Bearberry extract (Latin name Arctostaphylos uva ursi) has antibacterial and antioxidant properties, and there is a small amount of research showing it can have skin-lightening properties. [1, 2] Bearberry extract’s potential efficacy is derived from its active components: hydroquinone and arbutin. 
Hydroquinone is well established as a melanin-inhibiting agent; arbutin has far less quantitative information available, but in high concentrations has been shown to inhibit melanin production.  However, the small amount of bearberry extract present in skincare products makes it unlikely that these products can affect melanin production.
- Dykesa G, Amarowiczb R, Pegga R. Enhancement of nisin antibacterial activity by a bearberry (Arctostaphylos uva-ursi) leaf extract. Food Microbiol. 2003;20(2):211-216.
- Haddad A, Matos L, Brunstein F, Ferreira L, Silva A, Costa Jr D. A clinical, prospective, randomized, double-blind trial comparing skin whitening complex with hydroquinone vs. placebo in the treatment of melasma. Int J Dermatol. 2003;42(2):153-6.
- Parejo I, Viladomat F, Bastida J, Codina C. A single extraction step in the quantitative analysis of arbutin in bearberry (Arctostaphylos uva-ursi) leaves by high-performance liquid chromatography. Phytochem Anal. 2001;12(5):336-9.
- Matsuda H, Higashino M, Nakai Y, Iinuma M, Kubo M, Lang F. Studies of cuticle drugs from natural sources. IV. Inhibitory effects of some Arctostaphylos plants on melanin biosynthesis. Biol Pharm Bull. 1996;19(1):153-6.