Ginseng in Hair Growth and Viability

The hair follicle is the unique organ that has the capacity of undergoing cyclic transformations following periods of growth (anagen), regression (catagen), and rest (telogen) regenerating itself to restart the cycle. The dynamic capacity of hair to growth and rest enables mammals to control hair growth and length in different body side and to change their coats. Unlike what is observed in many animals in which the pelage synchronously passes from one phase of the cycle to other all stages of growth cycle are simultaneously found in the human pelage, the growth pattern is a mosaic where the hair cycling staging of one hair root is completely independent of it nearest hair follicle, meaning that each follicular unit (FU) can contain follicles in different stages at any given time. A variety of factors, such as nutritional status, hormones, exposure to radiations, chemotherapy or radiotherapy, environmental pollution or drugs may affect hair growth, and affects the number of hairs, this progressive hair loss has a cosmetic and social impact that often significantly affects social and psychological well-being of the patient that suffers from this hair loss. Although a number of therapies, such as finasteride and minoxidil, are approved medications, a wide variety of classes of phytochemicals and natural products, including those present in ginseng are being testing. The purpose of this chapter is to focus on study the potential of ginseng and its metabolites in hair loss.

The Distribution of Quetiapine and 7-Hydroxyquetiapine in Guinea Pig Hair Roots and Shafts after Repeated Administration: Exploration of the Mechanism of Drug Entry and Retention in Hair

This study investigated the distribution of quetiapine and 7-hydroxyquetiapine in guinea pig hair roots and shafts after five repeated intragastric administrations at three doses (5, 10 and 25 mg/kg) by segmental analysis to explore the mechanism of drug entry and retention in hair. Hair root samples were collected after 7, 10, 14, 21, 28 and 35 d in area A after the first dose, and a hair shaft was plucked 35 d after the first dose. The maximum concentrations of quetiapine in hair roots in the low-, medium- and high-dose groups occurred at 50, 74 and 98 h after the first administration, and the maximum concentrations were 0.71 ng/mg (range: 0.54–0.84 ng/mg), 6.72 ng/mg (range: 4.59–9.75 ng/mg) and 12.72 ng/mg (range: 10.74–15.76 ng/mg), respectively. The maximum concentrations of 7-hydroxyquetiapine in the low-, medium- and high-dose groups were 0.67 ng/mg (0.23–1.15 ng/mg), 1.07 ng/mg (0.44–1.19 ng/mg) and 3.92 ng/mg (0.656.14 ng/mg), respectively, at 26 h. The maximum concentrations of quetiapine and 7-hydroxyquetiapine in hair roots were significantly positively correlated with the dose (n = 18; r2 = 0.84; P < 0.0001 for quetiapine and n = 18; r2 = 0.61; P = 0.0001 for 7-hydroxyquetiapine). The concentrations of quetiapine and 7-hydroxyquetiapine in hair roots were higher than those in hair shafts 10 d after administration, indicating drug and metabolite entry into the hair through the roots in the first few days after administration. The highest concentrations of quetiapine in the hair shaft in the low-, medium- and high-dose groups were found at the hair ends, and 7-hydroxyquetiapine in the hair shaft showed no obvious peak concentration. Combined with previous studies, we think, by analyzing the drug concentrations in the hair roots and shaft, that the most important way for drugs to enter into and be retained in hair is that the drug enters the hair through the blood circulation from hair root, then spreads and redistributes as the hair grows.