Methods: The study was conducted in the Department of Medical Microbiology and Parasitology, University Putra Malaysia in 2014-2017. Saline extract protein from the infective larvae of S. ratti was used to immunize BALB/c mice and subsequent fusion of the B-cells with myeloma cells (SP2/0) using 50% PEG. The hybridomas were cultured in HAT medium and cloned by limiting dilutions. Positive hybrids were screened by indirect ELISA. The ascites fluid from the antibody-secreting hybridoma was purified and the MAb was characterized by western-blots and evaluated in sandwich ELISA for reactivity against the homologous and heterologous antigens.
Results: An IgG1 that recognizes a 30 and 34 kDa protein bands was obtained. The MAb was recognized by all S. ratti-related antigens and cross-reacted with only Toxocara canis antigens in both assays. The minimum antigen detection limit was found to be 5 ng/ml. All antibody-positive rat and dog sera evaluated have shown antigen-positive reactions in Sandwich-ELISA.
Conclusion: The MAb produced, was able to detect antigens in strongyloidiasis and toxocariasis in animal models and may also be useful for the serological detection of active strongyloidiasis and visceral toxocariasis in human sera.
AIM OF THE STUDY: Our study focuses on previously unreported anti-depressant activity of E. variegata bark ethanolic extract (EBE) and determination of its mechanism of action possibly through regulation of monoamine oxidase activity in mouse brain homogenates.
MATERIALS AND METHODS: EBE was characterized using standard protocols for phytochemical analysis, followed by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) analysis. Anti-depressant activity of EBE (50, 100, 200 and 500 mg/kg) was evaluated in Swiss white albino mice using acute and chronic forced swim test (FST) models. Furthermore, the potential use of the extract as an adjunct to selective serotonin reuptake inhibitor (SSRI), escitalopram, was evaluated using the chronic unpredictable mild stress test model wherein inhibitory effects on monoamine oxidase (MAO) A and B were assessed by spectrophotometric-chemical analysis in mouse whole brain homogenates.
RESULTS: The extract showed significant reduction in immobility time periods in both acute (200 mg/kg) and chronic (100, 200 and 500 mg/kg) FST models. When used as an adjunct with escitalopram (15 mg/kg), the extract (100, 200 and 500 mg/kg) showed significantly greater inhibition of MAO-A and B activities when compared to escitalopram alone (30 mg/kg). Phytochemical analysis of EBE revealed presence of sugars, steroids, glycosides, alkaloids and tannins. LC-MS and GC-MS analysis identified components such as 2-amino-3-methyl-1-butanol, phenylethylamine, eriodictyol, daidzein and pomiferin, N-ethyl arachidonoyl amine, inosine diphosphate, trimipramine, granisetron, 3,4-dihydroxymandelic acid, ethyl ester, tri-TMS and dodecane, previously reported for their anti-depressant activity.
CONCLUSIONS: The study thus demonstrated potential for use of the E. variegata bark ethanolic extract as an adjunct to currently available SSRI treatment. The study also identified components present in E. variegata bark ethanolic extract that may be responsible for its anti-depressant activity. Furthermore, the study thus confirms the traditional use of E. variegata barks in improving CNS function through its anti-depressant like activity.