Screening of antimicrobial potential of certain drug plants for enhancement of their therapeutic spectrum in vitro

Present paper deals with the in vitro screening of antimicrobial potential of Azadirachta indica and Holarrhena antidysenterica against four bacterial test species i.e. Escherichia coli, Sarcina lutea, Bacillus megaterium and Bacillus species for enhancement of their therapeutic spectrum. During this investigation, A. indica has shown more antimicrobial potential than H. antidysenterica against all bacterial species except Bacillus species. Maximum antibacterial activity was found at 100% of each drug plant extract which established a positive correlation between drug concentration and antimicrobial potential. Lowest antibacterial activity was found at 10% concentration. No activity was found against E. coli in H. antidysenterica. Investigation on drug potency at 100% concentration in terms of unit strength compared with different antibiotics, yielded that one ml of A. indica extract was equal to 5 units of Ciprofloxacin for B. megaterium and Bacillus species, and 4.2 units for E. coli. Low potency was recorded in Ampicillin than Ciprofloxacin. Drug extract of H. antidysenterica showed more unit when compared with Ciprofloxacin than Ampicillin for all bacterial test species

Atividade antibacteriana de extratos de Bidens pilosa L / Antibacterial activity of Bidens pilosa L. extracts

Foram preparados extratos de plantas de B. pilosa provenientes de diferentes regiöes as quais mostraram atividade contra S. aureus. Extratos preparados a 80ºC näo apresentaram atividade. Foi testada a atividade antibacteriana do extrato bruto de B. pilosa contra S. aureus, S. lutea e B. subtilis cultivados sob cinco diferentes valores de pH e, para isto, mediu-se o crescimento através da turvaçäo e da atividade catalásica. A S. lutea apresentou a maior sensibilidade. Dos diferentes solventes orgânicos utilizados no fracionamento do extrato bruto, o clorofórmico foi o melhor. Na avaliaçäo da presença de princípio ativo em diferentes fases do desenvolvimento de B. pilosa, a fase cotiledonar apresentou menor concentraçäo do princípio ativo e a fase de flor a maior concentraçäo