Janaína Artem Ataide

Plant‐based active photoprotectants for sunscreens

Excessive exposure to the suns radiation is the major exogenous mediator of skin damage, which accelerates skin ageing and increases the risk of developing skin cancer. Compounds with photoprotectant activity are extremely useful for decreasing the effect of ultraviolet (UV) radiation on the skin; however, numerous sun filters, especially organic sunscreens, are allergenic. Therefore, the development of formulations containing plant extracts, which may be potentially safer, is extensively being explored. Plant‐based cosmetics are commonly used to avoid skin ageing because they contain antioxidant agents that minimize free radical activity, and numerous studies have investigated the skin‐protectant effects of related plant species. In addition to their antioxidant properties, plant‐based cosmetics protect the skin against solar radiation because they contain polyphenols such as flavonoids and carotenoids. Therefore, this study aims to present a review of plant species commonly used in sunscreens to protect the skin against damage due to sunlight exposure.

Update on ultraviolet A and B radiation generated by the sun and artificial lamps and their effects on skin

Solar radiation, especially ultraviolet A (UVA) and ultraviolet B (UVB), can cause damage to the human body, and exposure to the radiation may vary according to the geographical location, time of year and other factors. The effects of UVA and UVB radiation on organisms range from erythema formation, through tanning and reduced synthesis of macromolecules such as collagen and elastin, to carcinogenic DNA mutations. Some studies suggest that, in addition to the radiation emitted by the sun, artificial sources of radiation, such as commercial lamps, can also generate small amounts of UVA and UVB radiation. Depending on the source intensity and on the distance from the source, this radiation can be harmful to photosensitive individuals. In healthy subjects, the evidence on the danger of this radiation is still far from conclusive.

Photostability study of commercial sunscreens submitted to artificial UV irradiation and/or fluorescent radiation.

Sunscreens contain molecules with the ability to absorb and/or reflect UVA (ultraviolet A) and UVB (ultraviolet B) radiation, thereby preventing this radiation from reaching the epidermis or dermis. Their photo stabilities after exposure to UV radiation are well known and described, but there is little data on the stability of these filters after fluorescent indoors light radiation, such as from light emitted by commercial lamps present in homes and offices. Those lamps can expose people to varying levels of UVB, UVA, visible light, and IR (infrared). This study assesses the photostability of four different commercial products containing chemical sun filters after artificial UV and fluorescent irradiation, correlating the UVB and UVA absorption efficiencies of each product against the different types of radiation. The tested products were applied on a plate of polymethylmethacrylate (PMMA) and irradiated by a solar simulator with specific filters for UVA and UVB and a commercial fluorescent light source. According to the results, three formulations did not show photostability, suffering significant changes in their UV absorption spectra, and one of the selected formulations can be considered photostable. This reinforces the importance of conducting stability studies for sunscreen formulations in different conditions, including under artificial (indoor) light exposure.

Bromelain Loading and Release from a Hydrogel Formulated Using Alginate and Arabic Gum

An ideal wound dressing ensures a moist environment around the wound area and absorbs exudates from the wound surface. Topical application of bromelain to incised wounds has been shown to reprogram the wound microenvironment to promote effective tissue repair. Combining the characteristics of hydrogels and bromelain is therefore of great interest. Herein, we describe the development of a hydrogel, formulated using alginate and Arabic gum, for bromelain loading and release. The hydrogel formulation was evaluated using response surface methodology, considering the pH value and the concentration of alginate and Arabic gum. Bromelain loading and release were evaluated based on passive diffusion. Differential scanning calorimetry and Fourier transform infrared spectroscopy were performed to confirm bromelain immobilization in the hydrogel. The final hydrogel formulation had a swelling ratio of 227 % and incorporated 19 % of bromelain from a bromelain solution. Bromelain immobilization in the hydrogel was the result of hydrogen bond formation and was optimal at 4 °C after 4 h of contact. This evidence suggests that bromelain entrapment into a hydrogel is a promising strategy for the development of wound dressings that support the debridement of burns and wounds.

Bacterial Nanocellulose Loaded with Bromelain: Assessment of Antimicrobial, Antioxidant and Physical-Chemical Properties

Bacterial nanocellulose (BNC) has desirable properties for wound healing such as high purity, good shape retention, and high water binding capacity. Bromelain is a protease found in pineapple tissues and has been applied in several fields, it has anti-inflammatory and anticancer properties, promotes cell apoptosis, amongst others. In this work, a BNC based device for the controlled release of bromelain was developed. BNC were submersed in sterilized bromelain solution and incubated at 25 °C under 100 rpm for 24 h. Physical-chemical properties, protein concentration, antioxidant and antimicrobial activities were measured. Results demonstrate that BNC could improve bromelain antimicrobial activity 9 times. Those findings allow concluding that bromelain is a promising molecule to be incorporated into BNC’s. The BNC’s characteristics seem to represent a new promising delivery system of the loaded biomolecule, and protected from external actions.

Evaluation of the enzymatic activity and stability of commercial bromelain incorporated in topical formulations

Bromelain is a mixture of proteolytic enzymes found in various tissues of the pineapple plant (Ananas comosus) and other species of Bromeliaceae. Owing to its proteolytic activity, bromelain has been used in the food, medical, pharmaceutical and cosmetic industries, for its cell renewal, anti‐ageing, whitening and anti‐cellulite properties.

Development and evaluation of microencapsulated sunscreen

ABSTRACT The aim of the present study was to carry out stability tests and in vitro sun protection factor (SPF) evaluations of formulations containing free or microencapsulated chemical sun filters to improve their use. To this end, three formulations were developed and subjected to stability studies. The most stable formulation was chosen as a vehicle for free and microencapsulated chemical sun filters, and subjected to further stability studies and in vitro SPF assays. The SPF values were approximately 12 and 11 for formulations containing free and encapsulated sun filters, respectively, and both types were stable under stress. Chemical sun filters can be microencapsulated, which may aid in generating innovative sunscreen formulations. GRAPHICAL ABSTRACT

Vitamin C in Acerola and Red Plum Extracts: Quantification via HPLC, in Vitro Antioxidant Activity, and Stability of their Gel and Emulsion Formulations

BACKGROUND The fruits acerola and red plum are known to be good sources of antioxidants, particularly vitamin C. Antioxidants are compounds that protect organisms from biomolecular damage, such as accelerated aging, caused by free radicals. OBJECTIVE The objective of this study was to extract vitamin C from acerola and red plum, incorporate these extracts into different topical formulations, and evaluate the physicochemical stabilities of these formulations under stress conditions. METHODS Vitamin C was extracted from acerola and red plum via dynamic maceration for 2 h at 50 ± 2°C and was quantified via HPLC. In vitro antioxidant activities were evaluated using DPPH assays. The extracts were then incorporated into emulsion and gel formulations in two types of packaging, and stability studies were carried out. RESULTS Red plum and acerola extracts were orange and red and contained vitamin C concentrations of 2732.70 ± 93.01 mg/100 g and 2.60 ± 1.2 mg/100 g, respectively. In vitro antioxidant activity resulted in over 90.0% inhibition of free radicals at 0.01 mL/mL acerola extract and 0.1 mL/mL red plum extract. In the stability study, pH values decreased for both acerola formulations when stored in the oven or in transparent glass containers. Formulations containing red plum extract were stable under all conditions. Acerola extracts contained a higher concentration of vitamin C than red plum extracts. Both extracts possessed antioxidant activity, although the acerola-based formulation was unstable when stored at high temperatures or in transparent glass containers. HIGHLIGHTS Extracts from red plum and acerola contained vitamin C; antioxidant activity of the extracts resulted in over 90.0% inhibition of free radicals. Formulations containing red plum were stable under all tested conditions, and formulations containing acerola were unstable when stored in the oven or in transparent glass containers.