Advancement in Medicinal Plant Research

1-4

Authors: Ali M. Badri, Mohamed I. Garbi, Ahmed S. Kabbashi, Mahmoud S. Saleh, Yousof S. Yousof, Suha F. Mohammed, Ibrahim T. Ibrahim and Amira A. Magzoub

Prosopis juliflora is the most widespread species of genus Prosopis and it is a good source of compounds that have been shown to be pharmacologically active. This plant has been used as a traditional treatment for several diseases such as microbial infections are major public health problems in the developed and developing countries. Infectious disease is a major cause of deaths accounting for one-half of all deaths in tropical countries. Therefore, this study was carried out to investigate the in vitro antimicrobial activity of Prosopis juliflora methanolic leafs extract against clinical isolates performed by cup-plate agar diffusion method against seven Gram negative bacteria: Escherichia coli, Escherichia coli ESBL, Shigella flexneri, Salmonella typhi, Proteus mirabilis, Pseudomonas aeruginosa, and Klebsiella pneumoniae; and three Gram positive bacteria: Enterococcus faecalis, Listeria monocytogenes and Bacillus cereus. The methanolic extract exhibited inhibitory effects against most of the tested microorganisms with zone of inhibition ranging from 12 to 41 mm. The largest inhibition zone were obtained from methanolic extract of P. juliflora (leaf) against the Gram negative P. aeruginosa (41 mm) in 100 mg/ml concentration, and Gram positive L. monocytogenes (33 mm) in 100 mg/ml concentration in comparison with Gentamicin 10 mgc. The methanol extract of Prosopis juliflora was found effective against different species of bacteria and considered for further exploration and isolation active compounds analysis.

11-20

Authors: François Munyemana and Adelício Lucas Alberto

Plutella xylostella (Lepidoptera: Plutellidae) popularly known as the moth-of-crucifers is a major pest of brassica worldwide which can cause damage to brassica crops up to 100% loss of total production. The use of synthetic pesticides for its control has harmful effects on public health and the environment, besides the development of resistance to these synthetic insecticides. One of the alternative control methods developed in recent years has been the use of plant extracts. In the present study, was evaluated the insecticidal potential of the leaves, root bark and stem bark extracts of three mozambican medicinal plants: Trichilia emetica, Anacardium occidentale and Cymbopogon citratus to control the development of diamondback moth (L.) on cabbage. The plant extracts were obtained by maceration in organic solvents (n-hexane, ethyl acetate and methanol). The preliminary phytochemical tests were conducted to identify classes of chemical constituents present in the extracts. To assess insecticidal activity, the extracts were tested on the second instar larvae of diamondback moth using the leaf disc immersion methodology, where the larvae were fed with cabbage leaves dipped in each extract, being observed larval mortality in function of extract concentration. The evaluation of the insecticidal activity showed that the methanol crude extract from the root bark of Trichilia emetica caused the highest larval mortality (LC50 = 0.94 mg.ml-1). The LC50 values obtained for all the extracts tested indicate that the crude methanol extracts have a higher larvicidal potential than those obtained in the sequential extraction. The results suggest that the larvicidal activity of the extracts under study can be related to the presence of the identified metabolites that act synergistically or individually in producing larval mortality.