Abstract: Disclosed is a microfluidic detection device including a circuit substrate and a transparent substrate. The circuit substrate is provided with at least one first light-emitting device used to emit a detection beam, a photodetector used to receive the detection beam and send out a sensing signal, and a control circuit electrically connected to the first light-emitting device and the photodetector. The transparent substrate overlaps the circuit substrate and is provided with a microfluidic channel and a light guide structure. The light guide structure has a light incident surface disposed corresponding to the first light-emitting device and a light exiting surface disposed corresponding to the photodetector. The light guide structure extends from each of the light incident surface and the light exiting surface to the microfluidic channel and is adapted to transmit the detection beam into and out of the microfluidic channel.

Abstract: Methods are provided for modulating pigmentation and melanin production by administering an extract of Polygonum multiflorum Thunb (PMT). Methods are also provided for treating conditions that may be regulated or associated with abnormal melanogenesis.