INTRODUCTION:

Plant-produced compounds are of interest as sources of safer or more effective substitutes for synthetically produced antimicrobial agents.¹ Since ancient times, plants have been a variable source of drugs, man tends to ignore the importance of herbal medicine.² Research work on medicinal plants is intensified and information on these plants be exchanged. This thought will go a long way in the scientific exploration of medicinal plants for the benefit of man and is likely to decrease the dependence or importance of drugs.³ Plants have been a rich source of drugs because they produce wide array of bioactive molecules, most of which probably evolved as chemical defense against predation or infection. Herbs are widely exploited in the traditional medicine and their curative potentials are well documented.⁴Antibacterial active principle isolated from higher plants is appeared to be one of the important alternative approaches to contain antibiotic resistance and the management of disease. It is believed that plant based drugs cause less or no side effect when compared with synthetic antibiotics.⁵

Calotropis gigantea L. is a traditional medicinal plant it belongs to the family of Asclepiadaceous habitat of Asian countries that includes India, Indonesia, Malaysia, Thailand, Srilanka and china. It is commonly known as milkweed or swallows worth. The plant grows up to 2-4.3 meters long. It has oral, light green leaves and milky stem. The leaves are very much succulent in nature. Calotropis gigantea L. is medicinally used to treat disease such as fevers, rheumatism, indigestion, cough, cold, eczema, asthma elephantiasis, nausea, vomiting, leprosy, diarrhea.⁶ Calotropis gigantea L. is scientifically reported for its cytotoxic, antipyretic and wound healing activity.^7-10The whole plant of Calotropis gigantean L. have many medicinal uses; milky sap is used to stop bleeding, and for treating boils, scabies, burns, bruises, cuts, sores and wounds. Milky sap (Latex) yields several tri-terpenes, cystein proteinases and galactin. Leaf is infused for severe chest colds and heart conditions.^11-13 In several species substantial amount of cardenolides have been found to be concentrated in the latex. The antimicrobial property was more effective against bacteria.¹⁴ The scope of this study is to investigate antimicrobial activity of the crude leaf extract of Calotropis gigantea L. against clinical isolates.The present communication attempts to study the antimicrobial activity of separate extraction using acetone, ethyl acetate, methanol and aqueous extracts from leaf of Calotropis gigantea L. is investigated against a few clinically isolated as well as standard microbial cultures of bacterial and fungal organisms using disc diffusion method.

MATERIALS AND METHOS:

Plant (leaves) materials

The fresh leaves materials of Calotropis gigantea L. (Asclepiadaceous) were collected from natural population growing in the waste land of Neyveli, Cuddalore district, Tamilnadu, India during June 2008 and indentified with the help of the Flora of Presidency of Madras. ^15,16

Extract preparation:

Plant leaves were collected and washed properly with distilled water and the leaves were shade dried at room temperature in laboratory for 3-4 days. The air dried leaves were dried in a hot air oven at 40°C for 24 hrs to remove moisture content. The completely dried leaves were ground into powders using mixer, about 5gms of the dried leaves were dissolved in different organic solvents like acetone, ethyl acetate, and methanol and aqueous. The solvents were chosen according to their polarity. Along with solvents dimethyl sulfoxide is added according to the concentration used since this acts as inert reagent. About 10gms of the dried leaf powder was mixed with water for aqueous extract was taken by using soxlet apparatus and concentrated under reduced pressure (T< 40ºC). The process of extraction was carried out in a water bath shaker at 40 ºC for 48 hrs. The extracts were filtered in a whatmann no.1 filter paper. The solvents were recovered and the extracts were concentrated by using rotar evaporator. The yield of acetone extract was 6.8 %, ethyl acetate extract was 6.4%, and methanol extract was 12.2% for 5 gm of leaf powder. The grid of aqueous extract was 20% for 10gm of leaf powder. One gram from each of different extract were weighed in dry clean bottle and diluted by using 10% solution of dimethyl sulfoxide (DMSO), to make 100mg/ml. The aqueous extract is diluted by using saline (0.9%). The diluted solution was used for further antimicrobial work.

Preparation of samples:

Acetone, ethyl acetate and methanol extracts were dissolved in DMSO at a concentration of 50 mg/ml and 100 mg/ml respectively and used as working stocks. Sterile discs (Hi-media Labs) were impregnated with 20μl of the stock solution. Gentamicin for bacteria and amphitricin for fungus was used as standards for comparative studies.

Micro organisms:

Both Gram positive and Gram negative bacterias and fungus were used as test organism for this study. They were obtained from the stock cultures of Life tech research centre and from SRM medical college hospital. Gram positive bacteria such as Staphylocpccus aureus, Bacillus subtilis, Bacillus cercus, Lactobacillus acidophillus and Bacillus circulans. Gram negative bacteria such as Pseudomonas aeruginosa, Aeromonas hydrophila, Vibrio cholerae, Salmonella typhi, Shigella flexineri, Enterabacter faecalis, Salmonella paratyphi A, Salmonella paratyphi B, Proteuse mirabilis, Serratia marscens, Vibrio paraheamolytuis, Vibrio vulnificus and Shigella dysenteriae, Escherichia coli and fungus like Asperigillus niger, Asperigillus fumigatus, Cephalosporium neoform, Candida albicans, Trichophyta mentagrophyte, Trichophyta rubrum,curvularia species, fusarium species. The organisms were sub cultured on to nutrient agar in order to determine their viability. The identity of each test organism was confirmed by using standard culture, morphological and biochemical techniques as described.¹⁷Stock cultures were maintained on nutrient agar slants at 4ºC and then sub-cultured in nutrient broth at 37ºC prior to each antimicrobial test. Inoculants of the test organisms were standardized by methods.¹⁵ Antimicrobial activities of leaf extract fractions were determined as diameter of inhibition zone using a disc diffusion method.^18-20

Anti-microbial assay:

Muller Hinton Agar (Hi media) for bacteria and potato Dextrose Agar (Hi-media) for fungus were prepared according to the manufacturer’s instructions. Muller Hinton Agar (MHA) contains Beef-2 g, casein acid hydrolysate 17.5 g, starch 105 g and agar 17 g; pH 7.4 ± 0.2. MHA (38 g) was weighed and dissolved in 1000 ml of distilled water. Potato Dextrose Agar (PDA) was used for cultivation of fungi and particularly pathogenic fungi associated with skin infections. It contains Peptone – 10g, dextrose 40g and agar 15g; pH 5.6 ± 0.2. PDA (65g) was dissolved in 1000 ml of distilled water. The medium was sterilized by autoclaving at 121ºC for 15 minutes at 15 psi pressure and was used for tests. Sterile molten cool (45ºC) agar was poured aseptically into sterile petri dishes (15 ml each) and the plates were allowed to solidify at room temperature in sterile condition.

After gelling and drying, the plates were seeded with appropriate micro organisms by streaking evenly on to the surface of the medium with a sterile cotton swab or pouring the appropriate microorganism on the surface of dry agar plate present in peptone broth. Care was taken for the even distribution of culture all over the plate. The inoculums were allowed to dry for 5 minutes. The discs of 6mm diameter were prepared from Whatmann filter paper No. 1 and were sterilized in a hot air oven at 160ºC for 1 hrs. The discs were then impregnated with the extracts and solvent DMSO, Amikacin, Gatifloxacin, Ciprofloxacin, Amphitrosine, discs were used as standard. Each disc contained 5 µg of corresponding standards.

Sterile Whattman No 1 filter paper with 100mg/ml were placed on to the agar with flamed forceps and gently pressed down to ensure contact along with the diluted extract, one appropriate control dry disc also placed at the centre. Then the plates were incubated below 37ºC for 24 hrs to allow perfusion of drugs being tested. The next day the zones of inhibition were measured with a measuring scale. This experiment was carried out in triplicate for their conformation. The results were read by the presence or absence of zone of inhibition. The lowest concentration of the each extract that inhibited the organisms was recorded as the MIC. This experimental procedure was repeated using several dilution of different successive extract until the minimal inhibitory zone was obtained.

Table 1: Antibacterial effect of separate extract of Acetone, Ethyl acetate, Methanol and Aqueous from of leaf extract of Calotropis gigantea L. for Gram positive bacteria (50mg/ml), (100mg/ml).

Name of the Bacterial organisms	Zone of inhibition
	Separate extracts
	Acetone		Ethyl Acetate		Methanol		Aqueous		Standard (Gentamycin)
	50mg	100mg	50mg	100mg	50mg	100mg	50mg	100mg
Staphylococcus aureus	6 cm	7 cm	6 cm	7 cm	6 cm	8 cm	-	-	22 cm
Bacillus subtilis	5 cm	7 cm	-	7 cm	--	8 cm	-	-	21 cm
Bacillus cereus	-	6 cm	-	5 cm	6 cm	7 cm	-	-	26 cm
Lactobacillus acidophilus	6 cm	7 cm	6 cm	7 cm	6 cm	7 cm	-	-	21 cm
Bacillus circulans	6 cm	-	8 cm	-	7 cm	-	-	-	23 cm

Table 2: Antibacterial effect of separate extract of Acetone, Ethyl acetate ,Methanol, and Aqueous from leaf extract of Calotropis gigantea L. for Gram negative bacteria (50mg/ml), (100mg/ml).

Name of the Bacterial organisms	Zone of inhibition
	Separate extracts
	Acetone		Ethyl Acetate		Methanol		Aqueous		Standard (Gentamycin)
	50mg	100mg	50mg	100mg	50mg	100mg	50mg	100mg
Pseudomonas aeruginosa	-	6 cm	-	5 cm	-	8 cm	-	-	15 cm
Aeromonas hydrophila	8 cm	5 cm	9 cm	6 cm	6 cm	10 cm	-	-	20 cm
Vibrio cholerae	7 cm	10 cm	10 cm	6 cm	6 cm	8 cm	-	-	21 cm
Salmonella typhi	7 cm	6 cm	6 cm	7 cm	5 cm	7 cm	-	-	24 cm
Shigella flexneri	-	7 cm	5 cm	8 cm	-	9 cm	-	-	22 cm
Enterobacter faecalis	-	5 cm	11 cm	7 cm	6 cm	10 cm	-	-	27 cm
Salmonella paratyphi A	-	6 cm	-	6 cm	-	6 cm	-	-	15 cm
Salmonella paratyphi B	-	9 cm	-	8 cm	-	10 cm	-	-	15 cm
Proteuse mirabilis	-	6 cm	-	7 cm	-	8 cm	-	-	20 cm
Serratia marcens	-	5 cm	-	5 cm	-	6 cm	-	-	20 cm
Vibrio parahaemolyticus	5 cm	8cm	-	7 cm	6 cm	7 cm	-	-	16 cm
Vibrio vulnificus	5 cm	6 cm	-	5 cm	5 cm	6 cm	-	-	20 cm
Shigella dysenteriae	-	5 cm	-	5 cm	-	6 cm	-	-	21 cm
Escherichia coli	-	5 cm	5 cm	6 cm	-	6 cm	-	-	17 cm

Antifungal Activity:

The plate technique was used to investigate the antifungal activity of Calotropis gigantea L. against fungal pathogens. About 1% concentration of leaf extract was prepared and mixed separately with potato dextrose agar medium and poured aseptically in sterilized petriplates of acetone, ethyl acetate, methanol and aqueous. Control contains only the potato dextrose agar (PDA). The standard was also prepared by using Amphitericin Antibiotics (2µl). A fungal organism was taken in the inoculation loop and it is spot inoculated at the centre of the Petri plates containing PDA agar. The growth of the fungal organisms was observed for 5 days. After 5^th day of incubation, the growth of organisms was measured and the present growth inhibition was calculated using the formula.

% Incubation =

Growth of Pathogen in Control – Growth of pathogen in test × 100

Growth of Pathogen in control

Disc diffusion method:

Antimicrobial activity was determined as diameter of inhibition zone using a disc diffusion method.^[^18,19]An even spread of micro organisms was prepared by mixing 200 ml of inoculum (adjusted to 105–106 CFU: ml) with 20 ml of agar at 50°C and allowed to set (NA for bacteria and PDA for fungi) in a petri dish (f 90 cm) (modified from Bauer et al., 1966). One milligram of different extract was loaded onto each Whatman No. 1 filter paper discs (f 6 mm) and placed on the previously inoculated agar. The plates were inverted and incubated for 24 h at 30°C. Antimicrobial activity was indicated by the presence of clear inhibition zones around the discs.

RESULTS AND DISCUSSION:

Medicinal plans are being probed as an alternate source to get therapeutic compounds based on their medicinal properties. Calotropis gigantea L. is easily available in most of the agricultural and non agricultural fields and the usage of this plant for medicinal purpose was reported by several researchers.

Table1 portraits that acetone, ethyl acetate methanol and aqueous extract of Calotropis gigantea L. for Gram positive bacteria. It is indicated that acetone extract shows zone of inhibition for Staphylococcus aureus is 6cm at 50mg/ml and 7cm at 100 mg/ml. Bacillus subtilis is 5 cm at 50mg/ml and 7cm at 100mg/ml. Bacillus cereus is 6cm at 100 mg /ml,. Lactobacillus acidophillus is 6cm at 50mg/ml and 7cm at 100mg/ ml, Bacillus circulans is 6cm at 50mg/ml. Ethyl acetate extract shows zone of inhibition for staphylococcus aureus is 6cm at 50mg/ml and 7cm at 100mg / ml, Bacillus subtilis is 7cm at 100mg/ml, Bacillus cereus is 5cm at 100mg/ml, Lactobacillus acidophillus is 6cm 50mg/ml and 7cm at 100mg/ml, Bacillus circulans is 8cm at 50mg/ml. Methanol extract shows zone of inhibition for Staphylococcus aureus is 6cm at 50mg/ml and 8cm at 100mg/ml, Bacillus subtilis is 8cm at 100mg/ml, Bacillus cereus is 6cm at 50mg/ml and 7cm at 100mg/ml, Lactobacillus acidophillus is 6cm at 50mg/ml and 7cm at 100mg/ml, Bacillus circulans is 7cm at 50mg/ml. No valuable activity was observed against bacteria in aqueous extract.

Table 2 explains that zone of inhibition of acetone extract for Pseudomonas aeruginosa is 6cm at 100mg/ml, Aeromonas hydrophila is 8cm at 50mg/ml and 5cm at 100mg/ml, Vibrio cholerae is 7cm at 50mg/ml and 10cm at 100mg/ml, Salmonella typhi is 7cm at 50mg/ml and 6cm at 100mg/ml, Shigella flexneri is 7cm at 100mg/ml, Enterobacter faecalis is 5cm at 100mg/ml, Salmonella paratyphi A is 6cm at 100mg/ml, Salmonella paratyphi B is 9cm at 100mg/ml, Proteuse mirabilis is 6cm at 100mg/ml, Serratia marcens is 5cm at 100mg/ml, Vibrio parahaemolyticus is 5cm at 50mg/ml and 8cm at 100mg/ml, Vibrio vulnificus is 5cm at 50mg/ml and 6cm at 100mg/ml Shigella dysenteriae is 5cm at 100mg/ml, Escherichia coli is 5cm at 100mg/ml.

Ethyl acetate extract shows zone of inhibition for Pseudomonas aeruginosa is 5cm at 100mg/ml, Aeromonas hydrophila is 9cm at 50mg/ml and 6cm at 100mg/ml. Vibrio cholerae is 10cm at 50mg/ml and 6cm 100mg/ml, Salmonella typhi is 6cm at 50mg/ml and 7cm at 100mg/ml. Shigella flexneri is 5 cm at 50mg/ml and 8cm at 100mg/ml. Enterobacter faecalis is 11cm at 50mg/ml and 7cm at 100mg/ml, Salmonella paratyphi A is 6cm at 100mg/ml, Salmonella paratyphi B is 8cm at 100mg/ml. Proteuse mirabilis is 7cm at 100mg/ml, Serratia marcens is 5cm at 100mg/ml, Vibrio Parahaemolyticus is 7cm at 100mg/ml, Vibrio vulnificus is 5cm at 100mg/ml, Shigella dysenteriae is 5cm at 100mg/ml, Escherichia coli is 5cm at 50mg/ml and 6cm at 100mg/ml.

Methanol extract shows zone of inhibition for Pseudomonas aeruginosa is 8cm at 100mg/ml, Aeromonas hydrophila is 6cm at 50mg/ml and 10cm at 100mg/ml, Vibrio cholerae is 6cm at 50mg/ml and 8cm at 100mg/ml, Salmonella typhi is 5cm at 50mg/ml and 7cm at 100mg/ml, Shigella flexneri is 9 cm at 100mg/ml, Enterobacter faecalis is 6cm at 50mg/ml and 10cm at 100mg/ml, Salmonella paratyphi A is 6cm at 100mg/ml, Salmonella paratyphi B is 10cm at 100mg/ml, Proteuse mirabilis is 8cm at 100mg/ml, Serratia marcens is 6cm at 100mg/ml, Vibrio Parahaemolyticus is 6cm at 50mg/ml and 7cm at 100mg/ml, Vibrio vulnificus is 5cm at 50mg/ml and 6cm at 100mg/ml, Shigella dysenteriae is 6cm at 100mg/ml, Escherichia coli is 6cm at 100mg/ml. No valuable activity was observed against bacteria in aqueous extract.

Table 3 shows that antifungal effect of acetone extract for Aspergillus niger is 14.6% at 50mg/ml and 13.3% at 100mg/ml. Aspergillus fumigatus is 09.6% at 50mg/ml and 11.7% at 100mg/ml. Cephalosporium neoforms is 09.0% at 50mg/ml and 23.5% at 100mg/ml. Candida albicans is 07.6% at 50mg/ml and 17.6% at 100mg/ml. Trichophyta mentagrophyte is 07.6% at 50mg/ml and 03.8% at 100mg/ml. Trichophyta rubrum is 03.5% at 50mg/ml and 03.8% at100mg/ml. Curvularia species is 29.1% at 50mg/ml and 08.1% at 100mg/ml. Fusarium species is 08.6% at 50mg /ml and 08.0% at 100mg/ml.

Table 3: Antifungal effect of separate Acetone extract from leaf of Calotropis gigantea L. for fungus (50mg/ml) and (100mg/ml).

Name of the Bacterial organisms	Acetone extract (50mg/ml) on 5^th Day			Acetone extract (100mg/ml) on 5^th Day
Name of the Bacterial organisms	Control	Test	% Inhibition	Control	Test	% Inhibition
Aspergillus niger	41 cm	35 cm	14.6%	45 cm	39 cm	13.3%
Aspergillus fumigatus	31 cm	28 cm	09.6%	34 cm	30 cm	11.7%
Cephalosporirum neoforms	11 cm	10 cm	09.0%	17 cm	13 cm	23.5%
Candida albicans	13 cm	12 cm	07.6%	17 cm	14 cm	17.6%
Trichophyta mentagrophyte	26 cm	24 cm	07.6%	26 cm	25 cm	03.8%
Trichophyta rubrum	28 cm	27 cm	03.5%	26 cm	25 cm	03.8%
Curvularia species	24 cm	17 cm	29.1%	37 cm	34 cm	08.1%
Fusarium species	23 cm	21 cm	08.6%	25 cm	23 cm	08.0%

Table 4: Antifungal effect of separate Ethyl acetate extract from leaf of Calotropis gigantea L. for fungus (50mg/ml) and (100mg/ml).

Name of the Bacterial organisms	Ethyl Acetate extract (50mg/ml) on 5^th Day			Ethyl Acetate extract (100mg/ml) on 5^th Day
Name of the Bacterial organisms	Control	Test	% Inhibition	Control	Test	% Inhibition
Aspergillus niger	41 cm	37 cm	09.7%	45 cm	36 cm	20.0%
Asperigillus fumigatus	31 cm	28 cm	09.6%	34 cm	30 cm	11.7%
Cephalosporium neoforms	11 cm	10 cm	09.0%	17 cm	12 cm	29.4%
Candida.albicans	13 cm	15 cm	07.6%	17 cm	14 cm	17.6%
Trichophyta mentagrophyte	26 cm	24 cm	07.6%	26 cm	23 cm	11.5%
Trichophyta rubrum	28 cm	26 cm	07.1%	26 cm	25 cm	03.8%
Curvularia species	24 cm	12 cm	50.0%	37 cm	35 cm	05.4%
Fusarium species	23 cm	20 cm	13.0%	25 cm	24 cm	04.0%

Table 5: Antifungal effect of separate Methanol extract from leaf of Calotropis gigantea L. for fungus (50mg/ml) and (100mg/ml).

Name of the Bacterial organisms	Methanol extract (50mg/ml) on 5^th Day			Methanol extract (100mg/ml) on 5^th Day
Name of the Bacterial organisms	Control	Test	% Inhibition	Control	Test	% Inhibition
Aspergillus niger	43 cm	34 cm	20.9%	45 cm	36 cm	20.0%
Asperigillus fumigatus	33 cm	27 cm	18.1%	34 cm	32 cm	06.2%
Cephalosporium neoforms	12 cm	9 cm	25.0%	17 cm	11 cm	35.2%
Candida albicans	23 cm	15 cm	08.6%	17 cm	15 cm	11.7%
Trichophyta mentagrophyte	25 cm	19 cm	24.0%	26 cm	24 cm	07.6%
Trichophyta rubrum	30 cm	27 cm	10.0%	26 cm	23 cm	11.5%
Curvularia species	25 cm	21 cm	16.0%	37 cm	32 cm	13.5%
Fusarium species	24 cm	20 cm	16.6%	25 cm	23 cm	08.0%

Table 6: Antifungal effect of separate Aqueous extract from leaf of Calotropis gigantea L. for fungus (50mg/ml) and (100mg/ml).

Name of the Bacterial organisms	Methanol extract (50mg/ml) on 5^th Day			Methanol extract (100mg/ml) on 5^th Day
Name of the Bacterial organisms	Control	Test	% Inhibition	Control	Test	% Inhibition
Aspergillus niger	41 cm	32 cm	40.0%	42 cm	40 cm	40.0%
Asperigillus fumigatus	28 cm	26 cm	29.0%	34 cm	32 cm	29.0%
Cephalosporium neoforms	23 cm	19 cm	23.0%	17 cm	11 cm	23.0%
Candida albicans	21 cm	19 cm	20.0%	17 cm	12 cm	20.0%
Trichophyta mentagrophyte	25 cm	22 cm	25.0%	26 cm	24 cm	25.0%
Trichophyta rubrum	35 cm	29 cm	33.0%	26 cm	24 cm	33.0%
Curvularia species	21 cm	20 cm	25.0%	37 cm	34 cm	25.0%
Fusarium species	27 cm	22 cm	29.0%	25 cm	23 cm	29.0%

Table 4 narrates that antifungal effect of ethyl acetate extract for Aspergillus niger is 09.7% at 50mg/ml and 20.0% at 100mg/ml. Aspergillus fumigatus is 09.6% at 50mg/ml and 11.7% at 100mg/ml. Cephalosporium neoforms is 09.0% at 50mg/ml and 29.4% at 100mg/ml. Candida albicans is 07.6% at 50mg/ml and 17.6% at 100mg/ml. Trichophyta mentagrophyte is 07.6% at 50mg/ml and 11.5% at 100mg/ml. Trichophyta rubrum is 07.1% at 50mg/ml and 03.8% at100mg/ml. Curvularia species is 50.0% at 50mg/ml and 05.4% at 100mg/ml. Fusarium species is 13.0% at 50mg /ml and 04.0% at 100mg/ml.

Table 5 describes that antifungal effect of methanol extract for Aspergillus niger is 20.9% at 50mg/ml and 20.0% at 100mg/ml. Aspergillus fumigatus is 18.1% at 50mg/ml and 06.2% at 100mg/ml. Cephalosporium neoforms is 25.0% at 50mg/ml and 35.2% at 100mg/ml. Candida albicans is 08.6% at 50mg/ml and 11.7% at 100mg/ml. Trichophyta mentagrophyte is 24.0% at 50mg/ml and 07.6% at 100mg/ml. Trichophyta rubrum is 10.0% at 50mg/ml and 11.5% at 100mg/ml. Curvularia species is 16.0% at 50mg/ml and 13.5% at 100mg/ml. Fusarium species is 16.6% at 50mg /ml and 08.0% at 100mg/ml.

Table 6 denotes that zone of inhibition of aqueous extract for Aspergillus niger is 40.0% for 50mg/ml and 100mg/ml. Aspergillus fumigatus is 29.0% for 50mg/ml and 100mg/ml, Cephalosporium neoforms is 23.0% for 50mg/ml and 100mg/ml. Candida albicans is 20.0% at 50mg/ml and 100mg/ml, Trichophyta mentagrophyte is 25.0% at 50mg/ml and 100mg/ml. Trichophyta rubrum is 33.0% at 50mg/ml and 100mg/ml. Curvularia species is 25.0% at 50mg/ml and 100mg/ml. Fusarium species is 29.0% at 50mg/ml and 100mg/ml.

CONCLUSION:

All fractions showed very good level of broad spectrum of antibacterial activity tested at a concentration 100mg/ml, particularly good activity was observed in methanol extract from the leaf of Calotropis gigantea L. No valuable activity was observed against bacteria in aqueous extract. Early studies on the antimicrobial activity of Calotropis gigantea L. root bark extracts revealed its antibacterial potential against Sarcina lutea, B. megaterium, B. subtilis, Shigella sonnei, Escherichia coli and P. Aerugeinosa.^[21]According to fungal strain, antifungal activity of acetone, ethyl acetate and methanol showed less inhibitory activity at the tested concentration than that of aqueous. Though less activity was observed against fungi, these results may prove scientific support for some uses of the plant in traditional medicine. In conclusion data presented in this study explain and justify the use of Calotropis gigantea L. extract in the treatment of diarrhoea, typhoid, cholera, chronic jaundice, fever, headache, skin disease etc. The present work has shown that the leaf of Calotropis gigantea L. is potentially good source of antibacterial agent and that further investigations are carried to support the view that traditional use in medicine and also assisting primarily health care.

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Received on 15.09.2011 Accepted on 08.11.2011

Asian J. Pharm. Res. 1(4): Oct. - Dec. 2011; Page102-107