No abstract

No abstract

The death of many people in tropical countries can be attributed to microbial infection, probably, because synthetic antibiotics are failing in the treatment of most microbial infections, attributed to the ability of the microorganisms to mutate and adapt to harsh conditions. This study evaluated, in vitro, the antimicrobial activities, antioxidant potentials, and the total phenolic as well as phytochemical contents of aqueous and ethanol extracts of the root of Cryptolepis sanguinolenta (Lindl.) and the crude sap of Pycnanthus angolensis (Welw) using selected standard bacteria strains (Staphylococcus aureus (ATCC 25,923), Staphylococcus saprophyticus (ATCC 15,305), Escherichia coli (ATCC 25,922), Salmonella typhi (ATCC 19,430), Pseudomonas aeruginosa (ATCC 27,853), and Proteus mirabilis (ATCC 49,565). The modified agar well diffusion method was used to evaluate the antimicrobial activities of the plant extracts. Chloramphenicol and tetracycline were used as positive controls. The extracts were screened for specific phytochemicals with total phenolic contents were determined using Folin Ciocalteu reagent test. The phytoconstituents observed were alkaloids, cardiac glycosides, and saponins in both Cryptolepis sanguinolenta and Pycnanthus angolensis. For the antimicrobial activities, all the test bacteria were susceptible to the crude sap of Pycnanthus angolensis except Proteus mirabilis. In the case of the Cryptolepis sanguinolenta, only S. aureus was susceptible to both aqueous and ethanol extracts. The total phenolic content, expressed in g/100 g GAE, recorded values of 55.427 ± 4.248 for the crude sap of Pycnanthus angolensis, and 11.642 ± 4.248 and 26.888 ± 4.248 for the aqueous and ethanol extracts of Cryptolepis sanguinolenta, respectively. It is concluded that Cryptolepis sanguinolenta and Pycnanthus angolensis are excellent candidates for further development of antimicrobial agents in the fight against microbial infections given the pressing need for novel efficacious agents.

The death of many people in tropical countries can be attributed to microbial infection, probably, because synthetic antibiotics are failing in the treatment of these microbial infections, attributed to the ability of the microorganisms to mutate and adapt to harsh conditions. This study evaluated, in vitro, the antimicrobial activities, antioxidant potentials, and the total phenolic contents of aqueous and ethanol extracts of the root of Cryptolepis sanguinolenta (Lindl.) and the crude sap of Pycnanthus angolensis (Welw) using selected standard bacteria strains (S. aureus (ATCC 25923), S. saprophyticus (ATCC 15305), E. coli (ATCC 25922), S. typhi (ATCC 19430), P. aeruginosa (ATCC 27853), and P. mirabilis (ATCC 49565). The modified agar well diffusion method was used to evaluate the antimicrobial activities of the plant extracts. Chloramphenicol and tetracycline were used as positive controls. The extracts were also screened for specific phytochemicals and using the Folin Ciocalteu reagent test, their total phenolic contents were determined. The phytochemical screening revealed the presence of alkaloids, cardiac glycosides, and saponins in both Cryptolepis sanguinolenta and Pycnanthus angolensis. For the antimicrobial activities, all the test bacteria were susceptible to the crude sap of Pycnanthus angolensis except P. mirabilis. In the case of the Cryptolepis sanguinolenta, only S. aureus was susceptible to both aqueous and ethanol extracts. The total phenolic content, expressed in g/100g GAE, recorded values of 55.427 ± 4.248 for the crude sap of Pycnanthus angolensis, and 11.642 ± 4.248 and 26.888 ± 4.248 for the aqueous and ethanol extracts of Cryptolepis sanguinolenta, respectively. It was concluded that Cryptolepis sanguinolenta and Pycnanthus angolensis are excellent candidates for further development of antimicrobial agents in the fight against microbial infections given the pressing need for novel efficacious agents.

Medicinal plants play a huge role in the treatment of various diseases in the Limpopo province (South Africa). Traditionally, concoctions used for treating tuberculosis and cancer are sometimes prepared from plant parts naturally occurring in the region, these include (but not limited to) Schotia brachypetala, Rauvolfia caffra, Schinus molle, Ziziphus mucronate, and Senna petersiana. In this study, the aim was to evaluate the potential antimycobacterial activity of the five medicinal plants against Mycobacterium smegmatis mc2155, Mycobacterium aurum A + , and Mycobacterium tuberculosis H37Rv, and cytotoxic activity against MDA-MB 231 triple-negative breast cancer cells. Phytochemical constituents present in R. caffra and S. molle were tentatively identified by LC-QTOF-MS/MS as these extracts showed antimycobacterial and cytotoxic activity. A rigorous Virtual Screening Workflow (VSW) of the tentatively identified phytocompounds was then employed to identify potential inhibitor/s of M. tuberculosis pantothenate kinase (PanK). Molecular dynamics simulations and post-MM-GBSA free energy calculations were used to determine the potential mode of action and selectivity of selected phytocompounds. The results showed that plant crude extracts generally exhibited poor antimycobacterial activity, except for R. caffra and S. molle which exhibited average efficacy against M. tuberculosis H37Rv with minimum inhibitory concentrations between 0.25–0.125 mg/mL. Only one compound with a favourable ADME profile, namely, norajmaline was returned from the VSW. Norajmaline exhibited a docking score of –7.47 kcal/mol, while, pre-MM-GBSA calculation revealed binding free energy to be –37.64 kcal/mol. All plant extracts exhibited a 50% inhibitory concentration (IC50) of < 30 μg/mL against MDA-MB 231 cells. Flow cytometry analysis of treated MDA-MB 231 cells showed that the dichloromethane extracts from S. petersiana, Z. mucronate, and ethyl acetate extracts from R. caffra and S. molle induced higher levels of apoptosis than cisplatin. It was concluded that norajmaline could emerge as a potential antimycobacterial lead compound. Validation of the antimycobacterial activity of norajmaline will need to be performed in vitro and in vivo before chemical modifications to enhance potency and efficacy are done. S. petersiana, Z. mucronate, R.caffra and S. molle possess strong potential as key contributors in developing new and effective treatments for triple-negative breast cancer in light of the urgent requirement for innovative therapeutic solutions.

No abstract