(MICROBIOLOGY MAJOR AND BIOCHEMISTRY MINOR)

Presentation on theme: "(MICROBIOLOGY MAJOR AND BIOCHEMISTRY MINOR)"— Presentation transcript:

1 (MICROBIOLOGY MAJOR AND BIOCHEMISTRY MINOR)
Ethnobotanical survey and in vitro antibacterial screening of ethnoveterinary medicinal plants of Ngoma, Zambezi region TOMAS A. – (MICROBIOLOGY MAJOR AND BIOCHEMISTRY MINOR) Supervisor: Dr. Kazhila C. Chinsembu Co-Supervisor: Mr Augustine Mbangu (Department of Biological Science, University of Namibia)

2 INTRODUCTION Namibia is one of the African countries, which up to date have a strong dependency on traditional ethnoveterinary medicine, especially in rural areas where veterinary services are situated several kilometres away from villages. Cos, Vlietinck, Vanden-Berghe, and Maes (2006) described ethnoveterinary plants as medicinal plants traditionally used to promote health, prevent and treat various infections affecting domestic animals. Ethnoveterinary medicine is developed by farmers rather than by scientists in laboratories and clinics, therefore, it is less systematic and less formalized (Mathias, 2001). This is because, the acquisition and transfer of ethnoveterinary medicinal knowledge is still vertical; from parents to children through oral means rather than in writings (Chinsembu & Hedimbi, 2010). Due to the nature of oral transmission, this form of local knowledge remains fragile and threatened, thus presents an urgent need for being recorded, documented, and screened, to provide scientific evidence for possible medicinal properties against microbial infections.

3 Statement of the Problem
Despite the fact that many communal farmers use plants to treat livestock diseases; the current status of information on ethnoveterinary plants usage is not well understood and documented. Moreover, there have been no empirical studies, to our knowledge, that have examined and evaluated the in vitro antibacterial activity of the Zambezi region ethnoveterinary flora. Objectives To conduct an ethnobotanical survey of indigenous knowledge of medicinal plants used to treat livestock diseases in Ngoma, Zambezi region. To screen and evaluate in vitro antibacterial activity of ethnoveterinary plants used in Ngoma, Zambezi region.

4 Research Hypotheses a) H0: There is no indigenous knowledge of medicinal plants used to treat livestock diseases in Ngoma, Zambezi region. H1: There is indigenous knowledge of medicinal plants used to treat livestock diseases in Ngoma, Zambezi region. b) H0: Ethnoveterinary medicinal plants used in Ngoma, Zambezi region have no in vitro antibacterial activity. H1: Ethnoveterinary medicinal plants used in Ngoma, Zambezi region have in vitro antibacterial activity.

5 Relevance and Significance of the study
The screening of indigenous knowledge of ethnoveterinary plants used in Zambezi region will provide scientific evidence, for their medicinal uses in treating livestock diseases. This is important as it could lead to the documentation of this knowledge on antibacterial activity, which can be shared between different communities. Therefore, promote the medicinal uses of these plants to manage bacterial infections, affecting livestock in rural areas where veterinary services have limited coverage. As a result, this will increase livestock production, socio-economic benefits, and reduce poverty in rural cash-less areas. In addition, this study is also of great importance, as it is an inaugural to the isolation of novel chemical compounds, which could be important source of useful medicinal natural products; as well as therapeutic and pharmaceutical novel compounds needed in the development of new veterinary medicine and antimicrobial drugs.

6 METHODOLOGY Study Area
Figure 1: A: The map of Namibia showing the location of Zambezi Region. B: The map of Zambezi Region showing the location for Ngoma.

7 Research Methods and Materials
Figure 2: Scheme of research methods

8 Data Analysis Zones of inhibition data, produced by plant extracts, was stored in Microsoft Excel 2013, before analysed for normality using the Shapiro-Wilk test (p < 0.05) in Statistical Package for the Social Sciences tool (SPSS) version 22. The normally distributed data was analysed using One way ANOVA test, whereas those that was not normally distributed was analysed using either Mann-Whitney U or Kruskall-Wallis tests (p < 0.05). These tests were used to compare the mean difference in inhibitory activities of plant extracts, test bacteria, and extraction methods. The MIC results were analysed by observing the lowest common inhibitory concentration of plant extracts for three replicate experiments against each test bacteria.

9 RESULTS 62.9% 54.3% 82.9% 65.7% 85.7% 57.1% 80% 71.4% 60% Figure 3: Ethnoveterinary medicinal plants from Ngoma. A: Searsia quartiniana (A.Rich.) A.J.Mill., B: Sclerocarya birrea, C: Aloe zebrina, D: Lannea schweinfurthii (Engl.) Engl. Var. tomentosa (Dunkley) Kokwaro, E: Pechue-Loescha luebnitziae, F: Marsdenia macrantha (Klotzsch) Schltr, G: Capparis erythrocarpos Isert, H: Flueggea virosa (Roxb. Ex Willd.) Voigt, I: Diospyros lycioides.

10 Figure 4: Overall number of respondents by age group.
Figure 5: The graph shows overall distribution of plant species across different families.

11 Figure 6: The graph shows overall percentage frequency of the plants used to treat diseases.
Table 1: Antibacterial activity of ethnoveterinary medicinal plants using disc diffusion method.

12 Table 2: Mean zone of inhibition (mm) on Escherichia coli and Staphylococcus aureus.
Table 3: Mean zone of inhibition (mm) for water and organic extraction methods.

13 Table 4: Overall minimum inhibitory concentration (MIC) of organic extracts against Escherichia coli and Staphylococcus aureus. Figure 7: The graph shows the overall minimum inhibitory concentration (MIC) of organic extracts against Escherichia coli and Staphylococcus aureus.

14 Table 5: Overall minimum inhibitory concentration (MIC) of water extracts against Escherichia coli and Staphylococcus aureus. Figure 8: The graph shows the overall minimum inhibitory concentration (MIC) of water extracts against Escherichia coli and Staphylococcus aureus

15 DISCUSSION Nine ethnoveterinary medicinal plants documented (Figure 3) were commonly used to treat diseases such as gall-sickness, wounds, skin infections, and gastrointestinal tract complications. Perhaps this is because the Zambezi region is the wettest region of Namibia, therefore provide the wet environment required by microbes to promote microbial diseases development. Subsequent detailed examination of the frequency index revealed that, Aloe zebrina, Pechue-Loescha luebnitziae and Capparis erythrocarpos Isert were the most commonly used, because they contain active components like anthraquinones, chromones, polysaccharides and enzymes, which are responsible for their medicinal (antibacterial) properties (Sahu, Giri, Singh, Pandey, Gupta, Shrivastava, Kumar, and Pandey, 2013). Female respondents were fewer than males among the respondents (Figure 4), because livestock ownership and management is usually a cultural preserve for males, especially those above 30 years of age.

16 Roots and leaves are the most commonly used medicinal plant parts in Ngoma, because the harvesting of leaves is not labor-intensive (Chinsembu, Negumbo, Likando, & Mbangu, 2014); and roots are normally available throughout the year, even during the long drought seasons. In addition, the antibacterial activity of plant extracts against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) supports the use of ethnoveterinary plant extracts in traditional medicine. For example, Sclerocarya birrea, Lannea schweinfurthii, and Capparis erythrocarpos Isert investigated for MIC, were observed with the lowest MICs ranging between mg/mL in aqueous extracts (Figure 9). Perhaps this is because the aqueous extracts are reported to contain higher amounts of plant constituents, impurities and other residual substances in addition to water-soluble bioactive compounds, which together have strong antibacterial activity (Okete, Inoeglu, Eze, Okoli, & Esimone, 2001).

17 The agar disc diffusion values indicated that antibacterial activities of organic extracts were more effective than those of aqueous extracts (Table 5), because the 1:1 mixture of dichloromethane and methanol (DCM:MeOH) has higher polarity than double distilled water. Therefore, it concentrates and extracts more bioactive compounds than water, which mostly disperse active compounds that are responsible for antibacterial activity. Yet, agar disc diffusion values showed that S. aureus was more sensitive to the plant extracts than E. coli, because E. coli are believed to have resistance mechanisms and impermeable to certain antibacterial compounds compared to S. aureus, which have complex and unique multi-layered organization of the cell wall (Tolossa, Debela, Athanasiadou, Tolera, Ganga & Houdijk, 2013). Even so, agar disc diffusion methods are not reliable, because they are strongly influenced by agar depth, diffusion rate of the antimicrobial agent and growth rate of the specific bacteria (WHO, 2010). Therefore, agar dilution methods which determine the MIC is regarded as the gold standard for antimicrobial tests, because its less likely to influenced by external factors as agar disc dilution methods.

18 CONCLUSION In conclusion, this study documented the indigenous knowledge of medicinal plants used to manage livestock diseases in Ngoma. Nine ethnoveterinary medicinal plants were commonly used to treat diseases such as gall-sickness, wounds, skin infections, and gastrointestinal tract complications. Although the disc diffusion data showed that the antibacterial activities of all the nine plants were similar, plant extracts showed different MIC values, which are more reliable than disc diffusion data. Nonetheless, Kruskal-Wallis test revealed no significant difference in the antibacterial activities of the plants extracts. Even so, Mann-Whitney U Test showed that plant extracts were significantly more potent on S. aureus than on E. coli, and organic extracts had significantly more antibacterial activity than aqueous extracts. The lowest MIC value of organic extract was observed with S. quartiniana (5 mg/mL) against E. coli, while for water extract was observed with L. schweinfurthii at 2.5 mg/mL against S. aureus, thus, support the traditional usage of medicinal plants for prevention and treatments of most of livestock diseases.

19 RECOMMENDATION In future, in vitro antimicrobial activity such as antiviral, antifungal, antitumor, etc. screening of ethnoveterinary medicinal plants of Ngoma is recommended. Also, further studies are needed to determine and characterize bioactive compounds, mode of action and toxicity for in vivo applications of ethnoveterinary medicinal plants documented from Ngoma, Zambezi region. Last but not least, more ethnobotanical surveys are recommended to document and evaluate the antimicrobial activity of ethnoveterinary medicinal plants used in different areas of Zambezi region, and other parts of Namibia.

20 REFERENCES Chinsembu, C. K., & Hedimbi, M. (2010). An ethnobotanical survey of plants used to manage HIV/AIDS opportunistic infections in Katima Mulilo, Caprivi region, Namibia. Journal of Ethnobiology and Ethnomedicine. 6, 25 Chinsembu, K. C., Negumbo, J., Likando, M., & Mbangu, A. (2014). An ethnobotanical study of medicinal plants used to treat livestock diseases in Onayena and Katima mulilo, Namibia. South African Journal of botany 94, Cos, P., Vlietinck, A. J., Vanden-Berghe, D., & Maes, L. (2006). Anti-infective potential of natural products: How to develop a stronger in vitro ‘proof-of-concept’. J. Ethnopharmacol, 106, 290–292. Mathias, E. (2001). Retrieved June 03, 2014, from Introducing ethnoveterinary medicine.: Sahu, P., Giri, D., Singh, R., Pandey, P., Gupta, S., Shrivastava, A., et al. (2013). Therapeutic and Medicinal Uses of Aloe vera: A Review,. Pharmacology & Pharmacy, (4) Tolossa, K., Debela, E., Athanasiadou, S., Tolera, A., Ganga, G., & Houdijk, J. G. (2013). Ethno-medicinal study of plants used for treatment of human and livestock ailments by traditional healers in South Omo, Southern Ethiopia. Journal of Ethnobiology and Ethnomedicine, 9, 32.