Antimicrobial potency of the ethanolic crude bark extract of Ziziphus mucronata Willd. subsp. mucronata Willd

Abstract

Ziziphus mucronata Willd. subsp. mucronata Willd. is a medicinal plant widely used in South Africa for the treatment of various diseases. Like many medicinal plants to which traditional claims including the treatment of ailments of infectious origin but without scientific reports have been associated, Z. mucronata is not an exemption. The ethanolic stems bark extract of Z. mucronata against medically important pathogens was investigated for the antimicrobial activity by the agar dilution method while the degree of its antimicrobial activity was determined by the macrobroth dilution method. The extract showed good antibacterial and antifungal activities. Both Gram-negative and Gram-positive bacteria were highly inhibited by the extract at very low concentrations. All the bacteria had inhibition zones greater than 20 mm at a concentration of 5 mg/ml with the exception of Pseudomonas aeruginosa (ATCC 19582) and Bacillus pumilus (ATCC 14884). For the bacteria, the minimum inhibitory concentration (MIC) values ranged between 0.078 and 0.625 mg/ml. For the fungi, the MIC values were between 2.5 to 10 mg/ml. The bacteria were more susceptible to the extract than the fungi. The antimicrobial activity of the extract indicated a broad spectrum, great therapeutic potential and justified the use of this plant by the rural communities in the treatment of microbial infections.

Pharmacological Assessment of the Medicinal Potential of Acacia mearnsii De Wild.: Antimicrobial and Toxicity Activities

“…Though there is a dearth of scientific reports on the pharmacological importance of this plant, Olajuyigbe and Afolayan [34] earlier indicated that its aqueous and ethanolic extracts exhibited significant antibacterial activities. The pronounced antibacterial effect of the extract in both gram-negative and gram-positive bacteria may be attributed to its ability to damage the different cell walls to allow the active compounds to adsorb, diffuse, penetrate and interact with the affected target sites as earlier indicated by Olajuyigbe and Afolayan [17]. Furthermore, the significant multifarious effects of the extract on the fungal isolates could be due to the differences in their morphology, disruption of membrane [35] or cell wall integrity [36], inhibition of mycelia growth [37], high potential to block morphogenetic transformation [38], indirect inhibition of cell wall synthesis [39] and spore germination [40].…”

“…The effects of plant extracts on microorganisms have been studied by a very large number of researchers in different parts of the world [15–17]. The presence of antibacterial, antifungal and other biological activities have also been demonstrated in extracts of different plant species used in traditional medicine practices [18–20].…”

Phytochemical screening and antibacterial properties of selected Nigerian long pepper (Capsicum frutescens) fruits

“…Although the mechanism of action of these extracts was not studied, the phytochemical compounds such as tannins are known to coagulate the wall proteins, while saponins facilitate the entry of toxic material or leakage of vital constituents from the cell (Onwuliri and Wonang, 2005). Flavonoids inhibit the activity of enzymes by forming complexes with bacterial cell walls, extracellular and soluble proteins, more lipophilic flavonoids disrupt cell wall integrity or microbial membranes at low concentrations (Olajuyigbe and Afolayan, 2012).…”

Phytochemical screening, thin-layer chromatography and antimicrobial activity study of Parquetina nigrescens leaf extracts

“…Antibacterial activity was determined using agar disc diffusion method [11]. In this technique, the bacteria were first grown on nutrient agar at 37 o C for 24 h before use.…”