Antimicrobial potentials of Catharanthus roseus by disc diffusion assay

Area of Science:

• Pharmacognosy
• Microbiology
• Natural Product Chemistry

Background:

• Catharanthus roseus (C. roseus) is a medicinal plant with a history of traditional use.
• Investigating the antimicrobial properties of plant extracts is crucial for discovering new therapeutic agents.
• Different solvent extraction methods yield compounds with varying biological activities.

Purpose of the Study:

• To evaluate the in vitro antimicrobial activity of various solvent extracts from C. roseus aerial parts.
• To determine the efficacy of hexane, ethyl acetate, chloroform, butanol, methanol, and water extracts against a panel of microbial species.
• To assess the activity against both human pathogens and plant pathogens.

Main Methods:

• Aerial parts of C. roseus (stem, leaf, fruit, flower) were extracted using different solvents.
• Disc diffusion assay was employed to test antimicrobial activity at concentrations of 1 and 2 mg/disc.
• Tested microbial species included human pathogens (e.g., E. coli, S. typhi, S. aureus, C. albicans) and plant pathogens (E. carotovora, A. tumefaciens).

Main Results:

• Ethyl acetate and methanol extracts demonstrated the most potent and broad-spectrum antimicrobial activity against tested microbes.
• Hexane extract was effective against most strains, except S. typhi.
• Chloroform, butanol, and water extracts showed variable efficacy, with some resistance observed in specific microbial strains and concentrations. All extracts were effective against plant pathogens.

Conclusions:

• C. roseus extracts, particularly ethyl acetate and methanol, possess significant in vitro antimicrobial properties.
• The efficacy of extracts varies depending on the solvent used and the target microorganism.
• These findings support the potential of C. roseus as a source for novel antimicrobial compounds against human and plant pathogens.