1. Introduction

There are many ways in which we are exposed to toxic substances: through the air we breathe, the food we eat, the water we drink, the clothes we wear, cosmetics, radiation exposure, which also has harmful effects. Toxic substance exposure is much more problematic today than it would have been in the past. The environmental repercussions include DNA damage, and this genome instability leads to diseases such as cancer, degenerative diseases, infertility, diseases associated with aging ^[1][4], among many other issues. A healthy lifestyle can reduce these issues, including consuming substances that protect the genome by several mechanisms reducing DNA damage. Genotoxicological studies are fundamental for knowing the hazards to genome and health, and antigenotoxicological studies are the answer to minimize genome instability.

The term cosmetics, as defined by the current European regulation on cosmetics, refers to a product applied to the body to beautify, cleanse, or improve the appearance and enhance attractive features ^[2][6]. Included in the definition of cosmetics are soaps, shampoos, toothpaste, cleansing and moisturizing creams for regular care, color cosmetics, hair colorants, and styling agents, fragrance products, and ultraviolet light (UV light) screening preparations ^[3][7]. Although conventional, natural and organic cosmetics have the same definition, they differ in their specificities. The formulation of conventional cosmetics does not need to contain certified natural and organic ingredients ^[4][8]. Natural cosmetics is a product that must have at least one ingredient “derived from” some natural substance, extracted directly from a plant or mineral rather than being synthesized. Natural cosmetics can contain percentages of organic ingredients. However, a natural product is not necessarily an organic product ^[5][9]. An organic cosmetic must contain at least 95% of certified organic ingredients in its composition. These raw materials are obtained through certified crops and extraction. They must be biodegradable and preserve the most natural chemical characterization. The remaining 5% of the formulation may be composed of water, natural raw materials from agriculture, or non-certified allowed extractive for organic formulation ^[3][4][5][7,8,9].

Modern-day cosmetics increasingly include noxious and chemically potent substances in modern days and have an ecological impact on the environment ^[6][10]. As awareness of this grows, people tend to buy organic and natural products more frequently. Analysts maintain an optimistic long-term outlook on the global natural and organic personal care products market. It is a market that has grown and amounts to €288.9 million in 2021. The market is expected to grow annually by 9.24% (2021–2025) ^[7][8][9][11,12,13]. A total of 80% of French women buy or have already bought natural and organic beauty products ^[10][14]. About 50% of French consumers decided to buy organic cosmetics after realizing the ecological impact of non-organic products ^[11][12][15,16]. The organic cosmetic market grew by 5.9% in Germany, reaching 1.26 billion EUR in 2018 ^[13][17].

Consumers exposed themself to these chemicals, perhaps daily. Since the genotoxic agents are present in many cosmetics, a substantial investigation into the benefits that plants and fruits can bring to health is required since it is clear that topical treatment with cosmeceuticals can help improve skin rejuvenation ^[14][25]. Identifying products with antigenotoxic effects is among the most promising research areas in recent years since they might protect against DNA damage and its consequences. Studies have shown that antigenotoxic properties are linked to anti-aging properties ^[1][15][4,26], and these properties are essential to revert genotoxic effects. Therefore, this review presents an overview of research conducted on natural ingredients common in the Northeast of Portugal with an antigenotoxic effect.

2. Characterization of Trás-os-Montes Region

Trás-os-Montes is limited to the west by the province of Minho, to the south by the Douro, to the east by the Douro River, and to the north by Spain. The climate is sub-Atlantic/continental and Mediterranean, represented by “Terra Fria de Planalto”, “Terra Fria de Montanha”, “Terra Fria de Alta Montanha”, “Terra de Transição” and “Terra Quente”. The climate is influenced in the west by the humidity from the Atlantic, in the east by the cold and dryness from the continent, and in the south by the heat ^[16][27]. The ecological zoning of Trás-os-Montes highlights the domains: Atlantic (50%), Iberic (26%) and Mediterranean (24%) and four agrotypes, “Granito e Xisto,” “Meia Encosta Nordestina,” “Terra Fria Transmontana” and “Terra Quente Transmontana” ^[17][28]. Physiography is dominated by mountain and sub-mountain hypsometry, from 450–700 m (natural limit of vine culture) to 1500 m ^[18][29]. The dominant soils are of granitic origin and the like, associated with schist ^[19][30]. In the Valleys of Vila Pouca de Aguiar, Chaves, Vila Real, and Boticas (<700 m), there is a greater variety of crops, such as vines, olive trees, fruit trees, wheat, potatoes, rye, maize, and permanent pastures ^[16][27]. This review will focus especially on Elderberry, Almonds, Olives, and Grapes.

Elderberry is commonly found in the north, especially in the Varosa Valley, which because of the surrounding mountains, produces a microclimate favorable for the development of this species ^[20][21][31,32]. The almond tree is one the most widely planted tree crops in the Trás-os-Montes area, occupying an area of 19,206 hectares ^[22][33]. The most common varieties are “Parada”, “Casanova”, “Verdeal” and “Pegarinhos” ^[23][34]. Trás-os-Montes is the second Portuguese olive growing region, currently representing between 12 and 15% of the national production of olive oil ^[24][35]. The more important varieties are “Cobrançosa”, “Madural” and “Verdeal” ^[25][36]. Portugal has a wine-growing area of 1/4 to 1/5 of the surface of the significant wine-growing countries in Europe. Of the 343 grape varieties listed, about 230 varieties are considered indigenous to Portugal or the Iberian Peninsula, reflecting the vast and unique Portuguese viticultural genetics. Trás-os-Montes area has 40 indigenous varieties in cultivation ^[26][37]. As such, natural ingredients are easily obtained in this area ^[27][38]. It is also a region with the most organic farmers, and the climatic, topographic, and pedological differences predispose this region for agricultural diversity ^[12][16].

3. Natural Ingredients from Northeast of Portugal

3.1.1. Chemical Composition

Chemical composition varies depending on the cultivar, development stage, ripening, and season. As for carbohydrates, elderberry berries contain 7.86–11.50% of total sugar and 2.8–8.55% of reducing sugar. The main sugars are glucose (33.33–50.23 g/kg FW) and fructose (33.99–52.25 g/kg FW). Sucrose is also found in small amounts (0.47–1.68 g/kg FW) ^[28][51]. Other carbohydrates were found such as dietary fibre, in particular, pectin (0.1593%), pectin acid (0.2299%), protopectin (0.0409%), Ca-pectate (1.53%), and cellulose (1.65%) ^[29][52]. As for proteins, they are present in berries (2.7–2.9%), flowers (2.5%), and leaves (3.3%). Thus protein includes sixteen amino acids, nine of which are essential (9% in flowers and 11.5% in leaves) ^[28][51]. Glutamic acid (0.311 g/100 mL), aspartic acid (0.303 g/100 mL) and alanine (0.238 g/100 mL) were reported as the dominant amino acids, whereas cysteine (0.008 g/100 mL), methionine (0.025 g/100 mL) and histidine (0.062 g/100 mL) where less abundant ^[29][52]. Fats are accumulated mostly in elderberry seeds (22.4%, with 75.15% of polyunsaturated fatty acids and 14.21% of monounsaturated fatty acids) and seed flour (15.9%, with 21.54% of polyunsaturated fatty acids and 4.21% of monounsaturated fatty acids) ^[28][51]. Organic acids represent 1.0–1.3% of the berry content. Four organic acids were detected in elderberry fruit. The most dominant was citric acid (3.08–4.81 g/kg FW), followed by malic acid (0.97–1.31 g/kg FW) and smaller concentrations of shikimic (0.14–0.93 g/kg FW) and fumaric acid (0.10–0.29 g/kg FW) ^[30][53]. Minerals are located both in berries and flowers and represent 0.90–1.55% of the fruit mass. They include K (391.33 mg/100 g), P (54.00 mg/100 g), Ca (28.06 mg/100 g), Na (2.17 mg/100 g), Mg (25.99 mg/100 g), Fe (1.86 mg/100 g), Zn (0.36 mg/100 g), Mn (0.27 mg/100 g) and Cu (0.14 mg/100 g) ^[29][52]. Elderberry fruit and flowers also include essential oils (0.01%), consisting of approximately 53 compounds in berries and 58 in flowers ^[28][51]. Vitamin C and cellulose are also found in elderberry fruit in concentrations of 34.10 mg/100 g and 1.65 mg/100 g, respectively ^[29][52].

According to the “Autoridade de Segurança Alimentar e Económica” (Food and Economic Safety Authority) in Portugal, the standard grades of olive oil currently available on the market are extra virgin olive oil, virgin olive oil, and “azeite lampante” ^[31][86]. The standard grades are based on the free acidity or degree of processing of the oil. The free acidity for extra virgin olive oil is ≤0.8%, virgin olive oil ≤ 2.0%, and “azeite lampante” ≥ 2.0%. Olive oil has minerals, such as calcium (1 mg/100 g), iron (0.56 mg/100 g), potassium (1 mg/100 g), and sodium (2 mg/100 g); vitamins, namely vitamin E (14.35 mg/100 g) and vitamin K (60.20 µg/100 g); and lipids, saturated fatty acids (15.40 g/100 g), monounsaturated fatty acids (69.20 g/100 g), and polyunsaturated fatty acids (9.07 g/100 g) ^[32][33][73,87]. Olive oil has diverse fatty acids, namely myristic, palmitic, palmitoleic, heptadecanoic, heptadecenoic, stearic, oleic, linoleic, linolenic, arachidic, eicosenoic, behenic, and lignoceric acids ^[34][79]. One of the major hydrocarbons present in olive oil is squalene. Squalene appears to be critical for reducing free radical oxidative damage to the skin and has been used as a moisturizing or emollient agent in cosmetic preparation ^[35][88].

Grape skin is rich in flavonoids (myricetin-glucuronide, myricetin-glucoside, quercetin-glucuronide, quercetin-glucoside, and kaempferol-glucoside) and anthocyanins (such as delphinidin-monoglucoside, cyanidin-monoglucoside, petunidin-monoglucoside, among others), with a total amount of 4863 mg/kg and 1670 mg/kg, respectively ^[36][130]. Phenolic acids are also present in the seeds, skin, and pulp. The ones found are gallic acid, protocatechuic acid, catechin, epicatechin, procyanidin, epigallocatechin, resveratrol, chlorogenic acid, coumaric acid, caffeic acid, and rutin. Organic acids and sugars are also present in seeds, skin, and pulp, the major ones being tartaric, malic, and citric acids, glucose, and fructose ^[37][131].

Grapes can be used in cosmetics as follows: bud extract, flower extract, fruit extract, fruit powder, fruit water, juice, juice extract, leaf extract, leaf oil, leaf/seed skin extract, leaf water, leaf water, leaf wax, root extract, seed, seed extract, seed powder, shoot extract, skin extract, skin powder, vine extract, and vine sap. The seed extract is used in 463 cosmetic formulations, fruit extract in 219 cosmetic formulations, and leaf extract is used in 78 cosmetic formulations ^[38][146]. Grape seeds contain fiber (40%), oil (16%), protein (11%), sugars, and minerals being a rich source of proanthocyanidins. Proanthocyanidins are potent antioxidants and have free radical scavenger activities ^[39][147]. The various components of grapes make them an excellent ingredient to be added to cosmetic formulations. Resveratrol’s proven ability to penetrate the skin barrier and anti-aging activity makes it an excellent complement for cosmetic formulation. It can also stimulate fibroblasts’ proliferation and increase the concentration of collagen III ^[40][148]. Phenolic acids and flavonoids, such as ferulic acid, caffeic acid, gallic acid, and proanthocyanidins, are efficient protectors by reducing oxidative stress and may be essential in cosmetic surgery formulation for post-sun skin care ^[41][149]. Grapes also provide phenolic components, like anthocyanins, gallic acid, catechin, epicatechin, conjugated flavonoids, oleic, linoleic, and linolenic acids, counteracting symptoms of epidermal aging and delaying the process of photoaging ^[42][43][150,151]. Currently, to optimize sun protection and photostability, sunscreens use natural antioxidant composition. Scientific evidence has shown the benefits of polyphenols’ topical and oral use from some plant species against UV radiation, including Vitis vinifera ^{[44][45][38][46]}[120,121,146,152]. Relevant studies of Grapes: Table 15 shows relevant studies developed on Grapes since 1999.

4. Conclusions

The present review synthesizes the most accurate evidence of the antigenotoxic capacity of some natural ingredients common in the Northeast of Portugal. Almonds, Grapes, Olives, and Elderberry proved to have an antigenotoxic effect. Natural occurring antigenotoxicity in natural ingredients could strongly counteract genome instability.

Even though these ingredients are already being used in cosmetics, the lack of antigenotoxicological studies makes it crucial to investigate further how to incorporate them in cosmetics to benefit human health. Studies have shown that plants, fruits, and vegetables with antigenotoxic properties show promising results for the cosmetic industry ^[54][55][56][193,194,195]. Additional investigation can be carried out, namely, evaluating the cosmetic properties of the natural ingredients towards promoting DNA integrity. Using Comet Assay and SMART, evaluating genoprotection, longevity, and prolificacy of the natural ingredients in D. melanogaster could reveal exciting results.