Antioxidant therapy in COVID-19: The crucial role of early treatment and antioxidant typology

Screening and evaluation of cytotoxicity and antiviral effects of secondary metabolites from water extracts of Bersama abyssinica against SARS-CoV-2 Delta

Background

Bersama abyssinica is a common herb in Africa, with diverse medical uses in different areas. The plant is well-known in Tanzania for treating respiratory disorders such as TB, tonsillitis, bronchitis, and asthma, and it has lately been utilized to treat COVID-19 symptoms. Water extract of leaf and stem bark has been registered as an herbal medication known as 'Coviba Dawa' in Tanzania for the relief of bacterial respiratory infections. The extracts, however, have not been scientifically tested for their anti-viral activities. The aim of this work was to test for the cytotoxicity and antiviral effects of bioactive ingredients from B. abyssinica extracts against the Delta variant of the SARS-CoV-2 coronavirus.

Methods

B. abyssinica leaves and stem bark were dried under shade in room temperature and then pulverized to obtain small pieces before soaking into different solvents. One hundred grams of each, leaves and stem bark, were extracted in petroleum ether, dichloromethane, ethyl acetate and methanol. Water extract was obtained by decoction of stem bark and leaves into water. Phenols, flavonoids, tannins, and antioxidants were confirmed as components of the extracts. Analysis of polar extracts of bark stem bark and leaves was done. Antiviral screening and cytotoxicity experiments were conducted in a Biosafety Level 3 (BSL-3) Laboratory facility according to International Standard Operating Procedures (SOPs).

Results

By the use of LC–MS/MS analysis, this study confirmed the existence of four phenolic compounds in B. abyssinica water extract; 2,4-di-tert-butylphenol, 4-formyl-2-methoxyphenyl propionate, 7,8-Dihydroxy-4-methylcoumarin, and 2,3, 6-trimethoxyflavone with antioxidant activity. This study showed that, while the water extracts of B. abyssinica had significant antiviral activity against SARS Cov2 virus, it showed no cytotoxicity effect on Vero E6 cells. In particular, the water extract (Coviba dawa) showed 75% while ethylacetate fraction of B. abyssinica leaves showed a 50% in vitro viral inhibition, indicating that these substances may be useful for the development of future anti-viral agents.

Conclusion

We therefore recommend isolation of compounds for further profiling and development with a broader concentration range. We further recommend studies that determine the antiviral activity of extracts of B.abyssinica on other viral pathogens of clinical concern.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03754-3.

Therapy of post-COVID-19 syndrome: improving the efficiency and safety of basic metabolic drug treatment with tiazotic acid (thiotriazoline)

COVID-19 leads to disruption of the blood coagulation system, to thrombosis, hypercoagulability, as a result, to an increased risk of strokes and heart attacks. During COVID-19, endothelial dysfunction develops associated with NO deficiency with decrease in the level of SH compounds. Tiazotic acid (Thiotriazoline) has immunomodulatory, anti-inflammatory, antioxidant, anti-ischemic, cardio- and endothelioprotective, antiplatelet, hepatoprotective activity. Our studies conducted at the National Research Medical Center “University Clinic of ZSMU” with the participation of 57 patients (from 30 to 65 years old) with post-COVID syndrome, who received thiotriazol with basic therapy in either tablets (200 mg each) or suppositories Dalmaxin (0.2 g each) twice a day for 30 days. Inclusion criteria for the study were a positive PCR test for COVID-19; if the PCR test was negative, then the presence of IgM COVID-19 or IgG COVID-19 (with radiologically confirmed pneumonia). The following biochemical parameters were studied: C-reactive protein - by immunoturbodimetric method; D-dimer - by enzyme immunoassay; ferritin - by immunochemiluminescent method; endothelial NO-synthase (eNOS) - by ELISA method; alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), total bilirubin; international normalized ratio (INR) and determination of platelet aggregation. During treatment with thiotriazoline, significant increase in the eNOS content was recorded, which indicated the presence of endothelioprotective activity of the drug. Thiotriazoline significantly reduced the level of D-dimer in the blood of patients, and also led to the normalization of INR. The established effects testified to the presence of antiplatelet and fibrinolytic action of thiotriazoline and its ability to reduce the risks of heart attacks and strokes in post-COVID syndrome. Thiotriazoline led to an objective improvement in general clinical parameters in patients with post-COVID syndrome, complaints of palpitations disappeared, blood pressure stabilized.

Neutralizing the free radicals could alleviate the disease severity following an infection by positive strand RNA viruses

Free radical release due to oxidative stress is gaining importance in the field of viral pathogenesis. Recent studies suggest the involvement of oxidative stress and ROS levels in regulating disease virulence during RNA virus infection. Most of the RNA virus infections lead to vascular dysfunction and disease severity. However, the biology of free radicals in maintaining vascular endothelium integrity is not completely understood. In the present review, we discuss some of the common features in positive-strand RNA virus infections such as dengue and SARS-CoV-2 and suggest that anti-oxidant therapy could pave the way to develop therapeutic strategies in combating emerging and re-emerging RNA viruses.

A pilot study on intravenous N-Acetylcysteine treatment in patients with mild-to-moderate COVID19-associated acute respiratory distress syndrome

Background

We designed this single-centre clinical trial to assess the potential benefits of N-Acetylcysteine (NAC) in patients with COVID19-associated acute respiratory distress syndrome (ARDS).

Methods

Ninety-two patients with mild-to-moderate COVID19-associated ARDS were allocated to the placebo (45-cases) or NAC groups (47-cases). Besides standard-of-care treatment, the patients received either intravenous NAC at a dose of 40 mg/kg/day or the placebo for three consecutive days. The efficacy outcomes were overall mortality over 28-day, clinical status on day 28, based on the WHO Master Protocol, the proportion of patients requiring mechanical ventilation, changes in ARDS-severity (based on the PaO₂/FiO₂ ratio), and Sequential Organ Failure Assessment (SOFA) scores 48 and 96 h after intervention,

Results

No differences were found in the 28-day mortality rate between the two groups (25.5% vs. 31.1% in the NAC and placebo groups, respectively). Although the distribution of the clinical status at day 28 shifted towards better outcomes in the NAC-treated group, it did not reach a statistical significance level (p value = 0.83). Similar results were achieved in terms of the proportion of patients who required invasive ventilator support (38.3% vs. 44.4%), the number of ventilator-free days (17.4 vs. 16.6), and median time of ICU and hospital stay. Results regarding the change in PaO₂/FiO₂ ratio and SOFA scores also showed no significant differences between the groups.

Conclusions

Our pilot study did not support the potential benefits of intravenous NAC in treating patients with COVID-19-associated ARDS. More studies are needed to determine which COVID-19 patients benefit from the NAC administration.

Trial registration

The trial was registered at Clinicaltrials.gov (identifier code: IRCT20120215009014N355). Registration date: 2020-05-18.