A Review on the Antiviral Activity of Functional Foods Against COVID-19 and Viral Respiratory Tract Infections

Abstract

Due to the absence of successful therapy, vaccines for protection are continuously being developed. Since vaccines must be thoroughly tested, viral respiratory tract infections (VRTIs), mainly coronaviruses, have seriously affected human health worldwide in recent years. In this review, we presented the relevant data which originated from trusted publishers regarding the practical benefits of functional foods (FFs) and their dietary sources, in addition to natural plant products, in viral respiratory and COVID-19 prevention and immune-boosting activities. As a result, FFs were confirmed to be functionally active ingredients for preventing COVID-19 and VRTIs. Furthermore, the antiviral activity and immunological effects of FFs against VRTIs and COVID-19 and their potential main mechanisms of action are also being reviewed. Therefore, to prevent COVID-19 and VRTIs, it is critical to identify controlling the activities and immune-enhancing functional food constituents as early as possible. We further aimed to summarize functional food constituents as a dietary supplement that aids in immune system boosting and may effectively reduce VRTIs and COVID-19 and promote therapeutic efficacy.

Inflammation Related to Association of Low Uric Acid and Progression to Severe Disease in Patients Hospitalized for Non-Severe Coronavirus Disease 2019

“…On the other hand, the administration of steroids, an anti-inflammatory medication, has been shown to reduce the level of severity [ 7 , 38 , 42 ]. In addition, other reports have noted that the administration of antioxidants resulted in reductions in inflammation and severity in respiratory viral infection cases [ 43 , 44 , 45 ], with similar effects expected in patients affected by COVID-19 [ 5 , 34 ]. Additionally, uric acid has been shown to gain an antioxidant property by scavenging ROS, such as singlet oxygen, and peroxyl and hydroxyl radicals, and is also known to provide approximately half of the free radical-scavenging capacity in the human body [ 8 , 46 ].…”

Supply of vitamins (A, E, D, C, B6, B12) and mineral substances (ZN, FE, MG, CA, P) for children with recurrent respiratory infections and deficiency correction of their deficiency as a possibility to prevent frequent respiratory infections

“…Наиболее значимую роль играют витамины A, D, E, C, B6, B12 и минеральные вещества, такие как железо (Fe), цинк (Zn), медь (Cu), селен (Se) и магний (Mg), которые взаимодополняют друг друга, поскольку имеют сходные механизмы действия [7][8][9][10][11][12]. Например, витамины A, D, C, E и цинк необходимы для обеспечения структурной и функциональной целостности слизистых респираторного тракта, которые представляют собой первую линию защиты от проникновения патогенов, а активность макрофагов и способность организовать эффективный окислительный взрыв зависят от достаточного количества витаминов A, D, C, E, B 6 и B 12 [13][14][15][16][17]. Активация системы комплемента и высвобождение провоспалительных цитокинов определяются уровнем витаминов А, D и С и минералов -Fe, Zn и Se.…”

Dietary phytochemicals against COVID‐19: A focus on thymoquinone

“…Numerous phytochemicals such as flavonoids including quercetin (e.g., apples, onions, parsley, and sage), kaempferol (spinach and kale), isoliquiritigenin (soybean and shallots), tangeretin (tangerine), and baicalein (Scutellaria baicalensis, Huang-qin) (Song et al, 2021) (Figure 1) are shown to be inhibitors of SARS-CoV-2 Mpro with a similar mechanism as Nirmatrelvir in Paxlovid (Mandal et al, 2021). Other phenolics such as epigallocatechin gallate (green tea) and hesperidin (citrus fruits) (Figure 1) could inhibit RdRp activity in a similar way as Remdesivir (Bahun et al, 2022;Omer et al, 2022).…”

“…To fight coronavirus, herbal medicines have been explored to treat COVID patients across the world. Many nutrients in food play important roles by boosting the immune system and/or reducing viral respiratory tract infections (Omer et al, 2022). For example, Zinc as an antioxidant mineral (Dhawan et al, 2022), and vitamin D in food (Wimalawansa, 2022) can exhibit immunomodulatory and anti‐inflammatory properties.…”