In Vitro Bacteriostatic and Bactericidal Activities of Senna alata, Ricinus communis and Lannea barteri extracts Against Wound and Skin Disease Causing Bacteria

Abstract

Antibacterial activities of the extracts of three medicinal plants, Senna alata, Ricinus communis and Lannea barteri from two different extractants were studied. Bacteria strains such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli are known wound and skin disease causing bacteria. For 100g of each plant material, the percentage yields of the extracts were determined and ranged between 5.20% and 12.40%. Phytochemical screening of the crude extracts of Senna alata, Ricinus communis and Lannea barteri revealed the presence of some bioactive components, including tannins, anthraquinones, saponins, flavonoids and alkaloids. All plant extracts showed inhibition on test organisms and were in the range of 12.0 ± 2.83mm to 36.0 ± 2.12mm for all the extracts. The MIC values obtained for the entire test ranged from 3.13mg/ml to 12.50mg/ml and MBC values were found to be 200mg/ml minimum and 400mg/ml maximum. Findings support the traditional use of Senna alata, Ricinus communis and Lannea barteri for the treatment of skin and wound infections and form a strong basis for further exploration of these plants.

Combination therapy: synergism among three plant extracts against selected pathogens

“…Additionally, an outcome of synergism resulting from combination therapy is to minimize or delay the emergence of resistance by the pathogenic organism to the individual components of the combination [ 4 , 17 ]. The synergy and additive effects exhibited by the extract-extract interactions in the current work could be attributed to the different phyto-compounds in the individual extracts [ 5 , 6 ] acting in concert, each introducing a different mechanism to inhibit or kill the microbial growth.…”

“…Different extracts from the same plant were not considered. The MICs of the extracts acting alone were reported in a previous study conducted in our laboratory [ 5 , 6 ]. It was observed that MICs ranged between 3.13 and 25.00 mg/mL.…”

“…The MIC of the extracts in combination was determined using similar procedure already described by Donkor et al and Suurbaar et al [ 5 , 6 ]. Briefly, overnight cultured bacteria were suspended in 5 mL sterile nutrient broth (NB) and incubated at 37 °C for 2–4 h to achieve a turbidity equivalent to 0.5 McFarland standard (1.0 × 10 8 cfu/mL).…”

“…Previous work conducted in our laboratory has already documented the in vitro activities of the extracts of Senna alata, Ricinus cummunis and Lannea barteri acting alone against some clinically isolated bacterial and fungal species [ 5 ]. The goal of this research was to investigate possible extract-extract interaction of the plants as a potential combination therapy against selected clinically isolated pathogenic microorganisms.…”

Evaluation of anti-infective potencies of formulated aloin A ointment and aloin A isolated from Aloe barbadensis Miller

“…The method described by Donkor et al [18] was used to determine the minimum fungicidal concentrations (MFCs). A commercial standard, Fluconazole (Sigma), was used as positive control (1-3000 μg/ml) and DMSO (99.9%) as negative control.…”