently shown by Bekondi et al. (2006, Int. J. Infect. Dis. 10, 387-395). It could also help to combat primary and opportunistic pathogens associated with meningitis in adults' relation to HIV serostatus.
文摘Hypericum perforatum is a perennial medicinal plant known as ＂St. John＇s wort＂ in Western Europe and has been used in the treatment of several diseases for centuries. In the present study, morphologic, phenologic and population variability in pseudohypericin and hyperforin concentrations among H. perforatum populations from Northern Turkey was investigated for the first time. The aerial parts of H. perforatum plants representing a total of 30 individuals were collected at full flowering from 10 sites of Northern Turkey to search the regional variation in the secondary metabolite concentrations. For morphologic and phenologic sampling, plants from one site were gathered in five phenological stages： vegetative, floral budding, full flowering, fresh fruiting and mature fruiting. The plant materials were air-dried at room temperature and subsequently assayed for chemical concentrations by high performance liquid chromatography. Secondary metabolite concentrations ranged from traces to 2.94mg/g dry weight （DW） for pseudohypericin and traces -6.29mg/g DW for hyperforin. The differences in the secondary metabolite concentrations among populations of H. perforatum were found to be significant. The populations varied greatly in hyperforin concentrations, whereas they produced a similar amount of pseudohypericin. Concentrations of both secondary metabolites in all tissues increased with advancing of plant development and higher accumulation levels were reached at flowering. Among different tissues, full opened flowers were found to be superior to stems, leaves and the other reproductive parts with regard to pseudohypericin and hyperforin accumulations. The present findings might be useful to optimize the processing methodology of wild-harvested plant material and obtain increased concentrations of these secondary metabolites.
