9,091
edits
Changes
Atreyabhadrakapyiya Adhyaya (view source)
Revision as of 10:32, 10 November 2017
, 10:32, 10 November 2017→Vidhi Vimarsha
=== ''Vidhi Vimarsha'' ===
=== ''Vidhi Vimarsha'' ===
#Assessment of ''panchamahabhuta'' in a substance can be carried out by taking into consideration, the most conspicuous characteristic of each ''mahabhuta''. For example, ''gandha guna, rasa guna, rupaguna, sparsh guna'' and ''shabd guna'' are chief characteristics of ''prithvi, jala, agni, vayu'' and ''akasha mahabhutas'' respectively. By these organ-specific methods, it becomes easy to assess the ''panchbhutika'' constitution of the substance. Rest of the gunas given for each mahabhuta should be clinically evaluated.
#Assessment of ''panchamahabhuta'' in a substance can be carried out by taking into consideration, the most conspicuous characteristic of each ''mahabhuta''. For example, ''gandha guna, rasa guna, rupaguna, sparsh guna'' and ''shabd guna'' are chief characteristics of ''prithvi, jala, agni, vayu'' and ''akasha mahabhutas'' respectively. By these organ-specific methods, it becomes easy to assess the ''panchbhutika'' constitution of the substance. Rest of the ''gunas'' given for each ''mahabhuta'' should be clinically evaluated.
#The gustatory effect of the initial, as well as final contact of the drug either in the dry or wet state with the tongue, is known as ''rasa'' or taste. ''Rasa'' is the only principle of drug action which can be directly perceived (''pratyaksha gamya''). This is to be assessed in human volunteers by a single blind method with a performa consisting of chief characteristics of each ''rasa''. As mentioned in [[Charaka Samhita]] (su. 26/73-79) sugarcane, milk, and sugar candy are all said to be sweet, but there is an obvious difference in the taste of these substances. So, the intensity of each ''rasa'' can be assessed by taste threshold method. Electronic tongue if developed may help to validate the information about the intensity of ''rasa''.
#The gustatory effect of the initial, as well as final contact of the drug either in the dry or wet state with the tongue, is known as ''rasa'' or taste. ''Rasa'' is the only principle of drug action which can be directly perceived (''pratyaksha gamya''). This is to be assessed in human volunteers by a single blind method with a performa consisting of chief characteristics of each ''rasa''. As mentioned in [[Charaka Samhita]] (su. 26/73-79) sugarcane, milk, and sugar candy are all said to be sweet, but there is an obvious difference in the taste of these substances. So, the intensity of each ''rasa'' can be assessed by taste threshold method. Electronic tongue if developed may help to validate the information about the intensity of ''rasa''.
#''Veerya'' and ''vipaka'' are inferred through the activities or final effects (''karma'') produced by intake of drug/diet.
#''Veerya'' and ''vipaka'' are inferred through the activities or final effects (''karma'') produced by intake of drug/diet.
#''Vipaka'' is a pharmacokinetic principle, and its activities are referred at the level of ''koshtha'' (''mutra'' and ''purisha''), ''dhatu'' (''shukra'') and ''doshas''. ''Rasa'' and ''veerya'' are pharmacodynamic principles. Assessment of ''veerya'' and ''vipaka'' are to be evaluated clinically.
#''Vipaka'' is a pharmacokinetic principle, and its activities are referred at the level of ''koshtha'' (''mutra'' and ''purisha''), ''dhatu'' (''shukra'') and ''doshas''. ''Rasa'' and ''veerya'' are pharmacodynamic principles. Assessment of ''veerya'' and ''vipaka'' are to be evaluated clinically.
#The concept of virudhaahara indicates the concepts of incompatibility and allergic reactions. For example, neither honey nor ghee is toxic to the body but if they both taken in equal quantity becomes unwholesome. A combination of it must be subjected to chemical analysis and pharmacological evaluation to assess the adverse effects.
#The concept of ''viruddhaahara'' indicates the concepts of incompatibility and allergic reactions. For example, neither honey nor ghee is toxic to the body but if they both taken in equal quantity becomes unwholesome. A combination of it must be subjected to chemical analysis and pharmacological evaluation to assess the adverse effects.
#Treatment of disease induced by ''viruddhaahara'' includes ''vamana, virechana,'' administration of antagonistic drugs and adaptation of prophylactic measures.
#The concept of ''prabhava'' clearly indicates the principle which contributes to the specific activity of the drug and is inexplicable in nature. ''Danti'' root which acts as a purgative loses its effectiveness when soaked in water and administered. Observations indicate that ''danti'' has water soluble qualities that contribute to its ability to work as a purgative ref. Once the causative principle is identified, the activity of ''danti'' can be explained in a rational way, and it cannot be quoted as an example of ''prabhava''. In the light of photochemical research, the explanation of drug action becomes rational and the ''prabhava'', a specific principle can be deleted from the list of principles of drug action.
Practical application of rasa, virya, vipaka and prabhava:
===== Practical application of ''rasa, virya, vipaka'' and ''prabhava'' =====
Let us examine the principles of Ayurvedic pharmacology in the light of modern science:
Let us examine the principles of Ayurvedic pharmacology in the light of modern science:
====== ''Rasa'' ======
Acharya Priya Vrat Sharma has discussed concept of ''rasa'' based on the physicochemical constitution of ''dravyas'' as follows: ''madhura'' (sugar, fat, and amino acids), ''amla'' (acids), ''lavana'' (salts), ''katu'' (essential oils, phenols), ''tikta'' (certain alkaloids and glycosides), and ''kashaya'' (tannins). According to his hypothesis, carbohydrates and proteins are present in ''madhura rasa dravyas''; all the ''amla rasa dravyas'' show acidic properties and all the drugs in ''lavana varga'' contain sodium chloride (NaCl). All the ''dravyas'' of ''katu varga'' contain essential oils while half of all ''katu dravyas'' contain alkaloids or glycosides or phenols. All the ''tikta dravyas'' contain alkaloids, and only 10% of ''dravyas'' contain glycosides. Many of the ''kashaya'' ''rasas'' contain tannin1.
Prabhava:
====== Guna ======
In recent years, some effort has been made to refine the objective parameters used for assessing ''snigdha-ruksha'' and ''sheeta-ushna gunas'' by employing animal experimentation. Absolute evaluation of one ''guna'' is not possible in a living body since there are infinite factors related to each and every biological event. Metabolic study (''dipana pachana'' experiment), intestinal secretion and motility test, and swimming stress test (swimming induced hypothermia) have been employed to assess the effects of various drugs having ''snigdha-ruksha'' and ''sheeta- ushna gunas''. ''Sheeta'' and ''snigdha guna'' drugs have shown an increase in body weight in metabolic experiments compared to ''ushna'' and ''ruksha guna'' drugs. ''Snigdha guna'' drugs alleviated stress-induced hypothermia whereas ''ruksha guna'' drugs aggravated it 2,3.
====== ''Veerya'' ======
An attempt has been made to assess the effects of sheeta and ushna virya drugs (samana pratyayarabdha dravyas) on basal metabolic rate (BMR). Two sheeta virya drugs, namely, yashtimadhu (Glycyrrhiza glabra) and Shatavari (Asparagus racemosus) and two ushna virya drugs, namely, chitraka (Plumbago zeylanica) and jatiphala (Myristica fragrans) were considered for this study. In healthy volunteers, initial BMR was recorded with Mc Kesson metabolizer. Then the drug was administered three times a day (chitraka and jatiphala 2gm each and yashtimadhu and Shatavari 5gm each). A significant increase (p<0.05) was observed with yashti, while the increase in BMR with Shatavari was not very significant. Chitraka and jatiphala brought about a significant decrease in BMR(p<0.05). Therefore, sheetavirya and ushnavirya drugs which represent the saumyatva and agneyatva of a drug or food may be responsible for synthesizing or metabolizing the dhatus due to their santarpaka or apatarpaka actions4.
====== ''Vipaka'' ======
An attempt has been made to assess vipaka of certain drugs by their effect on malas (feces and urine) and doshas (vata, pitta, and kapha). Drugs, namely bala and shatavari (madhura vipaka), vrikshamla and amalaki (Amla vipaka and madhura vipaka), maricha and pippali (katu vipaka and madhura vipaka), kushtha and nimba (katu vipaka), and lodhra and Ashoka (katu vipaka) were taken up for the study. The study was done for six days. For the first two days, kapardika bhasma (250 mg., thrice a day) as placebo was administered and from the third day onwards the trial drug, in decoction form, (96 ml, twice a day) was given to healthy volunteers for two days. The remaining two days were used for following up. The influence of these drugs on doshas and malas were assessed using a structured proforma. Madhura and Amla vipaka drugs increased the quantity of urine and stool. Madhura vipaka drugs increased kapha dosha while Amla vipaka drugs increased pitta dosha. Katu vipaka drugs decreased the urine and stool output and increased vata dosha5.
====== ''Prabhava'' ======
It is quite apparent that the acharyas formulated the hypothesis that explained the workings of drugs after observing various activities. In the context of the failure of the hypothetical principles to explain the drug action in a rational way, the concept of prabhava was formulated which may be interpreted as an empirical principle. Drugs with similar chemical structure should have similar actions. But it is not possible to predict the activity of a drug entirely by its chemical structure. Drugs with similar structures but having entirely different effects are known as isomers, for example, Antazoline & Tolazoline appear chemically similar but former is an antihistamine and the latter is an adrenergic blocking agent. Conversely, many dissimilar chemical agents have similar action, for example, phenobarbitone, chloralhydrate, and paraldehyde are all depressants of the central nervous system. The concept of prabhava may be interpreted using the concept of isomerism6.
=== References ===
=== References ===