Radical Scavenging and Anti-inflammatory Potentials of Aqueous and Hydroethanol Extracts of Heliotropium indicum Aerial Parts

Purpose: Heliotropium indicum (H. indicum) is widely used in traditional medicine to treat conditions linked to inflammation and oxidative stress, yet its antioxidant and anti-inflammatory properties remain scientifically unestablished. This study examined the radical-scavenging and anti-inflammatory effects of aqueous and hydroethanol extracts prepared separately from the leaves and flowers of H. indicum. Methods: Fresh leaves and flowers were washed, shade-dried, powdered, and steeped independently in distilled water or 50% hydroethanol for 72 hours, yielding four extracts: leaf aqueous extract (HILAE), leaf hydroethanol extract (HILHE), flower aqueous extract (HIFAE), and flower hydroethanol extract (HIFHE). Radical-scavenging activity was assessed via DPPH, ABTS, hydroxyl (OH), and nitric oxide (NO) assays against BHT, while anti-inflammatory activity was evaluated through membrane stabilization, inhibition of heat-induced hemolysis, protein denaturation, and proteinase inhibition assays against sodium diclofenac; IC50 values were determined using GraphPad Prism 10. Results: Activity generally rose with extract concentration. HILHE showed the strongest overall radical-scavenging activity, with IC50 values of 93.78, 54.10, 87.61, and 72.43 μg/mL for DPPH, ABTS, OH, and NO, respectively, in some cases matching or exceeding BHT. HIFHE gave IC50 values of 64.13, 83.36, and 88.54 μg/mL for membrane stabilization, hemolysis inhibition, and proteinase inhibition, comparable to diclofenac sodium, while HILHE recorded the lowest IC50 of 78.04 μg/mL for protein denaturation. Conclusion: Both extract types showed radical-scavenging and anti-inflammatory activity, with hydroethanol extracts performing more consistently across assays. These findings support the traditional use of H. indicum and point to bioactive compounds underlying its antioxidant and anti-inflammatory effects.