INTRODUCTION:

Vast natural resources of medicinal plants are being used for thousands of years for the cure of many diseases in all over the world. If we could use medicinal plants properly we could get medicines at low cost and then it might be possible to fulfill the demand of our medication. This will supply low cost medicine to our poor people and we could establish a better health care system ^[1]. Recently, some higher plant products have attracted the attention of microbiologists to search for some phytochemicals for their exploitation as anti-microbials. Such plant products would be biodegradable and safe to human health ^[2] . 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 ophthalmia, scabies and as an antiseptic agent ^[9] .

MATERIALS AND METHOD:

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.

Fungal Strains:

The antifungal activity of plant extract were investigated against six pathogenic fungal strains such as Aspergillus niger, Blastomyces dermattitidis, Candida albicans, Pityrosporum ovale, Trichophyton spp, Microsporum spp., Cryphcoccus neoformans. All the fungal strains were collected from Bangladesh Council of Scientific and Industrial Research ( BCSIR), Bangladesh.

Antifungal Assay:

In vitro antifungal screening was performed by disc diffusion assay method ^{[10, 11]} where Potato Dextrose Agar (PDA) medium was used for the antifungal activity. Their antifungal activity were tested against six fungal strains at a concentrations of 250 μg/disc, 500 μg/disc for each and the results were compared with griseofulvin (500 μg/disc). The activity was determined after 72 hours of incubation at 37.5oC.

Table- 1: Composition of the Potato Dextrose Agar (PDA) medium

Potato Dextrose Agar (PDA) medium (1000 ml)
Ingredients	Amount
Potato slice	200.0 gm
Dextrose	20.2 gm
Bacterial agar medium	16.0 gm
Distilled water	q.s

Preparation of the medium:

The weight amount of potato slice was boiled with a little amount of distilled water for 30 minutes and applied for course filtration by the help of cotton. The required amount of dextrose and bacterial agar medium were properly mixed in a conical flask. Finally the constituents of two flasks were mixed thoroughly after the adjustment of volume by the distilled water the medium was sterilized in an autoclave. The pH of the medium was adjusted to 5.6.

Result of the antifungal screening

The result of the antifungal screening assay of methanol extract of Alpinia conchigera Griff. against the tested fungal strains were shown in Table- 2

Table- 2: Anti-fungal activity of the crude extract of MEAC, standard and blank

Tested fungi	Zone of inhibition (mm)
	MEAC		S	C
	A	B	500 μg/disc
Aspergillus niger	15	26	27	-
Blastomyces dermatitides	12	25	27	-
Candida albicans	7	15	26	-
Pityrosporum ovale	10	19	22.5	-
Trichophyton spp	12	18	29	-
Microsporum spp	9	20	23	-
Cryphcoccus neoformans	11	15	21	-

[MEAC = Methanol extract of Alpinia conchigera Griff. A = 250μg/disc, B = 500μg/disc, S = Standard (Fluconazole) and C = Control]

Figure- 1: Comparison of Zone of Inhibition of different fungi with MEAC,standard and Control

DISCUSSION:

The antifungal activities of the crude extracts were evaluated by the disc diffusion method against seven fungal strains using Fluconazole as standards. In the screening, the methanol extract of Alpinia conchigera Griff showed strong antifungal activity with zone of inhibition of 7.0-26 mm respectively while the highest antifungal activity was seen against Blastomyces dermatitides, Aspergillus niger, Microsporum spp and Aspergillus nigerwas the most susceptible fungal strain of the methanolic extract of Alpinia conchigera Griff.

CONCLUSION:

The result shows that the methanolic extract of Alpinia conchigera Griff. possessed antifungal activity against all the tested fungal strains.. So the active principles which are responsible for this antifungal activity is to be explored. The isolation of these active constituents showing antifungal activity can be more useful and work is to be done in this regard.

REFERENCES:

1. Ghani A. (2003) Medicinal plants of Bangladesh, 2nd Ed. pp.238. The Asiatic Society of Bangladesh, Dhaka.

2. Kumar A, Shukla R, Singh P, Prasad CS, Dubey NK (2008).Assessment of Thymus vulgaris L. essential oil as a safe botanicalpreservative against post harvest fungal infestation of food commodities. Innov. Food Sci. Emerg., 4: 575-580.

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.

6. Baby Sabulal, Mathew Dan, Anil John J, Rajani Kurup, Nediyamparambu Sukumaran Pradeep, Renju Krishna Valsamma and Varughese George, Caryophyllene-rich rhizome oil of Zingiber nimmonii from South India: Chemical characterization and antimicrobial activity. Phytochemistry, 2006 November, Volume 67, Issue 22, Pages 2469-2473.

7. K. C. Wong, K. S. Ong, C. L. Lim. Compositon of the essential oil of rhizomes of Kaempferia galanga L. Flavour and Fragrance Journal, 2006, Volume 7, Pages 263-266.

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.

10. Bear AW, kirby WMM, Sherris JC, Turck M. (1966) Antibiotic susceptibility testing by standardized single disc method. Am. J. Clin. Pathol. 44: 493-496.

11. Rios JJ, Reico MC, Villar A. (1988) Antimicrobial screening of natural products. Enthopharmacol. 23: 127-149.

Received on 16.04.2012 Accepted on 18.05.2012

Asian J. Pharm. Tech. 2(2): April-June 2012; Page 44-46