The efficacy and safety of nine South African medicinal plants in controlling Bacillus anthracis Sterne vaccine strain. Issue 1 (December 2015)

• Record Type: Journal Article
• Authors: Elisha, Ishaku; Dzoyem, Jean-Paul; Botha, Francien; Eloff, Jacobus
• Is Part Of: BMC complementary and alternative medicine. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 7
• Publication Date: 2015-12
• Subjects: Bacillus anthracis -- Medicinal plants -- Antibacterial activity -- Total activity -- Cytotoxicity -- Selectivity index; Alternative medicine -- Periodicals; Complementary Therapies -- Periodicals; 615.505
• DOI: 10.1186/s12906-015-0980-1
• Languages: English
• ISSNs: 1472-6882

Abstract

Abstract Background Anthrax is a zoonotic disease caused byBacillus anthracis, a Gram-positive spore-forming bacterium. The presence of the bacteria and the toxins in the blood of infected hosts trigger a cascade of pathological events leading to death. Nine medicinal plants with good activities against other bacteria were selected to determine theirin vitro antibacterial activity againstBacillus anthracis Sterne strain. The cytotoxicity of the extracts on Vero kidney cells was also determined. Results The minimum inhibitory concentration (MIC) values of the extracts againstBacillus anthracis Sterne strain ranged from 0.02 to 0.31 mg/ml. Excellent MIC values were observed for the following plant species:Maesa lanceolata (0.02 mg/ml), Bolusanthus speciosus, Hypericum roeperianum, Morus mesozygia (0.04 mg/ml) andPittosporum viridiflorum (0.08 mg/ml). The total antibacterial activity of the extracts ranged from 92 to 5562 ml/g. Total activity presents the volume to which the extract from 1 g of plant material can be diluted and still inhibit microbial growth.Maesa lanceolata andHypericum roeperianum had the highest total activity with values of 5562 and 2999 ml/g respectively. The extracts ofCalpurnia aurea had the lowest total activity (92 ml/g). The cytotoxicity determined on Vero cells indicated that most of the extracts were relatively non-toxic compared to doxorubicin (LC50 8.3 ± 1.76 μg/ml), except for the extracts ofMaesa lanceolata, Elaeodendron croceum andCalpurnia aurea with LC50 values at 2.38 ± 0.25, 5.20 ± 0.24 and 13 ± 2.26 μg/ml respectively. The selectivity index (SI) ranged from 0.02 to 1.66.Hypericum roeperianum had the best selectivity index, (SI = 1.66) andElaeodendron croceum had lowest value (SI = 0.02). Conclusions The crude acetone extracts of the selected plant species had promising antibacterial activity againstBacillus anthracis. Maesa lanceolata extracts could be useful as a disinfectant andHypericum roeperianum could be useful to protect animals based on its high total activity and selectivity index. Further investigation of these plant extracts may lead to the development of new therapeutic agents to protect humans or animals against anthrax.