Formulation of a drug for the treatment of allergic conjunctivitis: Copper nanoparticles containing Olea europaea leaf aqueous extract

Olea europaea or Olive is the main ingredient of the Mediterranean diet. They are associated with many health benefits, especially for heart health and cancer prevention. Olive is rich in antioxidants and its health benefits range from fighting inflammation to reducing the growth of microorganisms. Recently, metallic nanoparticles green-formulated by ethnomedicinal plants have been used due to the antioxidant and anti-inflammatory potentials. Present research discloses the CuNPs biosynthesizing capability of the leaves of pharmacologically important Olea europaea. In addition, we investigated the Olea europaea green-formulated copper nanoparticles for the treatment of ovalbumin-induced allergic conjunctivitis. For determining the physicochemical properties of the recent nanoparticles, FT-IR, FE-SEM, UV–Vis and TEM were used. ELISA test was applied to measure the serum ovalbumin-specific IgG and IgE and total IgE. Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization and topical conjunctival challenge in guinea pigs were determined after a week’s daily treatment with 30 mg kg−1 prednisolone, 10 mg kg−1 chlorpheniramine, 2, 4, 8 and 16 µg kg−1 copper nanoparticles, or 10 mL kg−1 PBS. Ovalbumin-specific IgG and IgE as well as total serum IgE also decreased significantly (p < 0.01). All doses of copper nanoparticles treatment resulted in a significantly (p < 0.01) low clinical score of allergic conjunctivitis. The conjunctival tissue in copper nanoparticles treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration.