International Journal of Medicinal Plants Research

International Journal of Medicinal Plants Research ISSN 2169-303X Vol. 7 (9), pp. 414-417, September, 2018. © International Scholars Journals

Full Length Research Paper

A study of antimicrobial activities of some medicinal plants used in traditional medicine

D.A. Akinpelu¹* and T.M. Onakoya²

¹Department of Microbiology, Obafemi Awolowo University, Ile-Ife, Nigeria.

²Department of Microbiology, University of Agriculture, Abeokuta, Nigeria.

*Corresponding author. E-mail: [email protected].

Accepted 03 July, 2017

Abstract

In south-western part of Nigeria Psidium guajava and Mangifera indica are commonly used for herbal preparations in the treatment of toothache, gastrointestinal disorders, dynsentery, diarrhoea, sore gums and sore throats. This has, therefore, led to the investigation of the antimicrobial activities of methanolic extracts of P. guajava and M. indica. Fifteen different bacterial isolates comprising of both Gram negative and Gram positive organisms were used. The results show that P. guajava and M. indica extracts exhibited antimicrobial activities at a concentration of 20 mg/ml. The zones of inhibition exhibited by P. guajava extract ranged between 12 mm and 30 mm while that of M. indica varied between 11 and 28 mm. The minimum inhibitory concentration (MIC) exhibited by P. guajava extract against the tested organisms ranged between 0.313 and 0.625 mg/ml. On the other hand MIC exhibited by M. indica extract varied between 1.25 and 10.0 mg/ml. Overall, P. guajava extract show more antimicrobial activity than M. indica extract against tested organisms.

Key words: Psidium guajava, Mangifera indica, antimicrobial activity.

International Journal of Medicinal Plants Research ISSN 2169-303X Vol. 7 (7), pp. 402-406, July, 2018. © International Scholars Journals

Full Length Research Paper

A study of the chemical constituents of two Nigerian medicinal plants

D. E. Okwu* and C. Josiah

Department of Chemistry, Michael Okpara University of Agriculture, Umudike, P.M.B. 7267 Umuahia, Abia State, Nigeria

*Corresponding authors E-mail: [email protected].

Accepted 23 April, 2017

Abstract

Nigerian medicinal plants (Aspilia africana and Bryophyllum pinnatum) were analyzed for their chemical composition, vitamins and minerals. The results revealed the presence of bioactive constituents comprising alkaloids (1.24 to 1.48 mg/100 g), saponins (1.46 to 1.72 mg/100 g), flavonoids (1.46 to 1.86 mg/100 g), phenols (0.06 mg/100g) and tannins (0.04 to 0.5 mg/100g). The medicinal plants contained ascorbic acid (26.42 to 44.03 mg/100 g), riboflavin (0.20 to 0.42 mg/100 g), thiamine (0.11 to 0.18 mg/100 g), and niacin (0.02 to 0.09 mg/100 g). These herbs are good sources of minerals such as Ca, P, K, Mg, Na, Fe and Zn. The importance of these chemical constituents is discussed with respect to the role of these herbs in ethnomedicine in Nigeria.

Key words: Aspillia africana, Bryophyllum pinnatum, bioactive compounds, ethnomedicine.

International Journal of Medicinal Plants Research ISSN 2169-303X Vol. 7 (6), pp. 393-401, June, 2018. © International Scholars Journals

Full Length Research Paper

A study of the antibacterial activity of some medicinal plants used to cure diarrhoea, fever and other diseases

Samie A.^{1, 3}, Obi C.L.^1*, Bessong P.O.¹ Namrita L.²

¹University of Venda for Science and Technology, P/Bag X5050 Thohoyandou, South Africa.

²University of Pretoria, Pretoria, South Africa.

³Centre for Global Health, Department of Infectious diseases and international Health, University of Virginia.

*Corresponding   Author.    E-mail: [email protected], [email protected]; Tel: + (1) 434 924 5242. Fax : + (1) 434 977 5323.

Accepted 22 July, 2017

Abstract

Fourteen plants used in traditional medicine in the Venda region of South Africa were screened for activity against fifteen bacterial species. Methanol, acetone and hexane extracts and in some cases essential oils were tested using the disc diffusion and the microdilution methods. Most of the extracts were active against at least one bacterial species. Methanol and acetone extracts were the most active while Gram positive bacteria were the most sensitive as compared to Gram negative bacteria. This study has revealed the strong in vitro activity of Syzigium cordatum, Peltophorum africanum, Rhoicissus tridentata, Bridelia micrantha and Ximenia caffra against Gram positive and Gram negative bacteria. Essential oils of Lippia javanica was also effective against most of the bacterial species studied. However, Pouzolzia mixta and Mucuna coriaceae showed less activity. Some plants were more active than commercial antibiotics. This study is the first to test the activity of the selected plants from the Venda region against such number of bacterial isolates and justifies their use by local traditional healers. The identification of the active components of the plants and the determination of the effect of these plants on the immune system will give more information on their activity. Finally, these results may be of importance in identifying candidate plants and essential oils for eventual drug design and other therapeutic purposes, respectively.

Key words: Bacteria, Disc diffusion, Medicinal plants, Microdilution, South Africa, Venda.

International Journal of Medicinal Plants Research ISSN 2169-303X Vol. 7 (8), pp. 407-409, August, 2018. © International Scholars Journals

Full Length Research Paper

A study of the biological activity of methanol extracts of some medicinal plants from South Africa

Pascal O.Bessong^1*, Luis B. Rojas², Larry C. Obi¹, Peter M. Tshisikawe³ Eunice O. Igunbor⁴

¹Department of Microbiology, University of Venda, Thohoyandou, South Africa

²Laboratoire de Chimie des Substances Végétales, Centre de Recherche en Chimie Moléculaire, Université de Bordeaux 1, and Instituto de Investigaciones, Facultad de Farmacia, Universidad de Los Andes, Venezuela.

³Department of Biological Sciences, University of Venda, Thohoyandou, South Africa.

^*Corresponding author. E-mail: [email protected]. Tel: +27 15 962 8301. Fax: +27 15 962 4749.

Accepted 07 August, 2017

Abstract

The use of medicinal plants for AIDS- related conditions is common in South Africa. In order to establish an antiviral rationale for the use of these plants we screened fractions of the methanol extracts of medicinal plants for activity against HIV-1 reverse transcriptase (RT) and integrase (IN). The n-butanol fraction obtained from the crude methanol extracts of the roots of Bridelia micrantha (Hochst) Baill. (Euphorbiaceae) was observed to be as the most active inhibiting the RNA-dependent-DNA polymerization (RDDP) activity of HIV-1 RT with an IC50 of 7.3 g/ml. However, it had no activity on the 3’-end processing activity of HIV integrase. Bioassay-guided fractionation of the n-butanol fraction yielded friedelin and -sistosterol, which did not inhibit the RDDP of RT or 3’-end processing functions of IN even at a concentration of 500 M. An uncharacterized fraction obtained in the bioassay-guided fractionating process inhibited the RDDP with an IC50 of 9.6 g/ml, but had no inhibition on IN. Phytochemical screening indicated the presence of flavonoids and tannins in the uncharacterized fraction.

Key words: HIV-1; reverse transcriptase; integrase; medicinal plants; inhibition; Venda; South Africa.

International Journal of Medicinal Plants Research ISSN 2169-303X Vol. 7 (5), pp. 387-392, May, 2018. © International Scholars Journals

Full Length Research Paper                

A study of antioxidant and antimicrobial activities of polyphenols against pathogenic bacteria

Damintoti Karou¹, Mamoudou H. Dicko^{1, 2*}, Jacques Simpore³, and Alfred S. Traore¹

¹Université de Ouagadougou, UFR-SVT, CRSBAN, Laboratoire de Biochimie, 03 BP 7131 Ouagadougou 03, Burkina Faso.

²Wageningen University, AVT, Laboratory for Biochemistry, Dreijenlaan 3, 6703 HA, Wageningen, P.O Box 8128, 6700 ET Wageningen, Netherlands.

³Laboratoire de Biologie Médicale saint Camille de Ouagadougou, 01 BP 364 Ouagadougou 01, Burkina Faso.

*Corresponding Author E-Mail: Tel: +226 70 272643, Fax: +22650 33 73 73, E-mail: [email protected].

Accepted 06 July, 2017

Abstract

Polyphenols from four medicinal plants of Burkina Faso, Combretum micranthum, Khaya senegalensis, Pterocarpus erinaceus and Sida acuta, were screened for their antioxidant and antimicrobial activities against pathogenic bacteria. The medicinal plants displayed different polyphenols contents and antioxidant activities. The bark of P. erinaceus had the highest antioxidant activity. Some microorganisms were susceptible to polyphenol extracts with minimal bactericidal concentration values between 20 and 2000 mg/ml while other microorganisms appeared to be resistant to the extracts. Microbicide and microbiostatic activities of the extracts were dependent on the type of strains. Results suggest that these plants are not only interesting sources for antimicrobial activities but also potential sources of phenolic antioxidants.

Key words: Antioxidants, polyphenols, antimicrobials, medicinal plants.