The Classification of Sri Lankan Medicinal Herbs: An Extensive Comparison of the Antioxidant Activities

Sri Lanka has variety of herbs whose effectiveness has been proven across many generations. These herbs are classified into two groups — ‘heating’ and ‘cooling’, based on the physiological reactions upon consumption. Application-wise, the ‘cooling’ herbs are administered to patients contracted with diabetes, imbalances in the lipid profile, or even cancer. However, this classification has been misunderstood due to inconsistent interpretations and lack of scientific reasoning. This study systematically determines the rationale behind this classification, by specifically evaluating the antioxidant activity of 18 herbs — nine herbs from each category. The oxygen radical absorbance capacities, DPPH radical scavenging activities, and the total phenolic contents are analyzed here. The ‘heating’ herbs have a comparatively lower antioxidant potential than the ‘cooling’ herbs. The total phenolic contents correlate with the antioxidant values. It can be hypothesized that the high antioxidant potential of the ‘cooling’ herbs may have been responsible for the containment of the diseases mentioned previously.