## 4 Potential of Bioactive Compounds Obtained from By-Products of the Wine Industry
### Health and Cosmetics
This blend of phenolics exhibited impressive antioxidant activity by effectively scavenging superoxide anion radicals and maintaining lipid peroxidation in biological membranes. As a result, it has the potential to prevent or decrease oxidative stress linked to degenerative mechanisms in both type 2 diabetes mellitus and Alzheimer's disease [150]. According to various studies, flavonoids have been linked to the targeted decrease in the viability of cancer cells [153; 154; 155]. The presence of quercetin in all the extracts is believed to contribute to this effect. Quercetin has the potential to combat cancer, as it can trigger apoptosis and hinder the growth of various human cancer cell lines [156]. A study conducted by [PERSON] [157] suggests that grape seed extract may have anticancer properties through its ability to promote apoptosis, inhibit cell proliferation, and block inflammation in hepatocarcinoma. It is important to mention that grape seed extract has been discovered to possess significant anti-tumor properties against various types of cancers, such as lung, colon, breast, bladder, leukemia, and prostate tumors [158; 159]. According to a recent study, antioxidants found in grape stems have been found to protect against DNA damage caused by ROS, as well as inhibit the growth of liver (HepG2) and cervical (HeLa) cancer cells [160]. A recent study has further validated the usefulness of _V. vinifera_ by-products in the creation of effective oral hygiene products that can prevent and treat various oral infections. These by-products possess a high value in terms of their polyvalent effects [161]. Numerous in vitro studies have thoroughly documented the antimicrobial and antiplatelet properties of _V. vinifera_ extracts. Various phenolic compounds, such as flavonoids, gallic acid, hydroxycinnamic acid, trans-resveratrol, and epicatechin, are present in wine and _V. vinifera_ extracts, contributing to their antimicrobial activity [162; 163]. Several other researchers have investigated the antibacterial properties of red wine and various oenological extracts, such as grape seed extracts, on a distinct type of dental plaque biofilm. This biofilm model includes _Actinomyces oris, F. nucleatum, Streptococcus oralis, S. mutans_, and _Veillonella dispar_[164]. Among all the extracts studied, the highest antimicrobial activity was present in red wine extract solutions enriched with grape seed extracts. In comparison with other wine extracts, it has been observed that grape seed extracts possess potent antimicrobial properties, which can be attributed to their high concentration of flavonoids and their derivatives. These compounds are believed to be the primary contributors to the extracts' strong antimicrobial activity [161; 164]. In the studies presented in Table 2, the bioactive compounds found in wine production by-products mostly have an anti-aging and sun protect function [165]. Nevertheless, although the by-products of grape processing can be potential sources of bioactive compounds, they have not yet been sufficiently explored. For example, Douro SkinCare (Portugal) and DC Dermoteca Cosmetics (Portugal) are two new cosmetic brands on the market that use grape oils in their formulations [149]. However, these two companies do not use all the by-products or extracts from the grape. As a result, more companies that re-use grape by-products while implementing environmental standards would have a business advantage.