Majority of antibacterial drugs in clinical use are derived from natural origin. Hence, the
present study is designed for antibacterial and cytotoxic evaluation of different extracts of
Glycyrrhiza glabra Linn. roots against common poultry pathogens.
The four sequential i.e. hexane, chloroform, ethanol and aqueous extracts of Glycyrrhiza
glabra Linn. roots were prepared by soxhlet extraction. Antibacterial activity of these extracts was
determined by agar well diffusion method against Staphylococcus aureus, Clostridium perfringens
type A, Escherichia coli, Salmonella enterica and Haemophilus paragallinarum. Zone of
inhibitions were determined by well diffusion method. MICs of plant extracts were determined by
micro broth dilution method. Cytotoxic activity was evaluated by applying MTT assay on Vero
cell lines.
The zone of inhibitions showed by hexane, chloroform and ethanolic extracts of
Glycyrrhiza glabra Linn. roots against Staphylococcus. aureus were10.3mm, 13.0mm, 11.6mm;
against Clostridium perfringens type A were20.0mm, 17.3mm, 17.3mm; against Escherichia coli
were11.6mm, 19.3mm, 16.0mm; against Salmonella enterica were13.6mm, 14.0mm,14.0mm;
against Haemophillus paragallinarum were13.0mm, 15.0mm, 17.0mm respectively. Aqueous
extract showed no zone of inhibition against any test bacteria.
MICs values of hexane, chloroform and ethanolic extracts of Glycyrrhiza glabra Linn.
roots against Staphylococcu aureus were 13.0μg/ml, 312.5μg/ml and 104.1μg/ml; against
Clostridium perfringens type A were 9.766μg/ml, 71.61μg/ml and 520.8μg/ml; against
Escherichia coli were 65.1μg/ml, 52.8μg/ml and 156.25μg/ml; against Salmonella enterica were
Summary
86
19.5μg/ml, 130.2μg/ml and 78.12μg/ml; against Haemophillus paragallinarum were 91.1μg/ml,
29.2μg/ml and 130.2μg/ml respectively. Aqueous extract showed no MIC value as no zone of
inhibitions wereobserved against them. Hexane extract of Glycyrrhiza glabra Linn. roots was
cytotoxic at concentration ≥ 650μg/ml, chloroform extract at concentration ≥ 2500μg/ml and
ethanolic extract was not cytotoxic to cell.
The indigenous plant Glycyrrhiza glabra Linn. roots have antibacterial activity against
common poultry pathogens and helpful to develop new drug from plant origin.