Global evidence on the potential of some Ugandan herbal medicines to mitigate antibiotic resistance: a systematic review and meta-analysis from 1996 to 2021

Abstract

Background Diarrheal and respiratory ailments are major causes of global deaths, and are mostly escalated by antibiotic-resistant bacteria (ARB), warranting novel therapies against ARB. In Uganda, plants like C. pyrrhopappa, E. abyssinica, C. limon, M. foetida, C. flexuosus, and C. citrinus are often used to treat diarrhea and/or cough. Some of these are reported to demonstrate antibacterial properties in some countries, but the evidence is limited due to fragmented studies. We evaluated global antibacterial research on these plants, to derive practical insights, able to stimulate new thinking and inform drug development. Methods Electronic articles on antibacterial effects of the named plants (with a special focus on efficacy against ARB), were identified from 14 electronic databases. The eligible articles were examined using Standard Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). Sensitive ARB to the plant-extracts, Cochran’s Q test, and heterogeneity were evaluated with MedCalcs software, using a random-effects model. Sources of heterogeneity were examined through sensitivity analysis, subgroup analysis, and meta-regression (p < 0.05). Publication bias was assessed using Begg’s test and funnel plot asymmetry. Results Sixty-one articles met the inclusion criteria. Of these, 20 assessed the plants against 237 ARB invitro. C. flexuosus had the greatest efficacy (89.8%), while C. pyrrhopappa had the least (0.0%). Efficacy differences between C. flexuosus (the most efficacious species), and the rest of the plants were not significant except for M. foetida and C. pyrrhopappa (χ2, p < 0.05). The multidrug-resistant strains (resistant to at least three drug-classes), with 100% sensitivity to plant extracts included A. baumannii, S. aureus, and P. aeruginosa. Heterogeneity was high (I2 = 86.85%), with no evidence of publication bias, hence suggesting robust results. Conclusion Some herbal medicines in Uganda have vast potential to avert the global antibacterial resistance menace. Their efficacy against globally circulating bacteria that are resistant to vital drugs, such as carbapenems, shows possible treatment success if these species are used in drug development. More research is desired, especially on the potential efficacy of these plants against the world’s leading strains of resistant bacteria like K. pneumoniae and E. coli. Also, in-vivo studies are recommended due to their importance in drug discovery.