Diuretic and antimicrobial activity of leaves of Limnophila rugosa

Madhumitha.B^*, P Devi, Meera R, and Kameswari B

K.M.College of Pharmacy, Uthangudi, Madurai, TamilNadu , India

*Corresponding Author E-mail: madhu_10283@rediffmail.com

ABSTRACT

Solvent ether, Aqueous and alcoholic extracts of Limnophila rugosa leaves were investigated for Diuretic and antibacterial activity. The six hours acute study of successive aqueous, ethanolic extracts showed increase in urine volume and K ⁺ion excretion as compared to normal saline.The anti microbial activity was assessed by Disc diffusion method against E. coli, Staphylococcus aureus, Bacillus subtillis, Psuedomonas aeruginosa, Salmonella typhi, Vibrio cholerae. The extract was found to possess significant dose dependent diuretic activity and also effective against gram positive and gram negative bacteria

KEY WORDS: Limnophila rugosa leaves, Diuretic and Antibacterial activity, Amikacin, Furosemide

INTRODUCTION:

Limnophila rugosa (Solanaceae) commonly known as kala karpur. It is a erect herb.Infusion of leaves is used for stomachic and digestive tonic^1.No systematic studies have been reported for its diuretic activity. Hence an effort has been made to establish the diuretic activity of aqueous and alcoholic extracts of Limnophila rugosa .

MATERIALS AND METHODS:

The whole plant of Limnophila rugosa was collected in the month of June- July from Tirunelveli city.

Extraction:

In the present study the whole plant were shade dried. 400gms of powdered drug was extracted with alcohol in soxhlet apparatus for 24hrs. A dark brown green colored residue was obtained after concentrating the extract under reduced pressure.

The aqueous extract was obtained by macerating 400gm of powered Limnophila rugosa with 3 liters of distilled water (72 hrs) The extract was filtered and concentrated under reduced pressure to obtain greenish brown colored residue.

Experimental animals:

Male rats (wistar albino strain) weighing 150 to 180gm were maintained under standard conditions of temperature and humidity. The method of Lipschitz et al ³ was

employed for the assessment of Diuretic activity. Four groups of six rats, each weighing 150-180gm, were fasted and deprived of water for eighteen hours prior to the experiment.

On the day of experimental animals were given normal saline orally. (25ml/kg of body weight) in which the alcoholic and aqueous extracts were dissolved. Control animals received saline only. Immediately after dosing, the rats were placed in metabolic cages (3 in each cage) specially designed to separate urine and faeces. Animals were kept at room temperature of 25 ± 0.5 ⁰C throughout the experiment. The urine was collected in measuring cylinders up to 5 hr after dosing. During this period, no food or water was made available to animals. The parameters taken for individual rat were body weight (before and after test period) total urine volume, urine concentration of Na+, K^-, and Cl^-where applicable.

Na+, K^- concentrations were measured by Flame photometry⁴ and concentration was estimated by titration with silver nitrate solution (N/50) using one drop of 5% potassium chromate solution as indicator. Furosemide sodium salt⁵ was given by stomach tube. Optimal dose activity relation was found to be 100mg of Furosemide per kg body weight in a series of supportive experiments. Results are reported as mean ± SD, the test of significance (p <0.001) was statistically analyzed using student “t” test ⁶.

Anti bacterial activity:

Various extracts were reconstituted in Dimethyl Sulphoxide since this solvent does not demonstrate any antibacterial activity by itself. The antibacterial activity was assayed by 5the disc diffusion method⁷.The invitro screening was

TABLE: 1 Diuretic activity of Limnophila rugosa leaves on rats

Treatment

Dose mg/kg

No of Rats used

Urine Volume(ml)

Na+µ

Moles/kg

K+µ Moles/kg

Total Chloride

µMoles/kg

Na+/K+ Ratio

Normal

Aqueous extract

Alcoholic extract

Furosemide

Saline 25ml/kg

100mg/kg

2.0±0.10

2.9±0.13

1.9±0.30

3.6±0.36

1986±35

2890±31

2090±40

2998±44

905±29

1320±410^*

1120±24

1662±312

592±11

2010±12

2210±80

2690±110

2.194

2.189

1.866

1.550

The values are expression of the mean standard error. * P < 0.001 vs. control

carried out using 24 hour old cultures of E.coli, Staphylococcus aureus, Bacillus subtilis Pseudomonas aeruginosa, Salmonella typhi, Vibrio cholerae. Amikiacin was used as Standard and Nutrient Agar was used as the test medium. The plates were incubated at 37˚ and Zone of inhibition was measured after 24 hour using Digital Vernier Calipers.

RESULTS AND DISCUSSION:

Present study shows that the aqueous and alcoholic extract of Limnophila rugosa leaves possess diuretic activity. Urine volume, anion and cation excretion were increased. Na ⁺/K^-ratio of 2.189 and 1.866 were obtained for aqueous and alcoholic extracts respectively. The normal value for Na ⁺/K^- ratio is reported to be 2.05 to 2.83 ⁸. The concentration of aldosterone is found to be dependent on Na ⁺/K^- ratio. If the Na ⁺/K^- ratio falls below the normal in plasma the aldosterone secretion will be decreased and if the ratio rises above the normal value the aldosterone secretion will be increased. Significant increase in Na ⁺/K^- and Cl^- ion excretion was observed in aqueous and alcoholic extract treated animals but it was less than the Furosemide control.

TABLE: 2Anti bacterial activity of Limnophila rugosa leaves

Organisms	Diameter of Zone of Inhibition(mm)
	Solvent ether	Ethanolic extract	Aqueous extract	Standard Amikacin (5µg/disc)
E.coli	8.1	14	15	23.5
S.aureus	7.6	13	16	27
B.subtilis	9.5	13	17	32
P.aeruginosa	6.0	16	20	23
S.typhi	7.0	16	21	27
V.cholerae	8.0	15	22	24

The antimicrobial activity of the extract was performed by Disc Diffusion method on Nutrient Agar plates. The extract was dissolved in DMSO (10 mg/ml) and the discs were impregnated. Standard antibiotic discs of Amikacin (5µg/disc) were used for comparision. The microorganisms like E.coli, Staphylococcus aureus, Bacillus subtillis, Psuedomonas aeruginosa, Salmonella typhi, Vibrio cholerae were selected. The plates were incubated at 37˚ for 48 hours. The Zone of inhibition was calculated by measuring the minimum dimension of Zone of number of microbial growth around the disc.

REFERENCES:

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2. The Wealth of India, Council of Scientific and Industrial Research [CSIR] Publications New Delhi.1991:pp. 19.

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4. S.Kavimani, R.Ilango, J.G.Thangadurai, B.Jaykar, U.K.Manjumdar and Malaya Gupta.Indian Journal of Pharmaceutical Sciences.1997; 59: 96

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Received on 27.09.2008 Modified on 28.10.2008

Research J. Pharm. and Tech. 2(1): Jan.-Mar. 2009; Page 212-213