NAFDAC Listing Is Not Proof: The Case Against Animal-Only Evidence for Herbal Claims

Six healthy volunteers at a London hospital nearly died in 2006 after receiving a compound that had already passed animal testing. Olatunde Isaac invokes that incident, the TGN1412 trial at Northwick Park on 13 March 2006, as the core argument for why Nigeria's drug regulator, NAFDAC, must rethink how it approves herbal medicines.

His thesis is blunt: preclinical safety assessments alone cannot establish clinical safety or therapeutic efficacy in humans. Isaac is not calling for a ban on herbal medicine. He is calling for a regulatory system that separates traditional use from scientifically substantiated therapeutic claims.

What happened at Northwick Park?

Eight healthy male volunteers enrolled in a Phase I trial of TGN1412, an experimental monoclonal antibody. Six received the compound; two received a placebo. Shortly after administration, all six active-group participants suffered severe, potentially life-threatening reactions, including a cytokine storm and multiorgan dysfunction. All survived.

The preclinical animal studies had not predicted the outcome. Isaac draws the regulatory lesson carefully: a favourable safety profile in animals cannot be regarded as conclusive evidence of human safety.

TGN1412 was a biotechnology product, not a herbal preparation. Isaac concedes the difference. The broader principle, in his view, still holds for any medicinal substance seeking approval.

What does NAFDAC's listing actually certify?

Herbal products occupy a significant place in Nigerian healthcare, with generations of traditional use and widespread advertising for conditions including malaria, diabetes, infertility and hypertension. NAFDAC regulates these products through procedures covering quality, manufacturing practices, labelling and safety assessments.

The problem, Isaac argues, sits in a distinction most consumers miss. Certain herbal products may be listed without clinical evidence of therapeutic efficacy. Listing is not equivalent to scientific confirmation that a product can treat or cure a disease. Products making specific therapeutic claims face additional evidentiary requirements, including clinical evaluation where applicable.

Yet Nigerian consumers, he writes, sometimes interpret a NAFDAC number as an official endorsement of medicinal effectiveness. How many understand the difference between regulatory permission to market a product and scientific confirmation of its claimed benefits? Isaac does not supply survey data on consumer misunderstanding, which weakens the claim's empirical footing, though the regulatory distinction itself is not in dispute.

Why does the safety-efficacy gap matter?

Isaac separates two concepts that preclinical testing routinely conflates in public perception. Safety concerns whether a product causes harm under specified conditions. Efficacy concerns whether it produces the intended therapeutic benefit.

A herbal preparation may show low toxicity in animal studies while possessing no meaningful therapeutic effect at all. Absence of significant toxic effects in experimental animals, he notes, does not establish that a product can treat malaria, control blood glucose, reduce blood pressure or cure an infection.

Traditional use does not close that gap. Historical experience can guide scientific investigation, but it cannot answer questions of dosage, drug interactions, long-term safety or effects in pregnant women, children, older persons and people with chronic diseases. The stakes extend beyond toxicity: patients relying on ineffective treatments may delay proper care, discontinue effective medicines or suffer preventable complications.

What regulatory changes does Isaac propose?

His recommendations are proportionate rather than uniform:

• Evidence requirements should match the risk and the therapeutic claim, not apply identically to every preparation.
• Products with novel ingredients, unfamiliar formulations or uncertain safety profiles may require properly designed clinical trials.
• Other traditional products could be assessed through existing scientific evidence, documented traditional use, toxicological findings and the specific claims made.
• NAFDAC should tighten oversight of advertising, so that listed products are not promoted as clinically proven cures.
• The agency should state clearly, for each authorisation category, whether efficacy has been clinically evaluated.
• Post-market surveillance must strengthen to catch adverse reactions and quality failures.

Isaac also addresses the commercial dimension. Manufacturers who invest in research, standardised manufacturing and clinical evaluation currently compete against rivals making extravagant claims without evidence. A stricter framework, he argues, protects credible producers as much as consumers.

Can Nigeria build on this?

The country holds considerable potential for medicinal plant research and locally produced therapeutics. Isaac calls for collaboration among universities, research institutes, pharmaceutical scientists, traditional medicine practitioners and regulators, supported by government funding, technical assistance and clear evaluation pathways.

His argument ends where it began, with the Northwick Park precedent. If a compound tested in animals could produce such severe unexpected reactions in humans, regulators should treat animal toxicity data alone as an insufficient basis for conclusions about people. NAFDAC's task, in his formulation, is to ensure that regulatory authorisation is never mistaken for clinical validation.