Antimicrobial Potential of the Phytoextracts of Some Nyctaginaceae Members

Full Length Research Paper

Antimicrobial potential of the phytoextracts of some Nyctaginaceae members

Mukesh Sharma1*, Vimal Mohan1, Maneesha Abraham2 and Meenakshi Sharma1

1Microbiology laboratory, Department of Botany, University of Rajasthan, Jaipur, Rajasthan, India. 2Post Graduate Department of Botany, Devamatha College, Kuravilangad, Kottayam, Kerala, India.

Accepted 28 April, 2009

The emergence of drug resistant pathogens is becoming a serious threat to humanity and has necessitated the search for new antimicrobial drugs. The present study was done to evaluate the potential antimicrobial efficacy of some common members of Nictagenaceae against four bacterial strains; Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Proteus vulgaris. Different concentrations of Soxhlet extracts (aqueous, petroleum ether and ethyl alcohol) of the plants in different solvents were tested by standard filter paper disk diffusion method. The efficacy of the extracts determined from the zone of inhibition was compared with that of two common antibiotics (amphicillin and erythromycin). The minimum inhibitory concentration (MIC) values of the extracts were also determined from most efficient extracts. The selected plant extracts exhibited good antibacterial activity. The crude phytoextracts showed high degree of antimicrobial activity and confirms the traditional therapeutic claims of these plants. The results confirm that the plant extracts have great potential as antimicrobial compounds against microorganisms. Thus, they can be used in the treatment of infectious diseases caused by resistant microbes.

Key words: Antimicrobial activity, soxhlet extracts, disk diffusion method, antibiotics.

INTRODUCTION

Plants not only provide food for man but also give a antimicrobial drugs in the future is still uncertain. Surpris- number of active compounds with potent and varied ingly, despite increased bacterial resistance to existing therapeutic value. The world health organization reported drugs, antibiotic development in the pharmaceutical indu- that 80% of world’s populations rely chiefly on traditional stry is steeply declining (Projan, 2003; Wenzel, 2004). medicine (WHO, 1993) and would be the best source to The past few decades of modern medicines certainly obtain a variety of drugs (Santos et al., 1995). Traditional helped man in controlling and even eliminating some of therapy involves the use of plant extracts or their active deadly diseases caused by microorganisms, but it paved constituents and is within the reach of common people. the way for the formation of more deadly pathogens, Infections caused by multiple resistant strains are which are antibiotic resistant. Therefore, actions must be becoming common in the developing world. Bacteria are taken to reduce this problem, for example, to control the necessary for the existence of higher orders of life and use of antibiotic, understand the genetic mechanisms of majority of them are harmless. Relatively a small number resistance and to continue studies to develop new drugs, of bacteria are pathogenic, causing infectious diseases to either synthetic or natural. The ultimate goal is to offer plants and animals. These are the second leading cause appropriate and efficient anti-microbial drugs to the of worldwide mortality and the third leading cause in eco- patient. nomically developed countries. The problem of microbial In recent years, there is a great demand for plant- resistance is growing and the outlook for the use of based products of broad biological activities, low impact on environment and safety to non-target organisms. The effects of plant extracts on bacteria have been studied by a number of researchers in different parts of the world. *Corresponding author. E-mail: Plants produce a diverse range of bioactive molecules, [email protected] making them a rich source of different types of medicines.

Sharma et al. 7943

More than 80% of the population in developing countries MATERIALS AND METHODS depends on plants for their medical needs (Farnsworth, 1988; Balick et al., 1994). Collection of plant materials

The use of plant extracts and phytochemicals, both with The fresh plant materials of B. diffusa, B. spectabilis and M. Jalapa known antimicrobial properties, can be of great signif- were collected from Elackad, Kuravilangad, 23 km from Kottayam in icance in therapeutic treatments. In the last few years, a October- December, 2006. The plants were collected when the number of studies have been conducted in different coun- species were in the fruiting stage. This was done because the fruits tries to prove such efficiency (Almagboul et al., 1985; are important for species identification. The main author and co- authors collected the test plant species. The plants were identified Artizzu et al., 1995; Ikram and Inamul, 1984; Izzo et al., using the herbarium collection at the Deva Matha College, Kuravi- 1995; Kubo et al., 1993; Shapoval et al., 1994). Many langad, Kerala, India and finally from the Herbarium, University of plants have been used because of their anti-microbial Rajasthan, Jaipur, India. All the voucher specimens are deposited traits, which are due to compounds synthesized in the in the herbarium, Deva Matha College, Kuravilangad, Kerala, India. secondary metabolism of the plant. These products are known by their active substances, for example, the Extraction of plant material phenolic compounds which are part of the essential oils (Jansen et al., 1987) as well as in tannin (Saxena et al., Healthy plant parts were collected, dried in shade and powdered. 1994). About 30 g of powdered leaf, stem and root were extracted with 220 Boerhaavia diffusa L. (Common names, Hogweed, ml of hot water, ethanol and petroleum ether in a Soxhlet Pigweed, Punarnava, Thazhuthama) is also known as apparatus. The extracts were evaporated to dryness and solutions punarnava and it has a long history of use by indigenous of 5, 10, 15, 20 and 100% were prepared in the solvent in which it was extracted. and tribal people and in Ayurvedic herbal system of medicines. A perennial diffuse herb with stout root stock and many procumbent grows as common weed in waste- Isolation and maintenance of test organisms lands and roadsides. The plant is bitter, astringent, cooling anthelmintic, diuretic, aphrodisiac, cardiac stimu- Four pathogenic bacteria species; Escherichia coli, Staphylococus aureus, Pseudomonas aeruginosa and Proteus vulgaris were used lant, diaphoretic, emetic, expectorant, anti-inflammatory, for the antimicrobial assays. Bacterial strains were procured from febrifuge, laxative and tonic. It is useful in all types of the Microbiology and Pathology Department, S.M.S. Medical inflammations, strangery, leucorrhoea, opthalmia, lum- College and S.M.S. Hospital, Jaipur for the present study. The test bago, myalgia, scabies, cardiac disorders, jaundice, strains were raised in pure form on nutrient agar medium (Merck, anaemia, dyspepsia, constipation, cough, bronchitis and g/l). general debility (Varier, 1997). Bougainvillaea spectabilis

Willd. is a genus of flowering plants, native to the tropical Antimicrobial assays and subtropical regions of South America (from Brazil west to Peru and south to southern Argentina Chubut The filter paper disc diffusion method (Karaman et al., 2003) was province). It grows as a common garden plant throughout used to study the effect of plant extracts on bacteria. Agar plates India, as indoor houseplants in temperate regions and were prepared using nutrient agar (Hi-media, g/l). The plates, when they are kept small by bonsai techniques. They have half set were inoculated with bacteria using sterile cotton swabs, 3 sterile paper discs (1 cm diameter) of Whatman no. 1 filter paper, anthelmintic, analgesic, anti-inflammatory, heapto- one dipped in pure solvent and 2 in the plant extracts were placed protective, and anti-cancerous properties. Mirabilis jalapa above the inoculated plates. The disc dipped in the solvent was taken Linn. (Common names, Marvel of Peru, Four O’ clock, as the control. The 3 other discs as the experiment, gave 3 readings for Anthimalari, Gulabbas, Beauty of the night, Clavillia) are inhibition zone. The mean value was taken from 3 readings. All the above procedure was done in aseptic conditions provided by a large herbaceous plant grown in gardens throughout laminar airflow chamber. India. The plant is used as abortive, anti-bacterial, anti- The plates were then incubated in an inverted condition at 28°C candidal, anti-fungal, anti-viral, anti-spasmodic, uterine for 24 h in a BOD incubator.The inhibition zone formed due to the stimulant, anti-dysenteric, anti-parasitic, carminative (expels allelopathic effect of the extracts was measured in millimeters. The gas), detoxifier, digestive stimulant, diuretic, purgative mean of the 3 values of each plate was taken as the zone of (strong laxative), tonic, vermifuge (expels worms), and inhibition. The above procedure was repeated for different concentrations of leaf, stem and root extracts of B. diffusa, B. wound healer. spectabilis and M. jalapa. Hence, more studies pertaining to the use of plants as therapeutic agents should be emphasized, especially those related to the control of antibiotic resistant micro- Minimum inhibitory concentration (MIC) bes. The objective of this research was to evaluate the potential of plant extracts on standard microorganism The MIC was determined for the antimicrobially most efficient strains as well as multi-drug resistant bacteria, which extracts using microdilution broth method (Bassolé et al., 2003). All the extracts were made in DMSO. The extracts were diluted to give were isolated from hospitals. Moreover, we investigated one series with concentrations of 0.001 to 2.5 mg/ml. MIC was the synergistic effects of extracts with antimicrobial act- determined by incorporating different concentrations of extracts in activity in association with antibiotics against drugs resistant test media. A control without extracts was also run along with the bacteria. experiments. The lowest concentration of the extracts that did not

7944 Afr. J. Biotechnol.

Table 1. Antibacterial activity of phytoextracts of B. diffusa.

Zone of inhibition in millimeters Solvent Conc. E. coli S. aureus P. aeruginosa P. vulgaris Control Leaf Stem Root Leaf Stem Root Leaf Stem Root Leaf Stem Root 5% 0.00 0.00±0.00 1.20±0.01 0.00±0.00 0.00±0.01 0.00±0.00 0.00±0.00 0.00±0.00 1.50±0.02 0.00±0.01 0.50±0.02 2.70±0.21 1.13±0.04

e 10% 0.00 1.50±0.13 1.44±0.09 0.00±0.01 1.50±0.01 1.70±0.21 0.00±0.01 0.50±0.00 1.00±0.01 2.00±0.03 2.50±0.31 2.00±0.16 2.50±0.01 t

a 15% 0.00 1.70±0.12 1.50±0.12 2.00±0.03 1.80±0.05 2.00±0.11 2.00±0.08 1.50±0.15 1.20±0.02 1.50±0.21 2.70±0.05 3.00±0.17 2.00±0.02 W 20% 0.00 2.50±0.13 2.80±0.16 2.50±.04 2.00±0.12 1.55±0.21 3.00±0.02 1.70±0.05 2.90±0.08 1.70±0.02 3.10±0.02 2.00±0.18 2.30±0.14 25% 0.00 2.75±0.14 3.00±0.08 2.00±0.12 2.50±0.02 2.00±0.01 2.70±0.02 1.80±0.03 3.30±0.04 2.10±0.31 3.00±0.00 2.10±0.05 2.50±0.21

5% 0.00 0.00±0.00 0.00±0.00 0.00±0.01 0.00±0.01 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 2.50±0.21 0.00±0.01 1.10±0.01 m

u r 10% 0.00 1.20±0.15 0.00±0.00 0.00±.0.00 0.00±0.00 1.33±0.20 0.00±0.00 1.50±0.01 0.00±0.00 0.00±0.00 2.70±0.11 1.33±0.05 1.00±0.32 e e l h o t

r 15% 0.00 1.50±0.06 0.00±0.00 1.80±0.01 1.70±0.05 1.20±0.03 2.20±0.04 1.80±0.21 0.00±0.00 1.90±0.01 2.00±0.31 1.60±0.21 1.22±0.51 e t

e 20% 0.00 1.70±0.08 0.00±0.00 1.80±0.00 2.00±0.12 2.00±0.04 1.50±0.21 2.00±0.16 1.70±0.03 1.80±0.04 2.60±0.00 2.00±0.03 1.30±0.06 P 25% 0.00 3.00±0.05 0.00±0.00 2.00±0.06 2.20±0.15 2.20±0.02 1.70±0.01 3.00±0.20 2.00±0.02 2.00±0.06 3.30±0.04 2.50±0.06 2.00±0.04

o 5% 0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.01 0.00±0.00 0.00±0.01 1.20±0.08 0.00±0.00 h o

c 10% 0.00 1.20±0.02 1.10±0.05 1.15±0.07 1.33±0.21 0.00±0.01 1.30±0.04 1.25±0.03 0.00±0.01 0.00±0.00 1.50±0.04 1.20±0.00 0.00±0.01 l a

l 15% 0.00 1.75±0.00 1.50±0.01 1.60±0.01 2.00±0.13 0.00±0.00 1.50±0.01 2.00±0.01 0.00±0.00 0.00±0.00 1.60±0.04 1.33±0.03 0.00±0.00 y

h 20% 0.00 2.55±0.09 1.70±0.09 1.30±0.02 2.75±0.15 1.50±0.30 1.60±0.00 2.50±0.06 0.00±0.00 0.00±0.00 2.00±0.07 1.50±0.41 1.10±0.03 t

E 25% 0.00 3.10±0.06 1.90±0.05 1.60±0.20 3.20±0.22 1.80±0.12 1.50±0.02 3.13±0.04 0.00±0.00 0.00±0.00 2.50±0.10 1.80±0.15 1.20±0.02

The data given are mean (n=3) ± standard error.

show any viable growth after 48 h of incubation at 35°C B. diffusa and M. jalapa were prepared and tested Among the different extracts of B. spectabilis, (compared with control) was considered as MIC value. All for their antibacterial effect against 4 strains of leaf extracts in ethyl alcohol showed the maximum the tests were made in triplicate. bacteria like S. aureus, E. coli, P. aeruginosa and inhibition towards all the test bacteria. The

P. vulgaris, after 24 h of incubation. The alcohol aqueous and petroleum extracts of B. spectabilis Analysis of data extracts of all plants showed inhibition towards all leaves also showed inhibition towards all the bac- the 4 strain of bacteria, indicating clear inhibition teria studied. The stem and root extracts showed All values are expressed as means ± standard error. The zones around the paper discs. No inhibition was a lesser degree of inhibition towards the bacterial data collected was analyzed using one-way analysis of observed in the control. strains (Table 2). variance (ANOVA) and the effect of the differences among group means were considered significant when P value B. diffusa leaf extracts showed maximum inhi- M. jalapa leaf, stem and root extracts in water, was < 0.05. bition against all the test bacteria and seems to petroleum ether and ethyl alcohol showed certain contain more bactericidal compounds than stem degree of inhibition towards the bacterial strains. and root extracts. The ethanol extracts of leaf Among the different extracts of M. jalapa the root RESULTS showed maximum effect against S. aureus, E. coli extracts in ethyl alcohol showed maximum anti- and P. aeruginosa while the growth of P. vulgaris bacterial potency against S. aureus, E. coli and P. The leaf, stem and root extracts in water, petro- was inhibited maximally by the aqueous and vulgaris. The aqueous stem extract of M. jalapa leum ether and ethyl alcohol of B. spectabilis, petroleum ether extracts (Table 1). showed maximum inhibition of P. aeruginosa

Sharma et al. 7945

Table 2. Antibacterial activity of phytoextracts of B. spectabilis.

Zone of inhibition in millimeters Solvent Conc. E. coli S. aureus P. aeruginosa P. vulgaris Control Leaf Stem Root Leaf Stem Root Leaf Stem Root Leaf Stem Root 5% 0.00 0.00±0.00 0.00±0.01 0.00±0.13 0.00±0.00 1.50±0.03 0.00±0.00 1.50±0.04 1.60±0.03 1.25±0.02 1.60 ± 0.25 0.00±0.00 1.33±0.02

r 10% 0.00 1.50±0.08 2.00±0.03 0.00±0.09 1.50±0.04 1.30±0.01 0.00±0.00 1.50±0.10 2.00±0.09 1.50±0.52 2.00 ± 0.20 1.30±0.31 1.45±0.14 e t

a 15% 0.00 1.50±0.14 2.50±0.21 1.02±0.05 1.50±0.02 0.00±0.16 1.50±0.01 1.75 ± 0.03 1.00±0.01 1.55±0.05 1.50±0.34 1.70±0.23 1.50±0.16 W 20% 0.00 2.00±0.06 2.50±0.20 2.00±0.02 2.00±0.31 0.00±0.08 2.33±0.06 4.00±2.1 1.50±0.06 2.00 ± 0.57 1.50 ± 0.31 2.00±0.04 1.50±0.13 25% 0.00 2.00±0.09 3.00±0.04 2.00±08 2.33±0.21 1.75±0.01 2.25±0.05 2.00±0.4 1.45±0.31 2.00±0.08 1.50±0.41 2.70±0.41 2.00±0.31

5% 0.00 0.00±0.00 0.00±0.00 0.00±0.16 0.00±0.00 1.30±0.00 0.00±0.00 0.00±0.01 1.50±0.04 1.20±0.46 1.30 ± 0.05 0.00±0.01 0.00±0.00 m

u r 10% 0.00 1.20± 0.13 0.00±0.00 1.10±0.03 1.33±0.12 1.33±0.02 0.00±0.00 0.00±0.00 1.70±0.16 1.20±0.04 1.30± 0.26 1.10±0.07 0.00±0.00 e e l h o

t 15% 0.00 2.00±0.04 1.70±0.04 1.30±0.16 1.75±0.02 1.60±0.04 0.00±0.00 1.30±0.30 1.66±0.02 1.33±0.09 1.90±0.09 1.50±0.27 1.50±0.02 r e t

e 20% 0.00 2.00±0.03 1.50±0.02 1.75±0.50 2.00±0.04 1.90±0.36 0.00±0.00 0.00±0.00 2.00±0.04 1.33±0.18 2.30±0.26 1.70±0.08 1.70±0.06 P 25% 0.00 2.20±0.17 1.90±0.02 2.40±0.02 2.40±0.06 2.50±0.03 0.00±0.00 1.10±0.03 2.60±0.05 1.30±0.01 2.30±0.05 1.70±0.12 2.10±0.15

o 5% 0.00 0.00±0.00 0.00±0.00 0.00±0.00 1.10±0.13 0.00±0.13 0.00±0.00 1.20±0.21 0.00±0.00 0.00±0.00 1.33±0.02 0.00±0.00 0.00±0.00 h

o 10% 0.00 1.50±0.05 1.25±0.02 0.00±0.00 1.60±0.16 1.50±0.02 0.00±0.01 1.55±0.02 0.00±0.00 0.00±0.00 2.33±0.56 0.00±0.00 0.00±0.00 c l a

15% 0.00 2.20±0.04 1.50±0.02 0.00±0.00 2.50±0.13 1.50±0.01 1.30±0.08 3.00±0.15 1.20±0.02 1.10±0.17 5.00±0.38 0.00±0.00 1.20±0.52 l y

h 20% 0.00 2.33±0.05 1.50±0.06 0.00±0.00 2.66±0.06 1.70±0.09 1.50±0.01 3.20±0.08 1.27±0.09 1.20±0.02 4.90±0.05 0.00±0.01 1.25±0.07 t

E 25% 0.00 3.30±0.06 1.60±0.07 0.00±0.00 5.00±0.10 1.60±0.05 1.35±0.06 4.00±0.04 1.25±0.04 1.23±0.14 6.10±0.02 0.00±0.00 1.32±0.38 The data given are mean (n=3) ± standard error.

Table 3. Antibacterial activity of phytoextracts of M. jalapa.

Zone of inhibition in millimeters Solvent Conc. E. coli S. aureus P. aeruginosa P. vulgaris Control Leaf Stem Root Leaf Stem Root Leaf Stem Root Leaf Stem Root 5% 0.00 0.00±0.00 2.00±0.32 1.55±0.04 1.70±0.02 2.00±0.07 1.75±0.08 1.50±0.06 2.00±0.16 1.75±0.12 1.50±0.02 2.00±0.03 1.50±0.01

r 10% 0.00 0.00±0.00 2.00±0.04 2.00±0.05 1.80±0.04 2.10±0.08 2.00±0.21 1.90±0.05 2.80±0.05 2.00±0.08 1.50±0.09 2.00±0.31 2.00±0.13 e t

a 15% 0.00 0.00±0.00 3.00±0.05 2.00±0.12 2.00±0.01 2.00±0.09 2.00±0.22 3.00±0.14 3.00±0.03 2.00±0.20 2.00±0.30 2.12±0.03 2.00±0.05 W 20% 0.00 0.00±0.01 3.00±0.01 2.00±0.21 2.00±0.02 2.33±0.31 2.00±0.05 3.00±0.32 4.50±0.01 2.00±0.04 2.00±0.03 2.33±0.04 2.10±0.02 25% 0.00 0.00±0.00 3.20±0.02 3.00±0.05 2.30±0.00 3.30±0.04 2.50±0.02 2.90±0.05 12..0±0.12 2.33±0.04 2.50±0.05 3.00±0.07 2.50±0.01

5% 0.00 0.00±0.00 0.00±0.01 0.00±0.00 1.30±0.04 1.10±0.41 0.00±0.00 0.00±0.03 0.00±0.04 0.00±0.03 0.00±0.00 0.00±0.01 0.00±0.00 m

u r 10% 0.00 1.10±0.03 0.00±0.00 1.33±0.01 1.33±0.01 1.30±0.09 1.30±0.05 0.00±0.02 0.00±0.11 1.20±0.00 0.00±0.00 1.25±0.13 1.10±0.02 e e l h o

t 15% 0.00 1.50±0.02 1.40±0.14 1.50±0.06 1.43±0.04 1.33±0.09 1.50±0.05 0.00±0.02 0.00±0.06 1.55±0.03 0.00±0.00 1.30±0.05 1.60±0.01 r t e

e 20% 0.00 1.60±0.21 1.60±0.02 1.30±0.01 1.80±0.04 1.30±0.01 1.33±0.05 1.30±0.12 0.80±0.09 1.50±0.02 1.45±0.01 1.80±0.18 1.50±0.04 P 25% 0.00 2.10±0.03 2.10±0.07 1.45±0.11 2.30±0.01 1.70±0.00 1.50±0.07 1.50±0.21 1.20±0.02 1.30±0.01 2.00±0.02 2.30±0.06 1.40±0.06

o 5% 0.00 1.50±0.05 0.00±0.01 3.30±0.05 1.50±0.02 0.00±0.00 3.22±0.21 1.50±0.05 0.00±0.00 1.50±0.31 1.50±0.11 0.00±0.00 3.60±0.01 h

o 10% 0.00 1.50±0.06 1.25±0.00 4.00±0.08 1.50±0.00 1.10±0.01 4.35±0.09 1.30±0.06 0.00±0.00 1.50±0.02 1.50±0.04 1.15±0.01 6.10±0.13 c l a

15% 0.00 2.00±0.13 1.25±0.04 5.40±0.03 1.25±0.05 1.15±0.09 6.10±0.04 1.50±0.00 0.00±0.00 1.75±0.14 2.00±0.04 1.20±0.02 7.50±0.04 l y

h 20% 0.00 2.00±0.02 1.10±0.04 6.50±0.09 1.25±0.05 1.22±0.03 5.00±0.06 1.50±0.21 0.00±0.00 1.50±0.02 2.00±0.50 0.00±0.00 7.52±0.01 t

E 25% 0.00 1.50±0.03 1.20±0.06 7.00±0.12 1.50±0.04 1.20±0.09 7.30±0.01 1.25±0.12 0.00±0.00 2.10±0.09 2.00±0.10 0.00±0.00 9.30±0.03

The data given are mean (n=3) ± standard error.

7946 Afr. J. Biotechnol.

Table 4. Minimal inhibitory concentration (MIC) of plant extracts against pathogenic bacteria.

Bacterial strain Plant extracts (mg/ml) Standard antibiotics (mg/ml) B. diffusa (L) B. spectabilis (L) M. jalapa (R) Amphicillin Erythromycin E. coli 0.1 0.09 0.07 0.004 0.003 S. aureus 0.9 1.2 1.9 0.006 0.004 P. aeruginosa 0.08 0.8 0.6 0.003 0.007 P. vulgaris 0.7 1.0 0.9 0.006 0.003

L- leaf; R- entire root.

Table 5. Comparison of phytoextracts with antibiotics.

Zone of inhibition in millimeters Bacterial strain M. jalapa B. diffusa B. spectabilis Amphicillin Erythromycin E. coli 7.00±0.12 3.10±0.06 3.30±0.06 5.30±0.08 18.50±0.16 S. aureus 7.30±0.01 3.20±0.22 5.00±0.10 7.88±0.46 10.50±0.05 P. .aeruginosa 12..0±0.12 3.13±0.04 4.00±0.04 19.00±0.07 12.30±0.09 P. vulgaris 9.30±0.03 2.50±0.06 6.10±0.02 7.50±0.07 11.00±0.16

The data given are mean (n=3) ± standard error.

(Table 3). The leaf, stem and root extracts in water, petroleum Root extract of M. jalapa showed the lowest MIC values ether and ethyl alcohol of B. spectabilis, B. diffusa and M. against all the pathogenic bacteria tested. Standard anti- jalapa showed antibacterial effect against 4 strains of biotics also showed good MIC values against the patho- bacteria; S. aureus, E. coli, P. aeruginosa and P. vulgaris. genic bacteria (Table 4). The result is in agreement with the earlier reports of The comparison of phytoextracts with antibiotics (Table Hiremath et al. (1996, 1997) indicating that dicot plants 5) clearly indicates its efficacy in controlling the growth of produce certain alkaloids which can control the growth of pathogenic bacteria. Among all the phytoextracts used in microbial pathogens. the present study, 25% concentration of M. jalapa plant During the present study, the extracts from the leaves, showed best antibacterial activity followed by B. stems and roots of test plants exhibited strong anti- spectabilis. The large zone of inhibition of M. jalapa was microbial activity greater than those from other parts that reported against P. aeruginosa (12.0 ± 0.12) and small is bark, fruits, flowers ad seeds. The reason behind this was evaluated against E. coli (7.00 ± 0.12). Both standard point is that these plant organs, at the start, are more antibiotics used for antibacterial activity repre-sented susceptible to microbial attack. And at a later stage, excellent antibacterial activity but large inhibition zone these parts naturally get enriched with bioactive com- was presented by 25% concentration of erythromycin. E. pounds than some other parts to overcome this kind of coli was significantly affected (18.50 ± 0.16) and showed problem. Because of their stronger innate immunity, poor growth in test medium. The high anti-bacterial these plant organs are protected against microbial attack. potency of the plants confirms their traditional therapeutic Some previous reports confirm this statement (Alwadi claims. and Baka, 2001). The phytoextracts showed a lesser degree of inhibition when compared to antibiotics. The antibiotics are in extra DISCUSSION pure form when compared with the crude phytoextracts. The alkaloids responsible for the inhibitory effect of the Plant extracts are able to restrict the growth of bacteria phytoextracts have to be selected, purified and can be due to the presence of active principles in it. These active used as a broad-spectrum antimicrobial agent (Sakharkar principles may inhibit protein synthesis of bacterial cell and Pati, 1998; Nagendran and Thiruvalluvan, 1999). wall or alter the membrane function, inhibit protein syn- The results suggest the presence of good antibacterial thesis or synthesis of purine and pyrimidines, hinder potency, and have a high potential as a source of anti- respiration or antagonize the metabolic pathways of bacterial agent for therapeutic use. The use of antibiotics microorganism leading to retardation of growth of is not only expensive but also develops drug resistance in bacteria. These active principles in these plants could be bacteria. The microbial inhibitory compounds that is used as potent antibiotics. alkaloids, peptides and glycosides present in the

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phytoextracts of B. spectabilis, B. diffusa and M. jalapa Bassolé IHN, Ouattara AS, Nebie R, Ouattara CAT, Kaboré ZI, Traoré can be utilized for the effective control of pathogenic SA (2003). Chemical compostition and antibacterial activities of essential oils of lippia chevalieri and Lippia multiflora. bacteria. The present study revealed that the root part of Phytochemistry, 62: 209-2112. M. jalapa can be recommended for large scale production Farnsworth NR (1988). Screening plants for new medicines. In: E.O. of active compounds due to its significant as well as Wilson, Editor, Biodiversity, National Academic Press, Washington, excellent antibacterial efficiency. The high degree of DC. pp. 83-97. Hiremath SP, Rudresh K, Badami S (1997). Antimicrobiol activity of antibacterial activity seems to confirm the folk therapy of various plants extracts of Striga sulperea and Hemidesmus indicus. infection and traditional therapeutic claims of these Ind. J. Pharm. Sci. 59: 145-147. plants. Hiremath SP, Swamy HKS, Badami S, Patil SB, Londonker RL (1996). The antimicrobial results of this study also support Antibacterial and antifungal activities of Striga densifolia and Striga orobanchiodes. Int. J. Pharmacol. 34: 48-50. several of the traditional medicinal uses of Nicta- Ikram M, Inamul H (1984). Screening of medicinal plants for genaceae members in India and show that the ethno- antimicrobial activities. Fitoterapia 55: 62-64. botanical approach to screening plants as potential Izzo AA, Di Carlo G, Biscardi D, Fusco R, Mascolo N, Borreli F, sources of bioactive substances is of great value. The Capasso F, Fasulo MP, Autore G (1995). Biological screening of Italian medicinal plants for antibacterial activity. Phytother. Res. 9: potential for developing antimicrobial drugs from higher 281-286. plants appears rewarding, as it will lead to the Jansen AM, Cheffer JJC, Svendsen AB (1987). Antimicrobial activity of development of a phytomedicine to act against microbes. essencial oils: a 1976-1986 literature review. Aspects of test Therefore, such screening experiments form a primary methods. Plant Med. 40: 395-398. Karaman I, Sahin F, Güllüce M, Ögütcü H, Sengül M, Adıgüzel A platform for further phytochemical and pharmacological (2003). Antimicrobial activity of aqueous and methanol extracts of studies that may open the possibility of finding new Juniperus oxycedrus L. J. Ethnophormacol. 85: 231-235. clinically effective antibacterial compounds. The syner- Kubo L, Muroi H, Himejima M (1993). Structure-antibacterial activity gistic effect from the association of antibiotic with plant relationships of anacardic acids. J. Agric. Food Chem. 41:1016-1019. Nagendran NA, Thiruvalluvan M (1999). Effect of antibiotics and extracts against resistant bacteria leads to new choices Ocimum sanctum leaf extract on Pseudomonas sp. associated with for the treatment of infectious diseases. This effect flacheria disease. Asian J. Microbiol. Biotechnol. Environ. Sci. 1: 119- enables the use of the respective antibiotic when it is no 120. longer effective by itself during therapeutic treatment. Projan SJ (2003). Why is Big Pharma Getting Out of antibacterial drug discovering? Curr. Opin. Microbiol. 6: 427-430. The present findings show that the plant extracts had a Sakharkar PR, Pati AT (1998). Antimicrobial activity of Cassia alata. high antibacterial activity. Further research work is under- Ind. J. Pharmaco. Sci. 12: 311-312. way to purify and characterize the antibacterial proteins/ Santos PRV, Oliveira ACX, Tomassini TCB (1995). Controle peptides from the plants. microbiógico de produtos fitoterápicos. Rev. Farm. Bioquím. 31: 35- 38. Saxena G, McCutcheon AR, Farmer S, Towers GHN, Hancock REW (1994). Antimicrobial constituents of Rhus glabra. J. Ethnopharmacol. REFERENCES 42: 95-99. Shapoval EES, Silveira SM, Miranda ML, Alice CB, Henriques AT Almagboul AZ, Bashir AK, Farouk A, Salih AKM (1985). Antimicrobial (1994). Evaluation of some pharmacological activities of Eugenia activity of certain Sudanese plants used in folkloric medicine. uniflora. J. Ethnopharmacol. 44: 136-142. Screening for antibacterial activity. Fitoterapia. 56:331-337. Varier PS (1997). Indian medicinal plants. A compendium of 500 Alwadi HN, Baka ZAM (2001). Microorganisms associated with species. Orient Longman. Volume 2nd. Withania somnifera leaves. Microbiol. Res. 156:303-309. Wenzel RP (2004). The antibiotics pipeline challenges, costs and Artizzu N, Bonsignore L, Cottiglia F, Loy G (1995). Studies of the values. Engl. J. Med. 351:523-526. diuretic and antimicrobial activity of Cynodon dactylon essential oil. WHO (1993). Summary of WHO guidelines for the assessment of Fitoterapia 66: 174-175. herbal medicines. Herbal gram 28:13-14. Balick MJ, Arvigo R, Romero L (1994). The development of an ethnobiomedical forest reserve in Belize: its role in the preservation of biological and cultural diversity. Conserv. Biol. 8: 316-317.