1Department of Zoology, Annamalai University, Chidambaram 608002, Tamil Nadu, India, 2P. G. Department of Zoology, Government Arts College, Dharmapuri 636705, Tamilnadu, India
Email: gopal222@yahoo.com
Received: 05 Jan 2016, Revised and Accepted: 30 Mar 2016
ABSTRACT
Objective: Opuntia ficus indica is a medicinal plant belonging to family Cactaceae. It is a species of cactus that has long been a domesticated crop plant important in agricultural economies throughout arid and semiarid parts of the world. The fruit and stem are used to prepare worth added products, fruits jam, squash, drinks, preserve product of pickle, body lotion, shampoo and creams, etc.
Methods: For the preliminary study, various extracts of stem and fruit has been used to check the efficacy of antibacterial activity against Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli bacteria of gram-positive and gram-negative strain respectively using disc diffusion method.
Results: The stem and fruit extracts showed various levels of activity on different test organisms. The methanol fruit extracts showed high antibacterial activity against Escherichia Coli, Pseudomonas aeruginosa and Bacillus subtilis compared with other extracts. Aqueous extract of stem and fruit showed less antibacterial activity against the tested bacterial strains.
Conclusion: The present study suggests that the methanol extracts of the fruit of Opuntia ficus indica contain compounds that can form the basis for the development of a novel broad-spectrum antibacterial formulation.
Keywords: Opuntia ficus indica, Antibacterial activity, Methanol extract, Ethanol extract, Aqueous extract
© 2016 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
INTRODUCTION
The use of plants for treating diseases is as old as the human species. Popular observations on the use and efficacy of medicinal plants significantly contribute to the disclosure of their therapeutic properties, so that they are frequently prescribed, even if their chemical constituents are not always completely known. Medicinal plants represent a rich source of antimicrobial agents. Opuntia ficus-indica is a species of cactus that has long been a domesticated crop plant important in agricultural economies throughout arid and semiarid parts of the world. Cactus is a tropical and subtropical plant. It is a member of the Cactaceae [2] family. Prickly pear widely distributed in many countries such as Mexico, America and Africa [8]. Prickly pear is in mature stage up to 2 m long, with plump, even, rounded segments, armed with spines are called pads. The fruits are yellow and orange color; barrel or egg shaped and up to 10 cm long. The stems are green, plump, flattened and can be very large which approximately 60 cm length. However, the plant can spread up to 40m in diameter at from root region. The fruit pulp is disk-shaped and has numerous colors. An opuntia fruit has highly medicinal value and was established to display many pharmacological properties such as anti ulcerogenic [6], neuroprotective [4] antioxidant [10], hepatoprotective [7] and anticancer [3] activities. The use of prickly pear Opuntia ficus indica fruit is suggested for their beneficial and therapeutic properties [1]. In the present study was carried out to test the antibacterial efficacy of the stem and fruit extracts of Opuntia ficus indica with reference to bacteria spp.
MATERIALS AND METHODS
Plant material
Opuntia ficus indica stem and fruit were collected from the area of Jayankondam in Ariyalur district, Tamilnadu, India.
Test organisms
The strains of B. subtilis, P. aeruginosa and E. coli were obtained from Department of Microbiology, Annamalai University, Chidambaram, and Tamilnadu, India.
Preparation of plant extracts
The Opuntia ficus indica stem and fruit were collected and washed in distilled water. They were cut into small pieces, and air tried the dried stem and fruits were ground using a mixer into a fine powder and used for further studies.
Extractions
5 gm of the dried plant material was soaked in 15 ml of solvents separately (aqueous, ethanol, and methanol) and left for 5 d. The fraction was separated using mouslin cloth and filter through whatsman filter paper No1and the crude extracts were stored in a refrigerator at 4 ° C. All the extracts were then concentrated in a rotary vacum evaporator at 4 ° C.
Disc diffusion method
Antibacterial activities of stem and fruit extracts were tested using disc diffusion method [9]. 0.1 ml of the test bacterial culture was aseptically inoculated by spreading them evenly into the surface of nutrient agar plates. A 6 mm diameter discs were impregnated with stem and fruit extracts at different concentrations (50μ, 100μ and 150μ) individually and were placed on it. The inoculated plates were then incubated at 37 °C for 24hours [11]. The diameter of the zone of inhibition formed around the paper disc was measured and expressed in mm.
Fig. 1: Various solvent extracts of stem of Opuntia ficus indica
Statistical analysis
Each experiment was performed in triplicate. The results were expressed as the mean±SD. The statistical analyses were performed using SPSS 11.0 software package. Statistical variances were assessed using ANOVA. Significant differences (p<0.05) between the means were identified by Duncan’s Multiple Range Test (DMRT).
Table 1: Antibacterial activity of stem extracts of Opuntia ficus indica
Solvent |
Zone of inhibition (mm) |
|||||||||
Bacillus subtilis |
Pseudomonas aeruginosa |
Escherichia coli |
||||||||
C |
50 µl |
100 µl |
150 µl |
50 µl |
100 µl |
150 µl |
50 µl |
100 µl |
150 µl |
|
Ethanol |
- |
7.23±0.25 |
9.16±0.15 |
10.26±0.40 |
6.23±0.20 |
8.33±0.30 |
10.43±0.37 |
10.23±0.20 |
11.76±0.25 |
13.86±0.98 |
Methanol |
- |
8.36±1.09 |
14.63±1.28 |
17.63±0.32 |
9.66±0.30 |
14.66±0.28 |
20.56±0.40 |
8.73±0.25 |
17.53±0.41 |
14.76±0.37 |
Aqueous |
- |
5.66±0.57 |
6.1±0.17 |
6.06±0.05 |
6.56±0.23 |
6.56±0.11 |
6.66±0.20 |
6.1±1.08 |
6.3±0.17 |
6.5±0.43 |
Table 2: Antibacterial activity of fruit extracts of Opuntia ficus indica
Solvent |
Zone of inhibition (mm) |
|||||||||
Bacillus subtilis |
Pseudomonas aeruginosa |
Escherichia coli |
||||||||
C |
50 µl |
100 µl |
150 µl |
50 µl |
100 µl |
150 µl |
50 µl |
100 µl |
150 µl |
|
Ethanol |
- |
8.33±0.15 |
9.26±0.30 |
10.66±0.35 |
9.46±0.41 |
10.16±0.37 |
11.46±0.83 |
9.96±0.25 |
15.03±0.15 |
17.46±0.75 |
Methanol |
- |
8.83±0.20 |
14.36±0.70 |
16.56±0.61 |
17.93±0.30 |
18.46±0.70 |
19.96±0.15 |
13.56±0.40 |
18.96±0.45 |
22.16±0.66 |
Aqueous |
- |
6.16±0.15 |
6.46±0.05 |
6.6±0.34 |
6.2±0.2 |
6.46±0.11 |
6.73±0.05 |
6.33±0.05 |
6.43±0.32 |
6.73±0.20 |
C–Control, (-)-No activity, mm-Millimeter, Data given are mean of three replicates±standard deviation
Fig. 2: Various solvent extracts of fruit of Opuntia ficus indica
RESULTS AND DISCUSSION
The results of antibacterial activity are given in the table1 which clearly show that all the extracts have shown antibacterial activity against tested organisms. The antibacterial activity of the extracts and their potency was quantitatively assessed by the presence of inhibition zone and zone diameter respectively as given in (table 1 and table 2). The stem and fruit extracts of Opuntia ficus indica was evaluated for its clean activity in resistance to three bacterial strains such as Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli.
In this study, the methanol was found to be a better solvent for extraction of antibacterial activity. But, the highest activities were noted in methanol fruit and stem extracts (table 2) and compared with other extracts (table 1 and 2) ethanol and water. Organic extracts were active against both gram-positive and gram-negative bacteria and aqueous extract of Opuntia ficus indica showed lesser activity. The aqueous and organic extracts from the same plants showed different activities, and results were given in (table 1 &2). For all the tested microorganisms methanol and ethanol showed maximum antibacterial activity in Opuntia ficus indica stem and fruit extracts. However, the plants differ significantly in their activity against test micro-organisms. In this findings were supported by the previous report on antibacterial activities of methanol, ethanol and aqueous extract of Opuntia ficus indica have been studied on Vibrio cholera, indicating that the methanol extract was the most efficient [12]. According to Sathyabama et al. [13] the methanol extract has a high capacity to dissolve more organic and active antimicrobial compounds. These results confirmed the substantiation of previous studies which reported that methanol is a better solvent for more consistent extraction of antimicrobial substances from medical plants compared to other solvents, such as water and other organic solvents [5].
ACKNOWLEDGEMENT
We thank Department of Microbiology, Annamalai University for their support during the study.
CONFLICT OF INTERESTS
Declare none
REFERENCES