Search Results (8)

Objectives: Acute temperature stress was explored in Hippocampus abdominalis through a comprehensive RNA-seq analysis. Methods: RNA-seq was conducted on 20-day-old H. abdominalis after 24 h of temperature stress. Four experimental conditions were established: a control group (18 °C) and three temperature treatment groups (21, 24, and 27 °C). Results: Seahorse larvae were found to be unaffected by 21 °C and 24 °C and were able to survive for short periods of time during 24 h of incubation, whereas mortality approached 50% at 27 °C. The sequencing process produced 75.63 Gb of high-quality clean data, with Q20 and Q30 base percentages surpassing 98% and 96%, respectively. A total of 141, 333, and 1598 differentially expressed genes were identified in the 21, 24, and 27 °C groups vs. a control comparison group, respectively. Notably, the number of up-regulated genes was consistently higher than that of down-regulated genes across all comparisons. Gene Ontology functional annotation revealed that differentially expressed genes were predominantly associated with metabolic processes, redox reactions, and biosynthetic functions. In-depth KEGG pathway enrichment analysis demonstrated that down-regulated genes were significantly enriched in pathways related to steroid biosynthesis, terpenoid backbone biosynthesis, spliceosome function, and DNA replication. Up-regulated genes were enriched in pathways associated with the FoxO signaling pathway and mitophagy (animal). The results indicated that temperature stress induced extensive changes in gene expression in H. abdominalis, involving crucial biological processes such as growth, biosynthesis, and energy metabolism. Conclusions: This study provided key molecular mechanisms in the response of H. abdominalis to temperature stress, offering a strong basis for future research aimed at understanding and mitigating the effects of environmental stressors on marine species. Full article

Overexposure to ultraviolet (UV) radiation can lead to photoaging, which contributes to skin damage. The objective of this study was to evaluate the effects of an antioxidant peptide (SHP2) purified from seahorse (Hippocampus abdominalis) alcalase hydrolysate on UVB-irradiated skin damage in human keratinocyte (HaCaT) and human dermal fibroblast (HDF) cells and a zebrafish model. The data revealed that SHP2 significantly enhanced cell viability by attenuating apoptosis through the reduction of intracellular reactive oxygen species (ROS) levels in UVB-stimulated HaCaT cells. Moreover, SHP2 effectively inhibited ROS, improved collagen synthesis, and suppressed the secretion of matrix metalloproteinases (MMPs) in UVB-irradiated HDF cells. SHP2 restored the protein levels of HO-1, Nrf2, and SOD, while decreasing Keap1 expression in UVB-treated HDF, indicating stimulation of the Keap1/Nrf2/HO-1 signaling pathway. Furthermore, an in vivo study conducted in zebrafish confirmed that SHP2 inhibited photoaging by reducing cell death through the suppression of ROS generation and lipid peroxidation. Particularly, 200 µg/mL of SHP2 exerted a remarkable anti-photoaging effect on both in vitro and in vivo models. These results demonstrate that SHP2 possesses antioxidant properties and regulates skin photoaging activities, suggesting that SHP2 may have the potential for use in the development of cosmetic products. Full article

Seahorses are valuable species for their use in traditional Chinese medicine, as well as for the aquarium trade as ornamentals and curiosities. To balance market demand and reduce pressure on wild populations, many countries have undertaken commercial seahorse cultivation. Skeletal development plays a crucial role in fish fry culture, affecting external morphology, feeding, and movement. This study investigated the ontogeny allometry, timing, and progression of skeletal development in H. abdominalis from DAB (day after birth) 1 to DAB 100 under mass-scale captive breeding conditions in north China. The results of this study revealed the growth rate was significantly increased between DAB 30 and DAB 54. Allometry analysis revealed that in the early stage, the head, trunk, and tail demonstrated almost isometric growth. However, in the later stage, the head and trunk exhibited negative isometric growth, whereas the tail displayed positive isometric growth. Skeletal staining results showed that newborn seahorses do not have ossified bones until DAB 11 (SL 28.14 ± 2.94 mm). Ossification was primarily observed in the jaw region and the tubular nasal structure of the cranium, which indicated the importance of the early development of feeding organs. The initial formation of ossified vertebral columns was observed at DAB 13 (SL 26.48 ± 0.63 mm), with the complete ossification of all vertebrae occurring by DAB 45 (SL 54.87 ± 4.70 mm). Furthermore, the cranium, rings, and plates were all fully ossified by DAB 30. Ossification of the fins began at DAB 23 (SL 31.27 ± 4.05 mm). However, neither of them were fully ossified by DAB 100. The pelvic fin and the complete structure of the caudal fin were not observed, possibly because of caudal fin ray structure degeneration within the pouch. In addition, no skeletal deformities were observed in all the tested samples. The results of this study provide valuable information on the developmental biology of H. abdominalis, enriching our understanding of their growth and offering insights for optimizing fish fry breeding technologies. Full article

Ovoviviparity and male pregnancy represent distinctive reproductive strategies in seahorses. However, the detailed process of gonadal development in seahorses, particularly in the pot-bellied seahorse (Hippocampus abdominalis), remains largely unknown. In this study, we investigated the complete gonadal development process of the pot-bellied seahorse under captive breeding conditions (18 ± 1 °C). Immediately after birth, primordial germ cells (PGCs) were found within the genital ridge, enclosed by a single layer of somatic cells. Around 7–9 days after birth (DAB), the ovary begins to differentiate. By 30 DAB, two germinal ridges had formed along the edge of the follicular lamina in the ovary. The primary oocytes, resulting from this differentiation process, gradually migrated from the dorsal sides to the mid-ventral area of the ovary, eventually maturing into eggs. In the testis, the primary and secondary spermatocytes appeared at 15 and 30 DAB, respectively, preceding the formation of the testicular lumen (50 DAB). The testis was observed to consist of a single large germinal compartment. Under captive breeding conditions in Northern China, the pot-bellied seahorse demonstrated year-round breeding capability, with each male producing approximately 100–150 larvae. The findings from this study contribute valuable insights into seahorse aquaculture and enhance understanding of the unique reproductive strategy employed by seahorses. Full article

The aim of this study was to assess the potential hypertensive effects of the IGTGIPGIW peptide purified from Hippocampus abdominalis alcalase hydrolysate (HA) for application in the functional food industry. We investigated the antihypertensive effects of IGTGIPGIW in vitro by assessing nitric oxide production in EA.hy926 endothelial cells, which is a major factor affecting vasorelaxation. The potential vasorelaxation effect was evaluated using 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate, a fluorescent stain. IGTGIPGIW significantly increased the expression of endothelial-derived relaxing factors, including endothelial nitric oxide synthase and protein kinase B, in EA.hy926 cells. Furthermore, oral administration of IGTGIPGIW significantly lowered the systolic blood pressure (183.60 ± 1.34 mmHg) and rapidly recovered the diastolic blood pressure (143.50 ± 5.55 mmHg) in the spontaneously hypertensive rat model in vivo. Our results demonstrate the antihypertensive activity of the IGTGIPGIW peptide purified from H. abdominalis and indicate its suitability for application in the functional food industry. Full article

Oxidative stress-induced endothelial dysfunction is strongly linked to the pathogenesis of cardiovascular diseases. A previous study revealed that seahorse hydrolysates ameliorated oxidative stress-mediated human umbilical vein endothelial cells (HUVECs) injury. However, the responsible compounds have not yet been identified. This study aimed to identify cytoprotective peptides and to investigate the molecular mechanism underlying the cytoprotective role in H₂O₂-induced HUVECs injury. After purification by gel filtration and HPLC, two peptides were sequenced by liquid chromatography-tandem mass spectrometry as HGSH (436.43 Da) and KGPSW (573.65 Da). The synthesized peptides and their combination (1:1 ratio) showed significant HUVECs protection effect at 100 μg/mL against H₂O₂-induced oxidative damage via significantly reducing intracellular reactive oxygen species (ROS). Two peptides and their combination treatment resulted in the increased heme oxygenase-1 (HO-1), a phase II detoxifying enzyme, through the activation of nuclear transcription factor-erythroid 2-related factor (Nrf2). Additionally, cell cycle and nuclear staining analysis revealed that two peptides and their combination significantly protected H₂O₂-induced cell death through antiapoptotic action. Two peptides and their combination treatment led to inhibit the expression of proapoptotic Bax, the release of cytochrome C into the cytosol, the activation of caspase 3 by H₂O₂ treatment in HUVECs, whereas antiapoptotic Bcl-2 expression was increased with concomitant downregulation of Bax/Bcl-2 ratio. Taken together, these results suggest that seahorse-derived peptides may be a promising agent for oxidative stress-related cardiovascular diseases. Full article

In the Compendium of Materia Medica, seahorse (Hippocampus) is considered effective for the reinforcement of kidney and men’s health. However, the role of seahorse on human health lacks scientific evidence. Therefore, we evaluated the effect of seahorse on human prostate cancer using various in vitro methods and identified bioactive compound. Seahorse lipid extract (SHL) decreased androgen receptor (AR) and prostate-specific antigen (PSA) expression in dihydrotestosterone (DHT)-induced LNCaP cells of prostate cancer. Gas Chromatography (GC)-mass spectrometry data showed that brassicasterol was present in H. abdominalis. Brassicasterol downregulated the expression of AR and PSA in DHT-induced LNCaP cells. Brassicasterol induced apoptosis accompanied by sub-G1 phase arrest and inhibited migration in LNCaP cells. We confirmed that AKT and AR mediated the anti-cancer effect of brassicasterol using siRNA transfection. Brassicasterol exerts an anti-cancer effect in AR-independent cancer as well as in AR-dependent cells by AKT inhibiting. Our findings suggest that SHL has the anticancer potential via inhibition of AR and demonstrated that brassicasterol from H. abdominalis exerted an anti-cancer effect by dual-targeting AKT and AR signaling in prostate cancer. Full article

The big belly seahorse (Hippocampus abdominalis), a well-known ingredient of traditional medicine, possesses anti-inflammatory, anti-aging, anti-fatigue, and anti-thrombotic properties, and also increases male fertility. This study demonstrates that the ethanolic extract of dried H. abdominalis (EEHA) has anti-melanogenic effects in B16F10 melanoma cells and zebrafish larvae. EEHA significantly reduced the α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis in B16F10 melanoma cells without causing cytotoxicity. At a concentration of 200 µg/mL, EEHA had significant anti-melanogenic activity in zebrafish larvae, accompanied by a severe reduction in the heart rate (118 ± 17 heartbeats/min) compared to that of the untreated group (185 ± 8 heartbeats/min), indicating that EEHA induces cardiotoxicity at high concentrations. Below 100 µg/mL, EEHA significantly reduced melanogenesis in zebrafish larvae in the presence or absence of α-MSH, while the heart rate remained unaltered. Additionally, EEHA downregulated the release of cyclic adenosine monophosphate (cAMP) and the phosphorylation of cAMP response element-binding protein (CREB) in B16F10 melanoma cells, which inhibited microphthalmia-associated transcription factor (MITF), leading to the inhibition of tyrosinase activity. EEHA also increased the phosphorylation of extracellular-signal regulated kinase (ERK). The ERK inhibitor PD98059 interfered with the anti-melanogenic activity of EEHA in B16F10 melanoma cells and zebrafish larvae, indicating that the ERK signaling pathway might regulate the anti-melanogenic properties of EEHA. Altogether, we conclude that EEHA represses the cAMP–CREB–MITF axis, which consequently inhibits tyrosinase-mediated melanogenesis. We propose that at low concentrations, EEHA can serve as a promising anti-melanogenic agent that could be used to prepare whitening cosmetics and for treating melanogenic disorders. Full article