"Combination of Two Promising Methodologies for Possible Treatment Against COVID-19"

SARS-CoV-2 (COVID-19) is one of the infectious agents causing
the disease Severe Acute Respiratory Syndrome...


SARS-CoV-2 (COVID-19) is one of the infectious agents causing
the disease Severe Acute Respiratory Syndrome. SARS-CoV-2 is an RNA virus of which SARS and MERS are also part [1,2]. It is a virus that infects the person when it binds to the receptor for the angiotensinconverting enzyme 2 (ACE2) and thus penetrates its target cell.
This receptor binds to the enzyme. It is involved in a series of effects such as: regulation of arterial hypertension, diabetic nephropathy, and congestive heart failure [3]. This receptor is ubiquitous in many cells (AT2 lung cells, respiratory epithelial cells, myocardial cells, cells of the esophagus and ileum, cells of the proximal tube of the kidney, and urothelial cells of the bladder) [4]. This may be one of the causes of its high spread in the body. For this purpose, the virus uses its Surface Glycoprotein S [3]. The virus could use the ACE2 pathway to enter cells to enhance their infectivity. The immune response against the virus is characterized by a strong activation of the immune system that produces a high production of proinflammatory cytokines called "cytokine storm", which could lead to viral sepsis and inflammation with lung injury characterized by marked leukopenia, failure respiratory, shock, organ failure and the possibility of death [5][6][7]. In this innate immune response, we can see the mannose-binding lectin receptors (MBL) to which some viral antigens bind, which when they carry out their binding, can induce complement activation, increased phagocytosis, as well as activation of the intracellular antiviral machinery of the proteasome.
Although these responses are beneficial in counteracting viral infections, if they override and stimulate uncontrolled responses DOI: 10.26717/BJSTR.2021.35.005761 by the immune system, they can cause septic shock and lead to widespread organ damage and death, a situation that is currently occurring in patients who die from COVID-19 infection [8]. SARS-CoV-2 is an RNA virus, therefore the best technology to attack it inside the cell is when it deposits its genetic material in the cell. The appropriate technique presented is CRISPR-Cas13, which attacks for several centuries and before the revolution in drug synthesis, it was the treatment of choice in various pathologies [12]. The use of several conventional therapies for the COVID-19 coronavirus, such as ACE2 [13] receptor agonists and also hydroxychloroquine, is currently being contemplated with different results depending on the type of patient [14,15].
Although hydroxychloroquine was suspended by the WHO, in this work it was taken as a model to test Hibiscus sabdariffa compounds by molecular docking, as previously appreciated in its mechanism of action and considering the recommendations in Pandey, et al. [16][17][18]. There is a medicinal alternative derived from a plant that has been documented in the past. Hibiscus sabdariffa, tropical plant that receives several generic names Flor de Jamaica, Roselle, among others [19,20]. This plant has been the subject of phytochemical studies that have led to several studies on its medicinal properties [21]. It has been found that they have the ability to act on the AEC2 receptor with agonist properties [20,22].
This study intends to give a suggestion for treatment against the SARS-CoV-2 virus, combining the possibility of mutating the virus's spike protein gene, which serves as a gateway to the cell using the CRISPR-Cas13 method and the agonist response with the AE2 receptor of the medicinal plant Hibiscus sabdariffa.

Methods
This study was based on a systematic review of updated  [23] was taken as a model. With the MEGA program [24] the amino acids of the protein involved in binding to the receptor and its counterpart in the virus genome were identified. The codons for these amino acids were changed by stop codons. For the analysis of the effect of the medicinal plant Hibiscus sabdariffa, the structures obtained from the phytochemical study made by Castañeda R, et al. [21] and the analysis of these structures found by Barral M [25] were taken as a model. These were compared with the structure of Hydroxychloroquine [26], found in the PubChem database, as well as the compounds Mannose [27], Rutin [28], Anthocyanin Flavylium [29], Protocatechuic acid [30] and Acetylsalicylic acid [31]. Starting from the agonist effect on the AE2 receptor found in Herrera-Arellano, A. 2007 [20]. For comparison, a molecular docking was carried out between hydroxychloroquine and rutin with the ACE2 receptor and protocatechuic acid and acetyl salicylic acid with the COX 2 cyclooxygenase protein. The SwissDock online program was used [32].

Results
Based on this, here is proposed the following strategy using   Hibiscus sabdariffa has a series of chemical compounds that have a structural similarity with hydroxychloroquine (Rutin and Anthocyanin) [25]. With high energy binding results with the ACE receptor when the two were compared. Furthermore, it has structures similar to mannose compounds that could bind to MLB receptors also in an agonist way. (Protocatechuic acid) [25]. Although the best binding energy results were presented when the molecules protocatechuic acid and acetylsalicylic acid were compared with the COX 2 receptor, protocatechuic acid was compared in Silico (Molecular Docking) with the receptor Cyclooxygenase 2 (COX2), together with acetylsalysilic acid, obtaining similar binding energies at the binding site, data not shown (Figures 1-6).

Discussion
Since the entry of the virus into the cell is done by the AE2 receptor, then the genome sequence of the virus Spike protein can be changed by the mutated genome with multiple stop codons, in this way the virus could not build its protein and this would prevent it from infecting other cells. The CRISPR-Cas13 technology, unlike the other CRIPSR technologies, is based on the identification of RNA sequences and not DNA [11]. This would take advantage of the fact that this coronavirus is RNA. And since its mechanism is to identify the specific sequence and replace it with another that carries Caspase13, then in this way the fragment that has the AE2 receptor binding sites could be replaced. In this way the virus will be incapacitated to infect other cells. Based on the information of Hibiscus sabdariffa and based on the similarity of the compounds found in the plant and the drug hydroxychloquine [21,25], the hypothesis of the use of this medicinal plant in the control of the inflammatory response against in COVID-19 can be raised, since by affecting the ACE2 receptor, it could cause its blockage, temporarily preventing binding from the virus to the recipient and give the immune system time to generate an adequate humoral and cellular response for its elimination and acquisition of immune memory. As an adjuvant response and by being able to block the MBL receptors, but with greater importance on its action on the COX 2 protein, blocking the main effects of this pathway, anti-inflammatories, anticoagulants and inhibition of the entire cascade of chemical mediators derived from arachidonic acid [33,34].
It could decrease the toxic shock caused by the storm of inflammatory cytokines, similar to the way that hydroxychloroquine does, which is not well known in its response in the body but its increase in immune system and decreased cytokines such as IL-1, IL-6, TNF (inflammatory triad) and increased antiviral INF-g.