## 6 Conclusions  
In conclusion, it seems that the inclusion of natural extracts either as active ingredients or as supporting ingredients is a promising project, laying the foundation for more and more natural and sustainable solutions in the field of cosmetic chemistry. Grape stems contain a variety of antioxidants, with flavonoids playing a dominant role. The main bioactive compounds are gallic acid, catechhin, epicatechin, epigallocatechin, and quercetin. However, flavonoids alone do not sufficiently attenuate or suppress photochemical reactions catalyzed by UV radiation, but synergism between flavonoids and UV filters can reduce the formation of harmful photodegradation products, enhancing the photoproduction provided. Various studies correlate the Total Polyphenol Content (TPC) of extracts with their photoprotective effect. The incorporation of such substances in sunscreen products may therefore be particularly beneficial. However, in research (2015) on changes likely to occur in the bioactive components of grapes after exposure to UV radiation in a day, it was found that in components such as polyphenols, anthocyanins were significantly reduced in amounts (in aqueous solutions), but retained their ability to bind free radicals even after 24 h. Moreover, tannins, due to the stability of their properties, are evaluated as candidate compounds not only for sunscreen products, but also many more. In addition, in subsequent research (2021) on the utilization of grape by-products in cosmetic chemistry, it was found that more extensive investigation is needed in terms of extraction techniques, which allow for the recovery of certain classes of polyphenols, as special attention is needed to establish the correct link between the extraction parameters, the recovered components, and their effect on the stability of cosmetic formulations. Sunscreens with the majority of their composition consisting of natural ingredients, in addition to preventing serious diseases such as basal cell carcinoma, melanoma, sunburn, premature aging, and many others, also act against inflammation. In other words, they are anti-irritant and often healing (especially due to the moisturizing agents they contain) and have a hypoallergenic composition, making them ideal for the most sensitive skins. But the main advantage of the action of these molecules is their ability to bind ROS; i.e., they bind free radicals, which cause serious problems in human health such as oxidative stress. Both the bioactive compounds in grape stems and lycopene in tomatoes are antioxidants that fight free radicals and provide a degree of photoproduction, especially in combination with sunscreen filters. In fact, it is worth pointing out that lycopene, while reducing the damaging effects of UV radiation, also enhances skin protection against both short-term UV effects (sunburn) and cumulative effects (cancer). However, even though lycopene has a variety of biological properties, it presents some difficulties due to characteristics like high lipophilicity and insolubility in aqueous solvents, as well as it exhibiting stability and degradation problems. For this reason, solutions are being sought for its proper utilization, such as its association with nanotechnology, in order to circumvent these difficulties. Moreover, it is worth highlighting the importance of grape stems and tomato extracts for their use in sunscreen products and in cosmetic chemistry products in general, as an alternative solution that represents a step towards a circular economy. The circular economy contributes to the mitigation of major environmental, economic, and social problems related to the ever-increasing increase in food waste due to the continuous growth of the population, while simultaneously allowing the obtaining of compounds of a plant origin with high added value. This reduces the amount of waste, while, at the same time, benefits human beings, since these by-products are not in any way inferior in terms of the antioxidant benefits they offer, in comparison to the original fruit.