ジャーナル・オブ・ファーマコビジランス

概要

Unregulated Promotion and Sale of Herbal Remedies: A Safety and Efficacy Evaluation of Twelve Such Commercial Products Claimed to be Beneficial and Patronised for a Variety of Ailments in Nigeria

Nworu CS, Vin-Anuonye T, Okonkwo ET, Oyeka CO, Okoli UB, Onyeto CA, Mbaoji FN, Nwabunike I and Akah PA

Preparation, distribution, advertisement, and usage of phythomedicinal products in Nigeria are weakly regulated raising genuine concern for public safety. In this study, twelve highly patronised commercial herbal products (S1- S12) claimed to be beneficial in the management of either diabetes mellitus, diarrhoea, or hypertension were procured from herbal vendors in Nigeria and evaluated against their claims of efficacy and safety using established whole animal and in vitro models. S1, S2, and S3 were tested for anti-hyperglycaemic activity in normoglycemic and diabetic rats and only S1 and S2 showed some reductions in blood glucose at some time points but S3 produced no reduction in blood sugar at all the time points. Three samples, S4, S5, and S6 significantly (P ≤ 0.05) inhibited the frequency of diarrhoea drops in rats at a dose of 250 mg/kg and caused minimal (P>0.05) reduction in intestinal transit of a charcoal meal in mice. Infusion of aqueous extract of samples (S7-S12) up to 1mg/kg, showed that only the mean arterial blood pressure of cannulated cat was reduced by S7 and S8 but samples S9, S10, S11, and S12 did not cause any reduction in the arterial blood pressure. At a dose of 1 mg/kg, S7 and S8 caused a BP reduction of 150 and 76.92% relative to the reduction produced by ACh (1 μg/kg). The safety of these samples was assessed by determining the acute toxicity of these preparations and checking the nature of contaminating organisms and the levels of such contamination (bio-load). Acute toxicity studies in mice showed that at doses above 5000 mg/kg, per os, all the herbal samples did not cause death or produced signs of acute intoxication in mice. The samples were found to be contaminated with a variety of microorganisms, although their bio-loads were largely within pharmacopoeia specification. S7 is the most heavily contaminated; S3, S4, and S12 are contaminated with Gram negative organisms that may be potentially pathogenic. The outcome of this preliminary investigations demonstrates the need for stricter regulation and registration of commercial herbal products. Post-marketing surveillance, pharmacovigilance, and random screening of herbal products should be entrenched in the regulatory framework to quickly dictate any possible adverse effect and ensure consistency in the quality of distributed herbal medicines.