NEW YORK (Reuters Health) – Injections of onabotulinum toxin A increase skin pliability and elastic recoil, new findings show.
“Apart from just seeing the paralysis in the muscles that are treated, we are also seeing changes in the skin that are indicative of possible changes in fibroblasts,” Dr. James Bonaparte of the University of Ottawa in Ontario, Canada, one of the new study’s authors, told Reuters Health.
The findings raise the possibility that botulinum toxin A has direct anti-aging effects on the skin, and also suggest that it may be useful for scar treatment, Dr. Bonaparte added in a telephone interview.
Previous investigations have shown that wrinkles fade after repeated botox injections, but the reason why is not clear, Dr. Bonaparte and Dr. David Ellis of the University of Toronto noted in their report, published online May 21 in JAMA Facial and Plastic Surgery.
In a 2014 study, Dr. Bonaparte and Dr. Ellis reported biomechanical changes in the skin after botox injections, but their study only followed patients for up to two months (http://bit.ly/1J1Om02). Critics had questioned whether these changes were due to inflammation from the injections.
In the current study, to address this issue, the researchers followed patients for four months. They enrolled 48 women with no previous botox injections and with mild wrinkles at the glabella and lateral orbit. Forty-three women completed the study. The researchers used a Cutometer MPA 580 skin elasticity meter (Courage & Khazaka Electronic, Cologne, German), which measures deformation and relaxation of the skin when suction is applied and removed.
All patients received injections to the glabella, supraorbit, and lateral orbit, and all showed increases in skin pliability and elastic recoil at all sites.
Study participants also had reductions in the ratio of the viscoelastic component of resistance to elastic resistance, indicating that the changes were not related to swelling and inflammation. All measurements had returned to baseline levels by four months.
It’s possible, Dr. Bonaparte said, that fibroblasts may have receptors that interact with botox, causing the cells to produce more collagen, elastin and other substances that tighten the skin. He pointed to a 2014 laboratory study that found onabotulinum toxin A blocked the expression of aging-related proteins in fibroblasts exposed to UV B radiation, while increasing collagen production (http://bit.ly/1FDrNuA).
If this hypothesis is true, he added, it may be possible to reduce wrinkles by injecting onabotulinum toxin A directly into the skin, rather than using it to paralyze facial muscles. And if the injections do produce these changes in fibroblasts, he added, they could prove useful for scar treatment.
In an editorial, Dr. Catherine Winslow of Indiana University School of Medicine in Bloomington notes that onabotulinum toxin A could also directly affect skin by preventing the release of free radicals that occurs with muscular contraction.
“Piecing together this research with continued studies on elasticity and collagen content of injected skin will further the ability of facial plastic surgeons to refine their strategy for long-term planning of antiaging strategies with patients and educate them as to the importance of nonsurgical therapies for maintenance, in addition to opening new fields of potential treatment options for difficult scars and skin conditions,” she concludes.
Dr. Ellis and Dr. Bonaparte have received funding from Allergan, which markets onabotulinum toxin A as Botox.
JAMA Facial Plastic Surg 2015.