Exploring the binding affinity and non-covalent interactions of anthocyanins with aging-related enzymes through molecular docking

Background and Objective@#Anthocyanins are associated with aging and longevity. However, the mechanism involving the pure anthocyanin compounds in aging remains elusive. To investigate the possible mechanism of action of the different anthocyanin compounds towards aging-associated enzymes, the lead-likeness, binding affinity, and binding interactions were evaluated.@*Methodology@#The different anthocyanin compounds such as cyanidin, delphinidin, malvidin, pelargonidin, peonidin, and petunidin were assessed for lead-likeness following the criteria of Lipinski's rule of five (Ro5). These same compounds were virtually docked to different aging-related enzymes involved in MAPK, AMPK, and insulin signaling pathways. The top binding anthocyanins for each enzyme were visualized and compared to the enzyme inhibitors. @*Results@#The different anthocyanin compounds abide with Ro5 denoting its potential as a lead compound. For each enzyme, there were different top-binding anthocyanins. The crystal structures of the docked anthocyanins reveal that there were different substructures involved during the non-covalent interaction. Some substructures, particularly the hydroxy groups, have different roles during the H-bond formation. These findings suggest that the various anthocyanin compounds may have a distinct mechanism of action towards a specific enzyme. @*Conclusion@#Taken together, these results suggest that the anthocyanin compounds may have varying effects in aging enzymes, which may be due to the differences in their substructures. Nonetheless, further investigations are needed to understand these findings using cells and animal models.

Solanum melongena (Eggplant) Crude Anthocyanin Extract and Delphinidin-3- glucoside protects Caenorhabditis elegans against Staphylococcus aureus and Klebsiella pneumoniae

Background and Objectives@#During infection, Reactive oxygen species (ROS) signaling is activated to protect the cells from invading microorganisms. However, a high level of ROS may also damage the host tissue. The anthocyanin delphinidin is known to have a strong antioxidant activity that protects cells from oxidative damage. This study explored the potential of crude anthocyanin extract from the fruit of Solanum melongena (Eggplant) and Delphinidin-3-glucoside in enhancing the innate immunity in Caenorhabditis elegans against Staphylococcus aureus and Klebsiella pneumoniae.@*Methodology@#Caenorhabditis elegans was used to study innate immune response because it lacks adaptive immunity. First, the sublethal concentration of S. melongena crude anthocyanin extract (SMCAE) and Delphinidin-3-glucoside (D3G) in C. elegans was determined. The sublethal concentration of SMCAE and D3G was used to supplement the nematodes during its exposure to S. aureus and K. pneumoniae. The survival rate was then observed until day five post-L4. SMCAE and D3G were also tested for probable antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae. @*Results and Conclusion@#This study found that both SMCAE and D3G showed no inhibitory effect on the growth of the bacteria. However, both SMCAE and D3G enhanced the survival of the nematode when exposed to S. aureus and K. pneumoniae. Overall, this study indicates that the anthocyanin delphinidin in S. melongenacrude extract protected the C. elegans against S. aureus and K. pneumoniaeinfection through its antioxidant activity.