Ethiopian medicinal plants used for their anti-inflammatory, wound healing or anti-infective activities: protocol for systematic literature review and meta-analysis

Objectives Medicinal plants are used globally as alternative medicines in the management of a range of disease conditions and are widely accepted across differing societies. Ethiopia hosts a large number of plant species (>7000 higher plant species), of which around 12% are thought to be endemic, making it a rich source of plant extracts potentially useful for human health. The aim of this review is to evaluate Ethiopian medicinal plants for their anti-inflammatory, wound healing, antifungal or antibacterial activities. Methods and analysis The guidance of the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) statement will be used. This review will consider all controlled studies of anti-inflammatory and wound healing properties (both in vivo and in vitro) and in vitro anti-infective properties of medicinal plants found in Ethiopia. Data sources will be EMBASE, PubMed/Medline, Scopus and Google Scholar. Guidance documents on good in vitro methods and checklists for reporting in vitro studies will be used for quality assessment of in vitro studies. The risk of bias tool for animal intervention studies (the SYRCLE RoB tool) will be used to assess the validity of studies. The main outcomes will be percent inhibition of inflammation, time of epithelisation and tissue tensile strength in wounds and microbial growth inhibition. Ethics and dissemination The findings of this systematic review will be disseminated by publishing in a peer-reviewed journal and via conference presentations. Ethical clearance was obtained from the Brighton and Sussex Medical School, Research Governance & Ethics Committee (RGEC) and Addis Ababa University, College of Health Science, Institutional Review Board

Antibacterial activity of methanol extracts of the leaves of three medicinal plants against selected bacteria isolated from wounds of lymphoedema patients

Background: Patients with lymphoedema are at high risk of getting bacterial and fungal wound infections leading to acute inflammatory episodes associated with cellulitis and erysipelas. In Ethiopia, wound infections are traditionally treated with medicinal plants. Methods: Agar well diffusion and colorimetric microdilution methods were used to determine the antibacterial activity of methanol extracts of the three medicinal plants against Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Shewanella alage, methicillin-resistant S. aureus ATCC®43300TM, Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Klebsiella pneumoniae ATCC700603, and Pseudomonas aeruginosa ATCC37853. Results: The methanol extract of L. inermis leaves showed high activity against all tested bacterial species, which was comparable to the standard drugs. Similarly, the extracts of A. indica showed activity against all tested species though at higher concentrations, and higher activity was recorded against Streptococcus pyogenes isolates at all concentrations. However, the extract of A. aspera showed the lowest activity against all tested species except Streptococcus pyogenes isolates. The lowest minimum inhibitory concentration (MIC) was recorded with the extract of L. inermis against E. coli isolate and S. aureus ATCC 25923. Conclusion: Methanol extracts of L. inermis, A. indica, and A. aspera leaves exhibited antimicrobial activity against selected bacterial isolates involved in wound infections, of which the methanol extracts of L. inermis exhibited the highest activity. The results of the present study support the traditional use of plants against microbial infections, which could potentially be exploited for the treatment of wound infections associated with lymphoedema

Antibacterial and antioxidant potential analysis of Verbascum sinaiticum leaf extract and its synthesized silver nanoparticles

The potential applications of plant extract and nanoparticles in antibacterial and antioxidant studies have garnered significant interest in recent times. Despite being utilized in Ethiopian traditional medicine, Verbascum sinaiticum (qetetina) constituents and its usage in nanoparticle synthesis remain relatively unexplored. This study explores the potential of the plant extract and its nanoparticles for antibacterial and antioxidant applications, with a focus on the leaf extracts and its silver nanoparticles. The leaf extract was analyzed using LC-MS and GC-MS and found to contain over 70 compounds, including glycosides, phenolic compounds, flavonoids, and fatty acids. The synthesized nanoparticles had a maximum absorbance of 408 nm, with a size range of 2–40 nm and showed a spherical shape. Using the agar well diffusion method, the extract and nanoparticles were evaluated against Gram-positive (Staphylococcus aureus ATCC 2592, Streptococcus agalactia ATCC12386) and Gram-negative bacteria (Acinetobacter baumannii ATCC19606, Pseudomonas aeruginosa ATCC27853) bacterial strains. In terms of antibacterial effects, both the silver nanoparticles and leaf extract displayed a greater impact on gram-positive bacterial strains over gram-negative bacterial strains. Additionally, the tests for lowest inhibitory and bactericidal concentration indicated similar outcomes. Notably, the silver nanoparticles exhibited greater antibacterial activity compared to the leaf extract alone. The DPPH (2, 2-diphenylpicrylhydrazyl) assay was conducted to investigate antioxidant activity. The results showed that the plant extract had an IC50 value of 143 μg/ml, while the synthesized nanoparticle had an IC50 value of 216 μg/ml, indicating that the plant extract had greater antioxidant activity than the synthesized silver nanoparticles

Optimization, Identification, and Quantification of Selected Phenolics in Three Underutilized Exotic Edible Fruits Using HPTLC

This study aimed to investigate selected bioactive components in three underutilized wild edible exotic fruits (Syzygium guineense Wild. DC, Ziziphus spina-christi L., and Citrus medica L.), using high-performance thin-layer chromatography and ultraviolet-visible spectrophotometry (HPTLC-UV-Vis), treated under three drying conditions. Ultrasound-assisted extraction was used to extract the target bioactive components under specified conditions, i.e., time of 15 min, temperature of 35 °C, methanol and water 75/25, v/v, and fruit powder-to-solvent ratio of 1:15, w/v. The mobile phase ratio for rutin, kaempferol, myricetin, and quercetin was toluene/ethylacetate/methanol/formic acid at 20:12:8:4, whereas, for phenolic acids, the ratio was 10:15:10:5, respectively. The HPTLC plates were scanned to identify and quantify selected compounds (phenolic acids, quercetin, rutin, myricetin, and kaempferol) at their maximum optimized absorption wavelengths. The contents of target bioactive components ranged from 0.64 ± 0.19 mg/100 g for rutin to 320.04 ± 7.10 mg/100 g for chlorogenic acid. Based on the results of this investigation, the phenol content of freeze-dried fruit was significantly (p ≤ 0.05) higher than other drying methods. The calculated average limit of detections and quantifications ranged from 0.37 to 75 ng/spot to 2.5 to 250 ng/spot, respectively. The average recoveries were 99.91 ± 5.65% for quercetin and 99.08 ± 5.96% for rutin. Overall, the validated HPTLC method was simple, selective, sensitive, and stable for the simultaneous identification and determination of phenolic acids and flavonoids. As a result, this study revealed that the contents of phenolic acids and flavonoids in selected exotic edible fruits can be used as effective antioxidants