RESUMO
BACKGROUND: Hair loss and hair growth is the subject of tremendous amount of research. OBJECTIVE: This study investigated the efficacy of three chemical treatments used in humans for hair loss, using a rat model of hair regrowth. The products tested were 2% minoxidil, Hairgrow (Dar-Al-Dawa Pharma), Aminexil, Dercos (Vichy Laboratoires), and Kerium, Anti-chute (La Roche-Posay). METHODS: Thirty-two adult female Wistar-Bratislava rats were assigned to 4 groups. Two rectangular areas (2x4 cm) were shaved on either sides of the mid dorsal line (left side - control; right side - test area). Group I was treated topically with 2% minoxidil, group II with Aminexil, and group III with Kerium. Each rat received 0.3 ml of substance applied topically to the shaved dorsal skin every day for 28 days. Rats in group IV served as sham controls receiving no treatment. Hair regrowth was evaluated by trichoscopy (with a dermatoscope), grown hair weight (from a surface area of 1 cm2), and histopathological examination for skin thickness, follicle count, and percentage of anagen induction (morphometric assessment). RESULTS: Treatment with 2% minoxidil significantly induced hair regrowth as assessed by trichoscopy, hair weight examination, and morphometric evaluation. Hair weight examination and morphometric assessment demonstrated the lowest hair growth effect with Aminexil among the tested products. Treatment with Kerium was found to significantly induce hair regrowth (p<0.05 as compared to the control group). CONCLUSION: Our study demonstrates that hair regrowth efficacy of products recommended for human use is not similar when tested on an animal model.
Assuntos
Adulto , Animais , Feminino , Humanos , Ratos , Cabelo , Minoxidil , Modelos Animais , Regeneração , PeleRESUMO
<p><b>OBJECTIVE</b>To evaluate the influence of an extract of Genista tinctoria L. herba (GT) or methylparaben (MP) on histopathological changes and 2 biomarkers of oxidative stress in rats subchronicly exposed to bisphenol A (BPA).</p><p><b>METHODS</b>Adult female Wistar rats were orally exposed for 90 d to BPA (50 mg/kg), BPA+GT (35 mg isoflavones/kg) or BPA+MP (250 mg/kg). Plasma and tissue samples were taken from liver, kidney, thyroid, uterus, ovary, and mammary gland after 30, 60, and 90 d of exposure respectively. Lipid peroxidation and in vivo hydroxyl radical production were evaluated by histological analysis along with malondialdehyde and 2,3-dihydroxybenzoic acid detection.</p><p><b>RESULTS</b>The severity of histopathological changes in liver and kidneys was lower after GT treatment than after BPA or BPA+MP treatment. A minimal thyroid receptor antagonist effect was only observed after BPA+MP treatment. The abnormal folliculogenesis increased in a time-dependent manner, and the number of corpus luteum decreased. No significant histological alterations were found in the uterus. The mammary gland displayed specific estrogen stimulation changes at all periods. Both MP and GT revealed antioxidant properties reducing lipid peroxidation and BPA-induced hydroxyl radical generation.</p><p><b>CONCLUSION</b>GT L. extract ameliorates the toxic effects of BPA and is proved to have antioxidant potential and antitoxic effect. MP has antioxidant properties, but has either no effect or exacerbates the BPA-induced histopathological changes.</p>