Houttuynia cordata Thunb. leaves were collected from Assam Medical College and Hospital campus, Dibrugarh in the month from April to August 2012, and plant materials were authenticated by Dr. L.R. Saikia, Reader, Department of Life Sciences, Dibrugarh University, Dibrugarh, Assam, India.

Houttuynia cordata Thunb. leaves were collected and washed thoroughly and dried at room temperature separately. The dried leaves were ground into powder. A sufficient number of powdered leaves were moistened with 95% ethyl alcohol and allowed to remain for 6 hours in a percolator. When the liquid began to drop from the percolator, the orifice was closed and the content was allowed to macerate for 24 hours. After 24 hours, it was allowed to percolate slowly at a rate not exceeding 1 ml/ min and the solution was collected in Petri dishes. Alcohol was allowed to evaporate at room temperature. When the extract got completely dried, it was scrapped out, weighed, and stored. 13

The study was carried out in healthy albino rats (6-8 months aged) of Wistar strain (Rattus norvegicus) of either sex of body weight between 150-200 g. Animals were procured from the Central Animal House (Committee for the Purpose of Control and Supervision on Experiments on Animals (CPCSEA) registration number: 634/GO/Re/S/02/CPCSEA), Assam Medical College and Hospital, Dibrugarh, Assam. They were given a standard animal diet consisting of Bengal gram, wheat, maize, and carrot in sufficient quantity, and water was given ad libitum during the entire period of the experiment. The animals were housed in standard conditions with natural light and dark cycles and adequate ventilation. The study was permitted by the Institutional Animal Ethics Committee (IAEC), Assam Medical College, Dibrugarh, Assam, with approval number IAEC/AMC/02 dated 07/08/11 and conducted in accordance with the CPCSEA guidelines.

Under all aseptic and antiseptic measures and under ether inhalation anaesthesia, blood samples were collected from the retro-orbital sinus with the help of a capillary tube. The capillary tube was inserted at the medial canthus into the retro-orbital plexus with gentle rotation so that blood flowed into it by capillary action. 14

The acute toxicity of Ethanolic Extract of leaves of Houttuynia cordata Thumb. (EELHC) was determined on female albino rats of Wistar Strain weighing 150-200g. After administration of different doses of the extract, the mortality with each dose was noted as per OECD (Organization for Economic Cooperation and Development, 2006) guidelines 425. 15

A high-fat diet, consisting of coconut oil and vanaspati ghee, in a ratio of 2:3 v/v at a dose of 10 ml/Kg body weight, was fed to the animals, orally, daily, in addition to the normal diet for a period of 8 weeks. 16, 17

A total of 20 animals of either sex weighing 150-200g were divided into four groups of five animals each and were treated as follows:

Group I (Normal Control): Received normal diet and normal saline at a dose of 10 ml/Kg/day.

Group II (Hyperlipidaemic Control): Received high-fat diet at a dose of 10 ml/Kg/day.

Group III (Hyperlipidaemic Test): Received high-fat diet at a dose of 10 ml/Kg/day and EELHC at a dose of 500 mg/Kg/day.

Group IV (Hyperlipidaemic Standard): Received high-fat diet at a dose of 10 ml/Kg/day and Simvastatin at a dose of 1.8 mg/Kg/day.

The drugs were administered once daily orally for a period of 8 weeks by intragastric feeding tube. At the end of 8 weeks, all the animals were kept fasting for 12 hours and blood samples were collected from each rat to assess the various parameters of lipid profile and antioxidant status. This fasting may hold true due to two main reasons –

Serum was separated from the blood after clotting and centrifuged for 5 minutes at 3000 rpm. The serum thus obtained was used for biochemical estimations.

The total serum cholesterol estimation was done by the method described by Allain CC et al. (1974) 20 using Qualigens-Diagnostics Cholesterol Kit manufactured by Sigma Diagnostics (India) Pvt. Ltd., Baroda.

Triglycerides were measured by enzyme colorimetric method as described by Fossati P et al. (1982) 21 using Qualigens-Diagnostics Triglyceride Reagent GPO manufactured by Sigma Diagnostics (India) Pvt. Ltd., Baroda.

HDL–Cholesterol was assayed by the method of Izzo C et al. (1981) 22 using Qualigens-Diagnostics HDL-cholesterol Kit manufactured by Sigma Diagnostics (India) Pvt. Ltd., Baroda.

LDL–Cholesterol was measured by using the formula of Friedewald WT et al. (1972).23

Figure 0

The Atherogenic Index (AI) and Percent Protection were calculated using the following formulae: ²⁴

Figure 0

Figure 0

Malondialdehyde (MDA) was measured in plasma while Catalase (CAT) and Superoxide Dismutase (SOD) were measured in the erythrocytes. MDA level was estimated by the method described by Satoh K, 25 the CAT level was estimated by the method described by Beers and Sizer 26 and the SOD level was estimated by the method described by Kakkar et al. 27

Statistical Analysis was done using the software Graph pad Prism version 5. All the values were expressed as mean ± SEM. The results were analyzed for statistical significance by using one-way ANOVA, followed by Dunnett’s test. P values that were < 0.05 were considered significant.

There was no mortality recorded for the extracts of the leaves of Houttuynia cordata Thunb. among the rats up to the maximum dose of 2000 mg/Kg when administered orally. Hence, the LD50 can be said to be above 2000mg/kg.

At the end of the experiment, the hyperlipidaemic control group showed a significant (p<0.05) elevation of total cholesterol, triglycerides, and LDL cholesterol together with a significant (p<0.05) decrease in HDL Cholesterol when compared with the normal control group. Results are presented in Table 1.

In the hyperlipidaemic test group as well as in the hyperlipidaemic standard group there was a significant (p<0.05) reduction in total cholesterol, triglycerides, and LDL Cholesterol. HDL cholesterol was also increased significantly (p<0.05) in both groups.

This indicates that EELHC is effective in reducing total cholesterol, triglycerides, and LDL cholesterol and increasing HDL cholesterol. The results are presented in Table 1.

At the end of the experiment, there was a significant increase (p<0.05) in the serum MDA level and a significant decrease (p<0.05) in blood CAT and SOD levels in the hyperlipidaemic control group when compared to the normal control group.

There was a significant (p<0.05) decrease in serum MDA levels in the hyperlipidaemic test group and Hyperlipidaemic standard group when compared to the hyperlipidaemic control group. Blood CAT and SOD levels were increased significantly in the hyperlipidaemic test group and hyperlipidaemic standard group when compared to the hyperlipidaemic control group. This indicates that EELHC decreases lipid peroxidation and increases the antioxidant enzymes in the blood. The results are presented in Table 2.