Prevention Of Chemotherapy-induced Alopecia By Tea Polyphenols

Chemotherapy has many side-effects like hair loss,nausea,vomiting,and diarrhea.Most traditional cytotoxic anticancer drugs attack rapidly dividing hair follicle cells and induce alopecia(hair loss).Chemotherapy-induced alopecia(CIA) is one of the most physically and psychologically distressing side effects of cancer chemotherapeutic drugs and represents one of the major unresolved problems of clinical oncology.Green tea polyphenols(GTP) consist mainly of(-)-epigallocatechin-3-gallate(EGCG), (-)-epigallocatechin(EGC),(-)-epicatechin-3-gallate(ECG),(-)-epicatechin(EC), (+)-gallocatechin(GC) and catechin(C).Previous investigations demonstrated that oral feeding of GTP significantly increased normal hair re-growth in mice,and EGCG promoted hair growth and the proliferation of cultured dermal papilla cells in vitro,and might be useful in the prevention or treatment of androgenetic alopecia by selectively inhibiting 5α-reductase activity.In our previous work,it was found that tea polyphenols(TP) might be effective to human CIA,and oral application of TP was found to significantly decrease cyclophosphamide(CYP)-induced alopecia and increase hair re-growth in a mouse CIA model.However,no other report has been issued to date on the effect of tea polyphenos on CIA.This study was undertaken to further evaluate the effect of TP on CYP-induced alopecia in the mouse and rat CIA models and its mechanism of action;to investigate its effect on hair follicle growth,ADM-induced toxicity to hair follicles and dermal sheath cells(DSCs) in vitro,and to study its effect on the anticancer activity and toxicity of chemotherapeutic drugs.C57BL/6 mouse CIA model was used to investigate the effect of TP on CYP-induced alopecia.Alopecia was induced by a single intraperitoneal(i.p.) injection of CYP (100～120 mg/kg) on mice on day 9 after depilation.Fourteen or 20 days after depilation, the percentage of alopecic back skin in TP treated mice was significantly decreased compared with CYP treated alone,indicating that oral application of TP significantly reduced CYP-induced alopecia and increased hair regrowth in the mouse CIA model.A neonatal rat CIA model was used to investigate the effect of TP on CYP-induced alopecia.Alopecia was induced by a single i.p.injection of CYP(35 mg/kg) on 13 day-old rats.Eight days after CYP injection,most of the TP(100 mg/kg,i.p.) treated rats had mild alopecia with less than 50%hair loss,while CYP treated alone rats had total alopecia, indicating that i.p.injection of 100 mg/kg TP significantly prevented CYP-induced alopecia in the newborn rat CIA model.On day 8 after CYP injection,the apoptotic cells in the hair follicles of back skin of TP+CYP treated rats were obviously reduced compared with that of CYP treated ones,and most hair follicles were in anagen stage of hair cycle. This indicated that TP markedly alleviated CYP-induced apoptosis in hair follicle cells, prevented hair follicle regression and increased anagen duration.Mouse and neonatal rat vibrissa follicles were cultured in William' medium E supplemented with 10 mg/l insulin,50 U/ml of penicillin and 50μg/ml of streptomycin. The increase in hair fiber length in 0.1～1000μg/ml TP-treated groups decreased in a concentration-dependent manner,and that in the 10～1000μg/ml TP-treated ones significantly increased compared with the vehicle-treated control.On the other hand,the increase in hair fiber length in 10^-9～10^-3μg/ml TP-treated groups increased,and 10^-5～10^-3μg/ml TP-treated groups significantly increased compared with the vehicle-treated control. The results indicated that higher concentrations of TP inhibited the growth of hair follicles and lower concentrations of TP increased the growth of hair follicles in vitro.Hair follicle and hair follicle cell culture models were used to investigate the in vitro effect of TP on ADM-induced toxicity to hair follicles and hair follicle cells.The hair fiber length of 0.1,1 and 10μg/ml TP-treated hair follicles increased significantly compared with ADM-treated ones,indicating that 0.1,1 and 10μg/ml TP significantly alleviated ADM-induced toxicity to hair follicles in vitro.1 and 10μg/ml TP significantly increased the cell viability of DSCs compared with the ADM-treated control,indicating that 1 and 10μg/ml TP significantly alleviated ADM-induced toxicity to DSCs.Tissue sections from vibrissa skin of rats after incubation with ADM or ADM plus TP were examined with hematoxylin and eosin(H&E) staining and Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling(TUNEL) staining.The apoptotic cells in the hair bulb of TP+AMD treated hair follicles were obviously reduced compared to that of AMD treated ones.This indicated that TP markedly alleviated AMD-induced apoptosis in hair follicle cells.In a cell colony-forming assay,hair follicle cell colonies were formed from 29.30%ADM+TP-treated hair follicles and 9.30%ADM-treated ones,and the cell number of colonies formed from ADM+TP-treated hair follicles was greater than that from ADM-treated ones.This indicated that TP marked inhibited ADM-induced toxicity to hair follicles.In a mouse model of S₁₈₀ tumor,TP(150 mg/kg),or CYP(30 mg/kg) combined with TP (150,300 or 600 mg/kg) inhibited the growth of S₁₈₀ significantly compared with untreated control,and CYP combined with TP(150,300 or 600 mg/kg) also enhanced the anti-tumor activity compared with CYP alone;however the differences were not statistically significant.Meanwhile,TP(150,300 or 600 mg/kg) co-administrated with CYP did not increase total white blood cell(WBC) count significantly compared with CYP alone, although TP(150,300 or 600 mg/kg) increased total WBC count,and TP(150 mg/kg) increased total WBC count significantly compared with untreated control.The results indicated that TP inhibited the growth of S₁₈₀ and did not affect the anti-tumor activity of CYP,but did not reduce CYP-induced leucopenia in S₁₈₀-bearing mice.Human HepG2 cell culture model was used to investigate the effect of TP on the antitumor activity of ADM.In vitro,ADM and TP had cytotoxic effect on HepG2 cells, and combination of TP and ADM did not affect the cytotoxicity of ADM.In a mouse model of CYP-induced leucopenia,there was a significant decrease in the total white blood cell(WBC) count of both CYP alone and CYP along with the TP treated animals on 7th day,but later total WBC count was found to be significantly higher in TP treated group.The results indicated that oral administration of TP significantly reduced CYP-induced leucopenia in normal mice.In summary,this study demonstrated that TP significantly prevented CYP-induced alopecia in the mouse and rat CIA models.In the rat CIA model,TP markedly alleviated CYP-induced apoptosis in hair follicle cells,prevented hair follicle regression and increased anagen duration.TP inhibited or increased the growth of hair follicles in vitro; TP significantly alleviated ADM-induced apoptosis in DSCs and ADM-induced toxicity to hair follicles and DSCs in vitro.TP did not affect the anticancer activity of CYP in mice, but did not reduce CYP-induced leucopenia in S₁₈₀-bearing mice although it significantly reduced CYP-induced leucopenia in normal mice and increased total WBC count in S₁₈₀-bearing mice;Furthermore,combination of TP and ADM did not affect the cytotoxicity of ADM in vitro.Thus,TP may be a promising drug for the prevention of CIA, and the mechanism of prevention may be related to its inhibition of the proliferation of keratinocytes of hair follicles and alleviation of apoptosis,the cellular and molecular mechanism remains to be further investigated.