Grape seed extract (GSE) is having abundant source of polyphenols. Polyphenols and flavonoids present in the GSE have been shown remarkable interest based on positive reports of their antioxidant properties and ability to serve as free radical scavengers. In comparison to other well-known antioxidants (such vitamin C, vitamin E, and β-carotene), grape seed polyphenols have a higher antioxidant activity. Along with its antioxidant property, it also has several enzymes that catalyze the release of histamine in allergic reactions and inflammatory conditions. The amount of oil present in grape seed depends on the variety of the grape (usual range 10 – 16% of dry weight). In addition, grape seed oil has a high amount of unsaturated fatty acids, including α-linolenic acid (ω – 3) and g-linolenic acid (ω – 6) from 85 to 90%. These fatty acids are related to a reduction of cardiovascular disease, cancer, hypertension, and autoimmune disorders. An oil containing high amount of linoleic acid results in the reduction of total blood cholesterol and low-density lipoprotein (LDL) cholesterol. Due to the fact that LDL cholesterol is responsible for the formation of arteriosclerosis, the application of grapeseed oil has a good impact on the decrease of arteriosclerosis. Linoleic, linolenic, oleic, and palmitic acids are among the fatty acids present in GSE and play a significant role in lipid metabolism. The major fatty acid in GSE is linoleic acid followed by oleic acid and palmitic acid. The seeds and peels of grapes also contains considerable portion of dietary fiber that lowers the risks of colon cancer, heart disease, diabetes and obesity .
The Benefits of Grape Seed Extract
Wound Healing Activity
The most effective growth factor in the process of wound healing is vascular endothelial growth factor (VEGF). GSE contains polyphenyl phenolic bioflavonoids, proanthocyanidins which accelerates the process of wound healing. Proanthocyanidins specifically induces the VEGF expression in human keratinocytes cells responsible for wound healing. A phenolic component found in GSE has been shown in some epidemiological studies to decreases the endothelial contraction of vessels, activate nitric oxide synthesis, regulate platelet aggregation and prevent LDL cholesterol oxidation .
Pro-inflammatory cytokines are activated through downstream cascades during persistent inflammation in wounds. These cytokines include tumor necrosis factor (TNF), interleukin (IL)-1, IL-6, and IL-17. There are studies that have demonstrated the anti-inflammatory potential of GSE on murine macrophage RAW264.7 cells. According to these studies, GSE has a significant potential to reduce the production of inflammatory markers including tumor necrosis factor-α (TNFα), inducible isoform of nitric oxide synthase (iNOS), IL-6, and nitric oxide (NO). This is accomplished by inhibiting the phosphorylation p38, ERK1/2, JNK, and NF-κB signaling pathways through a synergistic interaction of the phenolic compounds and flavonoids present in the GSE .
It is well known that plant polyphenols, particularly GSE, have antioxidant property. These bioactive molecules exert their beneficial effects by neutralizing reactive oxygen species (ROS) and chelating pro-oxidative metal ions [1, 3]. Polyphenols may play a key role in the prevention of degenerative processes, such as cancer, diabetes, chronic inflammation and aging. Additionally, polyphenolic compounds inhibit the oxidation of LDL and prevent platelet aggregation, decreasing the development of cardiovascular and coronary diseases .
Numerous studies have demonstrated the immunity function of GSE. The immunity may be influenced by oxidative stress, and the improved antioxidant function may enhance their immune function in poultry. It has been showed in pigs that polyphenols may boost immune function by suppressing inflammation via nuclear factor-kappaB and nuclear factor-2-dominant pathways in the small intestine. Interferon-γ (IFN-γ) serves as an important regulator in the activation of lymphocytes and monocytes and serum IL-2 promotes the proliferation of activated natural killer cells, B lymphocytes, T lymphocytes, and antibody production. Complement4 (C4) is a crucial component of the body’s immunological defense system and plays a significant role in immune response. According to the current findings, the supplementation of GSE improved serum C4, IL-2, and INF-γ, indicating GSE could enhance immune response by regulating antibodies, complements, and cytokines .
In the presence of risk factors for cardiovascular diseases (CVDs), including hypertension, diabetes mellitus, dyslipidemia, and smoking, increased generation of ROS contributes to endothelial dysfunction. For example, elevated ROS levels in hypertensive patients leads to reduced vascular bioavailability of NO. Hence, antioxidants that improve oxidative stress status are expected to promote vascular health, thereby preventing CVDs. Several studies involving rodents and humans with hypertension or CVDs have demonstrated how antioxidants, such as the vitamins C and E, genistein, and polyphenols, improve vascular endothelial function and lower blood pressure by reduction in ROS levels. A type of polyphenols called proanthocyanidin has potent antioxidant properties. Proanthocyanidin has greater antioxidant activity than vitamins C and E, β-carotene, or monomeric flavanol, including (+)-catechin. Furthermore, grape seed extracts containing 39-73% proanthocyanidin have also been shown to have strong antioxidant potency .
The in vitro and in vivo studies show a relation between presence of antioxidant phenolics and the reduction of oxidized LDL particles, and intake of diets high in phenolic antioxidants decreased the incidence of heart disease. The ability of the polyphenols in GSE avert radical oxidation of the polyunsaturated fatty acids of LDL, which occurs frequently through oxidative modification of the apoprotein toward an atherogenic form, has a direct follow up on the prevention of CVDs .
Grape seed has the ability to improve skin health and reduce skin aging by: (a) functioning as antioxidants and encouraging the Nrf2 pathway to generate other antioxidants, (b) promoting collagen, elastin, and TIMP 1 while, at the same time, inhibiting MMPs and the enzyme elastase, (c) inhibiting inflammatory molecules such as the interleukins and cyclo-oxygenase (COX) compounds, and the inhibition or counteracting of ROS formation, (d) inhibiting NF kappaB and AP-1, (e) stimulating SIRT 1 gene expression (the anti-aging biomarker), (f) binding of the potent androgen, 5α-DHT, and inhibiting the 5α-reductase enzyme in fibroblasts, and (g) binding to estrogen receptor β in the keratinocytes in the epidermis and fibroblasts in the dermis .
- Gupta M, Dey S, Marbaniang D, Pal P, Ray S, Mazumder B. Grape seed extract: having a potential health benefits. Journal of Food Science and Technology. 2020 [cited 2022 October 27]; 57: 1205-15. Available form: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7054588/
- Ajit A, Vishnu A, Varkey P. Incorporation of grape seed extract towards wound care product development. 3 Biotech. 2021 [cited 2022 October 27]; 11: 1-10. Available form: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8113434/
- Szabó É, Marosvölgyi T, Szilágyi G, Kőrösi L, Schmidt J, Csepregi K, et al. Correlations between Total Antioxidant Capacity, Polyphenol and Fatty Acid Content of Native Grape Seed and Pomace of Four Different Grape Varieties in Hungary. Antioxidants (Basel). 2021 [cited 2022 October 27]; 10: 1-12. Available form: https://www.mdpi.com/2076-3921/10/7/1101
- Ao X, Kim I. Effects of grape seed extract on performance, immunity, antioxidant capacity, and meat quality in Pekin ducks. Poultry Science. 2020 [cited 2022 October 27]; 99: 2078-86. Available form: https://www.sciencedirect.com/science/article/pii/S0032579119580580?via%3Dihub
- Odai T, Terauchi M, Kato K, Hirose A, Miyasaka N. Effects of Grape Seed Proanthocyanidin Extract on Vascular Endothelial Function in Participants with Prehypertension: A Randomized, Double-Blind, Placebo-Controlled Study. Nutrients. 2019 [cited 2022 October 27]; 11: 1-12. Available form: https://www.mdpi.com/2072-6643/11/12/2844#B20-nutrients-11-02844
- David L, Virginia A, Edwin D. Enhancing Skin Health: By Oral Administration of Natural Compounds and Minerals with Implications to the Dermal Microbiome. International Journal of Molecular Sciences. 2018 [cited 2022 January 31]; 19: 1-35. Available form: https://www.mdpi.com/1422-0067/19/10/3059