Saponins and their synergistic antibacterial activity with traditional antibiotics against Staphylococcus aureus and Escherichia coli: Review

Abstract

The rapidly increasing rate of antimicrobial drug resistance requires novel ways of treating infections. Harnessing the synergistic effect of the combined use of conventional antibiotics with naturally occurring antimicrobial substances is an emerging frontier in the fight against the spread of antimicrobial resistance. Synergy is measured by using the fractional inhibitory concentration index (FICI). Saponins are secondary metabolites produced by plants and they help defend the plant against natural stressors. This article aims to review the synergistic activity of saponins with traditional antibiotics. Thirteen plants were included in the final review, out of which eight species showed a FICI score below 0.5 (synergistic). These were _Jatropha curcas_, _Melanthera elliptica_, _Glycine max, Tribulus terrestris, Salvia officinialis, Spergulara marginata, Paromychia argenetea_, and _Syzigium aromaticum_. The highest degree of synergy was observed against S. aureus with the combined use of J_atropha curcas_ and rifampicin (FICI 0.04), _Melanthera elliptica_ and tetracycline (0.05), and _Glycine max_ and benzylpenicillin (0.22). In addition, a high degree of synergy against E. coli was observed with the combined use of _Melanthera elliptica_ and tetracycline (0.07), _Jatropha curcas_ and rifampicin (0.08), _Salvia officinialis_ and amoxicillin (0.38).

Antimicrobial Potential and Biochemical Profile of Methanolic Extracts of Common Solanum Species in Nigeria

“…Saponins are crucial nutritional supplements and nutraceuticals; they have antibacterial properties that aid in shielding their users against microbial infections. 31 Because eggplants contain saponins, their use in traditional medicine is justified. Glycosides are sugars that can resemble carbohydrates structurally and are a substrate of α-glucosidase.…”

"Review: Studi Kandungan Fitokimia dan Aktivitas Antibakteri Daun Pepaya (Carica Papaya L.)"

“…Flavonoid diduga dapat menjadi agen antibakteri dengan cara menghambat sintesis asam nukleat dan menghambat fungsi membran sitoplasma suatu bakteri [25]. Saponin diduga memiliki aktivitas antibakteri dengan berinteraksi dengan kolesterol membran sel sehingga menciptakan pori-pori dan akhirnya memaksa membran sel pecah [26]. Tanin diduga memiliki aktivitas antibakteri dengan cara khelasi besi, menghambat sintesis dari dinding dinding sel, mengganggu membran sel dan menghambat jalur biosintesis asam lemak [27].…”