Azadirachta indica (Neem) is a large tree that is native to India and is traditionally used due to its several properties, mainly to treat skin diseases, as well as its “herbicidal” activity. Its bark, leaves, seeds, fruits and flowers are widely used in medicinal treatment due to the presence of active secondary metabolites with biological effects, mainly limonoids and tetranortriterpenoids, such as azadirachtin. Thus, A. indica was studied in a variety of conditions, such as anticancer, antiseptic, anti-inflammatory and chemopreventive agents, as well as a biopesticide. Furthermore, differentiated cell tissue in A. indica cultivation was reported to produce active metabolites for different purposes. However, only a few studies have been developed regarding its potential use in cosmetics. For instance, most studies explained the antimicrobial properties in health conditions, such as acne, dandruff and personal health care. Here, we summarized not only the most common cosmetic claims to treat acne but also mitigating other skin disorders related to inflammatory and oxidant processes in recent in vivo studies and patents to aid researchers and industrialists to select A. indica derivatives as novel cosmetic ingredients.

Although aesthetic benefits are a desirable effect of the treatment of skin aging, it is also important in controlling several skin diseases, mainly in aged people. The development of new dermocosmetics has rapidly increased due to consumers’ demand for non-invasive products with lower adverse effects than those currently available on the market. Natural compounds of plant origin and herbal-derived formulations have been popularized due to their various safe active products, which act through different mechanisms of action on several signaling pathways for skin aging. Based on this, the aim of the review was to identify the recent advances in herbal-derived product research, including herbal formulations and isolated compounds with skin anti-aging properties. The studies evaluated the biological effects of herbal-derived products in in vitro, ex vivo, and in vivo studies, highlighting the effects that were reported in clinical trials with available pharmacodynamics data that support their protective effects to treat, prevent, or control human skin aging. Thus, it was possible to identify that gallic and ferulic acids and herbal formulations containing Thymus vulgaris, Panax ginseng, Triticum aestivum, or Andrographis paniculata are the most promising natural products for the development of new dermocosmetics with skin anti-aging properties.

Sustainable ingredients in cosmetics have been discussed for the past decade, and the COVID-19 pandemic has increased awareness of this significant topic. Consumers are informed and vigilant about clean labels, driving the necessity for sustainability throughout the cosmetic production chain. Moreover, nanotechnology and green chemistry approaches have emerged as innovative perspectives to develop sustainable and eco-friendly cosmetic ingredients. In this sense, in this review, we present examples and applications of sustainable ingredients derived from several types of sources (i.e., plants, animals, microorganisms, cell cultures, and recycled materials/biomaterials). The benefits and drawbacks of all classes of compounds were organized and discussed in relation to novel formulations/products. Finally, we addressed perspectives on cosmetic ingredients that prioritize sustainability and safety, with an emphasis on exploring sustainable ingredients, compounds, or molecules as promising areas for research and development.

The skin acts as a protective barrier, guarding the body against microorganisms, chemicals, and several environmental factors. Accordingly, this all-important organ must be kept healthy to maintain its optimal functionality. One approach to maintain skin health is the application of multifunction bioactive sunscreens containing antioxidant molecule(s). Rosmarinic acid (RA), a phenolic compound, is known for its antioxidant activity. Herein, the safety and efficacy of a multifunction prototype sunscreen were investigated, aiming to evaluate the performance of this polyphenol with two known and widely used UV filters (bemotrizinol and octyl p-methoxycinnamate). Samples protected the DNA fragmentation compared to UV control, by the comet assay, and showed good skin compatibility in subjects. Formulations F1 and F3 were able to increase skin hydration, and, possibly, the RA interfered with this attribute. An increase in transepidermal water loss was observed for formulations F1, F2, and F4, which may be related to the vehicle, containing the RA or not. No decreases were observed in the inflammatory reaction caused by the ethyl nicotinate with any of the samples. As a perspective, we suggest trials with a greater number of subjects or protocol modifications. Altering the vehicle qualitative and quantitative composition is also a pertinent perspective.

In addition to dermatological complications, acne can affect the quality of life of individuals in numerous ways, such as employment, social habits and body dissatisfaction. According to our expertise, caprylic acid and propanediol would not have a direct action on Cutibacterium acnes. Despite this, we investigated the existence of a synergistic effect among xylitol, caprylic acid and propanediol as a mixture of compounds representing a single topical active ingredient that could benefit the treatment against acne. In vitro and in vivo assays were performed to challenge and to prove the efficacy of propanediol, xylitol and caprylic acid (PXCA) against acne. PXCA had its MIC challenged against C. acnes (formerly Propionibacterium acnes) and Staphylococcus aureus, resulting in concentrations of 0.125% and 0.25%, respectively, and it also developed antimicrobial activity against C. acnes (time-kill test). PXCA was able to reduce the 5-alpha reductase expression in 24% (p < 0.01) in comparison with the testosterone group. By the end of 28 days of treatment, the compound reduced the skin oiliness, porphyrin amount and the quantity of inflammatory lesions in participants. According to the dermatologist evaluation, PXCA improved the skin’s general appearance, acne presence and size.