Anti-COVID-19 Potential of Ellagic Acid and Polyphenols of Punica granatum L.

Pomegranate (Punica granatum L.) is a rich source of polyphenols, including ellagitannins and ellagic acid. The plant is used in traditional medicine, and its purified components can provide anti-inflammatory and antioxidant activity and support of host defenses during viral infection and recovery from disease. Current data show that pomegranate polyphenol extract and its ellagitannin components and metabolites exert their beneficial effects by controlling immune cell infiltration, regulating the cytokine secretion and reactive oxygen and nitrogen species production, and by modulating the activity of the NFκB pathway. In vitro, pomegranate extracts and ellagitannins interact with and inhibit the infectivity of a range of viruses, including SARS-CoV-2. In silico docking studies show that ellagitannins bind to several SARS-CoV-2 and human proteins, including a number of proteases. This warrants further exploration of polyphenol-viral and polyphenol-host interactions in in vitro and in vivo studies. Pomegranate extracts, ellagitannins and ellagic acid are promising agents to target the SARS-CoV-2 virus and to restrict the host inflammatory response to viral infections, as well as to supplement the depleted host antioxidant levels during the stage of recovery from COVID-19.

Medicinal uses, pharmacological activities, phytochemistry, and the molecular mechanisms of Punica granatum L. (pomegranate) plant extracts: A review.

Punica granatum L (pomegranate) is one of the Mediterranean medicinal plants that has been used for generations in treating ulcers, diarrhea, and male infertility. Increasing evidence has revealed that pomegranate possesses myriads of pharmacological activities such as anti-diabetic, anti-tumor, anti-inflammatory, anti-malaria, anti-fibrotic, anti-fungal, anti-bacterial, and other effects. Consumption of pomegranate could be used to improve gut microbiota, and therefore prevent obesity and diabetes. The mechanisms of actions of pomegranate, mainly involve nuclear factor-erythroid factor 2-related factor 2 (Nrf2), nuclear factor kappa B (NF-kB), and mitogen-activated protein kinase (MAPK) signaling pathways. In recent times, in silico molecular docking studies demonstrated that pomegranate extract and or its phytochemicals are potential inhibitors of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) spike protein and angiotensin-converting enzyme 2 (ACE2) receptor contact. Also, some clinical trials have indicated that pomegranate can be consumed for alleviation of non-alcoholic fatty liver disease, metabolic syndrome, dental infections, and menopausal symptoms. To date, active compounds, viz. alkaloids, anthocyanidins, tannins, flavonoids, phenolics, proanthocyanidins, sterols, terpenes, terpenoids, xanthonoids, fatty acids, organic acids, lignans, saccharides, and vitamin C have been isolated from pomegranate. Therefore, the current review article aimed to gather and presents an update on the ethnomedicinal uses, pharmacological activities, phytochemistry, and molecular mechanisms of Punica granatum L. This knowledge is of paramount importance in the future in drug discovery for the development of novel natural drugs for the treatment of various ailments.