2.1.2. Preparation of extract
Fresh leaves of R. nasutus (L) were shade dried and milled to fine powder using a mechanical grinder. The powdered plant material was macerated and shaken in methanol for 48 h using a bath shaker. The extract was then filtered with filter paper (Whatman No.1) and concentrated to dryness under vacuum and reduced pressure using Rota evaporator at 40 曟. The concentrate was then layered on aluminum foil and freeze dried for further use