Indian Journal of Experimental Biology

Total visitors:3,043 since 23-08-05
ISSN : 0019-5189

CODEN : IJEB (A6) 43(8) 667-754 (2005)

VOLUME 43

NUMBER 8

AUGUST 2005

CONTENTS

Papers

The "Third Eye"- A new concept of trans-differentiation of pineal gland into median eye in amphibian tadpoles of Bufo melanostictus

    

671

     O P Jangir, P Suthar, DVS Shekhawat, P Acharya, 
        K K Swami & Manshi   Sharma

Effect of vitamin A on lens regeneration in pigs

       

679

   O P Jangir, Deepshikha Modi & Manshi Sharma

Glycolytic inhibitor, 2-deoxy-D-glucose, does not enhance radiation-induced apoptosis in mouse thymocytes and splenocytes in vitro

            R K Swamy, J Manickam, J S Adhikari & B S Dwarakanath

686

 

Isolation, identification and characterization of secretory proteins of IVMFC embryos and blood circulation of estrus and early pregnant goat

           Dhruba Malakar & A C Majumdar

693

 

Insulin regulates ionic metabolism in a fresh water teleost, Anabas testudineus (Bloch)

           A S Vijayasree, L Divya, P Sreejith, J Cyril, M Smita & O V Oommen

702

 

Evaluation of vasopressin mediated effects on hemostatic mechanisms: Relationship with aquaporins and caveolin proteins

            Manoj G Tyagi & Keshavan V Namboodri

710

 

Effect of standardized extract of Ocimum sanctum Linn. on gastric mucosal offensive and defensive factors

      R K Goel, K Sairam, M Dorababu, T Prabha & Ch V Rao

715

 

        Hepatoprotective activity of Leucas hirta against CCl4 induced hepatic damage in rats

B K Manjunatha, S M Vidya, Promilla Dhiman & R Pallavi

722

 

Hepatotoxic effects of tert-butyl hydroperoxide (t-BHP) and protection by antioxidants

Sangram Singh, Sudhir Mehrotra, Rajeev Pandey & Rajat Sandhir

728

 

Evaluation of free radical scavenging properties of two classical polyherbal formulations

            Milind S Bagul, Niranjan S Kanaki & M Rajani

732

 

Evaluation of mercury toxicity by some cytological indices in leucocyte cultures

           A Halder, M Patra & M De

737

 

Effect of water stress and heavy metals on induction of somatic embryogenesis in wheat leaf base cultures

Debasis Patnaik, A Mahalakshmi & Paramjit Khurana

740

 

Enhanced proteolysis leads to pre-mature cell death under the influence of elicitor like mycelial components from Karnal bunt (Tilletia indica) pathogen in wheat callus cultures

Shalini Mani, Manoj K Yadav, Gohar Taj Khan, U S Singh & Anil Kumar

746

 

Note

Heat stable antimicrobial activity of Allium ascalonicum against bacteria and fungi

M Amin & B P Kapadnis

751

 

Announcements

670

7th National Conference of Society of Science & Environment

1st Indo-Japanese Conference on Advances in Pharmaceutical Research and Technology: Drug discovery, development and delivery

 

Announcements

7th National Conference of Society of Science & Environment

17 and 18 September 2005, Udaipur 313001

 

Organized by the Department of Zoology, College of Science, M. L. S. University, Udaipur, the focal theme of conference will be "Challenges beyond 2005". The Conference will provide platform for interaction of the scientists in the fields of biotechnology, toxicology, pharmacology, oncology, environment and microbiology. For Further details, please contact the Organizing Secretary, Professor Maheep Bhatnagar, Department of Zoology, M. L. Sukhadia University, Udaipur 313001. Phone: 0294-2413995(O), 2441250(R); Fax: 0294-2425010; E-mail: mbhatnagar@yahoo.com

 

 

1st Indo-Japanese Conference on Advances in Pharmaceutical Research and Technology: Drug discovery, development and delivery

2629 November 2005, Mumbai, India

Jointly organized by Shri B V Education Trust and PERD Center, SciTech Centre, India, The Nagai Foundation, Japan, and the Academy of Pharmaceutical Research and Technology of Japan, and co-sponsored by IDMA, Pharmexcil and Indian Pharmaceutical Alliance, the Conference will be held at the Grand Hyatt Mumbai, Mumbai, India. Following topics will be discussed in major thematic sessions: (i) identification and validation of targets, (ii) finding and optimizing molecules, (iii) genomics and pharmacogenomics, (iv) biotech derived drugs and biotech approaches in drug discovery, (v) technological and conceptual advances in getting the drugs to the site of actions by using conventional and non-conventional routes like drug delivery through lung and skin, (vi) preparation and delivery through nanoparticles and nanotechnology, (vii) delivery of peptide and oligonucleotide drugs, and (viii) pharmacogenetics led individualization of drug metabolic capacity and the resultant therapeutic surgery. For further details, please contact, Professor H L Bhalla, Conference Convener & Chairman Scientific Committee, Advisor, SciTech Centre, 7, Prabhat Nagar, Jogeshwari (W), Mumbai 400102, India. [Phone: +91-22-26780127-29; 26903981, Fax: +91-22-26780131, E-mail: scitech@bomb5.vsnl.net.in] or Professor Harish Padh, Conference Secretary, Director, B V Patel PERD Centre, Thaltej, Ahmedabad 380054, India. [Phone: +91-79-27439375, 27416409, Fax: 91-79-27450449, E-mail: symposium@perdcentre.com or prd@perdcentre.com]. Details can be viewed at www.perdcentre.com also.

AUTHOR INDEX

Acharya P

671

Adhikari J S

686

Amin M

751

Anil Kumar

746

Bagul Milind S

732

Cyril J

702

De M

737

Dhiman Promilla

722

Divya L

702

Dorababu M

715

Dwarakanath B S

686

Goel R K

715

Halder A

737

Jangir O P

671

Jangir O P

 679

Kanaki Niranjan S

732

Kapadnis B P

751

Khan Gohar Taj

746

Khurana Paramjit

740

Mahalakshmi A

740

Majumdar A C

693

Malakar Dhruba

693

Mani Shalini

746

Manickam J

686

Manjunatha B K

722

Mehrotra Sudhir

728

Modi Deepshikha

679

Namboodri Keshavan V

710

Oommen V O

702

Pallavi R

722

Pandey Rajeev

728

Patnaik Debasis

740

Patra M

737

Prabha T

715

Rajani M

732

Rao Ch V

715

Sairam K

715

Sandhir Rajat

728

Sharma Manshi

671

Sharma Manshi

679

Shekhawat DVS

671

Singh Sangram

728

Singh U S

746

Smita M

702

Sreejith P

702

Suthar P

671

Swami K K

671

Swamy R K

686

Tyagi Manoj G

710

Vidya S M

722

Vijayasree A S

702

Yadav Manoj K

746

 

 

KEYWORD  INDEX

Allium ascalonicum

751

Allium cepa

751

Allium sativum

751

Alloxan monohydrate

702

Antimicrobial activity

751

Antioxidant

715,

 t-hydroperoxide

728

Apoptosis

686

Aquaporin

710

t-BHP

728

Bleeding

710

Brain

702

Bufo melanostictus

671

Ca2+ATPase

702

Cadmium

740

Caveolin

710

Cell viability

728

Chadraprabha Vati

732

Chromosomal aberration

737

Clotting

710

2-Deoxy-D-glucose

686

Diabetes

702

Elicitor

746

Embryo

693

Eugenol

715

Factor VIII

710

Flow cytometry

686

Free radicals

732

Gastric ulcer protection and healing

715

Gill

702

Goat

693

Guggulu

732

Heat stable

751

Heavy metals

740

Hepatoprotective activity

722

Insulin

702

Ionic metabolism 

702

IVM

693

IVMFC

693

Karnal bunt

746

Leaf extract

722

Lens regeneration

679

Leucas hirta

722

Leucocyte culture

737

Lipid peroxidation

728

Maha yogaraja

732

Mercury pollution

737

Mucosal offensive and defensive factors

715

Ocimum sanctum

715

Oocyte

693

Oxidative stress

728

Pig

679

Pineal gland

671

Polyherbal formulation

732

Programmed cell death

746

Proteolysis

746

Secretory protein

693

Somatic embryogenesis

740

Splenocytes

686

Teleost

702

Third eye

671

Thymocytes

686

Trans-differentiation

671

Vitamin A

671

Water stress

740

Wheat callus

746

Wheat

740

Vitamin A 679

 

 

 

 

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 671-678

 

Papers

The "Third Eye"¾ A new concept of trans-differentiation of pineal gland into median eye in amphibian tadpoles of Bufomelanostictus

O P Jangir, P Suthar, DVS Shekhawat, P Acharya, K K Swami & Manshi Sharma

 

Received 23 July 2004; revised 26 April 2005

Median third eye was found to develop from transplanted pineal gland of external gill stage tadpoles in the recipient
5 toe stage tadpoles of Bufo melanostictus. Pineal gland along with a bit part of brain tissue of the donor external gill stage tadpole was cut out and transplanted into a pit made between two lateral eyes of 5 toe stage recipient tadpoles. Half of the operated tadpoles were treated with vitamin A (15 IU/ml.) for 15 days. Median "third eye" was found to develop in the both untreated and vitamin A treated tadpoles. However, vitamin A increased the percentage of the development of median eyes. Morphological and histological study revealed that newly transformed median eyes were similar to that of normal functional eyes. A stalk like structure developed which connects the median eye to the brain. The median third eye could not develop when pineal gland of 5 toe stage mature tadpole was transplanted into the tadpole of the same age.

 

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 679-685

Effect of vitamin A on lens regeneration in pigs

O P Jangir, Deepshikha Modi & Manshi Sharma

 

Received 29 November 2004; revised 26 April 2005

Intraperitoneal injections of vitamin A (0.5 ml of 1500 IU/ml) to lentectomized pigs on alternate days up to 60th day after lentectomy induced lens regeneration in not only 10 days old young ones but also in 40 and 100 days old pigs. Lens regeneration did not occur even in a single case of control groups. In shape, size, transparency and histological features regenerated lenses were similar to normal intact lenses. The experimental model is the first to show that mitogenic and dedifferentiate activity of vitamin A can induce iris pigmented epithelial cells to trans-differentiate into new lens in pigs.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 686-692

 

Glycolytic inhibitor, 2-deoxy-D-glucose, does not enhance radiation-induced apoptosis in mouse thymocytes and splenocytes in vitro

R K Swamy, J Manickam, J S Adhikari & B S Dwarakanath

 

Received 29 July 2004; revised 29 March 2005

Earlier studies have shown that 2-deoxy-D-glucose (2-DG), a glucose analogue and inhibitor of glycolytic ATP production selectively enhances radiation-induced damage in cancer cells by inhibiting the energy (ATP) dependent post-irradiation DNA and cellular repair processes. A reduction in radiation induced cytogenetic damage has been reported in normal cells viz., peripheral blood lymphocytes and bone marrow cells. Since induction of apoptosis plays a major role in determining the radiosensitivity of some most sensitive normal cells including splenocytes and thymocytes, we investigated the effects of 2-DG on radiation induced apoptosis in these cells in vitro. Thymocytes and splenocytes isolated from normal Swiss albino mouse were irradiated with Co60 gamma-rays and analyzed for apoptosis at various post-irradiation times. 2-DG added at the time of irradiation was present till the termination of cultures. A time dependent, spontaneous apoptosis was evident in both the cell systems, with nearly 40% of the cells undergoing apoptosis at 12 hr of incubation. The dose response of radiation-induced apoptosis was essentially similar in both the cell systems and was dependent on the incubation time. More than 70% of the splenocytes and 60% of the thymocytes were apoptotic by 12 hr following an absorbed dose of 2 Gy. Presence of 2-DG marginally reduced the fraction of splenocytes undergoing apoptosis at all absorbed doses, while no change was observed in thymocytes. Presence of 2-DG did not significantly alter either the level or the rate of induction of spontaneous apoptosis in both these cell systems. These results are consistent with the earlier findings on radiation-induced cytogenetic damage in human PBL in vitro and mouse bone marrow cells and lend further support to the proposition that 2-DG does not enhance radiation damage in normal cells, while radiosensitizing the tumors and hence is an ideal adjuvant in the radiotherapy of tumors.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 693-701

 

Isolation, identification and characterization of secretory proteins of IVMFC embryos and blood circulation of estrus and early pregnant goat

Dhruba Malakar & A C Majumdar

Received 13 January 2005; revised 27 April 2005

The aim of the present study was to isolate, identify and characterize the secretory proteins of IVM oocytes and IVMFC embryos to evaluate its immunogenecity and identify of such proteins if any, in blood circulation of estrus and early pregnant goats. Oocytes were matured in TCM-199 with 1m g/ml, estradiol-17b ; 0.5 m g/ml, FSH; 100 IU/ml, LH and 10% FCS on granulosa cell monolayer. After 18 hr of maturation, oocytes were further cultured in maturation medium containing 3 mg/ml polyvinyl alcohol (PVA) without serum and BSA for 12 hr and medium was collected. The IVF embryos of 4-8 cell stage were cultured in medium containing PVA without serum and BSA. Embryo culture medium was collected after 24 hr of culture and was pooled. The proteins were analyzed on SDS-PAGE (12.5%). Four secretory proteins of oocytes with approximately molecular weight of 45, 55, 65 and 95 kDa and three secretory proteins of embryos 45, 55 and 65 kDa were obtained on SDS-PAGE in silver staining. The protein profile of midluteal, estrus and early pregnant goat serum was similar and no variation was observed among the proteins on SDS-PAGE. Two secretory proteins of 55 and 65 kDa of both IVM oocytes and IVMFC embryos were observed on Western analysis. None of such proteins was observed in midluteal, estrus and early pregnant goat serum on western blotting. It can be concluded that IVM oocytes and IVMFC embryos secrete proteins in medium and two of them can develop antibody. The proteins secreted from embryos till morula stage was similar to that of oocytes. None of these oocyte/embryo released proteins were observed in blood circulation of estrus and early pregnant goats.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 702-714

 

Insulin regulates ionic metabolism in a fresh water teleost,
Anabas testudineus (Bloch)

A S Vijayasree, L Divya, P Sreejith, J Cyril, M Smita & O V Oommen

 

Received 8 November 2004; revised 6 May 2005

Short term effects of insulin on total brain and branchial Na+K+ATPase, Ca2+ATPase and Na+, K+ and Ca2+ ions were investigated in A. testudineus. The increase in brain Ca2+ATPase after alloxan treatment may account for an increased amount of intracellular calcium required for biochemical events taking place inside the cells. Branchial Na+K+ATPase was significantly stimulated while Ca2+ATPase significantly inhibited after alloxan treatment. This suggests that alloxan exerts its inhibitory effect on the ATP-driven Ca2+ transport via; its action on the Ca2+ pump protein rather than the membrane permeability to Ca2+ . The increased activity of brain Na+K+ATPase at 3 and 24 hr by insulin to alloxan pretreated fish may account for the stimulated co-transport of glucose and its utilization for energy requirements and the excitatory action on neurons in the brain. The elevated brain Ca2+ATPase may be due to the role of calcium as a second messenger in hormone action. At 24 hr, the activity of branchial Na+K+ATPase and Ca2+ATPase in alloxan pretreated specimens was significantly stimulated by insulin. This may be due to increased synthesis of these enzyme units. Administration of insulin (1U/fish) in normal fish significantly inhibited the activity of brain and branchial Na+K+ATPase while brain Ca2+ATPase showed a stimulatory effect at 3 and 24 hr compared to control. Inhibition of total branchial Ca2+ATPase activity by insulin may be due to increased Ca2+ concentration. Higher plasma glucose level in alloxan treated groups confirms the diabetic effect of alloxan. Insulin reverses this effect. The possible mechanism by which insulin controls Na+K+ATPase activity appears to be tissue specific. The results seem to be the first report on the effect of insulin on ATPase activity in a teleost. These data are consistent with the hypothesis that insulin performs a role in hydro mineral regulation in freshwater teleosts.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 710-714

 

Evaluation of vasopressin mediated effects on hemostatic mechanisms: Relationship with aquaporins and caveolin proteins

Manoj G Tyagi & Keshavan V Namboodri

 

Received 16 September 2004; revised 4 April 2005

With a view to evaluate the role of AQP-1 and caveolin proteins in the hemostatic actions of vasopressin, hemostasis was evaluated by bleeding and clotting time respectively.Groups of mice and guinea pigs were treated with arginine vasopressin (AVP) and 1-deamino-8D-AVP (DDAVP) to evaluate their effects on the hemostasis. DDAVP and AVP were able to appreciably reduce the bleeding and clotting time after sodium thiopentone, but not effectively after TEA treatment. Animal groups were pretreated with aquaporin-1 (AQP-1) blockers or water deprived to enhance the expression of AQP-1 water channels. Another group of animals were treated with caveolin protein modulators, cholera toxin (CTX) and the effect of vasopressin analogues evaluated. The results suggest that AQP-1 water channels and caveolin proteins contribute to modulate the hemostatic mechanisms of vasopressin.

 

 

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 715-721

 

Effect of standardized extract of Ocimum sanctum Linn. on
gastric mucosal offensive and defensive factors

R K Goel, K Sairam, M Dorababu, T Prabha & Ch V Rao

 

Received 20 October 2004; revised 9 May 2005

The standardized methanolic extract of leaves of O. sanctum (OSE; eugenol content 5%) given in doses of
50-200 mg/kg, orally, twice daily for five days showed dose-dependent ulcer protective effect against cold restraint stress induced gastric ulcers. Optimal effective dose (100 mg/kg) of OSE showed significant ulcer protection against ethanol and pyloric ligation-induced gastric ulcers, but was ineffective against aspirin-induced ulcers. OSE significantly healed ulcers induced by 50% acetic acid after 5 and 10 days treatment. OSE (100mg/kg) significantly inhibited the offensive acid-pepsin secretion and lipid peroxidation and increased the gastric defensive factors like mucin secretion, cellular mucus, and life span of mucosal cells and had antioxidant effect, but did not induce mucosal cell proliferation. The results indicate that the ulcer protective and healing effects of OSE may be due to its effects both on offensive and defensive mucosal factors.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 722-727

 

Hepatoprotective activity of Leucas hirta against CCl4 induced
hepatic damage in rats

B K Manjunatha, S M Vidya, Promilla Dhiman & R Pallavi,

and

K L Mankani

Methanol and aqueous leaf extracts of L. hirta demonstrated hepatoprotective activity against carbon tetrachloride induced liver damage in rats. The parameters studied were serum total bilirubin, total protein, alanine transaminase, aspartate transaminase and alkaline phosphatase activities. The hepatoprotective activity was also supported by histopathological studies of liver tissue. Results of the biochemical studies of blood samples of CCl4 treated animals showed significant increase in the levels of serum markers and decrease in total protein level reflecting the liver injury caused by CCl4. Whereas blood samples from the animals treated with methanol and aqueous leaf extracts showed significant decrease in the levels of serum markers and increase in total protein indicating the protection of hepatic cells. The results revealed that methanol leaf extract followed by aqueous extract of L. hirta could afford significant protection against CCl4 induced hepatocellular injury.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 728-731

 

Hepatotoxic effects of tert-butyl hydroperoxide (t-BHP) and
protection by antioxidants

Sangram Singh, Sudhir Mehrotra, Rajeev Pandey & Rajat Sandhir

 

Received 6 February 2004, revised 29 March 2005

t-BHP induced oxidative stress and Ca2+ function impairment in fresh hepatocytes was studied in order to understand its role in cytotoxicity. Viability of hepatocytes by the release of lactate dehydrogenase and methyl thiazoletetrazolium reduction method alongwith malondialdehyde formation indicated oxidative stress in the hepatotoxic action of t-BHP.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 732-736

 

Evaluation of free radical scavenging properties of two classical
polyherbal formulations

Milind S Bagul, Niranjan S Kanaki & M Rajani

 

Received 2 July 2004; revised 26 April 2005

Two polyherbal formulations of Ayurveda viz., Chandraprabha Vati and Maha yogaraja Guggulu were evaluated for their free radical scavenging properties. Methanolic extracts of the formulations were studied in four different in vitro and ex vivo models. Total phenolic content of Chandraprabha Vati and Maha yogaraja Guggulu was found to be 5.24% and
10.74% respectively. Methanolic extracts of the formulations were good scavengers of all the radicals but there was a difference in the activity of the two formulations in different models. Chandraprabha Vati was a good scavenger of superoxide radical and Maha yogaraja Guggulu was efficient in scavenging nitric oxide (NO), while both inhibited lipid peroxidation efficiently. Free radical scavenging activity of the different extracts can be attributed to the presence of various chemical components including phenolics.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 737-739

 

 

Evaluation of mercury toxicity by some cytological indices in leucocyte cultures

A Halder, M Patra & M De

 

Received 18 August 2004; revised 30 March 2005

The genotoxicity induced by different levels of inorganic mercury was evaluated by chromosome metaphase analysis in human leucocytes, treated in vitro for 72 hr. Mitotic index gradually decreased with an increase in concentration of mercury but the reverse phenomenon was observed with respect to chromosomal aberration due to its probable interaction with protein and DNA.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 740-745

 

Effect of water stress and heavy metals on induction of somatic embryogenesis in wheat leaf base cultures

Debasis Patnaik, A Mahalakshmi & Paramjit Khurana

 

Received 14 March 2005; revisd 5 May 2005

In vitro cultures of plant tissues are known to mimic the response of field-grown plants when subjected to stress treatments. This investigation on Triticum aestivum explores the effect of drought stress on somatic embryogenesis and endogenous proline content. Leaf bases were cultured on MS medium supplemented with 2,4-D (10 M) and different concentrations of PEG (2.5, 5, 7.5%) or mannitol (0.25 and 0.5 M) and also subjected to different periods of aerial drying in the laminar flow for one-day and subsequently transferred to MS basal medium. PEG treatment induced a high percentage (up to 50%) of embryoid formation. However, with mannitol and aerial drying, percentage of embryoid formation decreased with increasing concentrations and duration. After ten days, the endogenous proline content of explants treated with different concentrations of PEG, mannitol and different durations of aerial drying increased with increasing concentration and increasing duration of the treatment, thus, corroborating the role of proline as an osmolyte during stress conditions. Similarly, addition of metals such as cadmium and cobalt caused a reduction in percentage explants depicting embryogenesis. However, when cadmium was employed alone, 22% explants displayed somatic embryogenesis as compared to 54% in 2,4-D treated cultures.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 746-750

 

Enhanced proteolysis leads to pre-mature cell death under the influence of elicitor like mycelial components from Karnal bunt (Tilletia indica) pathogen in wheat callus cultures

Shalini Mani, Manoj K Yadav, Gohar Taj Khan, U S Singh & Anil Kumar

 

Received 5 July 2004; revised 20 April 2005

Calli raised from mature embryos of susceptible wheat cultivar WH 542 were used in the present study as in vitro bioassay system to study the influence of disease determinant(s) of Karnal bunt (Tilletia indica), a semi-biotrophic fungal pathogen of wheat. Influence of elicitor and conditioned medium (CM) prepared from fungal cultures of T. indica was investigated on induction of programmed cell death (PCD). Induction of PCD was observed as hypersensitive response (HR) in terms of browning at localized regions of callus cultures and induction of proteolytic enzyme(s). Elicitor treated calli showed higher induction of protease activity than untreated and CM-treated cultures, which showed not much change in the activity. It was further substantiated by gel protease assay and activation of caspase-3 like protein(s) in callus cultures that clearly suggested the presence of signaling molecule(s) in the fungal elicitor preparation rather than in conditioned medium. This study further demonstrated that only elicitor preparation possesses such molecule(s), which might be cell wall bound components, rather than secretory in nature as CM was unable to induce PCD in wheat callus cultivars.

Indian Journal of Experimental Biology
Vol. 43, August 2005, pp. 751-754

Note

Heat stable antimicrobial activity of Allium ascalonicum against bacteria and fungi

M Amin & B P Kapadnis

 

Received 2 December 2004; revised 22 March 2005

To study antimicrobial activity of shallot in comparison with that of garlic and onion against 23 strains of fungi and bacteria, water extracts of garlic, shallot and onion bulbs were prepared. Each extract was studied in different forms for their antimicrobial activity viz., fresh extract, dry extract and autoclaved extract. Minimal inhibitory concentration and minimal lethal concentrations of these extracts were determined against all organisms by broth dilution susceptibility test. Fresh extract of garlic showed greater antimicrobial activity as compared to similar extracts of onion and shallot. However, dried and autoclaved extracts of shallot showed more activity than similar extracts of onion and garlic. Fungi were more sensitive to shallot extract than bacteria. Amongst bacteria, B. cereus was most sensitive (MIC=5 mg ml-1). The lowest minimum bactericidal concentration of shallot extract amongst bacteria tested was 5 mg ml-1 for B. cereus. Amongst fungi, Aureobasidium pullulans and Microsporum gypseum were most sensitive (MIC= 0.15 mg ml-1). The lowest minimum lethal concentration was 2.5 mg ml-1 for Microsporum gypseum and Trichophyton mentagrophytes. It was therefore, expected that the antimicrobial principle of shallot was different than the antimicrobial compounds of onion and garlic. In addition, the antimicrobial component of the shallot extract was stable at 121oC.