Our group previously demonstrated that Caesalpinia mimosoides Lamk exhibits many profound biological properties, including anticancer, antibacterial, and antioxidant activities. However, its antiviral activity has not yet been investigated. Here, the aqueous extract of C. mimosoides was prepared from the aerial parts (leaves, stalks, and trunks) to see whether it exerts anti-influenza (H1N1) effects and to reduce the organic solvents consumed during extraction, making it a desirable approach for the large-scale production for medical uses. Our plant extract was quantified to contain 7 g of gallic acid (GA) per 100 g of a dry sample, as determined using HPLC analysis. It also exerts potent antioxidant activities comparable to those of authentic GA. According to untargeted metabolomics (UPLC-ESI(-)-QTOF-MS/MS) with the aid of cheminformatics tools (MetFrag (version 2.1), SIRIUS (version 5.8.3), CSI:FingerID (version 4.8), and CANOPUS), the major metabolite was best annotated as “gallic acid”, phenolics (e.g., quinic acid, shikimic acid, and protocatechuic acid), sugar derivatives, and dicarboxylic acids were deduced from this plant species for the first time. The aqueous plant extract efficiently inhibited an influenza A (H1N1) virus infection of MDCK cells with an IC₅₀ of 5.14 µg/mL. Of equal importance, hemolytic activity was absent for this plant extract, signifying its applicability as a safe antiviral agent. Molecular docking suggested that GA interacts with conserved residues (e.g., Arg152 and Asp151) located in the catalytic inner shell of the viral neuraminidase (NA), sharing the same pocket as those of anti-neuraminidase drugs, such as laninamivir and oseltamivir. Additionally, other metabolites were also found to potentially interact with the active site and the hydrophobic 430-cavity of the viral surface protein, suggesting a possibly synergistic effect of various phytochemicals. Therefore, the C. mimosoides aqueous extract may be a good candidate for coping with increasing influenza virus resistance to existing antivirals.

The increasing antimicrobial-resistant prevalence has become a severe health problem. It has led to the invention of a new antimicrobial agent such as antimicrobial peptides. Heteroscorpine-1 is an antimicrobial peptide that has the ability to kill many bacterial strains. It consists of 76 amino acid residues with a cecropin-like region in N-terminal and a defensin-like region in the C-terminal. The cecropin-like region from heteroscorpine-1 (CeHS-1) is similar to cecropin B, but it lost its glycine-proline hinge region. The bioinformatics prediction was used to help the designing of mutant peptides. The addition of glycine-proline hinge and positively charged amino acids, the deletion of negatively charged amino acids, and the optimization of the hydrophobicity of the peptide resulted in two mutant peptides, namely, CeHS-1 GP and CeHS-1 GPK. The new mutant peptide showed higher antimicrobial activity than the native peptide without increasing toxicity. The interaction of the peptides with the membrane showed that the peptides were capable of disrupting both the inner and outer bacterial cell membrane. Furthermore, the SEM analysis showed that the peptides created the pore in the bacterial cell membrane resulted in cell membrane disruption. In conclusion, the mutants of CeHS-1 had the potential to develop as novel antimicrobial peptides.

Houttuynia cordata Thunb. holds a longstanding reputation as a traditional folk remedy in East Asia, where it has been employed to treat a variety of inflammatory conditions, nephritis, hepatitis and cancer. Despite its extensive use, there exists a paucity of research examining its efficacy in managing thyroid disorders and diabetes. Moreover, the bioactive components responsible for modulating the molecular pathways remain elusive. Objectives: This research aimed to determine the key bioactive components in the ethanolic extract of H. cordata Thunb. (HCEE) responsible for its thyroid-modifying properties and examine its effects on rats with experimentally induced hypothyroidism and diabetes. Methods: Molecular docking was performed to investigate the possible mechanisms of thyroid regulation of HCEE constituents. Researchers induced hypothyroidism in rats by adding 6-propyl-2-thiouracil to their drinking water for a period of four weeks. To induce diabetes, the rats received an intraperitoneal injection of streptozotocin. The animals were then given daily oral doses of HCEE (500 mg/kg b.w.), levothyroxine (50 mg/kg b.w.), or glibenclamide (5 mg/kg b.w.) for 28 days. Following this treatment, standard methods were employed to measure biochemical parameters in the rats’ serum. Results: The results demonstrate that HCEE ameliorated hypothyroidism by increasing serum T3 (14.38%) and T4 (125.96%) levels and decreasing TSH (p < 0.01; −41.75%) levels. In diabetic rats with induced hypothyroidism, HCEE significantly (p < 0.001) increased T3 (149.51%) and T4 (73.54%) levels with reduced TSH (−64.39%) levels. In silico analysis demonstrated that the identified bioactive compounds from HCEE may enhance thyroid hormone function through interaction with the thyroid hormone receptor protein TRβ1 (PDB:3GWS), similar to the conventional pharmaceuticals levothyroxine and triiodothyronine (T3). Conclusions: HCEE exhibits potential as a natural alternative to synthetic medications in the prevention and treatment of thyroid dysfunctions.

Hyaluronidases have been a subject of great interest in medical and cosmeceutical applications. Previously, our group demonstrated that the venom glands of Vespa tropica contain hyaluronidase enzymes (VesT2s), and heterologous expression of the corresponding gene (VesT2a) in E. coli systems results in inclusion bodies, necessitating functional folding using urea. Here, we report the successful heterologous expression of VesT2a in the Pichia pastoris expression system, with gene construction achieved using GoldenPiCS. After confirming gene integration in the yeast genome, methanol-induced cultures yielded an exceptional amount of VesT2a, approximately two-fold higher than that obtained with the constitutive expression vector (PGAP). Upon culturing in a bioreactor, yeast cells harboring pAOX1-αMF-VesT2a produced secreted proteins with a total yield of 96.45 mg/L. The secreted VesT2a has a molecular weight of 59.35 kDa, significantly higher than the expected molecular weight (~40.05 kDa), presumably due to endogenous glycosylation by the yeast cells. It exhibits optimal activity at 37 °C and pH 3, showing a specific activity of 4238.37 U/mg, and remains active across a broad range of pH and temperature. Notably, it exhibits higher hyaluronidase activity than the crude venom and E. coli-expressed protein, likely due to improved folding via endogenous post-translational modifications, such as disulfide bonds and N-glycosylation; this underscores the potential of heterologous systems for producing venomous hyaluronidases from other species. In silico docking-based analyses further support its catalytic activity and provide insights into seeking natural inhibitors from phenolic-rich plant extracts to alleviate symptoms in patients suffering from insect bites and stings.

Oxidative stress-induced macrophage activation and vascular injury are major contributors to atherosclerosis, a chronic inflammatory disease associated with approximately twenty million deaths worldwide. This study investigated the antioxidant and anti-inflammatory activities of structurally characterized low-molecular-weight chitosan oligosaccharides (COS) derived from mud crab (Scylla olivacea) shell waste by hydrochloric acid hydrolysis and explored their molecular interactions with inflammation-related targets. Structural characterization by ¹³C-NMR and MALDI-TOF confirmed the identity of COS, while DPPH and ABTS analysis demonstrated concentration-dependent antioxidant activity. In LPS-induced RAW 264.7 macrophages, COS showed no cytotoxicity and significantly reduced nitric oxide production at 80 and 160 µg/mL. Molecular docking predicted favorable interactions of COS with several inflammation-associated receptors, including VEGFA, FGF1, and HPSE, showing stronger binding affinity than the reference drug diclofenac, and identified stable interactions with iNOS and COX-2 through extensive hydrogen-bond and polar contact networks. Transcriptomic profiling further revealed broad transcriptional remodeling and enrichment of pathways related to inflammation and atherosclerosis, including TNF, NF-κB, MAPK, Toll-like receptor, and lipid-and-atherosclerosis signaling. COS markedly suppressed inflammatory mediators, particularly Nos2 (iNOS; log₂FC = −7.92) and Ptgs2 (COX-2; log₂FC = −0.84), together with multiple cytokines and chemokines, consistent with reduced nitric oxide production and modulation of macrophage activation and foam cell-associated processes. Integration of docking and transcriptomic analyses identified iNOS and COX-2 as convergent candidate anti-inflammatory targets of COS, supporting its ability to attenuate inflammatory signaling through multi-target regulation rather than single-pathway inhibition. These findings suggest that COS may serve as a promising preventive strategy for atherosclerosis through coordinated regulation of oxidative stress, inflammatory responses, and vascular remodeling.

The hyaluronidase enzyme derived from Vespa tropica (VesT2a) venom contains two putative catalytic residues. Herein, a double mutation was introduced into VesT2a at its catalytic sites by substituting Asp107 and Glu109 with Asn and Gln, respectively, to assess their essential roles in enzymatic function. We used Pichia pastoris to produce the mutated version of the VesT2a (mVesT2a) protein, and the process was more efficient when employing the methanol-inducible promoter (P_AOX1) compared to the constitutive promoter (P_GAP). In bioreactor scale-up, P. pastoris harboring the pAOX1-αMF-mVesT2a plasmid secreted 34.03 ± 2.31 mg/L of mVesT2a, with an apparent molecular mass of 46.6 kDa, retaining only 2.9% of hyaluronidase activity, thus indicating successful mutation. The newly developed indirect ELISA-based method using mVesT2a demonstrated its potential as an alternative approach for measuring hyaluronic acid (HA) at low concentrations and was also used to confirm HA-binding capacity. In silico docking and molecular dynamics simulations further supported the stable interaction of the mVesT2a–HA complex while suggested other surrounded acidic amino acid residues, which may play a minor role in HA degradation, supporting the remaining activity observed in the in vitro experiments.