The frontal leaves of Tectona grandis were collected from the rural areas of Bangalore in the month of October 2006. The plant was identified and authenticated by the Regional Research Institute, Bangalore where the specimen voucher (RRCBI Acc no 12474) has been deposited for future reference. The material was shade dried, pulverized and preserved in air tight containers until further use.

The methanolic extract of dried powder (1 kg) of the leaves was prepared by using Soxhlet apparatus. The extract was then concentrated and dried to give dark brown mass. This extract was used for further investigation.

The extract was then subjected to preliminary phytochemical analysis using standard procedures and majority of the constituents were found to be polar in nature. The phytochemical screening was carried out using reagents like Mg and HCl for Flavonoids, ferric chloride for tannins ,Liberman’-Buchard’s for steroids, Molish’s and Benedict’s for carbohydrates and the ability to foam for saponins⁷.

The Institutional Animal Ethical Committee (No Krp/IAEC-27/2006) approved the experimental protocol and the guidelines for the animal care were strictly adhered to during the experimentation as recommended by committee for the purpose of control and supervision of experiments on animals (CPCSEA), Govt of India.Sprague-Dawley (SD) rats of either sex weighing 250-275 gm were used. The animals were maintained under standard conditions and were fed with commercial diet and water ad libitum during the experiment.

The acute oral toxicity study was performed according to OPPTS (office of the prevention, pesticides and toxic substance) guidelines.

Colony bred male rats of Wister strain (200-250g) were maintained under standard conditions. The rats were acclimatized for 5 days and fasted over night.

Analgesic activity of the frontal leaves was evaluated using the Eddy’s hot plate method.

Rats of either sex weighing 250-275 gm were used. The animals were maintained under standard conditions and were fed with commercial diet and water ad libitum during the experiment. The animals were divided into 4 groups of six animals each. Group 1 served as the control, group 2 was administered with standard indomethacin, group 3 and 4 were treated with 250mg/kg body weight (lower dose) and 500mg/kg body weight (higher dose) of the frontal leaves extract. The extracts were administered orally. The Eddy’s hot plate was maintained between 55-56 ⁰C.The animals were placed on the hot plate and the time taken for licking was recorded using a stop watch. The reaction was observed at 0, 15, 30, 60 and 120 mts⁹.

Anti inflammatory activity was evaluated using carrageenan induced paw edema method.

The animals were divided into four groups. Group 1 served as a control, group 2 was given ibuprofen, group 3 was given 250 mg/kg leaf extract which served as a lower dose and group 4 was administered 500 mg/kg.All the rats were injected with 0.1ml of carrageenan in normal saline into the sub planter region of the right hind paw. The volume of the paw was measured at 0, 15, 30, 60 and 120 mts using plethysmograph⁹.

Results were tabulated and the data was expressed as mean ± SEM. The difference between experimental groups were determined using one way analysis of variance (ANOVA) followed by Dunnet test. P<0.05 was considered significant.

The results of the phytochemical analysis has revealed the presence of Flavonoids, tannins, anthraquinones, saponins, carbohydrates, and proteins

Analgesic activity of the frontal was evaluated using the Eddy’s hot plate method. The extracts showed analgesic activity in a dose dependent manner. The frontal leaves at a dose of 250mg/kg exhibit significant activity within 15 minutes which lasted up to 120 minutes while the higher dose of the same extract showed significant activity after 30 minutes which gradually decreased after 60 mts .

Figure 1

Table 1: Analgesic activity of the methanolic extract of frontal leaves of

All values are mean ± SEM, n=5-6, ^*P<0.05 indicates significant and ^**P<0.001 is extremely significant when compared with control.

The extract also exhibited significant anti inflammatory activity. The frontal leaf extracts at a lower dose of 250mg/kg and a higher dose of 500mg/kg and the standard showed significant activity when compared to the control at 15 minutes up to 30 minutes which gradually decreased in case of the extract of the higher dose. At 120 minutes the activity of the frontal leaves at the lower dose was comparable to the standard while the higher dose of the extract did not show any activity at 120 mts.

Figure 2

Table 2: Anti inflammatory activity of the methanolic extract of frontal leaves of

All values are mean ± SEM, n=5-6, ^*P<0.05 indicates significant and ^**P<0.001 is extremely significant when compared with control.

The authors are thankful to Prof Suresh Nagpal, Chairman, Krupanidhi Trust of Education and Prof Sunil D, Head Department of Pharmacology and the principal Dr Amit Kumar Das for their encouragement and support.