Two new piperidine alkaloids from the leaves of Microcos paniculata.
Habropetaline A, an antimalarial naphthylisoquinoline alkaloid from Triphyophyllum peltatum.
Microbial production of plant benzylisoquinoline alkaloids.
Berberine is a component of some formulations. There is some evidence it is useful in the treatment of , and it has been a standard treatment for .
Berberine lowers elevated blood total , LDL cholesterol, and aterogenic (apo B) (Apo B), but the mechanism of action is distinct from . Berberine reduces LDL cholesterol by upregulating LDLR mRNA expression posttranscriptionally while downregulating the transcription of proprotein convertase subtilisin/kexin type 9 (PCSK9), a natural inhibitor of (LDLR), and increasing in the liver the expression of LDL receptors through extracellular signal-regulated kinase (ERK) signaling pathway, while statins inhibit cholesterol synthesis in the liver by blocking HMG-CoA-reduktase. This explains why berberine does not cause side effects typical to statins. Berberine and synergistically inhibit cholesterol absorption in hamsters. Berberin seems to improve the arterial endothelial function in humans. Berberine activates (AMPK), specifically (ERK), which plays a central role in glucose and lipid metabolism, suppresses proinflammatory cystokines, and reduces MMP-9 and EMMPRIN expression, which are all beneficial changes for heart health. Morevover, berberine reduces hepatic fat content in the rats of non-alcoholic fatty liver disease (NAFLD). Berberine also prevents proliferation of hepatic stellate cells (HSCs), which are central for the development of fibrosis during liver injury.
Enzymology of indole alkaloid biosynthesis in Catharanthus roseus.
During the last few decades, many studies have shown that berberine has various beneficial effects on the cardiovascular system and significant anti-inflammatory activities. Berberine exerts up-regulating activity on both low-density-lipoprotein receptor (LDLR) and insulin receptor (InsR). This one-drug-multiple-target characteristic might be suitable for the treatment of . Berberine has been tested and used successfully in experimental and human mellitus. Berberine has been shown to lower elevated blood glucose as effectively as . The mechanisms include inhibition of , inducing glycolysis, preventing through increasing insulin receptor expression and acting like . A new study suggest that berberine may overcome insulin resistance via modulating key molecules in insulin signaling pathway, leading to increased glucose uptake in insulin resistant cells. Berberine inhibits Foxo1, which integrates insulin signaling with mitochondrial function. Inhibition of Foxo1 can improve hepatic metabolism during insulin resistance and the metabolic syndrome. Berberine might exert its insulinotropic effect in isolated rat islets by up-regulating the expression of , which probably acts solely or together with other HNFs to modulate glucokinase activity, rendering β cell more sensitive to glucose fluctuation and response more effectively to glucose challenge. Berberine seems to inhibit human (DPP IV) as well as the pro-diabetic target human 1B (h-PTP 1B), which explain at least some of its anti-hyperglycemic activities. Berberine suppresses intestinal disaccharidases with beneficial metabolic effects in diabetic states.
Berberine has drawn extensive attention towards its antineoplastic effects. It seems to suppress the growth of a wide variety of tumor cells including breast cancer, leukemia, melanoma, epidermoid carcinoma, hepatoma, oral carcinoma, tongue carcinoma, glioblastoma, prostate carcinoma, gastric carcinoma. Animal studies have shown that berberine can suppress chemical-induced carcinogenesis, tumor promotion, tumor invasion, , neuroblastoma, and . It is a radiosensitzer of tumor cells but not of normal cells. How berberine mediates these effects is not fully understood, but its ability to inhibit angiogenesis and to modulate Mcl-1, Bcl-xL, cyclooxygenase (COX)-2, MDR, tumor necrosis factor (TNF)- and IL-6 , iNOS, IL-12, intercellular adhesion molecule-1 and ELAM-1 expression, MCP-1 and CINC-1, cyclin D1, activator protein (AP-1), HIF-1 , PPAR- , and topoisomerase II has been shown. By using yeast mutants, berberine was found to bind and inhibit stress-induced mitogen-activated protein kinase kinase activation. Because apoptotic, carcinogenic, and inflammatory effects and various gene products (such as TNF- , IL-6, COX-2, adhesion molecules, cyclin D1, and MDR) modulated by berberine are regulated by the transcription factor nuclear factor- B (NF- B), it is postulated that this pathway plays a major role in the action of berberine. Berberine suppressed NF-kappaB activation induced by various inflammatory agents and carcinogens. This alkaloid also suppressed constitutive NF-kappaB activation found in certain tumor cells. It seems to protect against side effects of radiation therapy in lung cancer. Berberine, 300 mg three times a day orally, also seems to inhibit complication of abdominal or pelvic radiation, called radiation-induced acute intestinal symptoms (RIAISs). The studies suggest that its use in clinical development may be more as a cytostatic agent than a cytotoxic compound.
Quaternary isoquinoline alkaloids from Xylopia parviflora.
It is known that the immediate precursor of protoberberine alkaloids in plants is . Berberine is an alkaloid derived from . and 4-hydroxypyruvic acid both come from L-Tyr. Although two molecules are used in the biosynthetic pathway, only the fragment of the ring system is formed via DOPA, the remaining carbon atoms come from via 4-hydroxyphenylacetaldehyde. loses carbon dioxide to form 1. Likewise, 4-hydroxypyruvic acid also loses carbon dioxide to form 4-hydroxyphenyl-acetaldehyde 2. 1 then reacts with 4-hydroxy-phenylacetaldehyde 2 to form (S)-norcolaurine 3 in a reaction similar to the . After oxidation and methylation by , 4 is formed. serves as a pivotal intermediate to other alkaloids. Oxidation of the then occurs and an is formed 5. In a Mannich-like reaction the ortho position to the phenol is nucleophilic, and electrons are pushed to form 6. Product 6 then undergoes to form (S)-scoulerine which is then methylated by SAM to form (S)-tetrahydrocolumbamine 7. Product 7 is then oxidized to form the ring from the ortho-methoxyphenol, via an O2-, NADPH- and cytochrome P-450-dependent enzyme. giving (S)-canadine 8. (S)-canadine is then oxidized to give the quaternary isoquinolinium system of berberine. This happens in two separate oxidation steps, both requiring molecular oxygen, with H2O2 and H2O produced in the successive processes.
Berberine is a component of some formulations. There is some evidence that it is useful in the treatment of , and it has been a standard treatment for . Berberine prevents and supresses proinflammatory cytokines, , and genes, and increases expression which partly explains its versatile health effects. Berberine is a nucleic acid-binding isoquinolone alkaloid with wide potential therapeutic properties.
Isoquinoline and isoindole alkaloids from Menispermum dauricum.
Benzylisoquinoline Alkaloid Metabolism: A Century of ..
Distribution and biological activity of alkaloidal glycosidase inhibitors from plants.
Benzylisoquinoline alkaloids, ..
Tetrahydroisoquinoline alkaloids and 2-deoxyribonolactones from Aristolochia arcuata.
Engineering in Isoquinoline Alkaloid Biosynthesis.
Biosynthetic incorporation of the aminobutyl group of spermidine into pyrrolizidine alkaloids.
of isoquinoline alkaloids in ..
Antisense-mediated reduction in ADC activity causes minor alterations in the alkaloid profile of cultured hairy roots and regenerated transgenic plants of Nicotiana tabacum.
Isoquinoline alkaloid biosynthesis ..
Berberine is a salt from the group of . It is found in such plants as , (Hydrastis canadensis), and , usually in the roots, , stems, and bark. Berberine is strongly yellow colored, which is why in earlier times berberis species were used to dye wool, leather and wood. Wool is still today dyed with berberine in Northern India. Under , berberine shows a strong yellow . Because of this it is used in for in . As a natural dye berberin has a (CI) of 75160.
the formation of the methylenedioxy bridge in berberine biosynthesis.
Potential active-site residues in polyneuridine aldehyde esterase, a central enzyme of indole alkaloid biosynthesis, by modelling and site-directed mutagenesis.
Metabolic Engineering in Isoquinoline Alkaloid Biosynthesis
Co-expression of three MEP pathway genes and geraniol 10-hydroxylase in internal phloem parenchyma of Catharanthus roseus implicates multicellular translocation of intermediates during the biosynthesis of monoterpene indole alkaloids Plant J.
Isoquinoline and Benzylisoquinoline Alkaloids
Involvement of the octadecanoid pathway and protein phosphorylation in fungal elicitor-induced expression of terpenoid indole alkaloid biosynthetic genes in Catharanthus roseus.
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