This review reports details on the natural products isolated from Taiwan soft corals during the period 2008–2012 focusing on their in vitro and/or in vivo anti-inflammatory activities. Chemical structures, names, and literature references are also reported. This review provides useful and specific information on potent anti-inflammatory marine metabolites for future development of immune-modulatory therapeutics.

Three decades ago, the marine-derived compound sinularin was shown to have anti-edematous effects on paw edema induced by carrageenan or adjuvant. To the best of our knowledge, no new studies were conducted to explore the bioactivity of sinularin until we reported the analgesic properties of sinularin based on in vivo experiments. In the present study, we found that sinularin significantly inhibits the upregulation of proinflammatory proteins, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) and upregulates the production of transforming growth factor-β (TGF-β) in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells according to western blot analysis. We found that subcutaneous (s.c.) administration of sinularin (80 mg/kg) 1 h before carrageenan injection significantly inhibited carrageenan-induced nociceptive behaviors, including thermal hyperalgesia, mechanical allodynia, cold allodynia, and hindpaw weight-bearing deficits. Further, s.c. sinularin (80 mg/kg) significantly inhibited carrageenan-induced microglial and astrocyte activation as well as upregulation of iNOS in the dorsal horn of the lumbar spinal cord. Moreover, s.c. sinularin (80 mg/kg) inhibited carrageenan-induced tissue inflammatory responses, redness and edema of the paw, and leukocyte infiltration. The results of immunohistochemical studies indicate that s.c. sinularin (80 mg/kg) could upregulate production of TGF-β1 in carrageenan-induced inflamed paw tissue. The present results demonstrate that systemic sinularin exerts analgesic effects at the behavioral and spinal levels, which are associated with both inhibition of leukocyte infiltration and upregulation of TGF-β1.Three decades ago, the marine-derived compound sinularin was shown to have anti-edematous effects on paw edema induced by carrageenan or adjuvant. To the best of our knowledge, no new studies were conducted to explore the bioactivity of sinularin until we reported the analgesic properties of sinularin based on in vivo experiments. In the present study, we found that sinularin significantly inhibits the upregulation of proinflammatory proteins, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) and upregulates the production of transforming growth factor-β (TGF-β) in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells according to western blot analysis. We found that subcutaneous (s.c.) administration of sinularin (80 mg/kg) 1 h before carrageenan injection significantly inhibited carrageenan-induced nociceptive behaviors, including thermal hyperalgesia, mechanical allodynia, cold allodynia, and hindpaw weight-bearing deficits. Further, s.c. sinularin (80 mg/kg) significantly inhibited carrageenan-induced microglial and astrocyte activation as well as upregulation of iNOS in the dorsal horn of the lumbar spinal cord. Moreover, s.c. sinularin (80 mg/kg) inhibited carrageenan-induced tissue inflammatory responses, redness and edema of the paw, and leukocyte infiltration. The results of immunohistochemical studies indicate that s.c. sinularin (80 mg/kg) could upregulate production of TGF-β1 in carrageenan-induced inflamed paw tissue. The present results demonstrate that systemic sinularin exerts analgesic effects at the behavioral and spinal levels, which are associated with both inhibition of leukocyte infiltration and upregulation of TGF-β1.

In recent years, several marine-derived compounds have been clinically evaluated. Diterpenes are secondary metabolites from soft coral that exhibit anti-inflammatory, anti-tumor and cytotoxic activities. In the present study, we isolated a natural diterpene product, excavatolide B, from cultured Formosan gorgonian Briareum excavatum and investigated its anti-inflammatory activities. We found that excavatolide B significantly inhibited the mRNA expression of the proinflammatory mediators, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in lipopolysaccharide (LPS)-challenged murine macrophages (RAW 264.7). We also examined the anti-inflammatory and anti-nociceptive effects of excavatolide B on intraplantar carrageenan-induced inflammatory responses. Excavatolide B was found to significantly attenuate carrageenan-induced nociceptive behaviors, mechanical allodynia, thermal hyperalgesia, weight bearing deficits and paw edema. In addition, excavatolide B inhibited iNOS, as well as the infiltration of immune cells in carrageenan-induced inflammatory paw tissue.

Heteronemin, a marine sesterterpenoid-type natural product, possesses diverse bioactivities, especially antitumor effect. Accumulating evidence shows that heteronemin may act as a potent anticancer agent in clinical therapy. To fully understand the antitumor mechanism of heteronemin, we further explored the precise molecular targets in prostate cancer cells. Initially, heteronemin exhibited potent cytotoxic effect against LNcap and PC3 prostate cancer cells with IC₅₀ 1.4 and 2.7 μM after 24 h, respectively. In the xenograft animal model, the tumor size was significantly suppressed to about 51.9% in the heteronemin-treated group in comparison with the control group with no significant difference in the mice body weights. In addition, the results of a cell-free system assay indicated that heteronemin could act as topoisomerase II (topo II) catalytic inhibitor through the elimination of essential enzymatic activity of topoisomerase IIα expression. We found that the use of heteronemin-triggered apoptosis by 20.1–68.3%, caused disruption of mitochondrial membrane potential (MMP) by 66.9–99.1% and promoted calcium release by 1.8-, 2.0-, and 2.1-fold compared with the control group in a dose-dependent manner, as demonstrated by annexin-V/PI, rhodamine 123 and Fluo-3 staining assays, respectively. Moreover, our findings indicated that the pretreatment of LNcap cells with an inhibitor of protein tyrosine phosphatase (PTPi) diminished growth inhibition, oxidative and Endoplasmic Reticulum (ER) stress, as well as activation of Chop/Hsp70 induced by heteronemin, suggesting PTP activation plays a crucial rule in the cytotoxic activity of heteronemin. Using molecular docking analysis, heteronemin exhibited more binding affinity to the N-terminal ATP-binding pocket of Hsp90 protein than 17-AAG, a standard Hsp90 inhibitor. Finally, heteronemin promoted autophagy and apoptosis through the inhibition of Hsp 90 and topo II as well as PTP activation in prostate cancer cells. Taken together, these multiple targets present heteronemin as an interesting candidate for its future development as an antiprostatic agent.

Crataegus pinnatifida is used to treat various diseases, including indigestion, congestive heart failure, hypertension, atherosclerosis, and myocardial dysfunction. We evaluated antioxidant and anti-α-glucosidase activities of various solvent extracts and major bioactive components from the fruit of C. pinnatifida. Ethyl acetate extracts showed potent antioxidant activities with IC₅₀ values of 23.26 ± 1.97 and 50.73 ± 8.03 μg/mL, respectively, in DPPH and ABTS radical scavenging assays. Acetone extract exhibited significant anti-α-glucosidase activity with IC₅₀ values of 42.35 ± 2.48 μg/mL. HPLC analysis was used to examine and compare the content of active components in various solvent extracts. We isolated four active compounds and evaluated their antioxidant and anti-α-glucosidase properties. Among the isolated compounds, chlorogenic acid and hyperoside showed potential antioxidant activities in ABTS and superoxide radical scavenging assays. Moreover, hyperoside also displayed stronger anti-α-glucosidase activity than other isolates. The molecular docking model and the hydrophilic interactive mode of anti-α-glucosidase assay revealed that hyperoside might have a higher antagonistic effect than positive control acarbose. The present study suggests that C. pinnatifida and its active extracts and components are worth further investigation and might be expectantly developed as the candidates for the treatment or prevention of oxidative stress-related diseases and hyperglycemia.

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by tremor, rigidity, bradykinesia, and gait impairment. In a previous study, we found that the marine-derived compound 11-dehydrosinulariolide (11-de) upregulates the Akt/PI3K pathway to protect cells against 6-hydroxydopamine (6-OHDA)-mediated damage. In the present study, SH-SY5Y, zebrafish and rats were used to examine the therapeutic effect of 11-de. The results revealed the mechanism by which 11-de exerts its therapeutic effect: the compound increases cytosolic or mitochondrial DJ-1 expression, and then activates the downstream Akt/PI3K, p-CREB, and Nrf2/HO-1 pathways. Additionally, we found that 11-de could reverse the 6-OHDA-induced downregulation of total swimming distance in a zebrafish model of PD. Using a rat model of PD, we showed that a 6-OHDA-induced increase in the number of turns, and increased time spent by rats on the beam, could be reversed by 11-de treatment. Lastly, we showed that 6-OHDA-induced attenuation in tyrosine hydroxylase (TH), a dopaminergic neuronal marker, in zebrafish and rat models of PD could also be reversed by treatment with 11-de. Moreover, the patterns of DJ-1 expression observed in this study in the zebrafish and rat models of PD corroborated the trend noted in previous in vitro studies.