Re-thinking Metronidazole: Anti-microbial Synergism of Hexane Extracts of Garcinia kola and Aframomum melegueta

Aims: This research evaluates knowledge, attitudes, and practice with regard to food poisoning treatment. It compares the antimicrobial effects of Garcinia kola (Gk) and Aframomum melegueta (Am) seeds with Metronidazole and Gentamicin as standards.

Study Design: A survey with questionnaires was carried out among community Pharmacists in Lagos, Nigeria on drug of choice for suspected food poisoning and the responses analyzed. Hexane extracts of Gk and Am seeds were used on selected microbials that cause food poisoning.

Place and Duration of Study: Department of Pharmacognosy; Phytochemistry Laboratory and Department of Pharmaceutics and Pharmaceutical Technology; Pharmaceutical Microbiology Laboratory, Faculty of Pharmacy. University of Lagos.

Methodology: Agar diffusion assays were carried out using and using Gk and Am with Metronidazole and Gentamicin as controls. Gas chromatography and Mass spectroscopy of the extracts was also carried out to ascertain the possible active phytocomponents.

Results: Our discovery on knowledge showed that 98.6% of the interviewed Pharmacists use Metronidazole for food poisoning treatment. 41.7% of the respondents prescribe Ciprofloxacin while 66.7% prescribed Tetracycline as adjunct medications. Gk and Am exerted powerful anti-microbial effects in a dose dependent manner. Gk on S. typhi showed 1.4-1.7 cm zone of inhibition (zi) at 200mg/ml and with E. coli, 1.2 cm at same concentration. Am with S. typhi showed1.2-1.8 cm and E. coli 1.5 cm zi at same concentration too, much better than Gk. Their mixture for the synergistic experiments had 2.0-2.2 cm and E. coli, 2.4 cm zi at 200 mg/ml, the best performance of the extracts as anti-infective agents against food poisoning. 19 compounds were discovered through GC/MS in Gk and 31 in Am. They each exerted more antimicrobial effects than Metronidazole and their mixture used for synergistic experiments compared favorably with Gentamicin.

Conclusion: Hexane extracts of Gk and Am are good alternatives for the treatment of food poisoning. The study encourages further drug discovery research in order to ascertain the particular bioactive compounds in the extracts responsible for their powerful antimicrobial actions. Metronidazole is not the drug of choice for food poisoning management.