Korean researchers standardize antioxidant data from 586 herbal extracts with new comparison index

South Korean researchers have successfully standardized antioxidant data from natural substances into a common comparison index, overcoming longstanding barriers posed by incompatible measurement methods and units.

A research team led by Kim Dong-sun of the Korea Institute of Oriental Medicine's Department of Korean Medicine Science announced Thursday that it has developed an EF (Effect Factor)-based standard comparison framework that allows antioxidant data measured by different methods to be evaluated against a single benchmark.

Antioxidant properties of natural substances such as ginseng and green tea are assessed through a range of methods — including ABTS, DPPH, TPC and TFC — but each uses different measurement approaches and units, making it difficult to compare results across substances or manage them in an integrated way.

The problem is particularly acute for multi-component herbal medicines and natural substance extracts, where results can vary significantly depending on experimental conditions and analytical methods, complicating objective prioritization of candidate materials and reproducible comparisons.

To address this, the research team converted four antioxidant-related indicators into a single common comparison index called EF, enabling experimental results obtained under different conditions to be compared against a standardized benchmark.

The research team further divided the EF into two types based on the nature of the data.

The team compiled an EF-based database of 586 natural substance extracts — derived from 271 individual herbal medicines and 22 herbal prescriptions prepared under water and 30 percent ethanol conditions.

The work produced a standardized antioxidant comparison platform that allows diverse herbal medicines and natural substance extracts to be interpreted against the same benchmark.

"What sets this research apart is that it is a database-type study that organizes large-scale data from 586 extracts under a single standard, rather than demonstrating the superiority of any particular material," Kim said. "The EF framework will be used to prioritize candidate materials and establish efficient screening strategies in the development of natural substance-based health functional foods, functional cosmetics and pharmaceuticals."

The findings were published May 6 in "Analytica," an international journal in the field of analytical chemistry.