Antimicrobial activity and brine shrimp toxicity of extracts of Terminalia brownii roots and stem

Abstract

BackgroundTernimalia 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.MethodsExtraction 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.ResultsExtracts 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 μg/ml, respectively. The stem wood extracts exhibited the highest toxicity against the shrimps (LC50 values 2.58–14.88 μg/ml), while that of cyclophosphamide, a standard anticancer drug, was 16.33 (10.60–25.15) μg/ml.ConclusionThese 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.

In vivo toxicity study of Lantana camara

“…Effects of exposure time on mortality percentage were depicted in Figure 2. After exposure to the extract for 6 h, LC 50 of leaf was 6 0419.1 毺 g/mL(70% CI=7 281.2-113 557.0), and the profile had a sharp rise in mortality at lower concentrations and a slowly increase at higher doses, while after exposure for 24 h the profile showed a gradual increase of mortality at lower concentrations and become constant at 5 000 毺 g/mL. …”

“…Although the toxicities of root extract, vitamin C and chloramphenicol are higher than other extracts in the experiment, based on one way ANOVA analysis, the differences in LC 50 among various parts of L. camara and also two reference drug are not significant (P>0.05). But if 100 毺 g/mL is regarded as an approximate border line for toxicity [6] all the tested compounds and extract exhibit very low toxicity on brine shrimp larva.…”

In vitroadditive effect ofHyptis martiusiiin the resistance to aminoglycosides of methicillin-resistantStaphylococcus aureus

“…With the increase of resistance to antibiotics, natural products could be an interesting alternative (Mbwambo et al, 2007). Many plants have been evaluated not only for direct antimicrobial activity, but also as a resistance modifying agents (Gibbons, 2004).…”

Anti-Pyretic Properties of Methanolic Bark Extracts of Terminalia brownii in Wistar Rats (Rattus novegicus)

“…The tree grows near rivers and wadies in dry areas and in moist savannas of semi-arid regions, thriving best on sandy loam soils [11]. T. brownii is used as a folklore remedy for jaundice, stomach ache, urogenital infections, malaria, gastric ulcers, epilepsy, cough, hepatitis and liver cirrhosis in different parts of Eastern and Central Africa [10]. Although T. brownii is used as a traditional remedy for fever, no studies have been conducted to validate this ethno-medicinal claim.…”

“…Terminalia brownii [Combretaceae] is native in Kenya, Democratic Republic of Congo, Tanzania and Ethiopia [10]. The tree grows near rivers and wadies in dry areas and in moist savannas of semi-arid regions, thriving best on sandy loam soils [11].…”