TiO2 Nanocrystals and Annona crassiflora Polyphenols Used Alone or Mixed Impact Differently on Wound Repair.

Wounds treated with TiO2 nanoparticles (TiO2-NPs) show an improvement in healing time. However, little is known about the parameters that can contribute to this result. On the other hand, the treatment of wounds with polyphenols is widely known. These compounds are found in the peel of Annona crassiflora fruit and have antioxidant, analgesic and anti-inflammatory properties. In this study, we evaluated the healing effect of TiO2 nanocrystals (TiO2-NCs), polyphenolic fractions obtained from ethanolic extract of A. crassiflora fruit peel (PFAC) and mix (PFAC + TiO2-NCs) on the parameters of wound closure, inflammation, collagen deposition, metalloproteinase activity (MMPs) and angiogenesis. TiO2-NCs and PFAC have activity for wound healing, showed anti-inflammatory action and a shorter wound closure time. These treatments also contributed to increased collagen deposition, while only treatment with TiO2-NCs increased MMP-2 activity, parameters essential for the migration of keratinocytes and for complete restoration of the injured tissue. The combination of PFAC + TiO2-NCs reduced the effectiveness of individual treatments by intensifying the inflammatory process, in addition to delaying wound closure. We conclude that the interaction between the hydroxyl groups of PFAC polyphenols with TiO2-NCs may have contributed to difference in the healing activity of skin wounds.

Topic use of Annona crassiflora Mart. contributes to wound healing due to the antioxidant and proliferative effects of fibroblasts.

Annona crassiflora Mart. is a species native to the Cerrado biome, whose fruit is known as araticum or marolo. Plant parts are widely used in folk medicine to treat inflammation and pain associated with rheumatism, wounds, venereal diseases, snakebites, and microbial infections. Thus, we investigated a fraction rich in phenolic compounds (PCAc) obtained from the crude extract of the peel of these fruits on non-cytotoxic, anti-inflammatory, antioxidant, and collagen biosynthesis properties in the healing of wounds induced on the back of BALB/c mice. For the control group, the induced wounds were not treated and for the others, wounds were treated topically with vehicle or vehicle plus PCAc. Both fractions contained in PCAc demonstrated effective protection on fibroblasts. We highlight the effect of the ethyl acetate fraction which, in addition to the protective effect, has a proliferative activity on these cells. In addition, PCAc caused improvement in healing after 7 days of treatment and in the longest period of treatment with PCAc (7, 14, and 21 days) there was a greater contraction of the wound, accompanied by resolution of the inflammatory process, antioxidant defense, increasing collagen synthesis, and modulation of metalloproteinases. PCAc demonstrated better re-epithelialization and organization of the dermis at the end of treatment. The changes promoted by the phenolic compounds of A. crassiflora were important in the healing process, especially in activities related to inflammation, oxidative stress, and fibrogenesis.