TY - JOUR
T1 - Evaluation of the antibacterial and anticancer activities of some South African medicinal plants
AU - Bisi-Johnson, Mary A.
AU - Obi, Chikwelu L.
AU - Hattori, Toshio
AU - Oshima, Yoshiteru
AU - Li, Shenwei
AU - Kambizi, Learnmore
AU - Eloff, Jacobus N.
AU - Vasaikar, Sandeep D.
N1 - Funding Information:
This study was supported by the Institutional Research Grant of Walter Sisulu University (WSU), the National Research Foundation (NRF) grant awarded under the aegis of the South Africa - Japan Research Collaborative Agreement and the Focus Area Grant of the NRF. Our profound gratitude goes to the traditional healers and the locals for sharing their folk knowledge on the plants studied. We also appreciate the technical support of Asai Teigo of the Natural Products Chemistry, School of Pharmacy, Tohoku University, Obayama, Sendai, Japan and David Wopula of WSU Botany Department for sourcing of plant materials. Ms Nomvula Twaise (Director, WSU HIV/AIDS Centre) is acknowledged for her useful information on L. camara. The general support obtained from the Department of Medical Microbiology, WSU, and the Phytomedicine group, Department of Paraclinical Science, University of Pretoria is worthy of appreciation.
PY - 2011/1/17
Y1 - 2011/1/17
N2 - Background: Several herbs are traditionally used in the treatment of a variety of ailments particularly in the rural areas of South Africa where herbal medicine is mainly the source of health care system. Many of these herbs have not been assessed for safety or toxicity to tissue or organs of the mammalian recipients.Methods: This study evaluated the cytotoxicity of some medicinal plants used, inter alia, in the treatment of diarrhoea, and stomach disorders. Six selected medicinal plants were assessed for their antibacterial activities against ampicillin-resistant and kanamycin-resistant strains of Escherichia coli by the broth micro-dilution methods. The cytotoxicities of methanol extracts and fractions of the six selected plants were determined using a modified tetrazolium-based colorimetric assay (3-(4, 5-dimethylthiazol)-2, 5-diphenyl tetrazolium bromide (MTT) assay).Results: The average minimum inhibitory concentration (MIC) values of the plants extracts ranged from 0.027 mg/mℓ to 2.5 mg/mℓ after 24 h of incubation. Eucomis autumnalis and Cyathula uncinulata had the most significant biological activity with the least MIC values. The in vitro cytotoxicity assay on human hepatocarcinoma cell line (Huh-7) revealed that the methanol extract of E. autumnalis had the strongest cytotoxicity with IC50 of 7.8 μg/mℓ. Ethyl acetate and butanol fractions of C. uncinulata, Hypoxis latifolia, E. autumnalis and Lantana camara had lower cytotoxic effects on the cancer cell lines tested with IC50 values ranging from 24.8 to 44.1 μg/mℓ; while all the fractions of Aloe arborescens and A. striatula had insignificant or no cytotoxic effects after 72 h of treatment.Conclusions: Our results indicate that the methanol fraction of E. autumnalis had a profound cytotoxic effect even though it possessed very significant antibacterial activity. This puts a query on its safety and hence a call for caution in its usage, thus a product being natural is not tantamount to being entirely safe. However, the antibacterial activities and non-cytotoxic effects of A. arborescens and A. striatula validates their continuous usage in ethnomedicine.
AB - Background: Several herbs are traditionally used in the treatment of a variety of ailments particularly in the rural areas of South Africa where herbal medicine is mainly the source of health care system. Many of these herbs have not been assessed for safety or toxicity to tissue or organs of the mammalian recipients.Methods: This study evaluated the cytotoxicity of some medicinal plants used, inter alia, in the treatment of diarrhoea, and stomach disorders. Six selected medicinal plants were assessed for their antibacterial activities against ampicillin-resistant and kanamycin-resistant strains of Escherichia coli by the broth micro-dilution methods. The cytotoxicities of methanol extracts and fractions of the six selected plants were determined using a modified tetrazolium-based colorimetric assay (3-(4, 5-dimethylthiazol)-2, 5-diphenyl tetrazolium bromide (MTT) assay).Results: The average minimum inhibitory concentration (MIC) values of the plants extracts ranged from 0.027 mg/mℓ to 2.5 mg/mℓ after 24 h of incubation. Eucomis autumnalis and Cyathula uncinulata had the most significant biological activity with the least MIC values. The in vitro cytotoxicity assay on human hepatocarcinoma cell line (Huh-7) revealed that the methanol extract of E. autumnalis had the strongest cytotoxicity with IC50 of 7.8 μg/mℓ. Ethyl acetate and butanol fractions of C. uncinulata, Hypoxis latifolia, E. autumnalis and Lantana camara had lower cytotoxic effects on the cancer cell lines tested with IC50 values ranging from 24.8 to 44.1 μg/mℓ; while all the fractions of Aloe arborescens and A. striatula had insignificant or no cytotoxic effects after 72 h of treatment.Conclusions: Our results indicate that the methanol fraction of E. autumnalis had a profound cytotoxic effect even though it possessed very significant antibacterial activity. This puts a query on its safety and hence a call for caution in its usage, thus a product being natural is not tantamount to being entirely safe. However, the antibacterial activities and non-cytotoxic effects of A. arborescens and A. striatula validates their continuous usage in ethnomedicine.
UR - http://www.scopus.com/inward/record.url?scp=79952195253&partnerID=8YFLogxK
U2 - 10.1186/1472-6882-11-14
DO - 10.1186/1472-6882-11-14
M3 - Article
C2 - 21329526
AN - SCOPUS:79952195253
SN - 1472-6882
VL - 11
JO - BMC Complementary and Alternative Medicine
JF - BMC Complementary and Alternative Medicine
M1 - 14
ER -
