Pharma Voice

Testing a siddha drug

Suresh Kumar S gives details of the anti-inflammatory studies of an indigenous siddha formulation.

The siddha system is one of the oldest systems of medicine in India, where yoga is coupled with clinical experience and experiments by siddhars. The siddha system is largely therapeutic in nature and has developed a rich and unique treasure of drug knowledge, in which, use of metals and minerals is very much advocated by highly developed methods of detoxification and purification, using herbal oils and calcining techniques.

There are various reports of siddha preparations containing materials of plant origin as indigenous drugs with reported effectiveness in clinical trials for anti-inflammatory activity by traditional practitioners. However, these have not been validated through pharmacological studies in a systematic manner. These preparations contain toxic metallic salts of mercury and arsenic, appropriately detoxified through various processing methods. And hence, there is an urgent need to conduct pharmacological studies and to test the acute toxicity level of the indigenous drug.

Scientific validation

The studies and analysis were conducted on living models to give a scientific proof for the activity of the siddha formulation. Studies were conducted on an indigenous siddha drug and its anti-inflammatory activity was studied systematically and found to have anti-inflammatory activity comparable to indomethacin, the standard drug. And the acute toxicity studies demonstrated non-toxic nature of the siddha formulation. Except the metallic salts, most of the ingredients of the drug is of plant origin and have medicinal properties in ethno medicine. This is an attempt for the scientific evaluation of the siddha formulations of traditional vaids. An attempt has been made to scientifically validate the medicinal effects of traditional practice and formulations through an interface of informal-formal segments by systematic studies and analysis.

The studies

The formulated tablet was ground with one percent CMC so as to make a suspension. Indomethacin, the standard drug was used as the control. Pharmacological studies were conducted on 48 albino rats of either sex weighing between 150 to 200 gram. They were housed in polypropylene cages in adequately ventilated rooms. They were given standard rat feed pellets supplied by Hindustan Lever, Mumbai and water ad libtum, throughout the course of the study.

The animals were divided into six groups of five each. The test drug was administered orally to different groups in increasing dose levels of 25, 50, 100, 200, 300 and 500 milligram per kg body weight. The animals were then observed continuously for one hour, and then frequently for 24 hours, and thereafter once daily for 14 days. During this period, the animals were observed for gross behavioural and morphological profiles.

Anti-inflammatory studies were done on a rat population of 48 albino rats of either sex ranging from 150 to 200 gram were randomly selected and fasted for 18 hours before the experiment, but they had free access to water. The animals were divided into six groups of six each and tested for Carragennan induced paw oedema. The paw thickness was taken in three planes and the average value was taken.

The drug was administered orally to six groups of six rats in doses of 150 milligram and 300 milligram per kg body weight. The control rats received five percent acacia solution in a volume of one millilitre per 100 gram body weight. One hour after the oral administration of the siddha medicine, control and the standard, 0.1 millilitre of each of one percent carrageenanin, normal saline was injected into the plantat aponeurosis of the left hind paw of the rat. Standard drug indomethacin was given at a dose of 10 milligram per kg of body weight in a volume of one millilitre per 100 gm body weight. The thickness of the paw was measured by using the vernier calipers and recorded.

The hind paw thickness of the each albino rats was again measured after three hours of the carrageen an injection. The difference in initial and final thickness of the paw indicates the increase in paw volume due to oedema. The activity of the drug was compared with that of standard indomethacin ten milligram per kg body weight.

Results

It was observed in the acute toxicity studies of the drug that there was no mortality up to a dose level of 500 milligram per kg body weight. The siddha formulation showed very significant anti-inflammatory activity comparable to indomethacin. The formulation at 150 milligram per kg showed 76 percent inhibition of edema and 300 milligram per kg showed 80.53 percent of inhibition of edema, when compared to the control.

These studies provide a basis for further detailed investigations on the therapeutic efficacy of the siddha formulation. And also, it has proved the claim of the siddha vaids for the anti-inflammatory activity of the tablet. The medicinal plants used for the preparation of this siddha formulation have been reported to have different biological effects, including hypocholestrolemic and anti-hypertensive effects. The presence of toxic metallic salts suspects the medicine for clinical use. But the scientific study on living models proved that the intercalation of mercury and arsenic with organic molecules of the plants, made the formulation more effective and non-toxic.

During the heat treatment at various stages of the preparation of the formulation, complexation with organic ligands, as is expected, makes these toxic metals non-toxic. The material properties of the formulated tablet have to be studied extensively to find the mechanism of action of these toxic metals in siddha formulations.

(The author is a Scientist and Head, Planning of Regional Research Labs, Trivandrum)