Chemical Compositions of Clove (Syzygium aromaticum (L.) Merr. & L.) Extracts and Their Potentials in Suppressing SARS-CoV-2 Spike Protein-ACE2 Binding, Inhibiting ACE2, and Scavenging Free Radicals

Chemical profiles of allspice (Pimenta dioica (L.) Merr.) water and ethanol extracts and their antivirus and radical scavenging activities

Chemical compositions of the allspice water and ethanol extracts were characterized using UPLC-HRMS/MS. A total of 20 compounds were tentatively identified, with 12 reported for the first time in allspice. Both extracts dose-dependently inhibited the binding of SARS-CoV-2 spike protein to ACE2. The water extract showed 100 % inhibition at a concentration of 33.3 mg allspices botanical equivalents per mL (mg AE/mL), whereas the ethanol extract had a 100 % inhibition at 3.3 mg AE/mL. Both extracts also showed dose-dependent inhibition of ACE2 activities, suggesting their potential in reducing the ACE2 availability. In addition, both extracts had significant phenolic contents, and the radical scavenging capacities against HO, DPPH and ABTS+. These findings support the potential allspice utilization in reducing the risk of SARS-CoV-2 virus infection and the development of COVID-19 severe symptoms.

Chemical Composition of Turmeric (Curcuma longa L.) Ethanol Extract and Its Antimicrobial Activities and Free Radical Scavenging Capacities

Turmeric (Curcuma longa L.) is a perennial tuberous plant from the genus Curcuma (Zingiberaceae) and has been widely used in foods for thousands of years. The present study examined the ethanol extract of turmeric for its chemical composition, antimicrobial activity, and free radical scavenging properties. UHPLC-MS/MS analysis tentatively identified eight compounds in the turmeric extract. Potential antimicrobial effects of 0.1, 1.0, and 10 mg turmeric equivalents (TE)/mL were evaluated in vitro against a variety of Gram-negative bacteria (i.e., Escherichia coli, Klebsiella pneumoniae, and Pseudomonas sp.) and Gram-positive bacteria (i.e., Enterococcus faecalis, Listeria innocua, and Staphylococcus aureus). Concentrations of 0.1 and 1.0 mg TE/mL inhibited the growth of S. aureus and significantly suppressed that of Pseudomonas sp., E. faecalis, and L. innocua. The growth of all strains, including E. coli, was inhibited by 10 mg TE/mL. Moreover, free radical scavenging capacities were determined using HO●, ABTS●+, and DPPH● (HOSC, ABTS, and RDSC, respectively) radicals. The turmeric ethanol extract had a TPC value of 27.12 mg GAE/g, together with HOSC, RDSC, and ABTS values of 1524.59, 56.38, and 1.70 μmol TE/g, respectively. Our results suggest that turmeric extract has potential applications for use in functional foods to reduce microbial burdens and oxidative stress-related health problems.

Chemical Compositions of Scutellaria baicalensis Georgi. (Huangqin) Extracts and Their Effects on ACE2 Binding of SARS-CoV-2 Spike Protein, ACE2 Activity, and Free Radicals

The water and ethanol extracts of huangqin, the roots of Scutellaria baicalensis Georgi. with potential antiviral properties and antioxidant activities, were investigated for their chemical profiles and their abilities to interfere with the interaction between SARS-CoV-2 spike protein and ACE2, inhibiting ACE2 activity and scavenging free radicals. A total of 76 compounds were tentatively identified from the extracts. The water extract showed a greater inhibition on the interaction between SARS-CoV-2 spike protein and ACE2, but less inhibition on ACE2 activity than that of the ethanol extract on a per botanical weight concentration basis. The total phenolic content was 65.27 mg gallic acid equivalent (GAE)/g dry botanical and the scavenging capacities against HO●, DPPH●, and ABTS●+ were 1369.39, 334.37, and 533.66 µmol trolox equivalent (TE)/g dry botanical for the water extract, respectively. These values were greater than those of the ethanol extract, with a TPC of 20.34 mg GAE/g, and 217.17, 10.93, and 50.21 µmol TE/g against HO●, DPPH●, and ABTS●+, respectively. The results suggested the potential use of huangqin as a functional food ingredient in preventing COVID-19.

Chemical Composition of Thyme (Thymus vulgaris) Extracts, Potential Inhibition of SARS-CoV-2 Spike Protein-ACE2 Binding and ACE2 Activity, and Radical Scavenging Capacity

Water and ethanol extracts of dried thyme (Thymus vulgaris) were analyzed for chemical composition, inhibition of the SARS-CoV-2 spike protein-ACE2 interaction, inhibition of ACE2 activity, and free radical scavenging capacity. Thirty-two compounds were identified in water extract (WE) and 27 were identified in ethanol extract (EE) of thyme through HPLC-MS. The WE (33.3 mg/mL) and EE (3.3 mg/mL) of thyme inhibited the spike protein-ACE2 interaction by 82.6 and 86.4%, respectively. The thyme WE at 5 mg/mL inhibited ACE2 activity by 99%, and the EE at 5 mg/mL inhibited ACE2 by 65.8%. Total phenolics were determined to be 38.9 and 8.8 mg of GAE/g in WE and EE, respectively. The HO• scavenging capacities were 1121.1 and 284.4 μmol of TE/g in WE and EE, respectively. The relative DPPH• scavenging capacities were 126.3 μmol TE/g in WE and 28.2 μmol TE/g in EE. The ABTS•+ scavenging capacities were 267.1 μmol TE/g in WE and 96.7 μmol TE/g in EE. The results suggested that the thyme extract could be potentially used to prevent SARS-CoV-2 infection and mitigate the complications from the infection.

Chemical Composition of Rosemary (Rosmarinus officinalis L.) Extract and Its Inhibitory Effects on SARS-CoV-2 Spike Protein-ACE2 Interaction and ACE2 Activity and Free Radical Scavenging Capacities

This study evaluated the chemical composition of rosemary water extract (RWE) and its influence on mechanisms by which the SARS-CoV-2 virus enters into cells as a potential route for reducing the risk of COVID-19 disease. Compounds in RWE were identified using UHPLC-MS/MS. The inhibitory effect of RWE was then evaluated on binding between the SARS-CoV-2 spike protein (S-protein) and ACE2 and separately on ACE2 activity/availability. Additionally, total phenolic content (TPC) and free radical scavenging capacities of RWE against HO•, ABTS•+, and DPPH• were assessed. Twenty-one compounds were tentatively identified in RWE, of which tuberonic acid hexoside was identified for the first time in rosemary. RWE dose of 33.3 mg of rosemary equivalents (RE)/mL suppressed the interaction between S-protein and ACE2 by 72.9%, while rosmarinic and caffeic acids at 3.3 μmol/mL suppressed the interaction by 36 and 55%, respectively. RWE at 5.0, 2.5, and 0.5 mg of RE/mL inhibited ACE2 activity by 99.5, 94.5, and 68.6%, respectively, while rosmarinic acid at 0.05 and 0.01 μmol/mL reduced ACE2 activity by 31 and 8%, respectively. RWE had a TPC value of 72.5 mg GAE/g. The results provide a mechanistic basis on which rosemary may reduce the risk of SARS-CoV-2 infection and the development of COVID-19.

TCM "medicine and food homology" in the management of post-COVID disorders

Background

The World Health Organization declared that COVID-19 is no longer a public health emergency of global concern on May 5, 2023. Post-COVID disorders are, however, becoming more common. Hence, there lies a growing need to develop safe and effective treatment measures to manage post-COVID disorders. Investigating the use of TCM medicinal foods in the long-term therapy of post-COVID illnesses may be beneficial given contemporary research's emphasis on the development of medicinal foods.

Scope and approach

The use of medicinal foods for the long-term treatment of post-COVID disorders is highlighted in this review. Following a discussion of the history of the TCM "Medicine and Food Homology" theory, the pathophysiological effects of post-COVID disorders will be briefly reviewed. An analysis of TCM medicinal foods and their functions in treating post-COVID disorders will then be provided before offering some insight into potential directions for future research and application.

Key findings and discussion

TCM medicinal foods can manage different aspects of post-COVID disorders. The use of medicinal foods in the long-term management of post-COVID illnesses may be a safe and efficient therapy choice because they are typically milder in nature than chronic drug use. These findings may also be applied in the long-term post-disease treatment of similar respiratory disorders.

Chemical Composition of Honeysuckle (Lonicerae japonicae) Extracts and Their Potential in Inhibiting the SARS-CoV-2 Spike Protein and ACE2 Binding, Suppressing ACE2, and Scavenging Radicals

Honeysuckle (Lonicerae japonicae) has been used in functional tea products. The chemical compositions of the water and ethanol extracts of honeysuckle were examined in the present study, along with their potential in inhibiting SARS-CoV-2 spike protein binding to ACE2, suppressing ACE2 activity, and scavenging reactive free radicals. Thirty-six compounds were tentatively identified from the honeysuckle extracts using HPLC-MS/MS, with ten reported for the first time in honeysuckle. Both honeysuckle extracts inhibited the binding of SARS-CoV-2 spike protein to ACE2, as well as ACE2 activity. The ethanol extract exhibited a 100% inhibition on binding of the SARS-CoV-2 spike protein to ACE2 at 100 mg botanical equivalent/mL, whereas the water extract had a 65% binding inhibition at the same concentration. Furthermore, the water extract exhibited 90% ACE2 activity inhibition, which was stronger than that of the ethanol extract (62% inhibition) at the same botanical weight concentration. In addition, higher total phenolic contents and greater scavenging activities against hydroxyl (HO•), DPPH•, and ABTS•+ radicals were observed in the water extract than the ethanol extract counterpart on a dry botanical weight concentration basis. These findings suggest honeysuckle has the potential to reduce the risk of SARS-CoV-2 infection and the development of severe COVID-19 symptoms.

Bioactive Compositions of Cinnamon (Cinnamomum verum J. Presl) Extracts and Their Capacities in Suppressing SARS-CoV-2 Spike Protein Binding to ACE2, Inhibiting ACE2, and Scavenging Free Radicals

Cinnamon (Cinnamomum verum J. Presl) bark and its extracts are popular ingredients added to food and supplement products. It has various health effects, including potentially reducing the risk of coronavirus disease-2019 (COVID-19). In our study, the bioactives in cinnamon water and ethanol extracts were chemically identified, and their potential in suppressing SARS-CoV-2 spike protein-angiotensin-converting enzyme 2 (ACE2) binding, reducing ACE2 availability, and scavenging free radicals was investigated. Twenty-seven and twenty-three compounds were tentatively identified in cinnamon water and ethanol extracts, respectively. Seven compounds, including saccharumoside C, two emodin-glucuronide isomers, two physcion-glucuronide isomers, and two type-A proanthocyanidin hexamers, were first reported in cinnamon. Cinnamon water and ethanol extracts suppressed the binding of SARS-CoV-2 spike protein to ACE2 and inhibited ACE2 activity in a dose-dependent manner. Cinnamon ethanol extract had total phenolic content of 36.67 mg gallic acid equivalents (GAE)/g and free radical scavenging activities against HO• and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS•+) of 1688.85 and 882.88 μmol Trolox equivalents (TE)/g, which were significantly higher than those of the water extract at 24.12 mg GAE/g and 583.12 and 210.36 μmol TE/g. The free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) of cinnamon ethanol extract was lower than that of the water extract. The present study provides new evidence that cinnamon reduces the risk of SARS-CoV-2 infection and COVID-19 development.