ethanol¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ The sedative effects of ethanol are mediated through binding to GABA receptors and glycine receptors (alpha 1 and alpha 2 subunits). In its role as an anti-infective, ethanol acts as an osmolyte or dehydrating agent that disrupts the osmotic balance across cell membranes. Caffeine¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Caffeine stimulates medullary, vagal, vasomotor, and respiratory centers, promoting bradycardia, vasoconstriction, and increased respiratory rate. This action was previously believed to be due primarily to increased intracellular cyclic 3¡Ç,5¡Ç-adenosine monophosphate (cyclic AMP) following inhibition of phosphodiesterase, the enzyme that degrades cyclic AMP. It is now thought that xanthines such as caffeine act as agonists at adenosine-receptors within the plasma membrane of virtually every cell. As adenosine acts as an autocoid, inhibiting the release of neurotransmitters from presynaptic sites but augmenting the actions of norepinephrine or angiotensin, antagonism of adenosine receptors promotes neurotransmitter release. This explains the stimulatory effects of caffeine. Blockade of the adenosine A1 receptor in the heart leads to the accelerated, pronounced "pounding" of the heart upon caffeine intake. Cyanocobalamin¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Vitamin B12 is used in the body in two forms: Methylcobalamin and 5-deoxyadenosyl cobalamin. The enzyme methionine synthase needs methylcobalamin as a cofactor. This enzyme is involved in the conversion of the amino acid homocysteine into methionine. Methionine in turn is required for DNA methylation. 5-Deoxyadenosyl cobalamin is a cofactor needed by the enzyme that converts L-methylmalonyl-CoA to succinyl-CoA. This conversion is an important step in the extraction of energy from proteins and fats. Furthermore, succinyl CoA is necessary for the production of hemoglobin, the substances that carries oxygen in red blood cells. Pyridoxine¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Vitamin B6 is the collective term for a group of three related compounds, pyridoxine (PN), pyridoxal (PL) and pyridoxamine (PM), and their phosphorylated derivatives, pyridoxine 5'-phosphate (PNP), pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP). Although all six of these compounds should technically be referred to as vitamin B6, the term vitamin B6 is commonly used interchangeably with just one of them, pyridoxine. Vitamin B6, principally in the form of the coenzyme pyridoxal 5'-phosphate, is involved in a wide range of biochemical reactions, including the metabolism of amino acids and glycogen, the synthesis of nucleic acids, hemogloblin, sphingomyelin and other sphingolipids, and the synthesis of the neurotransmitters serotonin, dopamine, norepinephrine and gamma-aminobutyric acid (GABA). Riboflavin¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Binds to riboflavin hydrogenase, riboflavin kinase, and riboflavin synthase. Riboflavin is the precursor of flavin mononucleotide (FMN, riboflavin monophosphate) and flavin adenine dinucleotide (FAD). The antioxidant activity of riboflavin is principally derived from its role as a precursor of FAD and the role of this cofactor in the production of the antioxidant reduced glutathione. Reduced glutathione is the cofactor of the selenium-containing glutathione peroxidases among other things. The glutathione peroxidases are major antioxidant enzymes. Reduced glutathione is generated by the FAD-containing enzyme glutathione reductase.
Pharmacology
ethanol¿¡ ´ëÇÑ Pharmacology Á¤º¸ Alcohol produces injury to cells by dehydration and precipitation of the cytoplasm or protoplasm. This accounts for its bacteriocidal and antifungal action. When alcohol is injected in close proximity to nerve tissues, it produces neuritis and nerve degeneration (neurolysis). Ninety to 98% of ethanol that enters the body is completely oxidized. Ethanol is also used as a cosolvent to dissolve many insoluble drugs and to serve as a mild sedative in some medicinal formulations. Caffeine¿¡ ´ëÇÑ Pharmacology Á¤º¸ Caffeine, a naturally occurring xanthine derivative like theobromine and the bronchodilator theophylline, is used as a CNS stimulant, mild diuretic, and respiratory stimulant (in neonates with apnea of prematurity). Often combined with analgesics or with ergot alkaloids, caffeine is used to treat migraine and other headache types. Over the counter, caffeine is available to treat drowsiness or mild water-weight gain. Cyanocobalamin¿¡ ´ëÇÑ Pharmacology Á¤º¸ Cyanocobalamin (Vitamin B12) is a water-soluble organometallic compound with a trivalent cobalt ion bound inside a corrin ring. It is needed for nerve cells and red blood cells, and to make DNA. Vitamin B12 deficiency is the cause of several forms of anemia. Pyridoxine¿¡ ´ëÇÑ Pharmacology Á¤º¸ Vitamin B6 (pyridoxine) is a water-soluble vitamin used in the prophylaxis and treatment of vitamin B6 deficiency and peripheral neuropathy in those receiving isoniazid (isonicotinic acid hydrazide, INH). Vitamin B6 has been found to lower systolic and diastolic blood pressure in a small group of subjects with essential hypertension. Hypertension is another risk factor for atherosclerosis and coronary heart disease. Another study showed pyridoxine hydrochloride to inhibit ADP- or epinephrine-induced platelet aggregation and to lower total cholesterol levels and increase HDL-cholesterol levels, again in a small group of subjects. Vitamin B6, in the form of pyridoxal 5'-phosphate, was found to protect vascular endothelial cells in culture from injury by activated platelets. Endothelial injury and dysfunction are critical initiating events in the pathogenesis of atherosclerosis. Human studies have demonstrated that vitamin B6 deficiency affects cellular and humoral responses of the immune system. Vitamin B6 deficiency results in altered lymphocyte differentiation and maturation, reduced delayed-type hypersensitivity (DTH) responses, impaired antibody production, decreased lymphocyte proliferation and decreased interleukin (IL)-2 production, among other immunologic activities. Riboflavin¿¡ ´ëÇÑ Pharmacology Á¤º¸ Riboflavin or vitamin B2 is an easily absorbed, water-soluble micronutrient with a key role in maintaining human health. Like the other B vitamins, it supports energy production by aiding in the metabolising of fats, carbohydrates, and proteins. Vitamin B2 is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Riboflavin also helps in the prevention or treatment of many types of eye disorders, including some cases of cataracts.
Caffeine¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ Low (25 to 36%). Cyanocobalamin¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ Very high (to specific plasma proteins called transcobalamins); binding of hydroxocobalamin is slightly higher than cyanocobalamin. Pyridoxine¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ 22% Riboflavin¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ 60%
Half-life
ethanol¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ Not Available Caffeine¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ 3 to 7 hours in adults, 65 to 130 hours in neonates Cyanocobalamin¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ Approximately 6 days (400 days in the liver). Pyridoxine¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ 15-20 days Riboflavin¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ 66-84 minutes
Absorption
ethanol¿¡ ´ëÇÑ Absorption Á¤º¸ Rapidly absorbed. Caffeine¿¡ ´ëÇÑ Absorption Á¤º¸ Readily absorbed after oral or parenteral administration. The peak plasma level for caffeine range from 6-10mg/L and the mean time to reach peak concentration ranged from 30 minutes to 2 hours. Cyanocobalamin¿¡ ´ëÇÑ Absorption Á¤º¸ Readily absorbed in the lower half of the ileum. Pyridoxine¿¡ ´ëÇÑ Absorption Á¤º¸ The B vitamins are readily absorbed from the gastrointestinal tract, except in malabsorption syndromes. Pyridoxine is absorbed mainly in the jejunum. Riboflavin¿¡ ´ëÇÑ Absorption Á¤º¸ Vitamin B2 is readily absorbed from the upper gastrointestinal tract.
ethanol¿¡ ´ëÇÑ Biotransformation Á¤º¸ Hepatic. Metabolized by cytochrome P450 enzyme CYP2E1. Caffeine¿¡ ´ëÇÑ Biotransformation Á¤º¸ Hepatic cytochrome P450 1A2 (CYP 1A2) is involved in caffeine biotransformation. About 80% of a dose of caffeine is metabolized to paraxanthine (1,7-dimethylxanthine), 10% to theobromine (3,7-dimethylxanthine), and 4% to theophylline (1,3-dimethylxanthine). Cyanocobalamin¿¡ ´ëÇÑ Biotransformation Á¤º¸ Hepatic Riboflavin¿¡ ´ëÇÑ Biotransformation Á¤º¸ Hepatic.
Toxicity
ethanol¿¡ ´ëÇÑ Toxicity Á¤º¸ Oral, rat LD50: 5628 mg/kg. Symptoms and effects of overdose include nausea, vomiting, CNS depression, acute respiratory failure or death and with chronic use, severe health problems, such as liver and brain damage. Caffeine¿¡ ´ëÇÑ Toxicity Á¤º¸ LD50=127 mg/kg (orally in mice) Cyanocobalamin¿¡ ´ëÇÑ Toxicity Á¤º¸ Anaphylactic reaction (skin rash, itching, wheezing)-after parenteral administration. ORL-MUS LD50 > 8000 mg/kg Pyridoxine¿¡ ´ëÇÑ Toxicity Á¤º¸ Oral Rat LD50 = 4 gm/kg. Toxic effects include convulsions, dyspnea, hypermotility, diarrhea, ataxia and muscle weakness. Riboflavin¿¡ ´ëÇÑ Toxicity Á¤º¸ Not Available
Drug Interactions
ethanol¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Not Available Caffeine¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Not Available Cyanocobalamin¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Not Available Pyridoxine¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Not Available Riboflavin¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Not Available
ethanol¿¡ ´ëÇÑ Description Á¤º¸ A clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is widely used as a solvent and preservative in pharmaceutical preparations as well as serving as the primary ingredient in alcoholic beverages. [PubChem] Caffeine¿¡ ´ëÇÑ Description Á¤º¸ A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine& Cyanocobalamin¿¡ ´ëÇÑ Description Á¤º¸ Cyanocobalamin (commonly known as Vitamin B12) is the most chemically complex of all the vitamins. Cyanocobalamin's structure is based on a corrin ring, which, although similar to the porphyrin ring found in heme, chlorophyll, and cytochrome, has two of the pyrrole rings directly bonded. The central metal ion is Co (cobalt). Cyanocobalamin cannot be made by plants or by animals, as the only type of organisms that have the enzymes required for the synthesis of cyanocobalamin are bacteria and archaea. Higher plants do not concentrate cyanocobalamin from the soil and so are a poor source of the substance as compared with animal tissues. Cyanocobalamin is naturally found in foods including meat (especially liver and shellfish), eggs, and milk products. [HMDB] Nicotinamide¿¡ ´ëÇÑ Description Á¤º¸ An important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and pellagra. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake. [PubChem] Pyridoxine¿¡ ´ëÇÑ Description Á¤º¸ The 4-methanol form of vitamin B 6 which is converted to pyridoxal phosphate which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. Although pyridoxine and Vitamin B 6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading (EE Snell; Ann NY Acad Sci, vol 585 pg 1, 1990). [PubChem] Riboflavin¿¡ ´ëÇÑ Description Á¤º¸ Nutritional factor found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as flavin mononucleotide and flavin-adenine dinucleotide. [PubChem]