The harsh environment of semi-arid and arid regions induces plants in these regions to produce numerous bioactive compounds with therapeutic or medicinal properties. An initial study of extracts from arid land plants Cymbopogon schoenanthus, Crithmum maritimum, Rhanterium suaveolens, and Artemisia herba-alba evaluated their effects on Type I allergic reactions and melanin biosynthesis using RBL-2H3 basophilic cells and B16 murine melanoma cells, respectively. Plant extracts were not cytotoxic at low concentrations. β-hexosaminidase release inhibition assay indicated that extracts significantly inhibited mast cell degranulation. Melanin assay results showed significant melanin biosynthesis regulatory effects in B16 cells. Further studies are being undertaken to understand the mechanism underlying the observed effects.