Antibacterial, Anti-inflammatory and Antioxidant Activities of Senna alata and Commelina benghalensis Extracts
Vincent Ngouana *
Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Dschang, Dschang, P.O. Box 96, Cameroon and Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaounde 1, Yaounde, P.O. Box 812, Cameroon.
Jean Polidor Nguetsa Demafo
Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Dschang, Dschang, P.O. Box 96, Cameroon.
Boniface Pone Kamdem
*
Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaounde 1, Yaounde, P.O. Box 812, Cameroon and Advanced Research & Health Innovation Hub, P.O. Box 20133, Yaounde, Cameroon.
Brice Rostan Pinlap
Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaounde 1, Yaounde, P.O. Box 812, Cameroon.
Raoul Kemzeu
Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaounde 1, Yaounde, P.O. Box 812, Cameroon.
Simionne Lapoupée Kuitcha Tonga
Research Unit of Environmental and Applied Chemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Paul Keilah Lunga
Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaounde 1, Yaounde, P.O. Box 812, Cameroon.
Léon Azefack Tapondjou
Research Unit of Environmental and Applied Chemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Rémy Bertrand Teponno
Research Unit of Environmental and Applied Chemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Fabrice Fekam Boyom
Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaounde 1, Yaounde, P.O. Box 812, Cameroon and Advanced Research & Health Innovation Hub, P.O. Box 20133, Yaounde, Cameroon.
*Author to whom correspondence should be addressed.
Abstract
Background: Bacteria affecting the cutaneous-digestive and oral spheres, causing pain, inflammation and sometimes serious complications such as septicemia, are exacerbated by the emergence of new antibiotic-resistant strains. The World Health Organization (WHO) encourages the use of medicinal plants to treat diseases caused by antibiotic-resistant pathogens; however, this practice should be supported by a proper scientific validation.
Objective: This study sought to evaluate in vitro antibacterial, anti-inflammatory and antioxidant activities of extracts from Commelina benghalensis and Senna alata. The crude extracts from C. benghalensis and S. alata by maceration in ethanol. This was followed by a liquid-liquid partitioning of the extracts using hexane, ethyl acetate and n-butanol to yield respective fractions. The as prepared extracts and fractions were evaluated for antibacterial activity against a panel of bacteria, such as Escherichia coli (reference strain) and S. aureus CPC, E. coli CPC, E. faecalis and S. mutans (3 clinical isolates) using a broth microdilution method. The phytochemical screening of C. benghalensis and S. alata extracts were determined using standard protocols. Antioxidant and anti-inflammatory effects of extracts were assessed using standard methods. The acute toxicity of the most promising antibacterial extract was performed according to the Organisation for Economic Co-operation and Development (OECD)’s guideline, protocole number 423.
Results: The yields of extraction for the ethanol extracts from C. benghalensis and S. alata were found to be 4.94% and 10.25%, respectively. The plant extracts were found to be rich in flavonoids, terpenoids and steroids, and phenolics. The plant extracts exhibited antibacterial activity with minimum inhibitory concentrations (MICs) ranging from 0.3125 to 2.5 mg/mL. Irrespective of the protocol used, the extracts displayed significant antioxidant activity with mean radical scavenging concentrations (SC50s) ranging from 30.09 to 500 µg/mL. The plant extracts revealed anti-inflammatory activity with mean inhibitory concentration (IC50) values ranging from 24.9 to 113.1 µg/mL. Upon acute toxicity study, the median lethal dose (LD50) of the most promising antibacterial extract was found to be greater than 2000 mg/kg.
Conclusion: This study demonstrates antibacterial, anti-inflammatory and antioxidant activities of extracts C. benghalensis and S. alata, thus validating the traditional use of these plants in treating infectious diseases.
Keywords: Commelina benghalensis, Senna alata, antibacterial activity, antioxidant activity, acute toxicity