In Vitro Assessment on the Synergistic Antibacterial Effect of Ginger (Zingiber officinale Roscoe) Extract with Clindamycin Antibiotic against Staphylococcus aureus

Objectives: Examine if there is a synergistic antibacterial effect of Ginger (Zingiber officinale Roscoe) extract with clindamycin antibiotic against S. aureus.  Methods: The ginger extract was prepared by air-drying 50 grams of ginger and macerating it in 500 mL of 95% ethanol for 24 hours, followed by filtration and evaporation to obtain a condensed extract. Staphylococcus aureus colonies were inoculated on nutrient agar and incubated at 37°C for 18 to 24 hours. A 1 mg/mL clindamycin suspension was prepared from 300 mg capsules. MHA plates were inoculated with S. aureus, and filter paper discs labeled Clindamycin (C), Ginger (G), and combinations (GC50, GC75, GC100) were placed on the agar. The plates were incubated at 37°C for 18 to 24 hours, and the zones of inhibition were measured using the Kirby-Bauer Test to assess the synergy through mean ZOI and cooperative effect synergy testing.  Results: The results of the study indicate that the combination of ginger extract and Clindamycin generally showed antagonistic interactions. However, GC100 (100% ginger extract and Clindamycin) had a mean zone of inhibition (ZOI) closest to Clindamycin alone, suggesting potential antibacterial benefits at higher concentrations of ginger extract. Further analysis using cooperative effect synergy models confirmed the lack of synergistic interaction. Pairwise comparisons revealed that GC50 (50% ginger extract and Clindamycin) had a significant difference in effectiveness compared to Clindamycin alone (p-value: 0.045), while GC75 (75% ginger extract and Clindamycin) and GC100 did not exhibit significant differences.  Conclusion: These findings underscore the complexity of combining natural extracts with antibiotics. Although the combination did not enhance antibacterial efficacy, the potential of high-concentration ginger extract to act as a complementary treatment warrants further investigation to develop effective strategies against antibiotic-resistant S. aureus.