Natural Antibiotics: A Study of the Biological Activity of a Quintet (Garlic, Turmeric, Cinnamon, Ginger, and Honey) as Safe Alternatives to Conventional Antibiotics

Abstract

ackground: Antibiotic resistance has emerged as one of the most critical 
global health threats, necessitating the search for safe and effective 
natural alternatives. 
Objective: This systematic review evaluates the biological activity of five 
natural agents – garlic, turmeric, cinnamon, ginger, and honey – as 
potential natural antibiotics. 
Methods: A comprehensive literature search was conducted in PubMed, 
Scopus, and Google Scholar databases (2000–2025) focusing on in vitro 
and in vivo studies assessing antimicrobial activity, mechanisms of action, 
and minimum inhibitory concentrations (MICs) of the selected natural 
products. 
Results: The bioactive compounds – allicin (garlic), curcumin (turmeric), 
cinnamaldehyde (cinnamon), gingerol/shogaol (ginger), and hydrogen 
peroxide/methylglyoxal (honey) – exhibit potent activity against a wide 
range of Gram‑positive and Gram‑negative bacteria, including 
multidrug‑resistant (MDR) strains. MIC values ranged from 0.3–3 mg/mL 
(garlic), 31.25–5000 μg/mL (curcumin), 1.5–12.5 μL/mL (cinnamon), 2.9
4.8 mg/mL (ginger), and 1–12.5% w/v (Manuka honey). Synergistic effects 
with conventional antibiotics and anti‑biofilm activities were documented. 
Conclusion: These natural agents represent promising safe alternatives or 
adjunctive therapies to synthetic antibiotics. Further clinical trials are 
needed to standardize dosages and evaluate long‑term efficacy.