In vitro Antimicrobial Activity of the Indian Medicinal Plant Coleus forskohlii Briq | Chapter 5 | Contemporary Research and Perspectives in Biological Science Vol. 7

For ages, traditional medicines have been used to treat all kinds of ailments of mankind. In present days when modern medicine is well developed, plant-based medicines still remain an important subject for pharmacological research. Traditionally, plants have been well exploited by man for the treatment of human diseases, Ayurveda is a good example, but not much information is available on the exploitation of plant wealth for the management of plant diseases, especially against phytopathogenic fungi. Fungi cause severe damage to stored food commodities.

Coleus forskohlii Briq. (syn. Coleus barbatus Benth.) belongs to the family Lamiaceae and is a well-known traditional medicinal plant throughout the country and known as ‘pashanbhedi’ in Sanskrit and ‘pathatchur’ in Hindi is one of the most potential medicinal plants of the future, as its pharmaco properties have been discovered only recently. Its tuberous roots are found to be a rich source of forskolin which is being used as a remedy for hypertension, glaucoma, asthma, congestive heart failure and certain types of cancers and also for individual use as vegetables. Keeping the above views in mind, the present investigation was undertaken to study the antimicrobial activity of tuber extracts of Coleus forskohlii. The MIC level of different tuber extracts (11, 33 and 55 µg ml-1) was also studied. In the present study, a Well diffusion assay was done for both gram-positive and gram-negative strains such as Staphylococcus aureus, Escherichia coli, Pseudomonas sp. and Vibrio cholerae. Three fungi were used in the study Alternaria alternata, Curvularia lunata and Fusarium oxysporum which were maintained on potato dextrose agar slant at 40C in our Laboratory. Different concentrations (11 µg, 33 µg and 55 µg ml-1) of the crude chloroform extract of C. forskohlii were subjected to antifungal activity assay by poisoned food technique. Coleus plants were grown in the experimental field of the Department of Botany, Burdwan University. The tubers of Coleus were collected during the months of December, 2011 to February, 2012. The higher inhibition zone was recorded in Pseudomonas sp. which was 3.5 cm. Staphylococcus aureus showed lowest inhibition zone of 2.0 cm. It is interesting to note that higher mycelial growth inhibition was found in Curvularia lunata (76.70% at 11 µg ml^-1 tuber extract) followed by Alternaria alternata (68.20% at 11 µg ml^-1 tuber extract) and Fusarium oxysporum(65.84% at 11 µg ml^-1 tuber extract). The 100% mycelial growth inhibition of the three phytopathogenic fungi was observed at the conc. level of 33 µg ml^-1 of Coleus tuber extract and 55µg ml-1 of Coleus tuber extract. Out of the three fungi, Curvularia lunata was found to be more vulnerable to growth inhibition by tuber extract. These results indicate that the extracts of Coleus tuber have a potential broad spectrum antimicrobial activity. It was also revealed that the antibacterial activity was more pronounced against gram-negative bacterial strains than that of gram-positive strains. However, this medicinal plant species may be subjected to detailed phytochemical and pharmacological studies in order to find new drugs against pathogenic bacterial and fungal strains.

 

Author (s) Details

Selima Khatun
Department of Botany, Government General Degree College, Singur, Hooghly-712409, West Bengal, India.

 

Please see the book here:- https://doi.org/10.9734/bpi/crpbs/v7/3523