RESUMO
Microbial infections remain a public health problem due to the upsurge of bacterial resistance. In this study, the antibacterial, antibiofilm, and efflux pump inhibitory activities of the stem bark of Acacia macrostachya, an indigenous African medicinal plant, were investigated. In traditional medicine, the plant is used in the treatment of microbial infections and inflammatory conditions. A crude methanol extract obtained by Soxhlet extraction was partitioned by column chromatography to obtain the petroleum ether, ethyl acetate, and methanol fractions. Antibacterial, efflux pump inhibition and antibiofilm formation activities were assessed by the high-throughput spot culture growth inhibition (HT-SPOTi), ethidium bromide accumulation, and the crystal violet retention assay, respectively. The minimum inhibitory concentrations (MICs) of the crude extract and major fractions ranged from 250 to ≥500 µg/mL. At a concentration of 3.9-250 µg/mL, all extracts demonstrated >80% inhibition of biofilm formation in S. aureus. In P. aeruginosa, the EtOAc fraction showed the highest antibiofilm activity (59-69%) while the pet-ether fraction was most active against E. coli biofilms (45-67%). Among the test samples, the crude extract, methanol, and ethyl acetate fractions showed remarkable efflux pump inhibition in S. aureus, E. coli, and P. aeruginosa. At ½ MIC, the methanol fraction demonstrated significant accumulation of EtBr in E. coli having superior efflux inhibition over the standard EPIs: chlorpromazine and verapamil. Tannins, flavonoids, triterpenoids, phytosterols, coumarins, and saponins were identified in preliminary phytochemical studies. Stigmasterol was identified in the EtOAc fraction. This study justifies the use of A. macrostachya in the treatment of infections in traditional medicine and highlights its potential as a source of bioactive compounds that could possibly interact with some resistance mechanisms in bacteria to combat antimicrobial resistance.
Assuntos
Acacia , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Casca de Planta , Extratos Vegetais/farmacologia , Caules de Planta , Antibacterianos/isolamento & purificação , Biofilmes/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Humanos , Moduladores de Transporte de Membrana/isolamento & purificação , Moduladores de Transporte de Membrana/farmacologia , Testes de Sensibilidade Microbiana/métodos , Extratos Vegetais/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologiaRESUMO
Xylia evansii is widely used in traditional medicine to stop bleeding gums and treat wounds. This study was undertaken to assess the wound healing activity and toxicity profile of the stem bark methanol extract of X. evansii (XES). Wound healing activity was determined by the dermal excision model in rats. The free radical scavenging capacity, antioxidant activity, total phenolic and flavonoid contents were evaluated by the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, total antioxidant capacity (TAC), aluminum chloride colorimetric and Folin Ciocalteu methods respectively. Acute and sub-acute oral toxicity assessment was performed following the Organization for Economic Co-operation and Development guidelines. Signiï¬cant (p < 0.05) dose-dependent wound healing effect, similar to that of 1 % silver sulphadiazine was elicit by the 10, 15 and 20 %w/w XES ointments. The highest effect was demonstrated by XES 20 %w/w which resulted in 98.3 % wound surface closure by day 9 of treatment (p < 0.0001). The total phenolic and ï¬avonoid contents were determined to be 381.2 ± 12.57 mg/g gallic acid equivalent (GAE) and 460 ± 29.07 mg/g quercetin equivalent respectively. XES exhibited remarkable free radical scavenging effect (IC50 = 68.13 ± 1.87 µg/mL) and had a total antioxidant capacity of 279.2 ± 32.08 mg/g GAE. The LD50 of XES was estimated to be > 5000 mg/kg. In sub-acute toxicity, 28 days treatment with XES (250, 500, 1000 mg/kg body weight) did not result in any significant (p > 0.05) change in the body weight or weight of the heart, lung, spleen, liver and kidneys. The haematological and biochemical profiles of XES-treated rats were not significantly (p > 0.05) affected after 4-weeks treatment with XES, except for platelet count which increased significantly (p < 0.0001) in a non-dose-dependent manner. Histopathological examination did not reveal any toxic effect to liver cells, however at 1000 mg/kg XES, slight abnormalities were identified in the glomeruli. Microscopy of the powdered stem bark displayed calcium oxalate crystals, pitted vessels and lignified fibres. Tannins, flavonoids, coumarins, saponins, triterpenes and alkaloids were identified in the bark. This is the first report on the wound healing potential and safety profile of X. evansii, giving scientific credence to its use in traditional medicine.
RESUMO
Background: Zingiber officinale Roscoe (ginger) rhizome is a global spice with marked pharmacological activities and industrial applications. The demand for the powdered spice soared in the wake of the COVID-19 global pandemic. The present study sought to assess powdered ginger products on the Ghanaian market for some quality parameters and compare their chemical composition via chemometric analysis of their FT-IR data. Methods: A survey was conducted in three major markets in Ghana to determine the commercially available powdered ginger products. These products were purchased and assessed for microbial load, heavy metals contents and ash values using official methods. Also, principal component and hierarchical cluster analysis, as multivariate algorithms, were applied to their FT-IR spectral fingerprints, using Z. officinale, Z. zerumbet and some dried ginger rhizomes from Nigeria as reference samples. Results: Seven products were found in the survey: three local and four foreign. The local products failed to meet regulatory label requirements. The microbial load, heavy metals and ash values of all commercial samples were generally within specifications except for the aerobic bacterial counts of some local samples. Pharmacopoeial identity test and the chemometric analysis revealed all the products to contain Z. officinale. The reference ginger sample from Nigeria also demonstrated some level of similarity with Z. officinale. The variations in physical attributes and slight difference in chemical composition of the different products was presumed to be due to chemical changes arising from different processing methods and possible adulteration with other flours. Conclusion: The sampled ginger products on the market originate from Z. officinale and have quality attributes that make them suitable for food and medicinal applications. The observed deviations, however, suggest an urgent need for standardized processing methods to ensure consistency in quality indices, as well as regular quality checks by regulatory bodies.
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The present study evaluated the wound healing, anthelmintic and antioxidant potentials of crude methanol extracts and fractions (petroleum ether, ethyl acetate and methanol) of the leaves and stem bark of Amphimas pterocarpoides. Wound healing activity was determined by the dermal excision model in rats; anthelmintic activity was evaluated by the adult worm motility test using the adult Indian worm, Pheretima postuma. Total flavonoid, phenolic content and antioxidant activity were assessed by the aluminum chloride colorimetric, Folin Ciocalteu, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and total antioxidant capacity (TAC) assays respectively. HPLC/UV fingerprints were developed for quality control. The maximum amount of phenolics and flavonoids were detected in the methanol fractions of the stem bark (225.0 ± 20.0 mg/g gallic acid equivalent (GAE) and 201.0 ± 1.41 mg/g quercetin equivalent (QCE) respectively) and leaves (84.54 ± 1.36 mg/g GAE and 130.7 ± 1.71 mg/g QCE, respectively). Both leaf and bark displayed remarkable free radical scavenging and TAC with the highest effect given by the methanol fractions. Significant (p < 0.05) wound contraction was achieved by topical application of the leaf (APL) and stem bark (APS) ointments (5-15%) with >90 % wound surface closure for 1% silver sulphadiazine, APS 15% and APL 10% treated groups by day 15. APL and APS demonstrated a concentration- and time-dependent paralysis and mortality of the P. posthuma with APL (6.25 mg/mL) causing worm paralysis at 82.60 min and death at 93 min, better than 10 mg/mL albendazole (paralysis at 76.30 min; death at 117 min). Tannins, triterpenoids, phytosterols, flavonoids, saponins and coumarins were detected in the leaves and bark. The results have proven the potential of A. pterocarpoides as a wound healing and anthelmintic agent, giving scientific credence to its use in traditional medicine.
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BACKGROUND: Vitex doniana Sweet fruit, an under-utilised crop specie of Ghana, has not been validated for its ethnomedical use in managing inflammatory conditions. Therefore, the study sought to investigate its anti-inflammatory and antioxidant activities as well as isolate and quantify one of its active constituents. MATERIALS AND METHODS: In-vivo anti-inflammatory activity of the methanol fruit extract was evaluated using the carrageenan-induced oedema model in chicks. The in-vitro antioxidant property was also investigated using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The acute and subacute toxicity studies of the fruit extract were evaluated in rodent models. RESULTS: No signs of autonomic and central nervous system stimulation/depression were recorded. The LD50 by oral route, was estimated to be beyond 3000 mg/kg. Subacute studies revealed an increase in red blood cell and lymphocyte counts. Liver enzymes, serum proteins and bilirubin levels did not significantly increase. The crude extracts at doses of 10, 30 and 100 mg/kg inhibited paw oedema considerably. The ethyl acetate fraction showed the highest antioxidant activity (IC50 = 99.35 ± 0.77 µg/mL). Oleanolic acid, isolated from the ethyl acetate extract, showed significant anti-inflammatory and antioxidant activities. A sensitive high-performance liquid chromatography method for the detection and estimation of oleanolic acid, as a biomarker compound for V. doniana fruit, was developed and validated for quality assurance purposes. CONCLUSION: The extract of V. doniana fruits possesses considerable anti-inflammatory and antioxidant properties and was non-toxic under laboratory conditions.
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The emergence and resurgence of P. falciparum resistance to generations of antimalarial drugs have prompted the search for new, effective, and safe antimalarial agents. This study aimed at investigating the in vivo antiplasmodial activity of the 70% hydroethanolic extract and constituents of the stem bark of Myrianthus libericus based on its ethnomedicinal use as an antimalarial agent. The antiplasmodial activity was assessed in Swiss albino mice employing the 4-day suppressive and Rane's tests. MLB significantly (p < 0.0001) suppressed parasitaemia by 52.26%, 65.40%, and 77.11% at 50, 100, and 200 mg·kg-1 doses, respectively, in the 4-day suppressive test. In Rane's test, the highest parasitaemia suppression of 72.50% was recorded at a dose of 200 mg·kg-1 of the extract. Fractionation of the bioactive ethyl acetate fraction by solvent-solvent partitioning and column chromatography led to the isolation of friedelan-3-one and stigmasterol being reported for the first time from this species. The compounds demonstrated remarkable antiplasmodial activity by suppressing parasitaemia by 65-72% in the suppressive test and 61-70% in the curative test at doses of 10-30 mg·kg-1. Both the extract and the isolated compounds significantly prolonged the survival time of infected mice and averted the cardinal signs associated with P. berghei-induced malaria including weight loss, hypothermia, and haemolysis. The results obtained confirm the prospect of M. libericus as an important source of new antimalarial compounds and justifies its folkloric use as an antimalarial agent.