I thought I will post this. I have searched the internet and saw a large number of threads on the forums on the positive hair growth effect (On rats and mice)
Yet I don't really see anyone posting this study (which is the only study done on human cells)
I am posting excerpts. I would appreciate it if someone has studies of TB4 on humans I might have missed out.
[h=1]Letter to the Editor[/h] Journal of Investigative Dermatology (2012) 132, 1516–1519; doi:10.1038/jid.2012.2; published online 8 March 2012
[h=2]Thymic Peptides Differentially Modulate Human Hair Follicle Growth[/h] Natalia Meier[SUP]1,6[/SUP], Dorothee Langan[SUP]1,6[/SUP], Heidegard Hilbig[SUP]2[/SUP], Enikö Bodó[SUP]1[/SUP], Nilofer P Farjo[SUP]3[/SUP], Bessam Farjo[SUP]3[/SUP], Franz P Armbruster[SUP]4[/SUP] and Ralf Paus[SUP]1,5[/SUP]
Topically applied TB4 reportedly enhances hair growth in rats and mice and stimulates early differentiation of rat vibrissae epithelial progenitor cells (Philp et al., 2004), whereas it is unknown whether TB4 impacts on human hair growth. Therefore, we wished to clarify in the current study whether human scalp HFs express any TPs, and whether selected TPs exert measurable effects on human scalp HFs in organ culture (Kloepper et al., 2010).
This hypothesis was tested in serum-free human HF organ culture (Supplementary Information S2 online). We first studied whether thymosin alpha 1, a peptide comprising amino acids 2–29 of PTMA, (Supplementary Information S1 online), TYL, and TB4 modulate hair shaft production (i.e., the hair shaft elongation rate) in vitro. Cultivation of HFs with 10 pg ml[SUP]−1[/SUP] TYL for 7 days in three independent experiments from three different human donors resulted in an increased hair shaft growth rate compared with vehicle-treated HFs (Figure 2a). In contrast, hair shaft elongation rates of HFs treated with 100 or 1,000 ng ml[SUP]−1[/SUP] thymosin alpha 1 for 7 days were slightly lower than those of control HFs (Figure 2a). In TB4-treated HFs, hair shaft production was 10–20% lower than in the vehicle control (Figure 2a and Supplementary Figure S1 online).
Next, we studied by quantitative hair cycle histomorphometry (Kloepper et al., 2010) whether the tested TPs had an effect on the transformation of anagen VI HFs into the regression stage of the hair cycle (catagen). This transformation is the clinically most relevant parameter one can study in HF organ culture, as any prolongation effect on anagen would be expected to correlate with a reduction of telogen effluvium in vivo (Cotsarelis and Millar, 2001; Paus and Foitzik, 2004; Kloepper et al., 2010). Moreover, the effect of each peptide on the hair cycle was further assessed by determining the hair cycle score in each treatment condition (Figure 2b and c; Supplementary Information S2 and Supplementary Figure S1b online).
These analyses showed that HFs treated with 10 pg ml[SUP]−1[/SUP] TYL for 7 and 9 days stayed longer in anagen VI than vehicle-treated controls (Figure 2b, Supplementary Figure S1b online). By two-tailed Student's t-test, these differences did not come up as significant in the 7-day treatment group where the effect of TYL 10 on the distribution of anagen vs. catagen had a P-value of 0.06. Hair cycle score analysis further indicated that treatment with TYL for 7 and 9 days inhibited the progression of HFs from anagen to catagen (Figure 2c, Supplementary Figure S1b online). This anagen-prolonging effect of TYL (which reached significance in the 9 day cultures) was independently corroborated by the demonstration that, compared with vehicle controls, treatment of HFs with 10 pg ml[SUP]−1[/SUP] TYL for 7 days increased the number of Ki67+ cells in the hair matrix of anagen VI HFs, whereas the number of TUNEL+ (i.e., apoptotic) cells was reduced (Figure 2d).
Despite its slight growth-inhibiting effect, treatment with 1,000 ng ml[SUP]−1[/SUP] thymosin alpha 1 for 7 days did not markedly change HF cycling in vitro in three independent experiments with HFs from three different patients (Figure 2d). Interestingly, there even was a stimulatory effect on hair matrix keratinocyte proliferation of anagen HFs (Supplementary Figure S2 online). Instead, treatment with 1,000 ng ml[SUP]−1[/SUP] TB4 for 7 days shortened the duration of anagen and prematurely induced catagen (Figure 2b and c), yet did not affect the number of Ki67+ hair matrix cells, if only anagen HFs were compared between test and control groups (Supplementary Figure S2 online).
Yet I don't really see anyone posting this study (which is the only study done on human cells)
I am posting excerpts. I would appreciate it if someone has studies of TB4 on humans I might have missed out.
[h=1]Letter to the Editor[/h] Journal of Investigative Dermatology (2012) 132, 1516–1519; doi:10.1038/jid.2012.2; published online 8 March 2012
[h=2]Thymic Peptides Differentially Modulate Human Hair Follicle Growth[/h] Natalia Meier[SUP]1,6[/SUP], Dorothee Langan[SUP]1,6[/SUP], Heidegard Hilbig[SUP]2[/SUP], Enikö Bodó[SUP]1[/SUP], Nilofer P Farjo[SUP]3[/SUP], Bessam Farjo[SUP]3[/SUP], Franz P Armbruster[SUP]4[/SUP] and Ralf Paus[SUP]1,5[/SUP]
- [SUP]1[/SUP]Department of Dermatology, University of Lübeck, Lübeck, Germany
- [SUP]2[/SUP]Institute of Anatomy, University of Leipzig, Leipzig, Germany
- [SUP]3[/SUP]Farjo Medical Centre, Manchester, UK
- [SUP]4[/SUP]Immundiagnostik AG, Bensheim, Germany
- [SUP]5[/SUP]School of Translational Medicine, University of Manchester, Manchester, UK
Topically applied TB4 reportedly enhances hair growth in rats and mice and stimulates early differentiation of rat vibrissae epithelial progenitor cells (Philp et al., 2004), whereas it is unknown whether TB4 impacts on human hair growth. Therefore, we wished to clarify in the current study whether human scalp HFs express any TPs, and whether selected TPs exert measurable effects on human scalp HFs in organ culture (Kloepper et al., 2010).
This hypothesis was tested in serum-free human HF organ culture (Supplementary Information S2 online). We first studied whether thymosin alpha 1, a peptide comprising amino acids 2–29 of PTMA, (Supplementary Information S1 online), TYL, and TB4 modulate hair shaft production (i.e., the hair shaft elongation rate) in vitro. Cultivation of HFs with 10 pg ml[SUP]−1[/SUP] TYL for 7 days in three independent experiments from three different human donors resulted in an increased hair shaft growth rate compared with vehicle-treated HFs (Figure 2a). In contrast, hair shaft elongation rates of HFs treated with 100 or 1,000 ng ml[SUP]−1[/SUP] thymosin alpha 1 for 7 days were slightly lower than those of control HFs (Figure 2a). In TB4-treated HFs, hair shaft production was 10–20% lower than in the vehicle control (Figure 2a and Supplementary Figure S1 online).
Next, we studied by quantitative hair cycle histomorphometry (Kloepper et al., 2010) whether the tested TPs had an effect on the transformation of anagen VI HFs into the regression stage of the hair cycle (catagen). This transformation is the clinically most relevant parameter one can study in HF organ culture, as any prolongation effect on anagen would be expected to correlate with a reduction of telogen effluvium in vivo (Cotsarelis and Millar, 2001; Paus and Foitzik, 2004; Kloepper et al., 2010). Moreover, the effect of each peptide on the hair cycle was further assessed by determining the hair cycle score in each treatment condition (Figure 2b and c; Supplementary Information S2 and Supplementary Figure S1b online).
These analyses showed that HFs treated with 10 pg ml[SUP]−1[/SUP] TYL for 7 and 9 days stayed longer in anagen VI than vehicle-treated controls (Figure 2b, Supplementary Figure S1b online). By two-tailed Student's t-test, these differences did not come up as significant in the 7-day treatment group where the effect of TYL 10 on the distribution of anagen vs. catagen had a P-value of 0.06. Hair cycle score analysis further indicated that treatment with TYL for 7 and 9 days inhibited the progression of HFs from anagen to catagen (Figure 2c, Supplementary Figure S1b online). This anagen-prolonging effect of TYL (which reached significance in the 9 day cultures) was independently corroborated by the demonstration that, compared with vehicle controls, treatment of HFs with 10 pg ml[SUP]−1[/SUP] TYL for 7 days increased the number of Ki67+ cells in the hair matrix of anagen VI HFs, whereas the number of TUNEL+ (i.e., apoptotic) cells was reduced (Figure 2d).
Despite its slight growth-inhibiting effect, treatment with 1,000 ng ml[SUP]−1[/SUP] thymosin alpha 1 for 7 days did not markedly change HF cycling in vitro in three independent experiments with HFs from three different patients (Figure 2d). Interestingly, there even was a stimulatory effect on hair matrix keratinocyte proliferation of anagen HFs (Supplementary Figure S2 online). Instead, treatment with 1,000 ng ml[SUP]−1[/SUP] TB4 for 7 days shortened the duration of anagen and prematurely induced catagen (Figure 2b and c), yet did not affect the number of Ki67+ hair matrix cells, if only anagen HFs were compared between test and control groups (Supplementary Figure S2 online).