Renova Retin-A
Comparison of the effects of tretinoin, adapalene and collagenase in an experimental model of wound healing.

Basak PY, Eroglu E, Altuntas I, Agalar F, Basak K, Sutcu R.

Department of Dermatology, Suleyman Demirel University Faculty of Medicine, Isparta, Turkey. pinarbasak ixir.com

Adapalene is a new naphthoic acid derivative with strong retinoid agonistic pharmacological properties. We propose that adapalene might contribute to the wound repairing process as is detected with retinoids. In this controlled study, the effects of topical adapalene, tretinoin and collagenase on full-thickness wound healing were compared in an animal model. Thirty-two adult male Wistar-Albino rats were used in the study. Two circular, full-thickness wounds were made for each animal with a standard 8-mm punch biopsy, on both sides of the midline on the back. No treatment was given to Group I rats (n:8) which comprised the control group. Tretinoin cream (0.1%) was applied topically in Group II (n:8), adapalene gel (0.1%) in Group III (n:8), and collagenase ointment in Group IV (n:8) once daily. On day 7, the wounds were photographed to measure the wound surface area. The wounds on the left side of each animal were excised on day 7, for histopathologic and biochemical examination. The treatments were continued for the right side wounds up to 14 days when the same procedure was repeated. In Group II, a significant decrease in hydroxylproline (HP) levels was detected at day 7 (p = 0.018), and an increase at day 14 (p = 0.002) compared to the control group. HP results revealed no difference either in Group III nor in Group IV versus control at day 7 or 14. However, findings of improved healing were more prominent in Groups II and III than the other groups in histopathologic examination. In conclusion, tretinoin and adapalene contributed to the wound healing process resulting in an enhancement of collagen production, angiogenesis and granulation tissue formation.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11872410&dopt=Abstract tretinoin Retin-A Renova



Renova Retin-A
Experimental nonsurgical tattoo removal in a guinea pig model with topical imiquimod and tretinoin.

Solis RR, Diven DG, Colome-Grimmer MI, Snyder N 4th, Wagner RF Jr.

University of Texas Medical Branch at Galveston, Department of Dermatology, 77555-0783, USA.

BACKGROUND: Tattoo removal is a common request in dermatologic surgery practices. Conventional tattoo removal modalities consist of mechanical, chemical, and thermal methods, but these interventions may result in undesirable dermal damage, disfiguring scars, and pigmentary changes. OBJECTIVE: To evaluate the efficacy of topical imiquimod and tretinoin for the removal of tattoos in a guinea pig model. METHODS: Five albino guinea pigs (A-E) were tattooed with black, red, green, and yellow. Beginning 6 hours after tattooing, A received no treatment, B was treated with petrolatum, C had imiquimod cream alternating with tretinoin gel, D had imiquimod cream alone, and E received tretinoin gel alone. The animals were treated for 7 days. Biopsies of the tattoos were taken at 6 hours, 7 days, and 28 days. RESULTS: Control guinea pig B had normal-appearing tattoos with consistent histopathology on day 28. Guinea pig D, treated with imiquimod cream clinically, had no visible tattoo, consistent with greatly diminished or no dye evident on histopathology. Guinea pig E, treated with tretinoin gel, and guinea pig C, treated with combination tretinoin gel and imiquimod cream, had faded tattoos and moderate clearance of pigment on histopathology. CONCLUSION: In the guinea pig, the use of imiquimod was successful as a nonsurgical method of acute-phase tattoo removal, but was associated with fibrosis and the loss of dermal appendages.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11998793&dopt=Abstract tretinoin Retin-A Renova



Renova Retin-A
Effect of melatonin and all-trans retinoic acid on the proliferation and induction of the apoptotic pathway in the culture of human breast cancer cell line MCF-7.

Czeczuga-Semeniuk E, Wolczynski S, Anchim T, Dzieciol J, Dabrowska M, Pietruczuk M.

Department of Gynaecological Endocrinology, Medical Academy, Bialystok.

Melatonin in the in vitro conditions inhibits cell growth and proliferation of estrogen sensitive (ER+) cell line MCF-7 in culture. In the present study, during a 48-hour incubation melatonin at a concentration of 10(-5) M inhibited [3H]thymidine incorporation into cancer cells at the level of 69.52% +/- 10.99. Melatonin had no inhibitory effect on the physiological stimulatory action of estradiol. Tamoxifen added to the medium modulated the melatonin action only when the latter was added 24 hours after tamoxifen (46.45% +/- 4.40, p < 0.05). Tretinoin added to the culture caused a statistically significant reduction in [3H]thymidine incorporation into the cancer cells, compared to the melatonin and tretinoin groups, when treatment with retinoid was synergistic (39.05% +/- 5.44, p < 0.05) or sequential (tretinoin and after 24 h melatonin) (39.96% +/- 1.55, p < 0.05). This was confirmed by immunocytochemical investigations, which showed a statistically significant reduction in the percentage of PCNA- and Ki67-positive cells. Apart from the inhibitory effect on MCF-7 cell proliferation retinoids induce the apoptotic pathway in a dose-dependent manner. Melatonin added to the culture enhances this effect, which may indicate the potential for the use of both substances in the treatment of breast cancer in women.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12140868&dopt=Abstract tretinoin Retin-A Renova



Renova Retin-A
Tretinoin peeling.

Cuce LC, Bertino MC, Scattone L, Birkenhauer MC.

Department of Dermatology, "Universidade de Santo Amaro" (UNISA) Medical School, and "Universidade de Sao Paulo"(USP), Sao Paulo, Brazil.

BACKGROUND: Topical tretinoin has been used for a long time to improve photoaged skin, but this therapy takes quite a few months to show some clinical changes. Because of that, we think tretinoin peeling would be an excellent choice for improvement of photoaged skin. OBECTIVE: Our objective was to show the clinical and histologic modifications of the skin after five sessions of tretinoin peeling. METHODS: The authors studied the clinical and histologic modification that occurred in 15 female patients after conducting tretinoin peeling procedures twice a week in concentrations of 1-5%. Conventional sectioning of punch biopsy specimens was conducted before and after the treatment. RESULTS: Clinical improvement was observed in the skin texture and appearance. Through histologic examinations, a decrease in the corneous layer and an increase in the epidermal thickness were noticed, inducing an improvement of its stratification, as well as the formation of cristae cutis. CONCLUSION: It was concluded that the peeling conducted with serial tretinoin showed good clinical and histologic results, especially for the treatment of photoaged skins I and II, melasma, ephelis, and acne degree I, as well as being practical, quick, and easily accomplished with no side effects.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11231233&dopt=Abstract tretinoin Retin-A Renova