Antimicrobial activity and brine shrimp toxicity of extracts of Terminalia brownii roots and stem.
BACKGROUND
Ternimalia brownii Fresen (Combretaceae) is widely used in traditional medicine to treat bacterial, fungal and viral infections. There is a need to evaluate extracts of this plant in order to provide scientific proof for it's wide application in traditional medicine system.


METHODS
Extraction of stem bark, wood and whole roots of T. brownii using solvents of increasing polarity, namely, Pet ether, dichloromethane, dichloromethane: methanol (1:1), methanol and aqua, respectively, afforded dry extracts. The extracts were tested for antifungal and antibacterial activity and for brine shrimp toxicity test.


RESULTS
Extracts of the stem bark, wood and whole roots of T. brownii exhibited antibacterial activity against standard strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhi, and Bacillus anthracis and the fungi, Candida albicans and Cryptococcus neoformans. Aqueous extracts exhibited the strongest activity against both bacteria and fungi. Extracts of the roots and stem bark exhibited relatively mild cytotoxic activity against brine shrimp larvae with LC50 values ranging from 113.75-4356.76 and 36.12-1458.81 microg/ml, respectively. The stem wood extracts exhibited the highest toxicity against the shrimps (LC50 values 2.58-14.88 microg/ml), while that of cyclophosphamide, a standard anticancer drug, was 16.33 (10.60-25.15) microg/ml.


CONCLUSIONS
These test results support traditional medicinal use of, especially, aqueous extracts for the treatment of conditions such as diarrhea, and gonorrhea. The brine shrimp results depict the general trend among plants of the genus Terminalia, which are known to contain cytotoxic compounds such as hydrolysable tannins. These results warrant follow-up through bioassay-directed isolation of the active principles.
Mbwambo
Zakaria H
ZH
Institute of Traditional Medicine, Muhimbili University College of Health Sciences, Dar es Salaam, Tanzania. zmbwambo@muchs.ac.tz
Moshi
Mainen J
MJ
Masimba
Pax J
PJ
Kapingu
Modest C
MC
Nondo
Ramadhani S O
RS
D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D001156:Artemia; D001419:Bacteria / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005658:Fungi / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D018517:Plant Roots; D029766:Terminalia; D023382:Toxicity Tests, Acute
D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D010936:Plant Extracts