Mechanistic Insights into the Inhibitory Activities of Chemical Constituents from the Fruits of Terminalia boivinii on α-Glucosidase.

Regulation of key digestive enzymes is currently considered an effective remedy for diabetes mellitus. In this study, bioactive constituents were purified from Terminalia boivinii fruits and identified by 1 H-NMR, 13 C-NMR and EI-MS. In vitro and in silico methods were used to evaluate α-glucosidase, α-amylase, and lipase inhibition activities. Compounds 1, 2, and 4-7 with IC50 values between 89 and 445 µM showed stronger α-glucosidase inhibitory activities than the antihyperglycemic drug acarbose (IC50 =1463.0±29.5 µM). However, the compounds showed lower inhibitory effects against α-amylase and lipase with IC50 values above 500 µM than acarbose (IC50 =16.7±3.5 µM) and ursolic acid (IC50 =89.5±5.6 µM), respectively. Lineweaver-Burk plots showed that compounds 1, 2, and 7 were non-competitive inhibitors, compounds 4 and 5 were competitive inhibitors and compound 6 was a mixed-type inhibitor. Fluorescence spectroscopic data showed that the compounds altered the microenvironment and conformation of α-glucosidase. Computer simulations indicated that the compounds and enzyme interacted primarily through hydrogen bonding. The findings indicated that the compounds were inhibitors of α-glucosidase and provided significant structural basis for understanding the binding activity of the compounds with α-glucosidase.

Tea Seed Kaempferol Triglycoside Attenuates LPS-Induced Systemic Inflammation and Ameliorates Cognitive Impairments in a Mouse Model.

(1) Background: The current research intended to obtain functional compounds from agricultural by-products. A functional tea seed flavonoid, kaempferol-3-O-[2-O-ß-d-xylopyranosyl-6-O-α-L-rhanmopyranosyl]-ß-d-glucopyranoside (KXRG), was isolated from tea seed dregs. We further determined its chemical structure and evaluated the protective effects of KXRG against local and systemic inflammation in vivo; (2) Methods: First, cytotoxicity and proinflammatory cytokine release were examined in a cell-culture system. The biological activities of KXRG were investigated in a mouse model of ear edema, and from inflammatory damage to organs as demonstrated by histologic examination, in addition to brain function evaluation using the Y-maze test. Serum biochemical analysis and western blotting were utilized to explore the related cellular factors; (3) Results: KXRG inhibited IL-6 in RAW264.7 cells at a non-toxic concentration. Further experiments confirmed that KXRG exerted a stronger effect than indomethacin in terms of the prevention of 12-O-tetradecanoylphorbol acetate (TPA)-induced ear inflammation in a mouse model. KXRG feeding significantly prevented LPS-induced small intestine, liver, and kidney inflammatory damage, as demonstrated by histologic examination. KXRG also significantly improved LPS-induced cognitive impairments. Serum biochemical analysis showed that KXRG elevated antioxidant capacity and reduced levels of proinflammatory cytokines. Western blotting revealed that KXRG reduced the COX-2 expression induced by LPS in mouse tissues; (4) Conclusions: KXRG can be purified from agricultural waste, and hence it is inexpensive, with large amounts of raw materials available. Thus, KXRG has strong potential for further development as a wide-use anti-systemic inflammation drug to prevent human disease.

Extraction Procedure, Characteristics, and Feasibility of Caulerpa microphysa (Chlorophyta) Polysaccharide Extract as a Cosmetic Ingredient.

The green alga Caulerpa microphysa, which is native to Taiwan, has a relatively high economic value and a well-developed culture technique, and is used mainly as a foodstuff. Its extract has been shown to exhibit antitumor properties, but the polysaccharide content of the extract and its anti-inflammatory and wound-healing effects and moisture-absorption and -retention capacity remain unknown. Hence, the objective of this study was to evaluate the potential of the polysaccharides in C. microphysa extract (CME) for use in cosmetics. The overall polysaccharide yield from the CME was 73.93% w/w, with four molecular weight fractions. The polysaccharides comprised 59.36 mol% mannose, 27.16 mol% glucose, and 13.48 mol% galactose. In addition, the CME exhibited strong antiallergic, wound-healing, transdermal-delivery, and moisture-absorption and -retention effects. In conclusion, the results suggested that CME potentially has anti-inflammatory and wound-healing effects and a good moisture capacity, which can be used in cosmetic applications.

Apoptosis Induction by Pseudorabies Virus via Oxidative Stress and Subsequent DNA Damage Signaling.

BACKGROUND: Pseudorabies virus (PRV) infection induces apoptosis in swine cells both in vitro and in vivo; however, the mechanism associated with host-cell signaling has not been studied. This study investigated the role of free radicals caused by cellular oxidative stress after viral infection and examined whether the DNA damage response plays an important role in PRV-induced apoptosis. METHODS: Several apoptosis assays and western blotting confirmed PRV-induced apoptosis. PRV-mediated oxidative stress was evaluated by reactive oxygen species (ROS) assay. RESULTS: Our results showed that PRV caused apoptosis in a porcine kidney cell line, PK15, and induced expressions of proapoptotic Bcl family proteins in a dose- and time-dependent manner. Expressions of specific DNA damage sensors and phosphorylation of histone H2AX were also significantly increased, which subsequently activated the expressions of checkpoint kinase 1/2 and proapoptotic p53. Caffeine, a known DNA damage inhibitor, was found to inhibit caspase-3 activation and protect cells from PRV-induced apoptosis. Additionally, the antioxidant N-acetyl-L-cysteine was shown to prevent the production of cellular ROS, protecting DNA from cleavage. CONCLUSIONS: Our results confirmed that oxidative stress and free radicals arising from PRV infection cause DNA damage, which consequently triggers apoptosis.

Avian reovirus S1133-induced apoptosis is associated with Bip/GRP79-mediated Bim translocation to the endoplasmic reticulum.

In this study the mechanism of avian reovirus (ARV) S1133-induced pathogenesis was investigated, with a focus on the contribution of ER stress to apoptosis. Our results showed that upregulation of the ER stress response protein, as well as caspase-3 activation, occurred in ARV S1133-infected cultured cells and in SPF White Leghorn chicks organs. Upon infection, Bim was translocated specifically to the ER, but not mitochondria, in the middle to late infectious stages. In addition, ARV S1133 induced JNK phosphorylation and promoted JNK-Bim complex formation, which correlated with the Bim translocation and apoptosis induction that was observed at the same time point. Knockdown of BiP/GRP78 by siRNA and inhibition of BiP/GRP78 using EGCG both abolished the formation of the JNK-Bim complex, caspase-3 activation, and subsequent apoptosis induction by ARV S1133 efficiently. These results suggest that BiP/GRP78 played critical roles and works upstream of JNK-Bim in response to the ARV S1133-mediated apoptosis process.

RhoA/ROCK1 regulates Avian Reovirus S1133-induced switch from autophagy to apoptosis.

BACKGROUND: Autophagy is an essential process in the control of cellular homeostasis. It enables cells under certain stress conditions to survive by removing toxic cellular components, and may protect cells from apoptosis. In the present study, the signaling pathways involved in ARV S1133 regulated switch from autophagy to apoptosis were investigated. RESULTS: ARV S1133 infection caused autophagy in the early to middle infectious stages in Vero and DF1 cells, and apoptosis in the middle to late stages. Conversion of the autophagy marker LC3-I to LC3-II occurred earlier than cleavage of the apoptotic marker caspase-3. ARV S1133 also activated the Beclin-1 promoter in the early to middle stages of infection. Levels of RhoA-GTP and ROCK1 activity were elevated upon ARV S1133 infection, while inhibition of RhoA and ROCK1 reduced autophagy and subsequent apoptosis. Conversely, inhibition of caspase-3 did not affect the level of autophagy. Beclin-1 knockdown and treatment with autophagy inhibitors, 3-MA and Bafilomycin A1, suppressed ARV S1133-induced autophagy and apoptosis simultaneously, suggesting the shift from autophagy to apoptosis. A co-immunoprecipitation assay demonstrated that the formation of a RhoA, ROCK1 and Beclin-1 complex coincided with the induction of autophagy. CONCLUSION: Our results demonstrate that RhoA/ROCK1 signaling play critical roles in the transition of cell activity from autophagy to apoptosis in ARV S1133-infected cells.

Antibacterial and antibiofilm effects of Camellia oleifera seed dreg extract and its application in cosmetics.

BACKGROUND: Cosmetic care products contain a high proportion of water and nutrients. Therefore, preventing bacterial growth is an important issue to ensure product quality and safety. The application of antibacterial natural ingredients derived from plants is considered to have the potential to maintain product quality and reduce the use of chemicals in formulations. Additionally, chemically synthesized antiseptic and antibacterial agents are widely used in the industry at present. However, some preservative ingredients have been reported that may cause skin irritation, redness, allergies, and even dermatitis. AIMS: This study aimed to prepare extract from Camellia oleifera tea seed dregs (CTSD), investigate the antibacterial effects on two pathogenic bacteria and evaluate the product preservative ability. METHODS: Ethanol extraction was prepared and subjected to characterize their triterpenoid contents. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum biofilm eradication concentration (MBEC) were determined for Pseudomonas aeruginosa and Staphylococcus aureus. The product's stability and preservative qualities, along with its ability to scavenge free radicals through antioxidant activity, were also assessed. RESULTS: The gram-positive S. aureus showed greater susceptibility to the treatment. In additional, CTSD possessed significant free radical scavenging activity in vitro and cultured normal human skin fibroblast CCD-966SK cells under nontoxic concentration. The challenge test and accelerated storage test confirmed the CTSD containing formulated emulsion is eligible for commercialization. CONCLUSIONS: CTSD has the potential to be developed as an alternative agent to control microbial biofilm formation, or can be used as an adjuvant compound for infectious disease control.

Positive Echocardiographic Association between Carotid Artery and Coronary Artery Diameter and Z-Score in a Mouse Model of Kawasaki Disease.

Kawasaki disease (KD) occurs in young children, has an unknown etiology, and can cause such life-threatening complications as coronary artery aneurysm. A mouse model using Lactobacillus casei cell wall extract (LCWE) with intraperitoneal injection was established for KD years ago. Histological examination of coronary artery lesions indicated features similar to those of vascular lesions of patients with KD. Since animals must be sacrificed during histological examination, the longitudinal survey of coronary artery lesions (CALs) is difficult. The aim of this study was to survey the vasculitis status of the coronary artery and the carotid artery in a KD mouse model. METHOD: LCWE was intraperitoneally injected into 5-week-old male C57BL/6 mice to induce CALs. We studied the longitudinal status of the carotid and coronary arteries and analyzed the Z-score of coronary artery diameter. RESULTS: Carotid artery wall thickness (day 7) and diameter (day 14) significantly increased in the LCWE group with a dose-dependent effect (p < 0.05). Aortic diameter and wall thickness demonstrated significant increases on day 28 and day 7, respectively (p < 0.05). Carotid artery outer diameter and wall thickness were positively associated with coronary artery diameter on day 28 (p < 0.01). Coronary artery diameter significantly increased in the LCWE group after day 7 (p < 0.05). The percentage of Z > 3.0 indicated was more than 80% in the high-dose LCWE group and 0% in the control group. CONCLUSIONS: This report is the first to use coronary artery Z-score in a mouse model of KD by echocardiography and to find a positive association between carotid artery and coronary artery diameter.

Suppression of AMF/PGI-mediated tumorigenic activities by ursolic acid in cultured hepatoma cells and in a mouse model.

Our previous studies demonstrated that autocrine motility factor/phosphoglucose isomerase (AMF/PGI) possesses tumorigenic activities through the modulation of intracellular signaling. We then investigated the effects of ursolic acid (UA), oleanolic acid (OA), tangeretin, and nobiletin against AMF/PGI-mediated oncogenesis in cultured stable Huh7 and Hep3B cells expressing wild-type or mutated AMF/PGI and in a mouse model in this study. The working concentrations of the tested compounds were lower than their IC10 , which was determined by Brdu incorporation and colony formation assay. Only UA efficiently suppressed the AMF/PGI-induced Huh7 cell migration and MMP-3 secretion. Additionally, UA inhibited the AMF/PGI-mediated protection against TGF-ß-induced apoptosis in Hep3B cells, whereas OA, tangeretin, and nobiletin had no effect. In Huh7 cells and tumor tissues, UA disrupted the Src/RhoA/PI 3-kinase signaling and complex formation induced by AMF/PGI. In the Hep3B system, UA dramatically suppressed AMF/PGI-induced anti-apoptotic signaling transmission, including Akt, p85, Bad, and Stat3 phosphorylation. AMF/PGI enhances tumor growth, angiogenesis, and pulmonary metastasis in mice, which is correlated with its enzymatic activity, and critically, UA intraperitoneal injection reduces the tumorigenesis in vivo, enhances apoptosis in tumor tissues and also prolongs mouse survival. Combination of sub-optimal dose of UA and cisplatin, a synergistic tumor cell-killing effects was found. Thus, UA modulates intracellular signaling and might serve as a functional natural compound for preventing or alleviating hepatocellular carcinoma.

Lactobacillus delbrueckii subsp. bulgaricus strain TCI904 reduces body weight gain, modulates immune response, improves metabolism and anxiety in high fat diet-induced obese mice.

The multiple probiotic characteristics of strain TCI904 isolated in this study from natural fermented milk were investigated using a mouse model. TCI904 was identified as Lactobacillus delbrueckii subsp. bulgaricu (LDB), a well-known lactic acid starter bacterium found in yogurt. TCI904 exhibited an outstanding pancreatic lipase inhibition activity among several strains of lactic acid bacteria in vitro. Its in vivo effects were further studied. In a comparison of mice fed a high-fat diet (HFD) and those fed a HFD combined with TCI904 for 9 weeks, differences were observed in various aspects of health, and the adverse effects of a HFD were prevented in the latter group. TCI904 effectively prevented fat and body weight accumulation without reducing food intake; it also modulated innate immunity and increased the level of IgA in feces, reversing the increased blood sugar and insulin levels and attenuated the hyperlipidemia caused by a HFD. Based on biochemical test data, compared with the HFD group, a HFD combined with TCI904 induced significant lowering of insulin resistance indicator, homeostasis model assessment-insulin resistance (HOMA-IR) and atherogenic indices of plasma (AIP), the atherogenic coefficient (AC) and cardiac risk ratio (CRR) and increased the cardioprotective index (CPI). In addition, the administration of TCI904 alleviated mood disorders caused by a HFD. Taking the recommended human dose of TCI904 did not affect the liver or kidney function, indicating that TCI904 has sufficient in vivo safety. Taken together, the results of the present study contributed towards validation of the probiotic benefits of lactic acid starter microflora. Orally taken TCI904 exhibited positive immune- and metabolic-modulating, and anxiolytic properties, especially in HFD-induced obesity. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03356-3.

Avian reovirus S1133-induced DNA damage signaling and subsequent apoptosis in cultured cells and in chickens.

In this study, intracellular signaling in ARV S1133-mediated apoptosis was investigated. A microarray was used to examine the gene expression profiles of cells upon ARV S1133 infection and ARV-encoded pro-apoptotic protein σC overexpression. The analysis indicated that in the set of DNA-damage-responsive genes, DDIT-3 and GADD45α were both upregulated by viral infection and σC overexpression. Further investigation demonstrated that both treatments caused DNA breaks, which increased the expression and/or phosphorylation of DNA damage response proteins. ROS and lipid peroxidation levels were increased, and ARV S1133 and σC caused apoptosis mediated by DNA damage signaling. ROS scavenger NAC, caffeine and an ATM-specific inhibitor significantly reduced ARV S1133- and σC-induced DNA breaks, DDIT-3 and GADD45α expression, H2AX phosphorylation, and apoptosis. Overexpression of DDIT-3 and GADD45α enhanced the oxidative stress and apoptosis induced by ARV S1133 and σC. In conclusion, our results demonstrate the involvement of the DNA-damage-signaling pathway in ARV S1133- and σC-induced apoptosis.

Chinese Soft-Shelled Turtle Oil in Combination With Swimming Training Improves Spatial Memory and Sports Performance of Aging Rats.

In this study, waste fat from the Chinese soft-shelled turtle (Pelodiscus sinensis) was used as the raw material, and soft-shelled turtle oil (SSTO) was extracted by water heating. Analysis of the fatty acid composition of SSTO revealed that unsaturated fatty acids (UFAs) comprised more than 70% of the oil, of which more than 20% were omega-3 poly-UFAs. DPPH radical scavenging and cellular ROS assays confirmed the reduction of oxidative stress by SSTO. In D-galactose-induced aging rats, SSTO feeding alone or in combination with swimming training resulted in improved memory and physical strength. In addition, SSTO feeding with swimming intervention significantly increased the SOD level and maintained better blood pressure in the aged rats. The serum DHEAS and soleus muscle glycogen level were also highly correlated with SSTO feeding and swimming training. In conclusion, the results of this study demonstrated that SSTO has the potential to be developed into a health food that exerts anti-aging effects, and those effects are stronger when combined with daily swimming exercise.

Upregulated claudin-1 expression confers resistance to cell death of nasopharyngeal carcinoma cells.

Accumulating evidence reveals that aberrant expression of claudins manifests in various tumors; however, their biological functions are poorly understood. Here, we report on the elevated expression of claudin-1 in nasopharyngeal carcinoma (NPC) cell lines under serum deprivation or fluorouracil (5-FU) treatment. Interestingly, an increase in expression of claudin-1 considerably reduced apoptosis rather than enhancing cell proliferation. However, claudin-1 expression and activity were unaffected by external stimuli or Akt and NF-kappaB activation. Notably, predominant cytoplasmic and nuclear localization of claudin-1 in NPC cells reflected the aforementioned feature. On the other hand, loss of epithelial morphology and E-cadherin expression was associated with serum withdrawal in NPC cells. Interestingly, restoration of E-cadherin inhibited the protein elevation and antiapoptotic activity of claudin-1. In conclusion, our data demonstrate the regulation and novel biological function of claudin-1 and indicate the important role of claudin-1 in NPC tumorigenesis.

Rosiglitazone enhances the radiosensitivity of p53-mutant HT-29 human colorectal cancer cells.

Combined-modality treatment has improved the outcome in cases of various solid tumors, and radiosensitizers are used to enhance the radiotherapeutic efficiency. Rosiglitazone, a synthetic ligand of peroxisome proliferator-activated receptors gamma used in the treatment of type-2 diabetes, has been shown to reduce tumor growth and metastasis in human cancer cells, and may have the potential to be used as a radiosensitizer in radiotherapy for human colorectal cancer cells. In this study, rosiglitazone treatment significantly reduced the cell viability of p53-wild type HCT116 cells but not p53-mutant HT-29 cells. Interestingly, rosiglitazone pretreatment enhanced radiosensitivity in p53-mutant HT-29 cells but not HCT116 cells, and prolonged radiation-induced G(2)/M arrest and enhanced radiation-induced cell growth inhibition in HT-29 cells. Pretreatment with rosiglitazone also suppressed radiation-induced H2AX phosphorylation in response to DNA damage and AKT activation for cell survival; on the contrary, rosiglitazone pretreatment enhanced radiation-induced caspase-8, -9, and -3 activation and PARP cleavage in HT-29 cells. In addition, pretreatment with a pan-caspase inhibitor, zVAD-fmk, attenuated the levels of caspase-3 activation and PARP cleavage in radiation-exposed cancer cells in combination with rosiglitazone pretreatment. Our results provide proof for the first time that rosiglitazone suppresses radiation-induced survival signals and DNA damage response, and enhances the radiation-induced apoptosis signaling cascade. These findings can assist in the development of rosiglitazone as a novel radiosensitizer.

Cucurbitane triterpenoids from Momordica charantia and their cytoprotective activity in tert-butyl hydroperoxide-induced hepatotoxicity of HepG2 cells.

Two novel pentanorcucurbitane triterpenes, 22-hydroxy-23,24,25,26,27-pentanorcucurbit-5-en-3-one (1) and 3,7-dioxo-23,24,25,26,27-pentanorcucurbit-5-en-22-oic acid (2) together with a new trinorcucurbitane triterpene, 25,26,27-trinorcucurbit-5-ene-3,7,23-trione (3) were isolated from the methyl alcohol extract of the stems of Momordica charantia. The structures of the new compounds were elucidated by spectroscopic methods. Compounds 2 and 3 showed potent cytoprotective activity in tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity of HepG2 cells.

Octanorcucurbitane triterpenoids protect against tert-butyl hydroperoxide-induced hepatotoxicity from the stems of Momordica charantia.

Four novel octanorcucurbitane triterpenes, octanorcucurbitacins A-D (1-4), together with one known octanorcucurbitane triterpene, kuguacin M (5), were isolated from the methyl alcohol extract of the stems of Momordica charantia. Their structures were elucidated on the basis of extensive spectroscopic analyses. Compound 3 inhibited tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity against HepG2 cells.

Triterpenoids from Angiopteris palmiformis.

Two new fernane triterpenoids, 7alpha-hydroxyfern-8-en-11-one (1) and 11beta-hydroxyfern-8-en-7-one (2), and two new filicane triterpenoids, 3beta-hydroxyfilic-4(23)-ene (3) and filicenol (5), together with one known filicane-type triterpenoid, 3alpha-hydroxyfilic-4(23)-ene (4), were isolated from the methyl alcohol extract of the leaves of Angiopteris palmiformis. Their structures were elucidated on the basis of extensive analyses of their spectroscopic data (NMR, MS, IR) and comparison with spectroscopic data in the literature.

Characterization of Novel Dipeptidyl Peptidase-IV Inhibitory Peptides from Soft-Shelled Turtle Yolk Hydrolysate Using Orthogonal Bioassay-Guided Fractionations Coupled with In Vitro and In Silico Study.

Five novel peptides (LPLF, WLQL, LPSW, VPGLAL, and LVGLPL) bearing dipeptidyl peptidase IV (DPP-IV) inhibitory activities were identified from the gastrointestinal enzymatic hydrolysate of soft-shelled turtle yolk (SSTY) proteins. Peptides were isolated separately using reversed-phase (RP) chromatography in parallel with off-line strong cation exchange (SCX) chromatography followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to determine sequences. Among these peptides, LPSW showed the highest DPP-IV inhibitory activity with an IC50 value of 269.7 ± 15.91 µM. The results of the pre-incubation experiment and the kinetic study of these peptides indicated that WLQL is a true inhibitor and its inhibition toward DPP-IV is of an uncompetitive model, while LPLF, LPSW, and VPGLAL are real-substrates and competitive inhibitors against DPP-IV. The DPP-IV inhibitory peptides derived from SSTY hydrolysate in study are promising in the management of hyperglycemia in Type 2 diabetes.

Potentiation of Differentiation and Apoptosis in a Human Promyelocytic Leukemia Cell Line by Garlic Essential Oil and Its Organosulfur Compounds.

BACKGROUND/AIM: The clinical course of acute leukemia is complicated, and it is often necessary to combine or change treatment methods due to the rapid increase and spread of malignant cells. In this study, the potential anti-leukemia activities of prepared garlic essential oil (GEO) and some organosulfur compounds contained therein were examined. MATERIALS AND METHODS: Garlic essential oil component identification by gas chromatography-mass spectrometry (GC-MS). MTT assay evaluated cytotoxicity of tested samples. Leukemia cell differentiation was determined by NBT assay. Apoptosis and related mechanisms were investigated by western blotting. RESULTS: GC-MS analysis confirmed that the two most abundant constituents, diallyl disulfide (DADS) and diallyl trisulfide (DATriS), constituted 80% of the composition. GEO and DADS exhibited the best effects in terms of significant production of intracellular reactive oxygen species (ROS), induction apoptosis and potentiation differentiation of human promyelocytic leukemia cell line HL-60 cells. The GEO-mediated apoptosis was alleviated by the free radical scavenger N-acetyl-L-cysteine (NAC). CONCLUSION: The anti-leukemia activity of GEO and organosulfur compound DADS through the action of ROS elevation was herein confirmed.

Development of an immunoassay using recombinant outer membrane protein A and flagellin for diagnosis of goats with melioidosis.

Among domestic animals, melioidosis is one of the most common diseases reported in goat, sheep, and swine. To evaluate the specific antibodies in goats with melioidosis, we developed a serology test using recombinant outer membrane protein A (OmpA) and flagellin (FliC) of Burkholderia pseudomallei as antigens. DNA corresponding to each antigen was cloned into a pET32a vector and expressed in Escherichia coli. Essentially, the recombinant OmpA and FliC were expressed in a soluble form that could be isolated with 95% homogeneity. Both recombinants could be recognized by rabbit antibodies prepared against heat-inactivated B. pseudomallei (1:1,000) on a Western blot. Subsequently, we demonstrated that both recombinants could capture the antibodies present in goat with naturally occurring melioidosis (optimized titer 1:40) while not cross-reacting with the serum samples of goats naturally infected by Corynebacterium pseudotuberculosis or Staphylococcus aureus. Finally, an enzyme-linked immunosorbent assay (ELISA) using 20 goat serum samples without melioidosis and 10 goat serum samples with melioidosis demonstrated that the infected group has significantly higher antibody titer levels than the normal group (P<0.001) when using either OmpA or FliC as an antigen. However, the sensitivity (100%) of the assay using OmpA was superior to that (90%) from using FliC. Serological tests that are commonly used often rely on antigens from crude cell extracts, which pose risks for laboratory-acquired infections and inconsistency in their preparation; however, use of recombinant OmpA is safe; it can potentially be used as a reagent in testing for goat melioidosis.