Antioxidant Efficacy and Sun Protection Factor Evaluation of Extracts From the Leaf, Stem and Root of <i>Dipteracanthus prostratus</i>

Prolonged exposure to ultraviolet (UV) light heightens the risk of skin disorders, including cancer and photoallergic responses. Plant-derived phytochemicals demonstrate noteworthy antioxidant properties, making them effective for UV absorbance and photoprotective functions. Dipteracanthus prostratus Nees (DP) is an important native medicinal plant of the Acanthaceae family known for their various biological properties. The present study evaluated the UV protection capabilities of extracts of leaves, stems and roots of the DP plant. All DP extracts had sun protection factors (SPFs) ranging from 0.102 to 4.1, with petroleum ether (PE) extract of leaf achieving the highest SPF; other extracts of leaf from other solvents demonstrated moderate-to-good activity. PE extracts of both stem (2.0-2.5) and root (2.0-2.4) exhibited a significant persistence for 21 days. The DPPH assay demonstrated that leaf extracts of PE and the aqueous extract of root had IC₅₀ values of 0.165 and 0.104 mg/mL. The leaf (water extracts) and root (PE extracts) demonstrated significant total antioxidant activity with IC₅₀ values of 0.629 and 0.57 mg/mL. The consistent photoprotection of DP makes it a viable candidate for developing natural, long-lasting sunscreen formulations, emphasizing its role in contemporary photoprotective therapies.