Laboratory of Microbiology and Antimicrobial Substances

Dschang, Cameroon

Laboratory of Microbiology and Antimicrobial Substances

Dschang, Cameroon

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Mouokeu R.S.,Laboratory of Microbiology and Antimicrobial Substances | Ngono R.A.N.,Laboratory of Biochemistry | Lunga P.K.,Laboratory of Microbiology and Antimicrobial Substances | Koanga M.M.,Laboratory of Biochemistry | And 4 more authors.
BMC Complementary and Alternative Medicine | Year: 2011

Background: The emergence in recent years of numerous resistant strains of pathogenic bacteria to a range of formerly efficient antibiotics constitutes a serious threat to public health. Crassocephalum bauchiense, a medicinal herb found in the West Region of Cameroon is used to treat gastrointestinal infections as well as liver disorders. The ethyl acetate extract from the leaves of C. bauchiense was evaluated for its antibacterial activity as well as acute and sub-acute toxicities.Methods: The plant extract was prepared by maceration in ethyl acetate. Its phytochemical screening was done by standard methods. The broth microdilution method was used to evaluate the in vitro antibacterial activity. The in vivo antibacterial activity of a gel formulation (0.05, 1 and 2% w/v) of this extract was evaluated using a Staphylococcus aureus-induced dermatitis in a murine model. Selected haematological and biochemical parameters were used to evaluate the dermal sub-acute toxicity of the extract in rats.Results: Phytochemical screening of the C. bauchiense extract revealed the presence of alkaloids, phenols, tannins and sterols. In vitro antibacterial activities were observed against all the tested microorganisms (MIC = 0.04-6.25 mg/ml). Formulated extract-gel (2% w/v) and gentamycin (reference drug) eradicated the microbial infection after five days of treatment. A single dermal dose of this extract up to 32 g/kg body weight (bw) did not produce any visible sign of toxicity. Also, daily dermal application of the C. bauchiense extract gel formulation for 28 days did not show any negative effect, instead some biochemical parameters such as alanine aminotransferase (ALT and AST), low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides were significantly (p < 0.05) affected positively.Conclusion: These results indicate that the C. bauchiense ethyl acetate extract can be used safely for the treatment of some bacterial infections. © 2011 Mouokeu et al; licensee BioMed Central Ltd.


Sama Fonkeng L.,Laboratory of Microbiology and Antimicrobial Substances | Mouokeu R.S.,University of Douala | Tume C.,Laboratory of Microbiology and Antimicrobial Substances | Njateng G.S.S.,Laboratory of Microbiology and Antimicrobial Substances | And 3 more authors.
BMC Research Notes | Year: 2015

Background: The emergence of bacterial infections including those associated with Staphylococcus aureus causes a benefit of interest to medicinal plants as an effective means of control. The present study was designed to investigate the activities of 12 selected Cameroonian medicinal plants against S. aureus isolates. Methods: The plant extracts were prepared by maceration in methanol at laboratory temperature. Qualitative phytochemical analysis was performed by chemical reaction methods. The broth microdilution method was used to evaluate the activities of plant extracts against 11 S. aureus clinical isolates. Results: Dacryodes edulis was found to have significant antibacterial activity on all the S. aureus isolates (MIC = 64-256 μg/ml). Occimum gratissimum revealed significant inhibitory activity on 9 of the 11 isolates while Commelina erecta and Spilanthes filicaulis revealed similar results on 6 of the 11 clinical isolates. Conclusion: The present findings showed that D. eduli, O. gratissimum, C. erecta and S. filicaulis possess interesting inhibitory properties against S. aureus species. These plants could therefore be good candidates to overcome infectious diseases associated with these microorganisms. © 2015 Fonkeng et al.


Mouokeu R.S.,University of Douala | Ngono Ngane R.A.,Laboratory of Biochemistry | Njateng G.S.S.,Laboratory of Microbiology and Antimicrobial Substances | Kamtchueng M.O.,Laboratory of Microbiology and Antimicrobial Substances | Kuiate J.-R.,Laboratory of Microbiology and Antimicrobial Substances
BMC Research Notes | Year: 2014

Background: Crassocephalum bauchiense is a flowering plant, found in the West Region of Cameroon. Previous studied has highlighted the antibacterial and the dermal toxicological safety as well as the immunomodulatory activities of the ethyl acetate extract of its dry leaves. As an extension of the previous researches, the current work has been undertaken to evaluate the in vitro antifungal and antioxidant activities of C. bauchiense dried leaves ethyl acetate extract and fractions. Methods. The extract was obtained by maceration in ethyl acetate and further fractionated into six fractions labeled F 1 to F6 by flash chromatography. The antifungal activity of the extract and fractions against yeasts and dermatophytes was evaluated using broth microdilution method. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and β-carotene - linoleic acid assays. Results: The extract (MIC = 0.125 - 4 mg/ml) was found to be more active on dermatophytes and yeasts compared to the fractions. The ethyl acetate extract and fractions exhibited strong scavenging activity on DPPH (CI50 = 28.57 - 389.38 μg/ml). The fractions F3 and F6 expressed best antioxidant activity on DPPH radicals compared to the crude extract. Conclusion: The results of these findings clearly showed that C. bauchiense ethyl acetate extract has a significant antifungal and antioxidant activity. It is therefore a source of active compounds that might be used as antifungal and antioxidant agents. © 2014 Mouokeu et al.; licensee BioMed Central Ltd.


Djafoua Y.M.,Laboratory of Microbiology and Antimicrobial Substances | Mouokeu R.S.,University of Douala | Tume C.,Laboratory of Microbiology and Antimicrobial Substances | Kamtchueng M.O.,Laboratory of Microbiology and Antimicrobial Substances | Kuiate J.-R.,Laboratory of Microbiology and Antimicrobial Substances
Journal of Complementary and Integrative Medicine | Year: 2015

Background: Medicinal plants have been used for centuries and have become part of complementary medicine worldwide because of their health benefits. Some have been successfully used directly in the treatment and prevention of infectious diseases or indirectly by stimulating the immune system. In the present study, the immunomodulatory activity of the methanol extracts of Adenocarpus mannii, Caucalis melanantha, Ocimum gratissimum, Asystasia intrusa and Clematis chinensis leaves was investigated. Methods: The extracts were prepared by maceration of dry leaves' powder in methanol. Phytochemical analysis was carried out by chemical reaction methods. The activity of plant extracts was evaluated in in vitro cell cultures by measuring their effect on nitric oxide production by peritoneal macrophages, the proliferation of lymphocytes and the cytotoxic effect on macrophages. The A. mannii extract was further evaluated at 50 and 100 mg/kg body weight in mice for the stimulation of delayed-type hypersensitivity (DTH) reactions and the ability to reverse the myelosuppression induced by cyclophosphamide. Results: All the extract inhibited nitric oxide production by peritoneal macrophages, the highest activity was achieved with C. chinensis extract. However, these extracts did not significantly affect the viability of macrophages. A. mannii, A. intrusa and C. chinensis extracts exhibited stimulatory activity on peripheral blood lymphocytes, whereas C. melanantha and O. gratissimum extracts displayed inhibitory activity. In vivo, the A. mannii extract significantly increased the DTH reaction in mice from 50 mg/kg. This extract also showed a significant increase in the white blood cells and relative weight of the spleen and liver. Conclusions: These results suggest that the A. mannii, C. melanantha, O. gratissimum, A. intrusa and C. chinensis methanol extracts possess immunomodulatory activity. This constitutes additional data on the well-known biological properties of these plants. © 2015 by De Gruyter 2015.


PubMed | University of Douala and Laboratory of Microbiology and Antimicrobial Substances
Type: | Journal: BMC research notes | Year: 2015

The emergence of bacterial infections including those associated with Staphylococcus aureus causes a benefit of interest to medicinal plants as an effective means of control. The present study was designed to investigate the activities of 12 selected Cameroonian medicinal plants against S. aureus isolates.The plant extracts were prepared by maceration in methanol at laboratory temperature. Qualitative phytochemical analysis was performed by chemical reaction methods. The broth microdilution method was used to evaluate the activities of plant extracts against 11 S. aureus clinical isolates.Dacryodes edulis was found to have significant antibacterial activity on all the S. aureus isolates (MIC = 64-256 g/ml). Occimum gratissimum revealed significant inhibitory activity on 9 of the 11 isolates while Commelina erecta and Spilanthes filicaulis revealed similar results on 6 of the 11 clinical isolates.The present findings showed that D. eduli, O. gratissimum, C. erecta and S. filicaulis possess interesting inhibitory properties against S. aureus species. These plants could therefore be good candidates to overcome infectious diseases associated with these microorganisms.

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