Huperzia
Huperzine B protects rat pheochromocytoma cells against oxygen-glucose deprivation-induced injury. (1/10)
AIM: To test the ability of huperzine B (HupB) to alleviate injury from oxygen-glucose deprivation (OGD) in the rat pheochromocytoma line PC12 cells. METHODS: After OGD for 3 h and reoxygenation for 24 h, neuronal morphology was observed by phase-contrast microscopy; cell survival was quantified by the reduction of MTT; malondialdehyde (MDA) was determined by the thiobarbituric acid; superoxide dismutase (SOD) was assayed by a modification of the xanthine/xanthine oxidase; and lactate (LA) was measured according to Marbach and Weil. RESULTS: OGD for 3 h and reoxygenation for 24 h triggered death in nearly 70 % of cells, along with major changes in morphology and biochemistry including elevated level of MDA, SOD activity, and LA content. Cells pretreated with HupB 1-100 micromol/L for 2 h showed significantly improved survival and reduced biochemical and morphologic signs of toxicity. CONCLUSION: HupB protected PC12 cells against OGD-induced injury, most likely by alleviating disturbances of oxidative and energy metabolism. (+info)Effects of huperzine A on secretion of nerve growth factor in cultured rat cortical astrocytes and neurite outgrowth in rat PC12 cells. (2/10)
AIM: To study the effects of huperzine A (HupA) on neuritogenic activity and the expression of nerve growth factor (NGF). METHODS: After being treated with 10 micromol/L HupA, neurite outgrowth of PC12 cells was observed and counted under phase-contrast microscopy. Mitogenic activity was assayed by [3H]thymidine incorporation. Cell cytotoxicity was evaluated by lactate dehydrogenase (LDH) release. AChE activity, mRNA and protein expression were measured by the Ellman method, RT-PCR, and Western blot, respectively. NGF mRNA and protein levels were determined by RT-PCR and ELISA assays. RESULTS: Treatment of PC12 cells with 10 micromol/L HupA for 48 h markedly increased the number of neurite-bearing cells, but caused no significant alteration in cell viability or other signs of cytotoxicity. In addition to inhibiting AChE activity, 10 micromol/L HupA also increased the mRNA and protein levels of this enzyme. In addition, following 2 h exposure of the astrocytes to 10 micromol/L HupA, there was a significant up-regulation of mRNA for NGF and P75 low-affinity NGF receptor. The protein level of NGF was also increased after 24 h treatment with HupA. CONCLUSION: Our findings demonstrate for the first time that HupA has a direct or indirect neurotrophic activity, which might be beneficial in treatment of neurodegenerative disorders such as Alzheimer disease. (+info)The mechanical diversity of stomata and its significance in gas-exchange control. (3/10)
Given that stomatal movement is ultimately a mechanical process and that stomata are morphologically and mechanically diverse, we explored the influence of stomatal mechanical diversity on leaf gas exchange and considered some of the constraints. Mechanical measurements were conducted on the guard cells of four different species exhibiting different stomatal morphologies, including three variants on the classical "kidney" form and one "dumb-bell" type; this information, together with gas-exchange measurements, was used to model and compare their respective operational characteristics. Based on evidence from scanning electron microscope images of cryo-sectioned leaves that were sampled under full sun and high humidity and from pressure probe measurements of the stomatal aperture versus guard cell turgor relationship at maximum and zero epidermal turgor, it was concluded that maximum stomatal apertures (and maximum leaf diffusive conductance) could not be obtained in at least one of the species (the grass Triticum aestivum) without a substantial reduction in subsidiary cell osmotic (and hence turgor) pressure during stomatal opening to overcome the large mechanical advantage of subsidiary cells. A mechanism for this is proposed, with a corollary being greatly accelerated stomatal opening and closure. Gas-exchange measurements on T. aestivum revealed the capability of very rapid stomatal movements, which may be explained by the unique morphology and mechanics of its dumb-bell-shaped stomata coupled with "see-sawing" of osmotic and turgor pressure between guard and subsidiary cells during stomatal opening or closure. Such properties might underlie the success of grasses. (+info)Crystallization and preliminary crystallographic analysis of an acridone-producing novel multifunctional type III polyketide synthase from Huperzia serrata. (4/10)
Polyketide synthase 1 (PKS1) from Huperzia serrata is a plant-specific type III polyketide synthase that shows an unusually versatile catalytic potential, producing various aromatic tetraketides, including chalcones, benzophenones, phlorogulucinols and acridones. Recombinant H. serrata PKS1 expressed in Escherichia coli was crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group I222 or I2(1)2(1)2(1), with unit-cell parameters a = 73.3, b = 85.0, c = 137.7 A, alpha = beta = gamma = 90.0 degrees. Diffraction data were collected to 2.0 A resolution using synchrotron radiation at BL24XU of SPring-8. (+info)Comparison of 454-ESTs from Huperzia serrata and Phlegmariurus carinatus reveals putative genes involved in lycopodium alkaloid biosynthesis and developmental regulation. (5/10)
(+info)Synthesis of (+/-)-7-hydroxylycopodine. (6/10)
(+info)Biotransformation of ursolic acid by an endophytic fungus from medicinal plant Huperzia serrata. (7/10)
Endophytic fungi were used not only for their producing bioactive products but also for their ability to transform natural compounds. An endophytic fungus, isolated from medicinal plant Huperzia serrata, was identified as Umbelopsis isabellina based on the internal transcribed spacer of ribosomal DNA (rDNA-ITS) region. It was used to transform ursolic acid (1), a pentacyclic triterpene. Incubation of ursolic acid with U. isabellina afforded three products, 3beta-hydroxy-urs-11-en-28,13-lactone (2), 3beta,7beta-dihydroxy-urs-11-en-28,13-lactone (3), 1beta,3beta-dihydroxy-urs-11-en-28,13-lactone (4). Although product 2 was a known compound, it was first obtained by microbial transformation. Products 3 and 4 were new compounds. The structural elucidation of the three compounds was achieved mainly by the 1D- and 2D-NMR, MS, IR data. The endophytic fungus U. isabellina can hydroxyate the C12-C13 double bond at position 13 of ursolic acid 1 and form a five-member lactone effectively. In the meantime, this fungus can also introduce the hydroxyl group at C-1 or C-7 of ursolic acid 1. (+info)Validation of a microscale extraction and high-throughput UHPLC-QTOF-MS analysis method for huperzine A in Huperzia. (8/10)
(+info)Huperzia is a genus of lycopod plants (Huperzia selago) that contains the alkaloid huperzine A, which has been studied for its potential cognitive-enhancing and neuroprotective effects in Alzheimer's disease and other neurological disorders.
Huperzia is actually not a medical term itself, but it refers to a genus of clubmosses (Huperzia serrata) that are found in Asia. This plant contains a compound called huperzine A, which has been studied for its potential cognitive-enhancing and neuroprotective effects.
Huperzine A is an acetylcholinesterase inhibitor, which means it can increase the levels of the neurotransmitter acetylcholine in the brain by blocking the enzyme that breaks it down. This has led to its investigation as a possible treatment for Alzheimer's disease and other neurological disorders characterized by cognitive decline.
While Huperzia itself is not a medical term, huperzine A has been studied in clinical trials and is available as a dietary supplement in some countries. However, it is important to note that the use of huperzine A as a treatment for any medical condition should be done under the supervision of a healthcare provider, as it can have side effects and interact with other medications.
Alkaloids are naturally occurring heterocyclic organic compounds that contain mostly basic nitrogen atoms, typically derived from plants and often possessing pharmacological properties.
Alkaloids are a type of naturally occurring organic compounds that contain mostly basic nitrogen atoms. They are often found in plants, and are known for their complex ring structures and diverse pharmacological activities. Many alkaloids have been used in medicine for their analgesic, anti-inflammatory, and therapeutic properties. Examples of alkaloids include morphine, quinine, nicotine, and caffeine.