INTRODUCTION:

A large number of factors such as chemical agents, stressful life style, drug induced, emotional motivation as well as physiological and pathological conditions may alter intestinal motility and transit time. Altered motility contributes in a general way to this process, as the extent of absorption, by and large, parallels transit time. Anti-motility compounds (diphenoxylate, loperamide, opium alkaloids, anti-cholinergics etc.) have been tried against diarrhoeal disorders but often with side effects after prolonged use^1.

Acetylcholine, the vagal neurotransmitter, enhances and atropine, a known anti-cholinergic agent decreases intestinal motility and secretion. Although various derivatives and congeners of atropine (such as propantheline, isopropamide and glycopyrrolate) have been advocated in patients in peptic ulcer or with non-specific diarrhea, the prolonged use of such agents is limited by other manifestations of parasympathetic inhibition such as dry mouth and urinary retention. There is, thus, a need for identifying new compounds and evaluating their anti-motility activity and developing these as selective inhibitors that decrease gastric secretion and intestinal motility at doses that have minimal anti-cholinergic effects at other sites and are completely free from other adverse effects².

Alpinia conchigera Griff. (Begali name: Khetranga) belonging to the family Zingiberaceae , or the Ginger family, is a family of flowering plants consisting of aromatic perennial herbs with creeping horizontal or tuberous rhizomes. Zingiberaceae is one of the largest families of the plant kingdom with 53 genera and over 1300 species ³. The taxonomic study of the family Zingiberaceae was first studied by Kai Larsen ⁴.

WHO proposed the key to genera of Thai Zingiberaceae. Zingiberaceous plants are distributed throughout Bangladesh. But wide varieties of species are mainly found in hilly areas like in Chittagong and Sylhet. The following species are identified in Bangladesh. Zingiberaceous plants are distributed throughout Bangladesh. But wide varieties of species are mainly found in hilly areas like in Chittagong and Sylhet. The following species are identified in Bangladesh ⁵. The rhizome of A. conchigera is used as a condiment and occasionally in folk medicine along the east coast to treat fungal infections. In some states of Peninsular Malaysia, the rhizomes are consumed as a post-partum medicine and the young shoots are prepared into a vegetable dish.The rhizomes of A. conchigera are used in Thai traditional medicine to relieve gastrointestinal disorders and in the preparation of Thai food dishes ^6,7. It was reported that the phenyl prepanoid derivatives, chavicol acetate and eugenol acetate are present in the fruit of A.conchigera ⁸ and have anti-inflammatory activity .The milky juice of the plant is used

in opthalmia , scabies and as an antiseptic agent ^9.

Materials and methods:

Collection of Plant material

The plants selected for present work A. conchigera (Family: Zingiberaceae) and was collected from Naramuk, Rajsthali of Rangamati district. After collection, suitable herbarium sheet for each plant with some general information were prepared and send to Bangladesh Council of Scientific and Industrial Research (BCSIR), Baluchara, Chittagong for identification. They provided us the scientific name of the plants.

Extraction:

The collected plant (leaves and stems) was separated from undesirable materials or plants or plant parts and was shed-dried (35-50°c). The plant was ground into a coarse powder with the help of a suitable grinder. The powder was stored in an airtight container and kept in a cool, dark and dry place until extraction commenced. About 185 gm of powdered plant material of A. conchigera (Family: Zingiberaceae) was was taken in a clean, flat bottomed amber glass container and soaked in 1700ml of methanol The container with its contents was sealed and kept for a period of 10 days accompanied by continuous shaking. The whole mixture then underwent a coarse filtration by a piece of clean, white cotton materials. Then they were filtered by using Whatman filter paper number 1 and the solvent was made to evaporate under the room temperature. The obtained extract was collected .The residues were stored in a refrigerator until further studies.

Experimental animals:

Young Swiss-albino mice of either sex, average weight 18-25 gm of either sex were employed in the experiment taking three in a group. The mice were purchased from the Animal Research Branch of the Bangladesh Council of Scientific and Industrial Research (BCSIR), Chittagong, Bangladesh. The mice were kept separately in plastic cages having dimension of (28 x 22 x 13) cm. Soft wood shavings were placed in the cages for housing of the mice.

Charcoal in stool before magnification

Charcoal in stool after magnification

Charcoal free stool before magnification

Charcoal free stool after magnification

Figure-1: Defecation of albino mice in charcoal induced gastrointestinal motility test

The room where the mice were housed was well ventilated for air and light. Husk and excreta were removed from the cages on every day. Fresh water and pellets of mice foods were given to the mice regularly. The mice were kept at least one week in the laboratory to get them adapted with the environment before being employed in any experiment.

Experimental Protocol:

The currently used protocol, for intestinal motility test in mice involves only 3 h for fasting before the experiment. The methanol extracts were investigated for anti-motility activity. The experimental animals are grouped into four, five of each group, positive control, control and two for the ethanol extract of the plant. They were weighed and deprived of food, with free access to water. Three hours after food deprivation of all the animals, loperamide (5mg/kg) was administrated orally for positive control, 10ml/kg of normal saline for control and 250mg/kg and 500mg/kg extracts for test group-I and II respectively ¹⁰.

After 90min, 0.3ml of an aqueous suspension of 5% charcoal was administered to each animal, orally. Sixty minutes later they had free access to food. The animals were observed at 5 min intervals until faeces with charcoal were eliminated (maximum time of observation was 450 min).

Charcoal was observed on the faeces using normal light when it was easily visible, or using a microscope to help the identification of the black spots. The results were based on the time for the charcoal to be eliminated.

Table- 1: Effect of MEAC on the defecation period of loperamide induced anti-motility

Clinical Groups	No. of mice	Body wt. of mice	Defaecation period (min)	MDP (min)	SD	SEM	t-test (P-value)
Control (Normal saline 10ml/kg)	1	18	259	288.6	37.35	18.68	3.02 (<0.05)
	2	19	245
	3	18	339
	4	20	299
	5	21	301
Positive Control (Loperamide, 3 mg/kg)	1	19	418	391.6	19.17	9.59	3.08 (<0.05)
	2	18	387
	3	22	398
	4	20	365
	5	21	390
MEAC (250 mg/kg)	1	18	309	297.4	30.1214	15.06071	2.79124
	2	19	254
	3	21	304
	4	20	285
	5	22	335
MEAC (500 mg/kg)	1	19	377	371.2	12.05	6.03	3.30 (<0.05)
	2	20	358
	3	22	389
	4	21	365
	5	18	367

MDP = Mean defaecation period, SD = Standard Deviation, SEM = Standard Error Mean

Table-2: Gastrointestinal motility (charcoal meal) in mice for MEAC

Treatment groups	MDP (Hrs)	% MDP	% MDP	Time until charcoal defecation
Control	4.81	100	0	4.81 ± 18.68
Positive Control	6.53	26.34	73.66	6.53 ± 9.59
TG-I	4.956	2.958	97.06	4.956 ± 15.06
TG-II	6.186	22.25	77.74	6.186 ± 6.024

*[TG = Test group, IMDP = Inhibition of mean defecation period, Total charcoal defaecation = MDP ± SEM]

Figure-2: Graphical Representation of MEPI on the defecation period of loperamide induced anti-motility episode in mice.

Results and Discussion:

Loperamide is an opioid-receptor agonist and acts on the μ-opioid receptors in the myenteric plexus of the large intestine. It works by decreasing the activity of the myenteric plexus. This increases the amount of time substances stay in the intestine, allowing for more water to be absorbed out of the fecal matter. Loperamide also decreases colonic mass movements and suppresses the gastrocolic reflex

Conclusion:

The remarkable antimotility effect of methanolic extract of Alpinia conchigera Griff against charcoal as promotility agent .It was found that Alpinia conchigera Griff possesses significant antimotility activity with the mean defecation period range 297.4 and 371.2 min the dose of 250 and 500mg/kg body wt. respectively. These properties could be a potential source of modern pharmaceutical products. Further studies are needed to completely understand the mechanism of antimotility action.

References:

1. Tripathi KD (2001), Essentials of Medical Pharmacology , 5^th ed., Jaypee BM , publisher (P) Ltd , India.

2. Ghani A., (1998). Medicinal Plants of Bangladesh with Chemical Constituents and Uses. 2^nd edition.pp.4-19 Asiatic Society of Bangladesh, Dhaka.

3. Kai Larsen, K. 1980. Annotated key to the genera of Zingiberaceae of Thailand. Nat. Hist. Bull.Siam Soc. 28: 151-169.

4. E.W.C. Chan, Y.Y.Lim, S.K.Ling, S.P. Tan, K.K. Lim and M.G.H. Khoo Caffeoylquinic acids from leaves of Etlingera species (Zingiberaceae). LWT - Food Science and Technology, 2009 June, Volume 42, Issue 5, Pages 1026-1030.

5. .Ghani A., (1998). Medicinal Plants of Bangladesh with Chemical Constituents and Uses. 2^nd edition.pp.4-19 Asiatic Society of Bangladesh, Dhaka.

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8. Pino.J.A, Marbot.R, Rosado.A, Batista.A. Chemical composition of the essential oils of Zingiber officinale( Roscoe L). from Cuba. Journal Essential Oils Research, 2004. Volume 16, Pages 186-188.

9. M.A. Sukari, N.W. Mohd Sharif, A.L.C. Yap, S.W. Tang, B.K. Neoh, M. Rahmani, G.C.L. Ee, Y.H. Taufiq-Yap and U.K. Yusof. Chemical constituents variations of essential oils from rhizomes of four zingiberaceae species.The Malaysian Journal of Analytical Sciences, 2008, Vol 12, No 3: 638 – 644.

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Received on 02.05.2012 Accepted on 26.05.2012

Asian J. Pharm. Res. 2(2): April-June 2012; Page 71-74