The florets of Carthamus tinctorius L. have traditionally been used for hair growth promotion. This study aimed to examine the potential of hydroxysafflor yellow A-rich C. tinctorius extract (CTE) on hair growth both in vitro and in vivo. The effect of CTE on cell proliferation and hair growth-associated gene expression in dermal papilla cells and keratinocytes (HaCaT) was determined. In addition, hair follicles from mouse neonates were isolated and cultured in media supplemented with CTE. Moreover, CTE was applied topically on the hair-shaved skin of female C57BL/6 mice, and the histological profile of the skin was investigated. C. tinctorius floret ethanolic extract promoted the proliferation of both dermal papilla cells and HaCaT and significantly stimulated hair growth-promoting genes, including vascular endothelial growth factor and keratinocyte growth factor. In contrast, CTE suppressed the expression of transforming growth factor-β1 that is the hair loss-related gene. Furthermore, CTE treatment resulted in a significant increase in the length of cultured hair follicles and stimulated the growth of hair with local effects in mice. The results provided the preclinical data to support the potential use of CTE as a hair growth-promoting agent.
Safflower (Carthamus tinctorius) has been used for centuries as a way to extract vegetable oils from its seeds and to flavor dishes.
It was also used for medicinal purposes such as helping patients with irregular and painful menstrual cycles. However, it is contraindicated in the case of pregnancy.
During the past few years, Carthamus tinctorius extract (CTE) has been used to reverse hair loss in patients diagnosed with androgenetic alopecia (AA). CTE exerts its effects by inhibiting the action of 5α-reductase, but there is more to the story.
Research and results
In a 2014 paper published by the Phytotherapy Research, scientists from the Center for Research and Development of Herbal Health Products, Thailand, studied the effects of CTE on hair growth of mice.
The goal of the study was to identify the underlying mechanisms that promote hair growth and the possible toxicity of CTE use.
CTE was shown to stimulate the production of hair promoting substances such as vascular endothelial growth factor (VEGF) and keratinocyte growth factor (KGF).
These two growth factors can stimulate hair growth by improving blood flow to dermal papilla where the stem cells for hair follicles are located.
Additionally, CTE seems to inhibit the enzyme 5α-reductase, leading to lower levels of dihydrotestosterone 5 or DHT-5, which is the main player in androgenic alopecia pathogenesis.
The study concluded the paper by stating:
CTE treatment resulted in a significant increase in the length of cultured hair follicles and stimulated the growth of hair with local effects in mice. The results provided the preclinical data to support the potential use of CTE as a hair growth-promoting agent.
How it works
Unlike other hair-promoting compounds that target one single enzyme or molecule, CTE exerts its functions on several cellular targets, including the promotion of VEGF and KGF while suppressing the action of the main enzyme that converts testosterone into DHT-5, which causes the regression of the hair follicles and prevent the transformation of stem cells into new hair follicles.
Although CTE showed high solubility in water, the skin permeability was rather low when using water as a vehicle. The preliminary results from the skin permeation study showed that the vehicle containing propylene glycol and ethanol promoted higher flux value and shorter lag time than those of the water.
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In other words, if CTE goes through the clinical trials, permeability will be a deciding factor in the efficacy of the drug.
Unfortunately, all the studies conducted so far did not include any human clinical trials, hence the lack of evidence that CTE may actually promote hair growth in patients with androgenic alopecia.
Nevertheless, the preliminary results may be a good sign that we can conduct further studies and clinical trials to determine the efficacy of this substance and its possible side effects.