Module 6 Vitamins AND Vitamin Containing Drugs PDF

Preview

Summary

MODULE 6: VITAMINS and VITAMIN-CONTAINING DRUGSESSENTIAL OUTCOME: Demonstrate understanding of the chemical structure and enumerate the natural sources of vitamins; explain their biosynthetic pathways of each chemical constituents and their specific sources, and the pharmaceutical and medicinal uses...

Description

PHARMACOGNOSY AND PLANT CHEMISTRY LECTURE

MODULE 6: VITAMINS and VITAMIN-CONTAINING DRUGS ESSENTIAL OUTCOME: Demonstrate understanding of the chemical structure and enumerate the natural sources of vitamins; explain their biosynthetic pathways of each chemical constituents and their specific sources, and the pharmaceutical and medicinal uses of the different chemical constituents. Vitamins • Organic components in food that are needed in very small amounts for growth and for maintaining good health • Not synthesized within the body, that are essential in small amounts for the maintenance of normal metabolic functions. Functions Vitamins are helpful for the health and life of the body in the following respects • They build up the resistance of the body against diseases. • Prevent and cure various diseases caused by deficiency. • Help the digestion and utilization of mineral salts and Carbohydrates in the body. • Stimulate and give strength to digestive and nervous system. • Help health protection • Help maintenance of proper health and normal growth Classification On the basis of their solubility vitamins are mainly 2 types • Fat soluble vitamins o Vitamins that dissolve in fat o They can accumulate and be saved for later use ▪ Because fat is easily stored on our body, fat-soluble vitamins can be stored within our fat o The fat-soluble vitamins are A, D, E and K. o Vitamin A ▪ Group of unsaturated nutritional organic compounds, that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids. ▪ Most toxic vitamin ▪ Retinol is the major natural form of the vitamin ▪ Beta-carotene is the most important. Its active form is present only in animal tissue ▪ Yellow to red oily liquid that may solidify when refrigerated and that should be protected from air and light ▪ Uses: vision, growth, and tissue differentiation ▪ Deficiency: nyctalopia (night blindness), xerophthalmia, hyperkeratosis of the skin, growth retardation, and decreased resistance to infection ▪ Dietary sources: Animal organs (heart, kidney, liver), eggs, dairy products, and fish, carrots and green leafy vegetable ▪ Drugs derived from Vitamin A Jose Philip G. Maglalang, RPh

1

PHARMACOGNOSY AND PLANT CHEMISTRY LECTURE

Tretinoin or all-trans retinoic acid • Used to treat acne vulgaris. • Topical purposes ▪ Isotretinoin or 13-cis retinoic acid • It is approved for use in severe recalcitrant cystic acne. • Oral use • Must not be taken by patients who are pregnant or who may become pregnant. will cause loss of the pregnancy, or will cause the baby to be born too early, to die shortly after birth, or to be born with birth defects (physical problems that are present at birth). ▪ Beta-carotene • It is approved for use in severe recalcitrant cystic acne. • Oral use Vitamin D ▪ Sunshine vitamin. • Irradiating provitamin D with ultraviolet light and are responsible for enhancing intestinal absorption of calcium, iron, magnesium, phosphate and zinc. ▪ Term that is used for several related steroids and their metabolites ▪ Absorbed readily from the small intestine of normal individuals ▪ Uses: development and maintenance of strong teeth and bones, Tx of hypophosphatemia & hypoparathyroidism ▪ Deficiency: rickets in children and osteomalacia in adults ▪ Cholecalciferol/Vitamin D3 • Primary form of the vitamin encountered in zoologic species • It is stored in a number of tissues, including the liver and skin. • Fish liver oils are a rich natural source of this material. • Absorbed with somewhat greater efficiency than ergocalciferol ▪ Ergocalciferol/Vitamin D2 • Derived from ergosterol, a plant steroid. • It is the form of this vitamin normally used to fortify such foods as milk, bread, and cereals. Vitamin E/α-tocopherol ▪ Refers to a group of compounds that include both tocopherols and tocotrienols ▪ Requires bile salts and dietary lipids for efficient absorption from the intestinal tract ▪ Stored extensively in adipose tissues of the body ▪ Wheat germ oil is a traditional natural source of vitamin E for therapeutic purposes. ▪ Uses: antioxidant, act as a cofactor in some enzyme systems ▪ Dietary sources: plant oils, green vegetables, whole grains, egg yolks and meats Vitamin K ▪ 2 - methyl-1,4-naphthoquinone and derivatives of this compound ▪

o

o

o

Jose Philip G. Maglalang, RPh

2

PHARMACOGNOSY AND PLANT CHEMISTRY LECTURE

Uses: essential for production of a type of protein called prothrombin & other factor involve in blood clotting mechanism. ▪ Deficiency: Hemorrhage ▪ Dietary sources: Dairy products and many fruits and vegetables, and green leafy vegetables ▪ Vitamin K1 • Phylloquinone/phytonadione • Absorbed from the intestinal tract only in the presence of bile salts. • Treatment of hypoprothrombinemia attributable to anticoagulant drugs and malabsorption ▪ Vitamin K2 • Prenylmenaquinone-7 • Larger aliphatic side chain than phytonadione • Not commercially available for medicinal use. ▪ Vitamin K3 • Menadione/menaquinone • Synthetic material with prothrombogenic properties • It is affected by sunlight and has irritating properties. • Not commercially available for medicinal use. ▪ Vitamin K4 • Menadiol • Water-soluble bis (dihydrogen phosphate) tetrasodium salt. • treatment of hypoprothrombinemia secondary to obstructive jaundice, biliary fistula Water soluble vitamins o Dominated by the vitamin b complex, but this solubility classification also includes ascorbic acid. o Range from simple to complex chemical molecules, play diverse physiologic roles, and have a wide scope of therapeutic applications o Vitamin B complex ▪ Vitamin B1/ Thiamine • The vitamin is stable in an acidic environment but decomposes readily above pH 5.0. • Substance is absorbed readily from the small intestine, alcohol inhibits its absorption • Deficiency: Beriberi • Dietary sources: Whole grains, legumes, and meats ▪ Vitamin B2/ Riboflavin • It is sensitive to light and will change into lumichrome or lumiflavin • Can be synthesized chemically, but bacterial synthesis is more convenient and economical for commercial purposes. ▪

•

Jose Philip G. Maglalang, RPh

3

PHARMACOGNOSY AND PLANT CHEMISTRY LECTURE

Deficiency: inadequate nutrition, intestinal malabsorption, and a few specific drug regimens (phenothiazines, tricyclic antidepressants, and probenecid). • Dietary sources: Dairy products, eggs, legumes, and meats, yeast (richest natural source). Vitamin B3/ Niacin/nicotinic acid • Naturally occurring pyridine derivative • Uses: inadequate nutrition, intestinal malabsorption, or genetic errors of metabolism • Deficiency: Pellagra • Dietary sources: Lean meats, fish, and dairy products Vitamin B5/ Pantothenic acid • Chick antidermatitis factor • Precursor of coenzyme A, a cofactor that is essential for metabolism of carbohydrates, lipids, and protein • Deficiency: Burning foot syndrome • Dietary sources: Lean meats, fish, and dairy products Vitamin B6/ Pyridoxine • Readily absorbed in the jejunum, but the vitamin synthesized by the microflora of the colon is largely excreted in feces • Deficiency: neurologic abnormalities (confusion, irritability, and convulsive seizures), skin lesions (glossitis, seborrheic dermatitis, and stomatitis), and hypochromic microcytic anemia. • Dietary sources: Meats, bananas, whole cereal grains, nuts, and potatoes Vitamin B9/ Folic acid • It is a conjugate of a pteridine derivative, ƿ-aminobenzoic acid, and glutamic acid • Available as tablet and injection dosage forms. It must be packed in well closed, light-resistant containers • Uses: Antidote in chemotherapeutic regimens employing a potent folate antagonist • Deficiency: megaloblastic and macrocytic anemias and glossitis. • Dietary sources: Leafy vegetables and liver Vitamin B12/ Cobalamins • Cyanocobalamin is the most stable of the cobalamins and most frequently utilized in therapy • Uses: Function as extrinsic factors to prevent pernicious anemia. • Deficiency: Pernicious anemia • Dietary sources: Meat, seafood, eggs, dairy products, and fermented foods Vitamin C/ L-ascorbic acid •

▪

▪

▪

▪

▪

▪

Jose Philip G. Maglalang, RPh

4

PHARMACOGNOSY AND PLANT CHEMISTRY LECTURE

Uses: essential for proper formation of collagen and other intercellular materials in tissues, especially in bones, skin, and teeth, Urinary acidifier to enhance the effect of methenamine • Deficiency: Scurvy • Dietary sources: citrus fruits, tomatoes, strawberries, and other fresh fruits and vegetables Vitamin H/ Biotin • Uses: essential for proper formation of collagen and other intercellular materials in tissues, especially in bones, skin, and teeth • Deficiency: alopecia, erythroderma desquamativa (Leier's disease), and seborrheic dermatitis • Dietary sources: Egg yolk, liver, cereal grains, and milk are good •

▪

Vitamins – Related Factors • Para-aminobenzoic Acid/PABA o Precursor of folic acid o It is not an essential nutrient for humans and should not considered a vitamin. o Added as an accessory food factor to a few multiple vitamin and mineral products o Blocks the formation of salicyluric acid (form in which salicylate are excreted readily in the body) from salicylic acid which will increase blood salicylate levels ▪ Sometimes used in rheumatic fever and other conditions benefiting from salicylate therapy o Interferes with the antibacterial activity of Sulfonamides o Used as UV sunscreen • Choline/ B-hydroxyethyltrimethylammonium hydroxide o Component of lecithin, a phospholipid, and a precursor of acetylcholine o Widely distributed in nature, occurring in egg yolk, animal organs (brain, heart, liver and thymus), fish, milk, cereal grains, fruits and root vegetables o Available as the bitartrate, chloride and dihydrogen citrate salts o Used as lipotropic agent such as liver cirrhosis, Huntington’s chorea, presenile dementia and tardive dyskinesia • Inositol o Sweet-tasting, optically inactive substance that is sometimes associated with the B vitamin o Large doses may cause moderate diarrhea Multivitamin therapy • Decavitamin capsules and Decavitamin tablets o Serve as a model multivitamin preparation o Providing 10 vitamins for which RDA have been established and one vitamin for which there is no such recommendation o Vitamin A, B1, B2, B6, B12, C, D, E, calcium pantothenate, folic acid and niacinamide o Usual dose: 1 capsule or tablet daily

Jose Philip G. Maglalang, RPh

5

PHARMACOGNOSY AND PLANT CHEMISTRY LECTURE

REFERENCES: • Evans, W. C., Evans, D., & Trease, G. E. (2009). Trease and Evans pharmacognosy (16th ed.). Edinburgh; New York: Saunders/Elsevier. • Tyler, V. E., Brady, L. R., Robbers, J. E., & Claus, E. P. (1976). Pharmacognosy. Philadelphia: Lea & Febiger.

Jose Philip G. Maglalang, RPh

6...