Androgenetic alopecia (AGA) is the most common type of hair loss in men and women. Dihydrotestosterone (DHT) and androgen receptor (AR) levels are increased in patients with AGA, and DHT-AR signaling correlates strongly with AGA pathogenesis. In this study, treatment with self-assembled micelle inhibitory RNA (SAMiRNA) nanoparticle-type siRNA selectively suppressed AR expression in vitro. Clinical studies with application of SAMiRNA to the scalp and massaging to deliver it to the hair follicle confirmed its efficacy in AGA. For identification of a potent SAMiRNA for AR silencing, 547 SAMiRNA candidates were synthesized and screened. SAMiRNA-AR68 (AR68) was the most potent and could be efficiently delivered to human follicle dermal papilla cells (HFDPCs) and hair follicles, and this treatment decreased the AR mRNA and protein levels. We confirmed that 10 µM AR68 elicits no innate immune response in human PBMCs and no cytotoxicity up to 20 µM with HFDP and HaCaT cells. Clinical studies were performed in a randomized and double-blind manner with two different doses and frequencies. In the low-dose (0.5 mg/ml) clinical study, AR68 was applied three times per week for 24 weeks, and through quantitative analysis using a phototrichogram, we confirmed increases in total hair counts. In the 24-week long high-dose (5 mg/ml) clinical study, AR68 showed average additional hair growth of 1.3-1.9 hairs/cm² per month, which is comparable to finasteride. No side effects were observed. Therefore, SAMiRNA targeting AR mRNA is a potential novel topical treatment for AGA.

Fucoxanthin is a bioactive compound that is a kind of natural carotenoid. Fucoxanthin is known to protect against UV-B-induced cell damage in hairless mice, even though it is physiochemically unstable to heat and acid due to its polyunsaturated structure, indicating that fucoxanthin possesses a low bioavailability, and this disadvantage limits its application in the cosmetic industry. Solid lipid nanoparticle (SLN) systems are known to be suitable as carriers for sunscreen agents. In this research work, the sunscreen-boosting effect of SLN, as a deliverer of functional ingredient, especially fucoxanthin, has been developed and evaluated by comparing the sunburn protection factors (SPF) of macroemulsion (cream and lotion type) and an SLN formula containing various kinds of sunscreen agents, respectively. Several results such as stability test, particle size, DSC analysis, and X-ray analysis show that the SLN formula loading fucoxanthin has the possibility of being a stable and high-functioning ingredient delivery system. Moreover, the SLN formula has shown a higher SPF value than others, meaning that the SLN formula exhibits a good sunscreen-boosting effect. This study indicates that the use of SLN as a carrier enhanced the bioavailability of fucoxanthin and shows that SLN could be a promising carrier for the production of sunscreen products by allowing the scaling-up of production.

Inula helenium (IH) is known to possess antifungal, anti-bacterial, anti-helminthic, and anti-proliferation activities. Caesalpinia Sappan (CS) is known to reduce inflammation and improve blood circulation. Based on their folkloric use, these plants are expected to be promising candidates for promoting hair growth and preventing hair loss. Moreover, these plants are rich sources of certain phytochemicals, which have been reported to promote hair growth. In this clinical trial, we investigate the efficacy of a scalp shampoo formulated by mixing extracts of IH and CS in preventing hair loss and promoting hair growth in patients with androgenetic alopecia. Using a phototrichogram (Folliscope 2.8, LeadM, Korea), we compared the hair density and total hair counts in patients receiving the scalp shampoo at baseline, and at 8, 16, and 24 weeks after use of the shampoo. We found a statistically significant increase in the total hair count in the test group (n = 23) after 16 and 24 weeks of using the scalp shampoo (2.17 n/cm² ± 5.72, p < 0.05; and 4.30 n/cm² ± 6.37, p < 0.01, respectively) as compared to the control subjects. Based on the results of this clinical study, we conclude that the IH and CS extract complex is a promising remedy for preventing hair loss and promoting hair growth.