Fruits, vegetables, and other food items contain phytochemicals or secondary metabolites which may be considered non-essential nutrients but have medicinal importance. These dietary phytochemicals exhibit chemopreventive and therapeutic effects against numerous diseases. Polyphenols are secondary metabolites found in vegetables, fruits, and grains. These compounds exhibit several health benefits such as immune modulators, vasodilators, and antioxidants. This review focuses on recent studies on using dietary polyphenols to treat cardiovascular disorders, atherosclerosis, and vascular endothelium deficits. We focus on exploring the safety of highly effective polyphenols to ensure their maximum impact on cardiac abnormalities and discuss recent epidemiological evidence and intervention trials related to these properties. Kaempferol, quercetin, and resveratrol prevent oxidative stress by regulating proteins that induce oxidation in heart tissues. In addition, polyphenols modulate the tone of the endothelium of vessels by releasing nitric oxide (NO) and reducing low-density lipoprotein (LDL) oxidation to prevent atherosclerosis. In cardiomyocytes, polyphenols suppress the expression of inflammatory markers and inhibit the production of inflammation markers to exert an anti-inflammatory response. Consequently, heart diseases such as strokes, hypertension, heart failure, and ischemic heart disease could be prevented by dietary polyphenols.

Type II diabetes mellitus and its related complications are growing public health problems. Many natural products present in our diet, including polyphenols, can be used in treating and managing type II diabetes mellitus and different diseases, owing to their numerous biological properties. Anthocyanins, flavonols, stilbenes, curcuminoids, hesperidin, hesperetin, naringenin, and phenolic acids are common polyphenols found in blueberries, chokeberries, sea-buckthorn, mulberries, turmeric, citrus fruits, and cereals. These compounds exhibit antidiabetic effects through different pathways. Accordingly, this review presents an overview of the most recent developments in using food polyphenols for managing and treating type II diabetes mellitus, along with various mechanisms. In addition, the present work summarizes the literature about the anti-diabetic effect of food polyphenols and evaluates their potential as complementary or alternative medicines to treat type II diabetes mellitus. Results obtained from this survey show that anthocyanins, flavonols, stilbenes, curcuminoids, and phenolic acids can manage diabetes mellitus by protecting pancreatic β-cells against glucose toxicity, promoting β-cell proliferation, reducing β-cell apoptosis, and inhibiting α-glucosidases or α-amylase. In addition, these phenolic compounds exhibit antioxidant anti-inflammatory activities, modulate carbohydrate and lipid metabolism, optimize oxidative stress, reduce insulin resistance, and stimulate the pancreas to secrete insulin. They also activate insulin signaling and inhibit digestive enzymes, regulate intestinal microbiota, improve adipose tissue metabolism, inhibit glucose absorption, and inhibit the formation of advanced glycation end products. However, insufficient data are available on the effective mechanisms necessary to manage diabetes.

Syzygium cumini, locally known as Jamun in Asia, is a fruit-bearing crop belonging to the Myrtaceae family. This study aims to summarize the most recent literature related to botany, traditional applications, phytochemical ingredients, pharmacological activities, nutrition, and potential food applications of S. cumini. Traditionally, S. cumini has been utilized to combat diabetes and dysentery, and it is given to females with a history of abortions. Anatomical parts of S. cumini exhibit therapeutic potentials including antioxidant, anti-inflammatory, analgesic, antipyretic, antimalarial, anticancer, and antidiabetic activities attributed to the presence of various primary and secondary metabolites such as carbohydrates, proteins, amino acids, alkaloids, flavonoids (i.e., quercetin, myricetin, kaempferol), phenolic acids (gallic acid, caffeic acid, ellagic acid) and anthocyanins (delphinidin-3,5-O-diglucoside, petunidin-3,5-O-diglucoside, malvidin-3,5-O-diglucoside). Different fruit parts of S. cumini have been employed to enhance the nutritional and overall quality of jams, jellies, wines, and fermented products. Today, S. cumini is also used in edible films. So, we believe that S. cumini’s anatomical parts, extracts, and isolated compounds can be used in the food industry with applications in food packaging and as food additives. Future research should focus on the isolation and purification of compounds from S. cumini to treat various disorders. More importantly, clinical trials are required to develop low-cost medications with a low therapeutic index.

Worldwide, there is an array of clinical trials under way to evaluate treatment options against coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2. Concurrently, several nutritional therapies and alternative supportive treatments are also being used and tested to reduce the mortality associated with acute respiratory distress in patients with COVID-19. In the context of COVID-19, improved nutrition that includes micronutrient supplementation to augment the immune system has been recognized as a viable approach to both prevent and alleviate the severity of the infection. The potential role of micronutrients as immune-boosting agents is particularly relevant for low- and middle-income countries, which already have an existing high burden of undernutrition and micronutrient deficiencies. A systematic literature review was performed to identify nutritional interventions that might prevent or aid in the recovery from COVID-19. The PubMed, ScienceDirect, Cochrane, Scopus, Web of Science, and Google Scholar databases were searched electronically from February to April 2020. All abstracts and full-text articles were examined for their relevance to this review. The information gathered was collated under various categories. Deficiencies of micronutrients, especially vitamins A, B complex, C, and D, zinc, iron, and selenium, are common among vulnerable populations in general and among COVID-19 patients in particular and could plausibly increase the risk of mortality. Judicious use of need-based micronutrient supplementation, alongside existing micronutrient fortification programs, is warranted in the current global pandemic, especially in low- and middle-income economies.

Globally grown and organoleptically appreciated Grewia species are known as sources of bioactive compounds that avert the risk of communicable and non-communicable diseases. Therefore, in recent years, the genus Grewia has attracted increasing scientific attention. This is the first systematic review which focusses primarily on the nutritional composition, phytochemical profile, pharmacological properties, and disease preventative role of Grewia species. The literature published from 1975 to 2021 was searched to retrieve relevant articles from databases such as Google Scholar, Scopus, PubMed, and Web of Science. Two independent reviewers carried out the screening, selection of articles, and data extraction. Of 815 references, 56 met our inclusion criteria. G. asiatica and G. optiva were the most frequently studied species. We found 167 chemical compounds from 12 Grewia species, allocated to 21 categories. Flavonoids represented 41.31% of the reported bioactive compounds, followed by protein and amino acids (10.7%), fats and fatty acids (9.58%), ash and minerals (6.58%), and non-flavonoid polyphenols (5.96%). Crude extracts, enriched with bioactive compounds, and isolated compounds from the Grewia species show antioxidant, anticancer, anti-inflammatory, antidiabetic, hepatoprotective/radioprotective, immunomodulatory, and sedative hypnotic potential. Moreover, antimicrobial properties, improvement in learning and memory deficits, and effectiveness against neurodegenerative ailments are also described within the reviewed article. Nowadays, the side effects of some synthetic drugs and therapies, and bottlenecks in the drug development pathway have directed the attention of researchers and pharmaceutical industries towards the development of new products that are safe, cost-effective, and readily available. However, the application of the Grewia species in pharmaceutical industries is still limited.

Cucumis sativus L., widely cultivated as an edible vegetable. Its seeds are well reputed for cardiovascular preventive properties. However, the mechanisms underlying for cardiovascular protection of C. sativus are still unidentified. Therefore, this study utilized a metabolomics approach to investigate putative mechanisms of C. sativus seeds in myocardial infarction (MI) and in vitro models of vasoconstriction, atrium, and invasive blood pressure measurement. Results showed that Cu.EtOH extract showed a vasorelaxant response with potent hypotensive effect in normotensive rats and L-NAME induced hypertension. Cu.EtOH caused a negative inotropic and positive chronotropic effect on the atrium. Cu.EtOH protected the animals from ISO-induced myocardial infarction (MI) interventions in left ventricular thickness, cardiomyocyte hypertrophy, mRNA gene expression, and biochemical assays. The metabolomics data suggested that Cu.EtOH mainly affected amino acid metabolism, BCAA degradation, ketone bodies degradation, and oxidative stress. Our study showed that Cu.EtOH suppressed inflammation with a strong anti-myocardial infarction impact. Additionally, our findings indicated Cu.EtOH reverted the amino acid metabolism, BCAA, and ketone bodies degradation. The findings show the antihypertensive mechanism of Cu.EtOH may include the modulation of endothelium-derived relaxing factor (EDRF) produced from nitric oxide (NO) and is connected with vascular endothelial function. C. sativus seeds, in particular, played a pivotal role in the treatment of myocardial and vascular disorders by enhancing the EDRF mechanism, energy generation, and antioxidant capacity. In summary, our findings showed the mechanistic insights on the therapeutic potential of C. sativus seeds for cardiovascular disorders.