Evaluation of an Undocumented Polyherbal (Faradin®) Used for the Treatment of Sickle Cell Disease in West Africa. Part II: Antibacterial Activity and Synergism

Abstract

Aim: This study focused on evaluation of the anti-bacterial effects and synergism of Faradin®), a polyherbal complementary alternative medicine (CAM) and anti-sickling agent. It is used for treatment of sickle cell disease (SCD) and co-morbidities (such as infection and inflammation) in some West African countries. It is made up of Zanthoxylum zanthoxyloides, Alnus glutinosa and Alchornea cordofolia, designated, not in order as F, M, and V. Methods: Antibacterial susceptibility effects were studied using various weight: weight (w/w) ratios (10:1-1.25:1) of Faradin (or single component extract, F, M and V):water and compared to standard controls - erythromycin and penicillin (5mg/ml). Gram (-) Pseudomonas aeruginosa and E. coli, and gram (+) Enterococcus faecalis, Staphylococcus aureus and Streptococcus pneumonia microorganisms were utilized. Well diffusion method was used with pre-prepared Mueller-Hinton agar plates for all species except S. pneumonia, for which sheep blood agar plates were employed. Synergism or Fractional Inhibitory Concentration Index (FICI) between Faradin and the antibiotics was calculated using modified minimum inhibitory concentration (MIC) for each microorganism [that was derived using lower concentrations (10:1 – 0.078:1 v/v ratios) in addition to the range used for the susceptibility study], FIC for Faradin, and each antibiotic. FICI of ≤ 0 = synergy, 0.5-1.0 = additive effect; > 1.0 = intermediate effect and values > 4 are suggestive of antagonism. Results: Faradin, F or M extract had a dose-dependent antibacterial effect, with more antibacterial activity against gram (+) bacteria than gram (-) bacteria.  Gram (+) S. aureus showed greatest susceptibility followed by S. pneumoniae (MICs of 1 mg.ml and 8 mg/ml respectively). The V extract showed no antibacterial activity. Greater than 4.0 FICI values were obtained, except for P. aeruginosa, indicative of antagonism between Faradin and the antibiotic controls, and possibly different mechanism of antibacterial action. P. aeruginosa had FICI of 0.88, indicative of additive effect. Conclusions: Polyherbal Faradin showed antibacterial action to certain microorganisms and could be potentially effective against co-morbid infections in sickle cell patients while functioning as an anti-sickling agent.