Corresponding Author:
S. Bose
Department of Pharmacognosy, Gupta College of Technological Sciences
College of Pharmacy Ashram More, G. T. Road, Asansol-713 301, India
E-mail: bose_cog@sify.com
Date of Submission 20 April 2007
Date of Revision 12 June 2008
Date of Acceptance 17 December 2008
Indian J. Pharm. Sci., 2008, 70 (6): 821-823  

Abstract

The antimicrobial activity of alcoholic, butanolic and chloroform extracts of leaves and roots of the plant Acanthus ilicifolius ware studied. Ampicillin and clotrimazole were used as standard antibacterial and antifungal agents respectively. The result of the study revealed that the alcoholic extract and chloroform extract of leaves exhibited strong inhibitory action against Bacillus subtilis, Staphylococcus aureus, Candida albicans, Aspergillus fumigatus and Aspergillus niger and moderate inhibitory action against Pseudomonas aeruginosa and Proteus vulgaris. The rest of the extracts showed moderate activity.

Keywords

Acanthus ilicifolius, agar cup-plate method, antimicrobial activity, mangrove.

Acanthus ilicifolius is a spiny herb found in mangrove of southern Thailand. In folklore and traditional practice, different parts of A. ilicifolius (Acanthaceae) have been used to treat rheumatism, asthma, paralysis, psoriasis and leucorrhoea [1]. Antioxidant, hepatoprotective, leishmanicidal, tumour reducing and anticancer activities of various extracts of A. ilicifolius have been reported [2-4]. These created an interest to test the possible antimicrobial activity of different parts of this plant, which has not been reported; hence, the present study was designed. The phytochemical literature reveals the presence of 2-benzoxazolinone, lignan glucosides, benzoxazinoide glucosides, flavone glycosides and phenylethanoid glycosides in this plant [5-8]. The present study was aimed at the preliminary investigation of antibacterial and antifungal activity of alcoholic, butanolic and chloroform extracts of leaves and roots of A. ilicifolius.

Micro Organisms Standards (mm) Zone of inhibition (mm)
    Alcohol Extract(10 mg/ml) Butanol Extract(10 mg/ml) Chloroform Extract(10 mg/ml)
   
    Leaves Roots Leaves Roots Leaves Roots
   
B. subtilis 25a 20 17 16 14 22 16
S. aureus 24a 18 16 08 12 21 11
P. aeruginosa 20a 18 14 10 10 20 13
P. vulgaris 21a 20 14 12 15 19 15
C. albicans 26b 22 20 15 14 26 20
A. fumigatus 28b 19 18 19 12 22 20
A. niger 28b 21 20 12 12 20 19

Table 1: Antimicrobial Activity Of Acanthus Ilicifolius (L.).

Leaves and roots of A. ilicifolius were collected from Netravati river valley of Mangalore in the month of October. The plant was authenticated in the Department of Botany, Netaji Mahavidyalaya, District Hoogly, West Bengal. The collected plant materials were shade dried at room temperature and mechanically reduced separately to course powders. The powders of leaves and roots (100 g each) were then extracted individually with 95% alcohol, butanol and chloroform in a Soxhlet apparatus by continuous heat extraction for 78 h. The extracts so obtained were concentrated to dryness by evaporating the solvents under reduced pressure.

The in vitro antibacterial and antifungal studies of the ethanolic, butanolic and chloroform extracts of the leaves and roots were carried out by the Agar cup-plate method [9]. All the extracts were separately dissolved in dimethylsulfoxide (DMSO) to get 10 mg/ml solutions. Ampicillin (1 mg/ml) and clotrimazole (1 mg/ml) were used as standard antibacterial and antifungal agents respectively. The antibacterial activity was evaluated by employing 24 h cultures of Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Proteus vulgaris using Muller Hinton Agar medium. Antifungal activity was carried out against 24 h cultures of Candida albicans, Aspergillus fumigatus and Aspergillus niger using Sabouraud dextrose agar medium. The bacterial and fungal strains employed in the study were obtained from NCIM, Pune. Accurately 0.2 ml of the test and standard solutions were transferred to cups aseptically and labeled accordingly. The microorganism inoculated plates were then maintained at room temperature for 2 h to allow the diffusion of the solutions into the medium. The petri dishes used for antibacterial screening were incubated at 37±1° for 24 h, while those used for antifungal activity were incubated at 28±1° for 48 h. The diameters of zone of inhibition surrounding each of the wells were recorded.

Table 1 enumerates the antibacterial and antifungal activity of the extracts of different parts of the title plant. The ethanol, butanol and chloroform extracts of the different parts of the plant exhibited strong to moderate activity against the test microorganisms. The results revealed that, the alcoholic and chloroform extracts of leaves exhibited strong inhibitory action against Bacillus subtilis, Staphylococcus aureus, Candida albicans, Aspergillus fumigatus and Aspergillus niger and moderate inhibitory action against Pseudomonas aeruginosa and Proteus vulgaris. The rest of the extracts showed moderate activity.

Acknowledgements

The authors would like to acknowledge Prof. T. K. Basu, Head, Department of Botany, Netaji Mahavidyalaya, Arambag, Hoogly, West Bengal for authenticating and giving information about the geographical distribution of the plant.

References