Anti-bacterial studies on Hemigraphis colorata (Blume) H.G. Hallier and Elephantopus scaber L

OBJECTIVE@#To examine the ethanol, aqueous, chloroform, benzene, acetone and petroleum ether extracts of, Hemigraphis colorata (H. colorata) leaves and stem and Elephantopus scaber (E. scaber) leaves, root and flower for the presence of phyto-constituents and screened the anti-bacterial activity against the selected pathogens.@*METHODS@#The fresh materials were shade dried and powdered using the tissue blender. The dried and powered materials (50 g) were extracted successively with 200 mL of aqueous, acetone, benzene, chloroform, ethanol, and petroleum ether by using Soxhlet extractor for 8 h at a temperature not exceeding the boiling point of the solvent. Aqueous, acetone, benzene, chloroform, ethanol, and petroleum ether extracts were prepared from powdered materials were used for preliminary phytochemical and antimicrobial studies using standard methods.@*RESULTS@#The crude aqueous, acetone, benzene, chloroform, ethanol, and petroleum ether extracts E. scaber leaves, flower and root and H. colorata leaves and stem demonstrated that out of (5×6×12 = 360) tests for the presence or absence of the above compounds, 188 tests gave positive results and the remaining 172 gave negative results. The results of the phytochemical screening revealed that phenol (12/12), carbohydrates (9/12), steroids (8/12), saponins and coumarins (7/12), tannins (6/12), proteins (5/12), carboxylic acid and flavonoids (4/12), xanthoproteins (3/12) and alkaloids (2/12) presence in the crude aqueous, acetone, benzene, chloroform, ethanol, and petroleum ether extracts of H. colorata leaves and stem. The crude aqueous, acetone, benzene, chloroform, ethanol, and petroleum ether extracts E. scaber leaves, flower and root displayed the presence of phenol (18/18), tannin (17/18), carbohydrates (16/18), steroids (14/18), carboxylic acid and coumarins (12/18), saponins (10/18), xanthoprotein (9/18), flavonoids (7/18), protein (4/18) and alkaloids (2/18). The root ethanolic extracts of E. scaber illustrated the highest zone of inhibition against three pathogens viz., Staphylococcus aureus (S. aureus) (24 mm), Escherichia coli (E. coli) (16 mm) and Pseudomonas aeruginosa (P. aeruginosa) (13 mm). The chlorofrom extracts of E. scaber showed the highest zone of inhibition against Bacillus cereus (B. cereus) (12 mm), The leaves ethanolic extracts of E. scaber demonstrated the highest zone of inhibition against three pathogens viz., Enterococcus faecalis (E. faecalis) (18 mm), Proteus mirabilis (P. mirabilis) (17 mm), Salmonella Typhi (S. typhi) (14 mm) and Enterobacter sp. (11 mm) While the benzene extracts of H. colorata demonstrated maximum zone of inhibition against the pathogen Acinetobacter sp. (14 mm) and S. aureus (12 mm).@*CONCLUSIONS@#It is hoped that this study would direct to the establishment of some compounds that could be used to invent new and more potent antimicrobial drugs of natural origin.

Antibacterial activity of selected ethnomedicinal plants from South India

OBJECTIVE@#To screen the antimicrobial potential of three ethnomedicinal plants Chassalia curviflora Thw. (C. curviflora), Cyclea peltata Hook. F. & Thomson (C. peltata) and Euphorbia hirta L (E. hirta) used in folk medicines in Aarukani hills Kani tribe, Tamil Nadu, India against human bacterial pathogens.@*METHODS@#Antibacterial efficacy was performed by disc diffusion method against the pathogens viz., Escherichia coli (E. coli) (ATCC 35218), Staphylococcus aureus (S. aureus) (ATCC 6538), Salmonella typhi (S. typhi) (MTCC 733), Proteus vulgaris (P. vulgaris), Proteus mirabilis (P. mirabilis) and Streptococcus pyogenes (S. pyogenes) and incubated for 24 h at 37 °C.@*RESULTS@#The maximum degree of antibacterial activity was observed in C. peltata followed by C. curviflora. While E. hirta showed comparatively low degree of antibacterial activity. The methanolic extract of C. peltata showed the antibacterial activity against three pathogens viz., S. pyogenes, P. vulgaris and E. coli with the inhibition zones 12 mm, 10 mm and 9 mm, respectively. hexane extracts of C. peltata also showed the antibacterial activity against two selected pathogens viz., P. vulgaris and P. mirabilis with 15 mm and 12 mm of inhibition zones. All the three different concentrations (0.25, 0.50 & 0.75 mg/mL) of methanolic extract of C. peltata show the inhibitory effect on the three susceptible bacteria S. pyogenes, P. vulgaris and E. coli with the maximum inhibition in the highest concentration (0.75 mg/mL). The methanolic and hexane extracts of C. curviflora exhibited the antibacterial activity against only one bacterium each i.e. P. vulgaris and S. typhi with the maximum zone of inhibition 13 and 11 mm respectively. The methanolic and hexane extracts of E. hirta exhibited the antibacterial activity against only one bacterium i.e. S. pyogenes with the maximum zone of inhibition 13 and 11 mm respectively.@*CONCLUSIONS@#The present investigation revealed that the C. curviflora, C. peltata and E. hirta are potentially good source of antibacterial agents and demonstrates the importance of such plants in traditional medicines.