JOURNAL ARTICLE

Antibacterial properties of traditionally used Indian medicinal plants

F Aqil, I Ahmad
Methods and Findings in Experimental and Clinical Pharmacology 2007, 29 (2): 79-92
17440624
In search of broad-spectrum antibacterial activity from traditionally used Indian medicinal plants, 66 ethanolic plant extracts were screened against nine different bacteria. Of these, 39 extracts demonstrated activity against six or more test bacteria. Twelve extracts showing broad-spectrum activity were tested against specific multidrug-resistant (MDR) bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum beta-lactamases (ESbetaL)-producing enteric bacteria. In vitro efficacy was expressed in terms of minimum inhibitory concentration (MIC) values of plant extracts. MIC values ranged from 0.32-7.5 mg/ml against MRSA and 0.31-6.25 mg/ml against ESbetaL-producing enteric bacteria. The overall activity against all groups of bacteria was found in order of Plumbago zeylanica > Hemidesmus indicus > Acorus calamus > Camellia sinensis > Terminalia chebula > Terminalia bellerica > Holarrhena antidysenterica > Lawsonia inermis > Mangifera indica > Punica granatum > Cichorium intybus and Delonix regia. In addition, these extracts showed synergistic interaction with tetracycline, chloramphenicol and ciprofloxacin against S. aureus and/or Escherichia coli. The ethanolic extracts of more than 12 plants were found nontoxic to sheep erythrocytes and nonmutagenic, determined by Ames test using Salmonella typhimurium test strains (TA 97a, TA 100, TA 102 and TA 104). Based on above properties, six plants-Plumbago zeylanica, Hemidesmus indicus, Acorus calamus, Punica granatum, Holarrhena antidysenterica and Delonix regia-were further subjected to fractionation-based study. Ethyl acetate, acetone and methanol fractions of more than six plants indicated that the active phytocompounds were distributed mainly into acetone and ethyl acetate fractions, whereas they were least prevalent in methanol fractions as evident from their antibacterial activity against MDR bacteria. Gram-positive and Gram-negative MDR bacteria are almost equally sensitive to these extracts/fractions, indicating their broad-spectrum nature. However, strain- and plant extract-dependent variations in the antibacterial activity were also evident. Time-kill assay with the most promising plant fraction Plumbago zeylanica (ethyl acetate fraction) demonstrated killing of test bacteria at the level lower than its MIC. Further, identification of active constituents in each fraction and their additive and synergistic interactions are needed to exploit them in evaluating efficacy and safety in vivo against MDR bacteria.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
17440624
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"