Luteolin inhibits mast cell degranulation, effectively blocking the release of histamine before it causes allergic symptoms. 2 Luteolin has been identified as the active ingredient in two herbal remedies that have historically been used for allergies: Impatiens textori (impatiens) and Perilla frutescens (perilla). 3,4 Experimental studies in mice have shown that luteolin is responsible for the anti-inflammatory as well as the anti-pruritic [anti-itch] effects of perilla leaves.