Importance of Snehapan and Swedan : A review article

Shodhan chikitsa is done for elimination of excess as well as vitiated doshas. For this chikitsa oleation therapy is used as Purvakarma. Snehapan which is taken in small dose along with diet is said to be brimhan Snehapan. It gives strength to the body & can be continued for many days. Regularly we are using this type of Snehapan with diets by ways of milk, ghee, oil etc. After Snehapan , whatever sneha is digested by Jatharagni, that sneha along with ahararasa will be carried out by Saman vayu upto the liver, where panchamahabhutagni will act on it. So the toxins present in the cells i.e. in intracellular fluid should come into the koshtha means ECF and then from ECF to circulation. From circulation to GIT and from GIT , these vitiated doshas are to be eliminated either by Vaman or Virechan karma. Although it is proved that Shodhanchikitsa eliminates toxins from the body, but which toxins are elevated within blood from purvakarma


Introduction:
Snehapan is administered to have effect of snigdhata (unctuousness), mriduta (softness), dravata (liquidity) & picchhilata (sliminess) in the body. So it has very essential and specific role as a method of purvakarma. Shodhan chikitsa is done for elimination of excess as well as vitiated doshas. For this chikitsa oleation therapy is used as Purvakarma. Oleation therapy includes external Oleation therapy (snehan) and internal Oleation therapy ( snehapan). For external snehan therapy there are many procedures. Internal snehan is carried out by three ways, Brimhan, Shaman & Shodhan Snehapan. Brimhan Snehapan -Snehapan which is taken in small dose along with diet is said to be brimhan Snehapan. It

Material & Method:
Classical references were taken from Brihatrayees mainly along with other Samhitas. To search Physiological concept of snehapan, reference books of modern physiology were referred. Evidence based resources such as: journals, books &databased information from various search engines were referred for updated information. Apart from indexed journals, peer reviewed and non-indexed journals were also reviewed from Ayurved and Modern science.

Observation
After Snehapan , whatever sneha is digested by Jatharagni, that sneha along with ahararasa will be carried out by Saman vayu up to the liver, where panchamahabhutagni will act on it. According to modern science this consumption of sneha comes under the group of fats. In GIT the fats are digested to form monoglycerides and free fatty acids, both these are the digestive end products of fats. Fats are insoluble in water and for their absorption bile salts are required. Fats first get dissolved in bile micelles. Because of these bile micelles dimensions ( 3 to 6 nanometer in diameter) and exteriorly highly charged, these micelles are soluble in chyme.
In this form, the monoglycerides and free fatty acids, are carried to surfaces of microvilli of the intestinal cells brush border and then penetrate into microvilli, where both diffuse immediately out of micelles and into interior of epithelial cells. The lipids are soluble in epithelial cell membrane. This releases bile micelles again to absorb more monoglycerides and free fatty acids 3 . After entering epithelial cells some fatty acids are absorbed directly into portal blood and some are converted into triglycerides by combining with glycerol. The triglycerides are passed to lacteals and then enter the lymphatic and reach the systemic circulation via thoracic duct 4 .

Discussion
We are using Snehapan as purvakarma in selected persons for elimination of toxins or vitiated doshas from shakha to koshtha. Shakha means cells and koshtha means spaces exterior to cells means extracellular as well as interstitial spaces. So the toxins present in the cells i.e. in intracellular fluid should come into the koshtha means ECF and then from ECF to circulation. From circulation to GIT and from GIT , these vitiated doshas are to be eliminated either by Vaman or Virechan karma. For internal oleation we are using plane cow ghee or medicated cow ghee. After digestion this will absorbed in the form of monoglycerides and free fatty acids. The structure of cell membrane is a bilipid layer. So fatty acids as well as lipid soluble substances like Oxygen , nitrogen, Carbon dioxide , alcohol can easily enter into the cells. Mostly toxins are fats soluble. During Snehapan sometimes symptom of diptagni is been observed 5 . This is because, of feed forward mechanism , the body remain prepared to digest food at that time. In his condition one feels the symptom of increased hunger 5 .
After consuming more Sneha, the absorbed excess fatty acids get stored within the adipose tissue. So we observe the symptom of Gatrasnigdhata 5 . The concentration of free fatty acids in the plasma under resting conditions is about 15 mg/dl which is total only 0.45 gm of fatty acid in entire circulatory system. The turnover rate of free fatty acid is extremely rapid. Half the plasma fatty acid is replaced by new fatty acid every 2 or 3 minutes. The fatty acids stored in adipose tissue are not same as that of today after one week 7 . This continuous transmission of fatty acids help to keep eliminated doshas into circulation.
Conditions that increase rate of utilization of fats for cellular energy also increases free fatty acid concentration in the blood (5 to 8 times) by increasing hydrolysis of triglycerides in to fatty acids and glycerol. During the complete snehapan the person is advised not to take diet unless it is needed. In normal condition, only 3 molecules of fatty acids combine with one molecule of albumin for its transport but, this ratio would increased up to 30 :1 in extreme need of fatty acid transport. During the process of digestion and absorption about 1500 ml chyme normally passes through ileo cecal valve in to large intestine each day. Most of water and electrolytes are absorbed within proximal intestine and about 100 ml fluid is excreted through feces. In large intestine, only water and electrolytes are absorbed. When the intake of sneha is more than required then it does not digest and moves in large intestine where these lipid molecules not get absorbed. So this sneha act as lubricant for intestinal wall which is then comes out into feces. This is samyak Snigdh Lakshan where snehapan should be stopped 8 . The duration of Snehapan differs from person to person. It depends on the type of Koshtha. So Snehapan is stopped only after the samyak snigdha lakshan is been observed. After samyak Snehapan there is the effect of picchilata (sliminess) within the body.So elimainated dosh can not stick anywhere.
During the process of Swedan, the skin temperature rises. The change in environmental temperature (in Swedan peti) or local simulation by nadi sweda, the body temperature rises, which stimulate the anterior hypothalamic pre-optic center for temperature regulation. Body always tries to maintain its core temperature. So to reduce body temperature, vasodilatation of skin blood vessel occurs by inhibiting the sympathetic center in posterior hypothalamus. This increases the rate of blood flow into skin more up to 30% of total cardiac output and fully vasodilatation takes place. This increases the rate of heat transfer to the skin 9 . Another change occurs is sweating and simultaneous inhibition of the mechanism that increases heat which results in shivering and chemical thermo genesis. The rise in temperature is basically the kinetic energy of molecular motion. The molecules of skin which are continuously undergoing vibratory motion give rise to continuous transmission of heat between environment and body by radiation, conduction and convection phenomenon 9 .

Conclusion
Before doing this Shodhankarma, external oleation (Snehan) and Swedan must be performed continuously at least for three days. This continuous stimulus to skin with Snehan and Swedan procedures eliminates doshas in circulation i.e. in koshthmarga only. When the person undergoes the process of either Vaman or Virechan, eliminated doshas come into GIT by the process of osmosis, from where these toxins or vitiated doshas are eliminated. Although it is proved that Shodhanchikitsa eliminates toxins from the body, but which toxins are elevated within blood from purvakarma to pradhan shodhanchikitsa and up to what level they get eliminated after shodhanchikitsa that analytical study is required to carry out.