INTRODUCTION:

Numbers of deaths in industrial world are increasing due to cardiac diseases are emerging as a single largest contributors for morbidity in India¹. The cardiovascular system includes spleen, lymphatic tissues and vessels the main function of this system is to maintain homeostasis by acting as transportation system that carries needed materials to cells and removes waste materials from cells. The conduction system functions by initiating the heart beat, conducting message around the heart, coordinating beats between the atria and ventricles². Various diseases related to cardiovascular system are aneurysm, atherosclerosis, cardiac arrhythmia, congestive heart failure, hypertension, myocardial infarction, phlebitis and angina pectoris etc^3-6.

Sida cordifolia Linn (Family: Malvaceae) is a shrubby, branched and common throughout the tropical and subtropical plains all over India and Ceylon growing wild along roadside. It is used in the folk medicine for several purposes: Root infusion is used as cardiotonic, nervous diseases, asthma, piles, and urinary diseases^{7, 8}. It has reported to posses’ antioxidant⁹, antistress¹⁰, adaptogenic¹⁰, antiinflammatory^11,12,13, analgesic^11,12,13, hypoglycaemic¹³, liver regeneration¹⁴.

The whole plant contains alkaloids, fatty oil, phytosterol, mucin, potassium nitrate and the alkaloid was identified is ephedrine^{7, 8, 15}. The cardiovascular effect of Sida cordifolia Linn leaves by using mammalian heart model was reported¹⁶, but there was no scientific data available regarding cardiotonic activity of Sida cordifolia Linn roots.

Material and method^{1, 2, 17, 18}

Drug: Root infusion of Sida cordifolia Linn

Chemical: Digoxin, Ringer solution

Animal: Frog

Instrument: Sherington rotating drum

Plant collection and preparation of infusion:

Plant was collected from western ghat and identified in Pharmacognosy department, Shardchandra Pawar College of Pharmacy, Otur, Pune. The root was washed, dried and powdered. The infusion was prepared by putting 1gm of powdered drug in 100ml warm water. The material was filtered through whatman filter paper no. 40 and filtrate was collected. The filtrate was diluted with the help of distilled water in varying proportion and labelled as follows,

A1- undiluted

A2- 1:1 Filtrate: distilled water

A3- 1:2 Filtrate: distilled water

A4- 1:4 Filtrate: distilled water

All the preparations were evaluated for their cardiotonic activity by using perfused frog heart assembly. The rate and force of contraction was determined.

Preparation of Digoxin:

The marketed digoxin (Sunpharma Ltd.) ampoules were obtained from local market. Various different dilutions were made with distilled water and labelled as follows B1- 25µg/ml, B2- 50µg/ml. The above prepared samples were evaluated for their cardiotonic activity and treated as standard.

Preparation of hypodynamic ringer solution:

Hypodynamic ringer solution was prepared by using standard method.

Evaluation of cardiotonic activity:

1. The frog of species Rana tigrina was pithed and pinned it to the frog board.

2. A midline incision was given on the abdomen, the pectoral girdle was removed and the heart was exposed.

3. The pericardium was carefully removed and put a few drops of hypodynamic frog ringer over the heart.

4. The inferior venacava was traced, put a thread around it and given a small cut in order to insert the venous cannula which is in turn connected to a perfusion bottle containing hypodynamic frog ringer solution. The cannula was inserted in the vein and the thread to assure the cannula in place.

5. A small cut in one of the aorta was given for the perfusate to come out.

6. A proper venous pressure of 2-4cm was given by altering the height of perfusion bottle. The effective venous pressure is the height in cms from level of the venous cannula and the ringer level in the perfusion bottle.

7. A thin pin hook was passed through the tip of the ventricle and with the help of a fine thread attached to the hook; it was tied to the free limb of the universal lever which is fixed to a stand. A proper tension and magnification was adjusted by altering the height of the lever. The normal heart rate was noted. All test samples that is A1, A2, A3, A4, B1 and B2 were administered in different doses viz. 0.1ml, 0.2ml, 0.3ml respectively. The rate and force of heart contraction were noted. (Table 1-6, Figure 1-6).

Observations:-

Table 1: Hypodynamic Heart

Sr. No.	Drug	Dose(in ml)	Beats/min.	Change in Force
1	.....	Normal	25	Normal
2	A1	0.1	24	Increase
3	A1	0.2	24	Slight increase
4	A1	0.3	22	No change

Table 2: Hypodynamic Heart

Sr. No.	Drug	Dose(in ml)	Beats/min.	Change in Force
1	.....	Normal	30	Normal
2	A2	0.1	25	Increase
3	A2	0.2	27	Slight increase
4	A2	0.3	24	Rapid Increase

Table 3: Hypodynamic Heart

Sr. No.	Drug	Dose(in ml)	Beats/min.	Change in Force
1	.....	Normal	34	Normal
2	A3	0.1	30	Increase
3	A3	0.2	28	Increase
4	A3	0.3	26	Slight decrease

Table 4: Hypodynamic Heart

Sr. No.	Drug	Dose(in ml)	Beats/min.	Change in Force
1	.....	Normal	31	Normal
2	A4	0.1	27	Increase
3	A4	0.2	28	No change
4	A4	0.3	23	Slight decrease

Table 5: Hypodynamic Heart

Sr. No.	Drug	Dose(in ml)	Beats/min.	Change in Force
1	.....	Normal	35	Normal
2	B1	0.1	31	Increase
3	B1	0.2	29	Decrease
4	B1	0.3	30	Increase

Table 6: Hypodynamic Heart

Sr. No.	Drug	Dose(in ml)	Beats/min.	Change in Force
1	.....	Normal	32	Normal
2	B2	0.1	28	Increase
3	B2	0.2	35	Slight decrease
4	B2	0.3	25	Sudden cardiac block

RESULTS AND DISCUSSION:

From the above observations, the infusion of Sida cordifolia Linn was found to restore cardiac activity of the hypodynamic frog heart, which means it increases the rapidity and force of contraction of the myocardial muscles of the perfused frog heart. The sample A1 i.e. the undiluted filtrate has shown the results with rapid increase in force of contraction at 0.1 and 0.2 and the maximum heartbeats/ min were found to be 24 beats / min at dose of 0.1 and 0.2ml the force of contraction was also increased at this dose. Another sample A2 i.e. the filtrate diluted with distilled water in the ratio 1:1 shown significant activity. It also restored the cardiac potentials in the dose dependent manner, the maximum heartbeats/min was found at the dose of 0.2ml. The sample A3 i.e. the filtrate diluted with distilled water in the ratio 1:2 has given satisfactory results with rapid increase in force of contraction at 0.1ml and 0.2ml of dose respectively. The sample A4 i.e. the filtrate diluted with distilled water in the ratio 1:4 has given significant results with increase in force of contraction at 0.1ml. As the digoxin was used as standard drug, the sample B1 i.e. 0.25 µg/ml solution of digoxin shown effective results but the sample B2 i.e. 50 µg/ml solution shown significant activity.

Thus, regarding the results obtained we can say that, all the dilutions of Sida cordifolia Linn restore cardiac activity of hypodynamic frog heart i.e. it increases rapidity and force of contraction. It was found that sample A2- 1:1 Filtrate: distilled water showed better response as compared to other samples. It is interesting to know that Sida cordifolia Linn has rapid onset of action compared to digoxin.

CONCLUSION:

These preliminary studies confirm the better cardiotonic activity of Sida cordifolia Linn and thus we can conclude that roots of Sida cordifolia Linn are having cardiotonic activity somewhat similar to that of digoxin a well known life saving cardiotonic drug.

REFERENCES: -

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Received on 22.12.2010 Modified on 20.01.2011

Research J. Pharm. and Tech. 4(6): June 2011; Page 913-916