30 patients with melasma (diagnosed according to Zaumseil, Klaus-Graupe) was treated by applying 2% hydroquinone in combing with 0.05% retinoic. After 6 month treatment, the disease recessed well and very well in 65.6%, the size of pigmented area reduced 87% in average, 15.6% of patients has reduced in 90-100% of size and 65.7% of 70-89%.
Melanosis ; Therapeutics ; Hydroquinones ; Tretinoin

30 patients aged 18-60 years old with melasma localized at the epiderm and epiderm plus mesoderm layer topically treated by 2% hydroquinone preparation within 6 months at the Venero-dermatol Institute were evaluated. Good and very good results reached in 42.5%. The size of lesion minimized by > 10% each months, especially 21% in the 2nd month. Mean size of lesion minimized by 75%. In 11.2% of patients, the size of lesion minimized by 90-100% and 56.3% of patients had got the lesion of 70-89% minimized size.
Therapeutics ; Melanosis ; Hydroquinones

30 patients with check sunburn, aged 18-60 years old treated by hydroquinone 2% in combining with sun protected cream. After 6 moths pigment reduced by 45,6%, mean size of lesion reduced by 78%. 90- 100% of patients had the size of lesion reduced by 13,4% and 61% of patients had the size of lesion reduced by 70-89%.
Therapeutics ; Melanosis/therapeutic use ; Hydroquinones

Treatment for 30 patients with melasma according to standard of Zaumseil, Klaus-Graupe by bleaching hydroquinon in combination with retinoid acid and sun cream. After 6 months, the result showed that: reduced 70% pigment of injury. Size of average injury reduce 87,1% after treatment. In 16,7% patients, the size reduce 90-100% and in 70%, the size reduce 70-89% after treatment.
Melanosis ; Therapeutics ; Hydroquinones ; Pharmaceutical Preparations

Azo dyes are widely used in textile, paper and packing industries, and have become one of the research hot spots in dye wastewater treatment because of their carcinogenicity, teratogenic mutagenicity, stable structure and degradation difficulty. In this study, the biodecolorization of acid orange 7 (AO7), an azo dye, by different white rot fungi was investigated, and the effect of different conditions on the decolorization rate of the dye was analyzed. At the same time, the degradation liquor was analyzed and the phytotoxicity experiment was performed to deduce the possible degradation pathway of AO7 and assess the toxicity of its degradation products. The results showed that the decolorization rate reached 93.46% in 24 h at pH 4.5, 28 ℃ by Pleurotus eryngii and Trametes versicolor when AO7 concentration was 100 mg/L. The biodegradation pathway of AO7 was initiated by the cleavage of the azo bond of AO7, generating p-aminobenzenesulfonic acid and 1-amino-2-naphthol. Subsequently, the sulfonic acid group of p-aminobenzene sulfonic acid was removed to generate hydroquinone. Moreover, the 1-amino-2-naphthol was de-ringed to generate phthalic acid and p-hydroxybenzaldehyde, and then further degraded into benzoic acid. Finally, hydroquinone and benzoic acid may be further oxidized into other small molecules, carbon dioxide and water. Phytotoxicity experiment showed that the toxicity of AO7 could be reduced by P. eryngii and T. versicolor.
Hydroquinones ; Trametes ; Azo Compounds ; Benzoic Acid

Melanin is produced in melanocytes and stored in melanosomes. In spite of its beneficial sun-protective effect, abnormal accumulation of melanin results in esthetic problems. Hydroquinone, competing with tyrosine, is a major ingredient in topical pharmacological agents. However, frequent adverse reactions are amongst its major limitation. To solve this problem, several alternatives such as arbutin, kojic acid, aloesin, and 4-n-butyl resorcinol have been developed. Herein, we classify hypopigmenting agents according to their mechanism of action; a) regulation of enzyme, which is subdivided into three categories, i) regulation of transcription and maturation of tyrosinase, ii) inhibition of tyrosinase activity, and iii) post-transcriptional control of tyrosinase; b) inhibition of melanosome transfer, and c) additional mechanisms such as regulation of the melanocyte environment and antioxidant agents.
Arbutin ; Chromones ; Glucosides ; Hydroquinones ; Hypopigmentation ; Melanins ; Melanocytes ; Melanosomes ; Monophenol Monooxygenase ; Pyrones ; Resorcinols ; Tyrosine

Catechols ; urine ; Chromatography, High Pressure Liquid ; methods ; Electrochemistry ; methods ; Humans ; Hydroquinones ; urine

OBJECTIVETo study the effect of TTRAP expression on apoptosis induced by hydroquinone in HL-60 cells in vitro, and explore the relationship between TTRAP expression and the apoptosis.

METHODSApoptotic and necrotic rate was examined by flow cytometer with Anti-AnnexinV/FITC Plus PI staining. The mRNA expression of TTRAP was detected by RT-PCR. The differences in different treated groups were compared.

RESULTSAfter different concentrations of hydroquinone to the cells for 0, 4, 8, 12 h culture, were added, the cell apoptotic rate in different concentrations of hydroquinone groups was significantly higher than that in blank control groups. The optimal concentration of hydroquinone was 200 micromol/L, lasting for 8 h. When it was 250 micromol/L, the necrotic rate increased significantly. The apoptosis induced by hydroquinone was associated with the culture time at the concentration of 200 micromol/L, and the peak apoptotic time was 8 h. Then the apoptotic rate decreased and necrotic rate increased. Furthermore, with the concentrations of hydroquinone increased and time lasted for 8 h, the apoptotic rate of cells increased, the amount of TTRAP expression in the mRNA level also increased accordingly. When the concentrations of hydroquinone was above 250 micromol/L, necrotic rate increased sharply, and the amount of TTRAP expression decreased.

CONCLUSIONHydroquinone could induce apoptosis of HL-60 cells. The up-regulation of TTRAP expression may promote hydroquinone to induce HL-60 cells to go into apoptosis in vitro with dose-effect and time-effect relationship.

Objective: Although benzene is a confirmed environmental carcinogen, the mechanism of its carcinogenicity remains largely unclear. The suggested oncogene, miR-221, is elevated and plays important roles in various tumors, but its role in benzene-induced carcinogenesis remains unknown. Methods: In the present study, we constructed hydroquinone (HQ, a representative metabolite of benzene with biological activity)-transformed malignant cell line (16HBE-t) and analyzed the level of miR-221 in it with qRT-PCR. Exosomes from 16HBE-t cells incubated with or without an miR-221 inhibitor were isolated by ultracentrifugation, characterized by transmission electron microscopy and laser scanning confocal microscope, and then transfected into 16HBE cells. The effects of exosomal miR-221 on apoptosis induced by HQ in recipient cells were determined using flow cytometry. Results: The amount of miR-221 in 16HBE-t was significantly increased compared with controls. When recipient cells ingested exosomes derived from 16HBE-t, miR-221 was increased, and apoptosis induced by HQ was inhibited. Blocking miR-221 in 16HBE-t using an inhibitor did not significantly alter miR-221 or apoptosis in recipient cells. Conclusion Exosomal miR-221 secreted by 16HBE-t inhibits apoptosis induced by HQ in normal recipient cells.
Apoptosis ; Bronchi/cytology* ; Cell Line, Transformed ; Epithelial Cells ; Exosomes ; Humans ; Hydroquinones ; MicroRNAs

Objective: To investigate the cell cycle and apoptosis in hydroquinone (HQ) -induced malignant transformation of TK6 cells and its related regulatory mechanisms. Methods: TK6 cells were exposed to 20 μmol/L HQ, 24 h/time, once a week, for 19 weeks as experimental group and TK6 cells treated with phosphate buffer (PBS) for 19 weeks was used as control group from March 2014. In regulatory mechanism research, the cells were divided into four groups: control group, experimental group, control inhibitor group and experimental inhibitor group (inhibitor groups were added 10 μmol/L P600125) . Cell cycle and apoptosis were detected by flow cytometry. The protein expression of cell cycle-related proteins and JNK signaling pathway proteins were detected by Western blot. Results: Flow cytometry showed that compared with control group, the ratio of cells in the G0/G1 phase of the experimental group was significantly decreased (P=0.001) , and the ratio of cells in the S phase was significantly increased (P=0.002) . Western blotting demonstrated that the protein expressions of p-Rb (Ser780) , E2F1, Cyclin D1, p-p16 (Ser152) , JNK1, p-JNK1 (Thr183/Tyr185) , c-jun, p-c-jun (Ser63) (P=0.015, 0.021, 0.001, 0.001, 0.005, 0.001, 0.039, 0.003) were up-regulated, while the protein expressions of Rb (P=0.048) and p16 (P=0.002) were significantly down-regulated. After exposed to SP600125, compared with experimental group, there were no significant changes in cell cycle distribution (P=0.946) and apoptosis rate (P=0.923) in experimental inhibitor group. The expression of c-jun (P=0.040) protein was down-regulated, while the expression of Rb (P=0.027) protein was up-regulated in experimental inhibitor group. Conclusion: In HQ-induced TK6 cells malignant transformation, the cell cycle is arrested in the S phase, and the p16/pRb signaling pathway is inhibited, while the JNK signaling pathway is activated. However, the activated JNK signaling pathway may not be involved in the regulation of cell cycle.
Humans ; Hydroquinones/toxicity* ; MAP Kinase Signaling System ; Cell Cycle ; Cell Transformation, Neoplastic ; Apoptosis