Author(s)

T. N. Shamu¹, Junna Lalitha², Manohar Shinde^1*

¹Department of Studies & Research in Biochemistry, Tumkur University, Tumakuru, Karnataka State, India.
²Department of Biochemistry, Gulbarga University, Kalaburagi, Karnataka State, India.

Melanocytes that form stratum basale of skin epidermis express tyrosinase enzyme, which catalyzes initial two rate-limiting steps in the biotransformation of tyrosine into dark pigment called melanin. Even today, Tyrosinase inhibitors are among the promising candidates in cosmetic industry for skin-lightening formulations. Overexpression of tyrosinase causes excess melanin biosynthesis and deposition resulting in dark skin color. Moreover, localized overexpression of tyrosinase cause variety of hyperpigmentation disorders like melanoma, melasma, chloasma, dark patches, liver patches, etc. There has been a renewed interest in the natural products as main ingredients in the formulation of safe products for skin-whitening and treatment options for hyperpigmentation disorders. In the present communication, the results of our investigations on tyrosinase inhibition, modulation of intracellular tyrosinase and melanin levels in cultured B16F10 melanoma cells by Bacopa monnieri (L.) methanol extract (BME) are presented and discussed as safe option for skin lightening and to treat hyperpigmentation disorders. BME showed 11%, 29%, 54% and 80% inhibition of mushroom tyrosinase activity at an initial 100, 200, 400 and 600 μg of extract. Treatment of α-melanocyte stimulating hormone (α-MSH) stimulated cultured murine melanoma B16F10 cells with 100 μg/ml of the extract showed a decrease in the levels of cellular melanin and cellular tyrosinase content by 22% and 46% respectively. The cytotoxicity studies by MTT assay revealed that the LC₅₀ of the BME is ≥1000 μg/ml in cultured mouse melanoma B16F10 and HEK293 cells.

Tyrosinase, Bacopa monieri, B16F10 Cells, Melanin, α-MSH

Shamu, T. , Lalitha, J. and Shinde, M. (2020) Mushroom Tyrosinase Inhibition and Antimelanogenesis Activities of Bacopa monnieri (L.) Methanol Extract in B16F10 Melanoma Cells. Journal of Biosciences and Medicines, 8, 189-202. doi: 10.4236/jbm.2020.85018.