Safety and Efficacy of Black Tea Extract in the Treatment of Acute Bacterial Conjunctivitis: A Rabbit Model

Eye Contact Lens. 2023 Jan 1;49(1):35-41. doi: 10.1097/ICL.0000000000000954. Epub 2022 Nov 10.

Abstract

Purpose: To determine the safety and efficacy of black tea extract in the treatment of bacterial conjunctivitis in a rabbit model and compare it with that of gatifloxacin drops.

Methods: Black tea extract was tested in vitro on bacterial cultures of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Forty-two rabbit eyes were cultured with either MRSA (n=21) or P. aeruginosa (n=21) and further divided into a control group (n=5), a tea group (n=8) treated with black tea extract, and a gatifloxacin group (n=8) treated with 0.3% gatifloxacin eye drops. Conjunctival swabs were collected on the third and fifth days.

Results: The tea extract successfully inhibited the growth of both organisms at a concentration of 400 mg/mL. Rabbits in the treatment groups showed a reduction in the clinical index on day 2 (P<0.01), unlike the control group (P=0.1), for both organisms. Resolution of conjunctivitis was achieved on days 4 and 5 in the tea and gatifloxacin groups, respectively. On days 3 and 5, while the control group still showed considerable bacterial growth, the tea and gatifloxacin groups showed its inhibition.

Conclusion: Tea extract has antimicrobial effects similar to those of gatifloxacin in a rabbit model of conjunctivitis.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Conjunctivitis* / drug therapy
  • Conjunctivitis, Bacterial* / drug therapy
  • Fluoroquinolones / therapeutic use
  • Gatifloxacin / pharmacology
  • Gatifloxacin / therapeutic use
  • Methicillin-Resistant Staphylococcus aureus*
  • Rabbits
  • Tea

Substances

  • Gatifloxacin
  • Fluoroquinolones
  • Tea
  • Anti-Bacterial Agents