Structure-based epitope prediction and assessment of cross-reactivity of Myrmecia pilosula venom-specific IgE and recombinant Sol g proteins (Solenopsis geminata).

The global distribution of tropical fire ants (Solenopsis geminata) raises concerns about anaphylaxis and serious medical issues in numerous countries. This investigation focused on the cross-reactivity of allergen-specific IgE antibodies between S. geminata and Myrmecia pilosula (Jack Jumper ant) venom proteins due to the potential emergence of cross-reactive allergies in the future. Antibody epitope analysis unveiled one predominant conformational epitope on Sol g 1.1 (PI score of 0.989), followed by Sol g 2.2, Sol g 4.1, and Sol g 3.1. Additionally, Pilosulin 1 showed high allergenic potential (PI score of 0.94), with Pilosulin 5a (PI score of 0.797) leading in B-cell epitopes. The sequence analysis indicated that Sol g 2.2 and Sol g 4.1 pose a high risk of cross-reactivity with Pilosulins 4.1a and 5a. Furthermore, the cross-reactivity of recombinant Sol g proteins with M. pilosula-specific IgE antibodies from 41 patients revealed high cross-reactivity for r-Sol g 3.1 (58.53%) and r-Sol g 4.1 (43.90%), followed by r-Sol g 2.2 (26.82%), and r-Sol g 1.1 (9.75%). Therefore, this study demonstrates cross-reactivity (85.36%) between S. geminata and M. pilosula, highlighting the allergenic risk. Understanding these reactions is vital for the prevention of severe allergic reactions, especially in individuals with pre-existing Jumper Jack ant allergy, informing future management strategies.

Characterization and Localization of Sol g 2.1 Protein from Solenopsis geminata Fire Ant Venom in the Central Nervous System of Injected Crickets (Acheta domestica).

Solenopsis geminata is recognized for containing the allergenic proteins Sol g 1, 2, 3, and 4 in its venom. Remarkably, Sol g 2.1 exhibits hydrophobic binding and has a high sequence identity (83.05%) with Sol i 2 from S. invicta. Notably, Sol g 2.1 acts as a mediator, causing paralysis in crickets. Given its structural resemblance and biological function, Sol g 2.1 may play a key role in transporting hydrophobic potent compounds, which induce paralysis by releasing the compounds through the insect's nervous system. To investigate this further, we constructed and characterized the recombinant Sol g 2.1 protein (rSol g 2.1), identified with LC-MS/MS. Circular dichroism spectroscopy was performed to reveal the structural features of the rSol g 2.1 protein. Furthermore, after treating crickets with S. geminata venom, immunofluorescence and immunoblotting results revealed that the Sol g 2.1 protein primarily localizes to the neuronal cell membrane of the brain and thoracic ganglia, with distribution areas related to octopaminergic neuron cell patterns. Based on protein-protein interaction predictions, we found that the Sol g 2.1 protein can interact with octopamine receptors (OctRs) in neuronal cell membranes, potentially mediating Sol g 2.1's localization within cricket central nervous systems. Here, we suggest that Sol g 2.1 may enhance paralysis in crickets by acting as carriers of active molecules and releasing them onto target cells through pH gradients. Future research should explore the binding properties of Sol g 2.1 with ligands, considering its potential as a transporter for active molecules targeting pest nervous systems, offering innovative pest control prospects.

Comparative Evaluation of Antioxidant and Anti-Inflammatory Activity of Active Compounds Identified in Ardisia elliptica Extracts from Different Plant Parts.

Ardisia elliptica Thunb. (AE) has been used as food and in traditional medicine to prevent and treat fever, diarrhea, chest pain, liver poisoning, and parturition complications in Southeast Asian countries. This study focused on phytochemical constituents of AE extracts and their antioxidant and anti-inflammatory activity in vitro by evaluating nitric oxide production, and DPPH and FRAP radical scavenging activity. The bioactive compounds from different plant parts, including old leaves, young leaves, flowers, roots, and fruits, were identified. The results showed the highest phenolic and flavonoid content in the root extract among all extracts, which resulted in the most potent free radical scavenging activity revealed by the DPPH and FRAP assay. The roots and flowers showed the highest bergenin (3.36±0.22 mg/g dry weight) and quercetin (2.99±0.10 mg/g dry weight) content, respectively. In contrast, embelin was found only in the fruits. Interestingly, AE extracts significantly suppressed the mRNA expression of inducible nitric oxide synthase, leading to inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages. Conclusively, the results suggest the natural products of AE extracts as effective antioxidant and anti-inflammatory agents that can be utilized for food and pharmaceutical applications.

Constituents of Huberantha jenkinsii and Their Biological Activities.

The phytochemical investigation of Huberantha jenkinsii resulted in the isolation of two new and five known compounds. The new compounds were characterized as undescribed 8-oxoprotoberberine alkaloids and named huberanthines A and B, whereas the known compounds were identified as allantoin, oxylopinine, N-trans-feruloyl tyramine, N-trans-p-coumaroyl tyramine, and mangiferin. The structure determination was accomplished by spectroscopic methods. To evaluate therapeutic potential in diabetes and Parkinson's disease, the isolates were subjected to assays for their α-glucosidase inhibitory activity, cellular glucose uptake stimulatory activity, and protective activity against neurotoxicity induced by 6-hydroxydopamine (6-OHDA). The results suggested that mangiferin was the most promising lead compound, demonstrating significant activity in all the test systems.