Medicinal Plants PHG 1101 Lecture 1 PDF

Summary

This lecture introduces the study of medicinal plants, covering definitions of crude drugs and natural products and discussing their origins and characteristics. It also covers different classifications of drugs and discusses cultivation of medicinal plants.

Full Transcript

 It is the objective study of crude drugs of vegetable, animal or mineral origin, treated scientifically.  Pharmacognosy derived from: - Pharmakon :meaning drug or poison. - gnosis :meaning to acquire knowledge. (The entire knowledge of drugs) “Natural products (NP)”: Biosynt...

 It is the objective study of crude drugs of vegetable, animal or mineral origin, treated scientifically.  Pharmacognosy derived from: - Pharmakon :meaning drug or poison. - gnosis :meaning to acquire knowledge. (The entire knowledge of drugs) “Natural products (NP)”: Biosynthetic substances produced by living cells. “ Synthetic compounds ” : do not occur in nature. Many NP can be used to treat, cure or prevent diseases and their undesirable effects. Crude drugs = raw drugs ‫عقار خام لم يصنع‬ i.e., harvested and dried plant or animal or mineral sources of pharmaceutically or medicinally useful products before they undergo any processing Examples  Entire plants or animals: Mentha (all plant), Cochineal.  Entire organ of plant or animal:  Senna leaves, clove bud, thyroid gland.  Minerals: Chalk, kaolin, bentonite, talc.  Substances derived from plant or animal gelatin, beeswax, resin, gum, opium  Fibres and fabrics - Surgical dressing (cotton) - Filter media (diatoms) NB:  organized drugs from organs e.g. Leaves, flowers, fruits, etc. (cellular structure)  unorganized drugs extracts, gums, resins, oil, waxes exudates (opium) etc... 1. Identification of the source of material for ming drug. 2. Deter mination of its morphological characters. 3. Investigation potency and purity. 4. Planning for cultivation of the medicinal plant yielding drug. 5. Prescription of details of collection and preparation. 6. Investigation of chemical nature of the active constituents present in the drug. Official drugs = listed and described in Phar macopoeia (Legal authority for standards) *British Pharmacopoeia: B.P. *Egyptian Pharmacopoeia: E.P. *Deutsch Pharmacopoeia: D.A.B. Pharmacopoeia  A book containing directions for the identification of compound medicines, with their uses, preparation, dosages, formulas, etc. and published by the authority of a government or a medical or pharmaceutical society.  In a broader sense it is a reference work for pharmaceutical drug specifications. i. Alphabetical: Latin or English name (Mentha piperita L) (Peppermint). This arrangement is employed for dictionaries, pharmacopoeias. ii. Taxonomic: The drugs are arranged according to the plants from which they are obtained , in classes, orders, families, genera, & species. iii. Morphological : o The drugs are divided into groups such as leaves, flowers, fruits, seeds, herbs etc… These groupings have some advantages for practical study of crude drugs & identification of powdered drugs. iv. Chemical: classification according to Active constituents: drugs containing alkaloids, volatile oils, flavonoids etc... v. Pharmacological or therapeutic: This classification involves the grouping of drugs according to the pharmacological action of their most important constituents or their therapeutic use. Ex. Astringents‫ قابض لالوعيه الدمويه‬, drugs treating GIT ‫الهضمى‬ ‫للجهاز‬, cardio tonic‫للقلب‬ ‫مقوى‬ , laxative ‫ملين‬, anthelmintic‫ طارد للديدان‬, etc.... 1. The Natural or biological origin or sources. 2. Geographical sources of drugs. 3. Commercial sources of drugs. 1. Natural (biological) origin  Binomial system made by the Swedish biologist Linnaus. Genus species author name. Specific names are usually chosen to indicate: 1. Some striking characters of the plant  Atropa belladonna ( bella = beautiful, donna= lady).  Hyoscyamus muticus (muticus = short).  Barosma serratifolia ( serratifolia, margin is serrate). 2. A characteristic color  Piper nigrum (nigrum = black)  Digitalis purpurea (purpurea = purple) 3. A certain aroma  Caryophyllus aromaticus (aromatic) 4. A geographical source  Cannabis indica (indica = India) 5. A pharmaceutical activity or active constituents:  Strychnos nux vomica (vomica = vomiting).  Quillaia saponaria (saponaria = saponin).  Papaver somniferum (induce sleeping or hypnotic). 6. A special meaning:  Allium sativum (sativum = cultivated).  Atropa belladonna (Atropos = greek fate who kills, being poisonous).  Glycyrrhiza glabra (Glycyrrhiza = sweet root, glabra = smooth). 2. Geographical sources of drugs It means the habitat i.e., region in which the plant or animal yielding drugs grows.  Plants growing in their native countries were said to be  Plants, not of native origin are called exotic plants (introduced from abroad but not fully naturalized).  Plants growing in a foreign land other than their native home are called Habitat is important to give indication about soil characters, climatic conditions, altitude. e.g.,  Native to Brazil and grows at high altitude and warm moist conditions resulted in plantswith high % of A.C.  In India, soil is similar to Brazil, but not the same altitude plants with low % of A.C. Refers to its production and its channels of trade. Examples:  Alexandrian Senna (cultivated in Sudan) shipped from Alexandria.  Spanish liquorice, produced in Spain. Refers to all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. 1. Cultivation ‫زراعة‬ 2. Collection ‫حصاد‬ 3. Dr ying ‫تجفيف‬ 4. Packing ‫تغليف‬ 5. Storage ‫تخزين‬ Plants Cultivated Wild growing plants 1. Distribution of wild plants over unlimited area. 2. The difficulty in reaching these plants. 3. Ruthless collection (continuous collection) leads to great deficiency. ‫الجمع الجائر‬ 4. Collection is usually done by ignorant unskilled people. 5. Difficulty of transport. 6. Insufficiency of supply of wild plants to meet market demand. 1. Concentration of a large number of medicinal plants in a small controlled area easy to reach. 2. Raising the quality of cultivated drugs by: - improving soil conditions (using fertilizers, different methods of cultivation, control of insects, pests and fungi). - selecting good strains of seeds. 3. Regular and constant sufficient supply. 4. All the operations are carried out by well-trained workers. 5. Cultivation of drugs is accompanied by the presence of pharmaceutical firms to assure immediate use of the drug and to reduce transportation costs. 6. High purity of the finished product is assured.

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