he crude methanolic extracts from the bark of Cinnamomum zeylanicum (C. zeylanicum) (Family: Lauraceae) were carried out for the evaluation of peripheral analgesic activity and anti-diarrheal activity in vivo bioassays using a group of Swiss Albino mice. Two different doses containing 400 mg/kg and 200 mg/kg with respect to the weight of the test animals were administered in both the cases for the assessment of action in comparison with the standards. In the estimation of analgesic effect peripherally, both the extracts of C. zeylanicum exhibited extremely significant pain relieving action with percent inhibition of licking responses of 63.89% at 400 mg/kg and 66.67% at 200 mg/kg close to the value of standard Acetyl Salicylic Acid with 75% inhibition of response induced by Acetic Acid at a dose of 0.1 ml/kg of body weight to each mouse. The bark extracts of C. zeylanicum at lower dose of 200 mg/kg showed extremely statistically significant anti-diarrheal activity with 68.18% reduction of diarrhea compared to the standard loperamide 59.09% in castor oil induced antidiarrheal assay protocol.

Traditional medicine is the application of theories, beliefs and experiences indigenous to different cultures through the knowledge, skill, and practices, may be definable or not, for the betterment of health in order to prevent, diagnose, improve or treat any type of ailment of human body. Sheng-Ji narrated ancient information containing description of 67 species of plants in about 450 to 600 B.C. from the Vedas. The barks of C. zeylanicum of were collected from Sher-e- Bangla Agriculture University area, Dhaka and sent to Bangladesh National Herbarium, Dhaka, Bangladesh for recognition. A voucher specimen with Accession number 44916 represents authenticity of the collected plant. The fresh barks were dehydrated for 15 days in order to have a proper grinding. The properly powdered material (500 g) which was obtained from desiccated barks after passing through the grinding machine was rinsed in 1.5 L of methanol. The Amber glass bottle with capacity of 5 L containing powder and 98% methanol was made secure by sealing with bottle cap and kept for a period of 21 days accompanying occasional shaking and stirring. A rotary evaporator was used to concentrate the 98% methanolic extract using low temperature and reduction of pressure after filtering through a cotton plug and with a filter paper respectively.

Peripheral analgesic activity can be assayed by using acetic acid induced writhing test. Physical sensation pain is exerted by injecting 0.1 ml/kg Acetic Acid subcutaneously into the right hind paw of the test animals. As a result writhing response at regular intervals due to distressed feeling by external stimuli occurs. The incorporation should continue as long as the pain sensation exists. The enumeration of response due to licking and biting experience is performed by each writhing and contrasted with the control group. Acetylsalicylic acid (Carva-Aspirin 75 mg/tablet) was taken as standard to compare effect at both higher and lower dose of 200 mg and 400 mg/kg body weight. Twelve randomly selected experimental animals were divided into four groups where they received a particular treatment. Prior to any treatment, each mouse was weighed properly and the doses of the test samples and control materials were adjusted accordingly. As it was difficult to observe the biologic response of the mice at a time receiving same treatment, it was necessary to identify individual animal of a group during the treatment as M1, M2, and M3.

In order to administer the extract at doses of 400 mg/kg body weight and 200 mg/kg body weight of mice, the exactly weighed extracts were measured respectively and triturated in unidirectional way by adding of small amount of Tween-80 (a suspending agent). After proper mixing of extract and suspending agent, normal saline was slowly added. The final volume of the suspension was made up to 3.0 ml. To stabilize the suspension, it was stirred well by vortex mixture. Acetylsalicylic acid at the dose of 50 mg/kg body weight was made for incorporation to the positive control group. At zero hour test samples, control {Tween-80 (0.5 ml/kg)} solution in saline) and Acetylsalicylic acid were administered orally by means of a long needle with a ball-shaped end. After 30 minutes Acetic Acid (0.1 ml/kg) at a dose of 10 ml/kg body weight was administered subcutaneously to each of the animals of all the groups. Each mouse of all groups were observed individually for counting the number of writhing responses they made in 5 minutes commencing just after the subcutaneous administration of acetic acid solution.

First time reporting of in vivo activities of C. zeylanicum for both the studies stipulate the possession of peripheral analgesic and anti-diarrheal activities while assessing the methanolic fractions. However, more secure cost effective active compounds responsible for those specific bioactivities will bring science to new horizon in the treatment of pain and diarrhoea through day to day used multipotential herb. Further study is required by using HPLC for precise identification.

With Regards,
Joseph Kent
Journal Manager
Journal of Der Chemica Sinica