Saponins: Research Progress and Their Potential Role in the Post-COVID-19 Pandemic Era

Abstract

In the post-COVID-19 pandemic era, the new global situation and the limited therapeutic management of the disease make it necessary to take urgent measures in more effective therapies and drug development in order to counteract the negative global impacts caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new infectious variants. In this context, plant-derived saponins—glycoside-type compounds constituted from a triterpene or steroidal aglycone and one or more sugar residues—may offer fewer side effects and promising beneficial pharmacological activities. This can then be used for the development of potential therapeutic agents against COVID-19, either as a therapy or as a complement to conventional pharmacological strategies for the treatment of the disease and its prevention. The main objective of this review was to examine the primary and current evidence in regard to the therapeutic potential of plant-derived saponins against the COVID-19 disease. Further, the aim was to also focus on those studies that highlight the potential use of saponins as a treatment against SARS-CoV-2. Saponins are antiviral agents that inhibit different pharmacological targets of the virus, as well as exhibit anti-inflammatory and antithrombotic activity in relieving symptoms and clinical complications related to the disease. In addition, saponins also possess immunostimulatory effects, which improve the efficacy and safety of vaccines for prolonging immunogenicity against SARS-CoV-2 and its infectious variants.

Triterpenoidal Saponins from the Leaves of Aster koraiensis Offer Inhibitory Activities against SARS-CoV-2

“…Since the antiviral effects of saikosaponins A, B 2 , C, and D have been reported as inhibitors of viral penetration into MRC-5 cells for human coronavirus (HCoV-229E), there has been significant research focusing on oleanane-type saponins and their role in blocking coronavirus membrane fusion [ 28 ]. Consistent with previous findings, our study indicates that oligosaccharides with four or more sugars are likely to bind to the C28 of triterpenoidal saponins, thereby obstructing the entry of pSARS-CoV-2 into host cells [ 12 , 27 , 29 , 30 ]. Next, we chose astersaponin J ( 1 ) to conduct a more detailed investigation, because this compound is a newly reported saponin and the most potent (except for astersaponin I, 4 ) in this study.…”

Immunostimulant Activity of Hantap (Sterculia Coccinea Jack) Leaves Extract on Non-Specific and Spesific Immune Responses

“…Steroids can act as an immunostimulator that stimulates the immune system by increasing its defense against bacterial attacks by inducing the multiplication of white blood cells. Steroids activate cellular defense cells by increasing cells that act as immune macrophages, granulocytes, and T and B lymphocytes [34][35][36]. The results of the research show that Hantap leaf extract has the potential to be developed into a powerful immunomodulator for modulating the immune response.…”

Critical review on anti‐inflammation effects of saponins and their molecular mechanisms

“…Saponins are a diverse group of natural compounds found in various plant species, and they have been studied for their potential health benefits, including anti‐inflammatory effects. TLR4 is a key component of the innate immune system and plays a crucial role in recognizing pathogen‐associated molecular patterns (PAMPs) and initiating inflammatory responses (Mieres‐Castro & Mora‐Poblete, 2023). Excessive TLR4 signaling can contribute to chronic inflammation, making it a target of interest for anti‐inflammatory interventions.…”