Chapter 0 INTRODUCTION (NEW).pdf

Phytotherapy and Aromatherapy Lecture I INTRODUCTION  Before synthetic drugs, What humans used for treatment of diseases in previous centuries? Tr a d i t i o n a l m e d i c i n e Herbal medicine Yo g a...

Phytotherapy and Aromatherapy Lecture I INTRODUCTION  Before synthetic drugs, What humans used for treatment of diseases in previous centuries? Tr a d i t i o n a l m e d i c i n e Herbal medicine Yo g a Acupuncture Meditation & Cupping therapy Hypnosis Massage  Tr a d i t i o n a l m e d i c i n e has a very long history: it is the sum of the practices based on the theories, beliefs and experiences of different cultures and times, used in the maintenance of health, as like in the prevention, diagnosis, improvement and treatment of illnesses. Herbal medicine is the use of medicinal plants for prevention and treatment of diseases: it ranges from traditional and popular medicines of every country to the use of standardized and titrated herbal extracts. Chemical medicine is now the standard. Traditional Medicine is now called “Complementary and Alternative Medicine” “CAM” Contributions of herbal medicine in modern medicine  As reported by studies, 490 out of 1010 drugs in the market registered in 25 years from 1981 to 2006 were natural products or semisynthetic from natural products or natural product mimics. Many conventional drugs originate from plant sources, one century ago; most of the few effective drugs were plant-based. Willow bark: Aspirin Digitalis: Digoxin Cinchona bark: Opium poppy: Quinine Morphine  The development of drugs from plants continues, as drug companies screen herbs for pharmacological activities in large-scale. Some relevant examples are - Khellin, from Ammi visnaga - Papaverine from Papaver somniferum which formed the basis for verapamil used in the treatment of hypertension - Atropine from Atropa belladonna - The antihypertensive agent, reserpine, isolated from Rauwolfia serpentine - The nasal decongestant drug, ephedrine, from Ephedra sinica  How far Herbs saved and treated populations throughout history? Is it true that Herbs used only for minor disorders? Like common cold, muscle pain, cough …etc. Can Herbs help in severe diseases, complicated disorders, fatal pandemics? Herbs and fatal pandemics  Can herbs control pandemics? Can the herbs we use everyday in our food control a contagious fatal pandemic? How was this pandemic defeated? Malaria pandemic In eighteenth century, cinchona bark was discovered was fatal and by chance as a good treatment for malaria fever. aggressive, It killed Since then, it was the only treatment for malaria for over 200 million lives 3 consecutive centuries. from ancient history It saved millions & millions of lives without even till now knowing the active constituent in it. Until 1820, when the active constituent “quinine” was first isolated from Cinchona bark & has been identified as the main anti-malarial active constituent. From this date till now, quinine is produced by the pharmaceutical companies as anti-malarial tablet all over the world.  After that, exactly in the last century, the world faced another fatal strain of malaria that is resistant to quinine, How the world faced this pandemic?  Nobel prize in Medicine in 2015 The prize was awarded for the scientist “TU Youyou” who was the first female Chinese scientist to win this prize. She was searching for The Nobel Prize website new treatment for the “In the 1970s, after studies of traditional new malaria strain. herbal medicines, Tu Youyou focused on She discovered a potent sweet wormwood and managed to extract anti-malarial active a substance, artemisinin, which inhibits constituent in this plant & the malaria parasite. called it “Artemisinin”, Drugs based on artemisinin have led to which is still produced as the survival and improved health of an anti-malarial tablet all millions of people.” over the world till now.  Herbs and severe diseases (Cancer) plants have played an important role as a source of effective anti cancer agents, and it is significant that over 60% of currently used anti- cancer agents are derived in one way or another from natural sources, including plants, marine organisms and micro-organisms. The search for anti-cancer agents from plant sources started early in the 1950s with the discovery and development of the vinca alkaloids, vinblastine and vincristine, and the isolation of the cytotoxic podophyllotoxins. As a result, the United States National Cancer Institute (NCI) initiated an extensive plant collection program in 1960, focused mainly in temperate regions. This led to the discovery of many novel cytotoxic compounds including the taxanes and camptothecins, but their development into clinically active agents spanned a period of some 30 years, from the early 1960s to the 1990s. Nowadays, herbal medicine is available in the global market under the name of “Dietary supplements”. They are used to treat diseases or to maintain health and are called herbal products, botanical products, or phytomedicines. Dietary supplements Ta b l e t s Capsules Powders Te a s Creams Gels Lotions Fresh & dried plants  How big the market of Dietary supplements globally? Consumers spending on herbal products in the United States, mainly from self-prescription of over-the-counter products. This type of herbal drug use is typically based on a simple matching of a particular herb to diseases or symptoms, such as valerian (Valeriana officinalis) for sleep disturbance.  WHOLE HERBS VS ISOLATED ACTIVE CONSTITUENTS  Herbal medicine generally use unpurified plant extracts containing several different constituents Typically, It is proved that these can work together synergistically so that the effect of the whole herb is greater than the sum total of the effects of its components. (Synergistic effects) (E.g.: total ginger extract more effective than isolated 6-gingerol) It is also proved that toxicity is reduced when whole herbs are used instead of isolated active ingredients. (Buffering effect) (E.g.: total cinnamon extract more safe than isolated cinnamaldehyde) Although 2 samples of a particular herbal drug (E.g.: ginger from Egypt and India) may contain constituent compounds in different proportions, this does not generally cause clinical problems. Some experiments have yielded evidence of synergy and buffering in certain whole plant preparations.  Experiments showed that whole food sometimes is more effective than isolated constituents: Apples; 100g of apple contains only 5.7g of vitamin C, but it gives the same antioxidant value of 1500g of isolated vitamin C. (Other compounds synergize vitamin C in apple) This means that Vitamin C is not the only contributes for less than 0.4% of the antioxidant value of apples. This confirms that whole apple extract is much more antioxidant than isolated vitamin C. In vitro, apples with peel inhibited colon cancer by 43%. While after removing the peel, inhibition reduced to 29%. HERB COMBINING  Several different herbs often are used together. It is supposed that the principles of synergy and buffering apply to combinations of plants and that combining herbs improves efficacy and reduces adverse effects. E.g.: Orange, apple, grapes, and blueberry; this combination of 4 fruits from different classes showed synergistic antioxidant activity. The median effective dose (EC50) of each fruit after combination was 5 times lower than the (EC50) of each fruit alone. This proves that consuming small amounts of wide variety of fruits, vegetables and grains is much more beneficial than consuming high amounts of only one. (important for Therapeutic nutrition) CLINICAL EVIDENCE “Researches are evidences, and not all evidence is the same” Scientists start with laboratory studies 1 “In-vitro” studies If succeeded, they turn to animal studies 2 “In-vivo” studies If succeeded, they turn to human studies 3 “Clinical” studies. RESEARCH EVIDENCE PYRAMID  Many meta-analysis and systematic reviews, the top of research evidence pyramid, proved the efficiency of herbal products in prevention and treatment of many diseases, on healthy individuals and patients. Meta-analysis and systematic reviews of clinical studies proved that: 1- Ginger & turmeric are effective for weight loss & treatment of obesity 2- St John's wort (Hypericum perforatum) for treating mild-to-moderate depression. 3- Fenugreek for glycemic control in diabetic patients. 4- Nigella sativa helps in treatment of Asthma. 5- Ginkgo (Ginkgo biloba) for Cognitive Impairment and Dementia. 6- Feverfew (Chrysanthemum parthenium) for migraine prophylaxis. SAFETY  Many people believe that products labeled "natural" are always safe and good for them. This is not necessarily true. Herbal medicines may cause problems as they don’t have to go through the testing that chemical drugs do. Some herbs even if standardized in tablets, such as Digoxin and ephedra, can cause serious harm. Some Herbs in powdered form may be contaminated, adulterated, or misidentified. Some herbs can interact with prescription or over-the-counter medicines. In general, patients taking herbal preparations regularly should receive careful follow-up. HERB-DRUG INTERACTION  Drug absorption Pharmacokinetic Drug distribution interaction Drug metabolism & bioavailability (Quantitative alteration) Drug elimination including renal & hepatic clearance. Herb-Drug Interaction Pharmacodynamic Antagonistic effect interaction Additive effect (Qualitative alteration) Agonistic effect  If patients are taking conventional drugs, herbal preparations should be used with extreme caution and only on the advice of an herbalist familiar with the relevant conventional pharmacology. Some examples of herb-drug interactions: 1- Echinacea used longer than 8 weeks with Anabolic steroids, methotrexate, amiodarone, ketoconazole causes Hepatotoxicity. 2- Feverfew, garlic, ginseng, ginkgo, and ginger with warfarin cause Altered bleeding time. 3- Licorice with Spironolactone causes Antagonism of diuretic effect. 4- Valerian with Barbiturates causes Additive effects, excessive sedation. 5- Chili pepper (Capsicum) with ACE inhibitor cause Cough. 6- Yohimbine (Pausinystalia yohimbe) with Tricyclic antidepressants causes hypertension. STANDARDIZATION AND REPRODUCIBILITY The multi‐ingredient character of herbal medicines makes efficacy testing more complex than with synthetic drugs. (synthetic drugs contains one active One active constituent: ingredient, while herbal drug contain tens of Paracetamol ingredients) (Paracetamol & ginger extract) The entire herbal extract is the active principle. It is often standardized through quantification of the key constituent of the extract e.g.: Gingerol in ginger, curcumin in turmeric, piperine in pepper, glycyrrhizin in licorice and cinnamaldehyde in cinnamon. Standardization can, however, only cover one or two More than 50 active ingredients; thus, variation of other ingredients may constituent remain, and it is possible that this could influence both efficacy and safety of the product. As a summary, Differences of herbal medicines from well-defined synthetic drugs are: - The active principles are frequently unknown. - Standardization, stability and quality control are feasible but not easy. - Availability & quality of raw materials are frequently problematic all the year. - Double-blind clinical and toxicological studies to prove their efficacy and safety are few. (but their experimental use in folk medicine is a very important characteristic.) - They have a wider range of therapeutic use than synthetic drugs due to presence of many compounds. (synergistic effect) - Have fewer side effects than synthetic drugs, (Buffering effect), So, more suitable for chronic diseases. - They usually cost less than synthetic drugs. Full product characterization and quality control are therefore essential for the reproducibility of scientific tests of herbal remedies.  Examples of MARKETED HERBAL DRUGS IN EGYPTIAN MARKET Herbal drugs for kidney Herbal drugs for Prostate & liver Herbal drugs for weak veins Herbal analgesic drugs (general & dental) Herbal Psychic drugs  Herbal drugs for gastroentistinal Herbal respiratory drugs Herbal drugs for general discorders Herbal drugs for muscles T H A N K YO U