Lonicerae japonicae flos (LJ) is an Asian traditional herb that is used as a dietary supplement, tea, and beverage to clear heat and quench thirst. However, no studies investigated its effect on activated human neutrophils, which played a crucial role in the bad prognosis of coronavirus disease of 2019 (COVID-19) patients by aggravating lung inflammation and respiratory failure. Herein, we evaluated the anti-inflammatory effect of LJ ethanol extract (LJEE) on human neutrophils activated by N-formyl-methionyl-leucyl-phenylalanine (fMLF). Our experimental results indicated that LJEE suppressed fMLF-activated superoxide anion (O2•−) generation, the expression of CD11b, and cell adhesion and migration, as well as the formation of neutrophil extracellular traps in human neutrophils. Further in-depth mechanical investigation revealed that pretreatment with LJEE accelerated the Ca2+ clearance, but did not affect the phosphorylation of mitogen-activated protein kinases (MAPKs) and protein kinase B (Akt) in activated human neutrophils. In addition, LJEE displayed a dose-dependent reactive oxygen species (ROS) scavenger activity, which assisted its anti-inflammatory activity. From the bioassay-coupled chromatographic profile, chlorogenic acids were found to dominate the anti-inflammatory effects of LJEE. Moreover, LJ water extract (LJWE) demonstrated an interrupting effect on the severe acute respiratory syndrome coronavirus-2 spike protein (SARS-CoV-2-Spike)/angiotensin-converting enzyme 2 (ACE2) binding. In conclusion, the obtained results not only supported the traditional use of LJ for heat-clearance, but also suggested its potential application in daily health care during the COVID-19 pandemic.
In recent decades, aquaculture techniques for soft corals have made remarkable progress in terms of conditions and productivity. Researchers have been able to obtain larger quantities of soft corals, thus larger quantities of biologically active metabolites, allowing them to study their biological activity in many pharmacological assays and even produce sufficient quantities for clinical trials. In this review, we summarize 201 secondary metabolites that have been identified from cultured soft corals in the era from 2002 to September 2022. Various types of diterpenes (eunicellins, cembranes, spatanes, norcembranes, briaranes, and aquarianes), as well as biscembranes, sterols, and quinones were discovered and subjected to bioactivity investigations in 53 different studies. We also introduce a more in-depth discussion of the potential biological effects (anti-cancer, anti-inflammatory, and anti-microbial) and the mechanisms of action of the identified secondary metabolites. We hope this review will shed light on the untapped potential applications of aquaculture to produce valuable secondary metabolites to tackle current and emerging health conditions.
Ultraviolet B (UVB) is one of the most important environmental factors that cause extrinsic aging through increasing intracellular reactive oxygen species (ROS) production in the skin. Due to its protective roles against oxidative stress, nuclear factor erythroid-2-related factor (NRF2) has been traditionally considered as a target for skin aging prevention. Here, we identified the extract of Prinsepiae Nux, a top-grade drug listed in Shen Nong Ben Cao Jing, as a potent NRF2 activator by high-throughput screening. A bioassay-guided fractionation experiment revealed that NRF2-activating components were concentrated in the 90% methanol (MP) fraction. MP fraction significantly increased the expression of NRF2 and HO-1 protein and upregulated HO-1 and NQO1 mRNA expression in HaCaT cells. Moreover, MP fraction pre-treatment dramatically reversed UVB-induced depletion of NRF2 and HO-1, accumulation of intracellular ROS, NF-κB activation, and the upregulation of pro-inflammatory genes. Finally, the qualitative analysis using UPLC-tandem mass spectroscopy revealed the most abundant ion peak in MP fraction was identified as α-linolenic acid, which was further proved to activate NRF2 signaling. Altogether, the molecular evidence suggested that MP fraction has the potential to be an excellent source for the discovery of natural medicine to treat/prevent UVB-induced skin damage.
The unmet need for specific anti-leukemic agents for the treatment of acute lymphoblastic leukemia led us to screen a variety of marine-derived bacteria. The fermentation broth extract of Streptomyces sp. LY1209 exhibited the most potent anti-proliferative effect against Molt 4 leukemia cells. A chromatographic anti-proliferative profiling approach was applied to characterize the metabolites with bioactive potential. Among all the metabolites, the major anti-leukemic constituents were staurosporine and a series of diketopiperazines (DKPs), including one novel and two known DKPs identified from nature for the first time. The structures of these compounds were identified using extensive spectroscopic analysis. The anti-proliferative potential of these metabolites against the Molt 4 cancer cell line was also determined. According to the in silico analysis utilizing a chemical global positioning system for natural products (ChemGPS-NP), it was suggested that these DKPs are potential anti-microtubule and alkylating agents, while staurosporine was proposed to be a tyrosine kinase inhibitor. Our findings not only identified a series of anti-proliferative metabolites, but also suggested a strategic workflow for the future discovery of natural product drug leads.
Inflammation is a critical defense mechanism that is utilized by the body to protect itself against pathogens and other noxious invaders. However, if the inflammatory response becomes exaggerated or uncontrollable, its original protective role is not only demolished but it also becomes detrimental to the affected tissues or even to the entire body. Thus, regulating the inflammatory process is crucial to ensure that it is resolved promptly to prevent any subsequent damage. The role of neutrophils in inflammation has been highlighted in recent decades by a plethora of studies focusing on neutrophilic inflammatory diseases as well as the mechanisms to regulate the activity of neutrophils during the overwhelmed inflammatory process. As natural products have demonstrated promising effects in a wide range of pharmacological activities, they have been investigated for the discovery of new anti-inflammatory therapeutics to overcome the drawbacks of current synthetic agents. Octocorals have attracted scientists as a plentiful source of novel and intriguing marine scaffolds that exhibit many pharmacological activities, including anti-inflammatory effects. In this review, we aim to provide a summary of the neutrophilic anti-inflammatory properties of these marine organisms that were demonstrated in 46 studies from 1995 to the present (April 2023). We hope the present work offers a comprehensive overview of the anti-inflammatory potential of octocorals and encourages researchers to identify promising leads among numerous compounds isolated from octocorals over the past few decades to be further developed into anti-inflammatory therapeutic agents.
Biscembranoids are the distinctive tetraterpenoids owing a 14/6/14 membered tricyclic scaffold that have been mainly discovered in the soft corals, especially the genera Sarcophyton, Lobophytum and Sinularia. Recent findings have demonstrated the great anti-inflammatory potential of biscembranoid analogues in human neutrophils, motivating more chemical and biological explorations targeting these marine-derived natural products. In the current study, the chemical diversity of biscembranoids derived from the cultured-type Sarcophyton trocheliophorum von Marenzeller was illustrated through MS/MS molecular networking (MN) profiling approach. Based on the MN patterns, the prioritization of unknown biscembranoid derivatives was putatively analyzed. As a result, the biscembrane targeting isolation afforded two new metabolites, sarcotrochelides A (1) and B (2), along with six known analogues (3–8). Their structures and relative configurations were determined by spectroscopic methods. In vitro neutrophil inflammatory inhibition was further investigated for all isolates based on reduced superoxide anion (O2•−) generation detections. Compounds 5–8 showed significant dose-dependently inhibitory effects, suggesting the cruciality of 6,7-dihydrooxepin-2(5H)-one moiety and saturated γ-lactone ring in their reactive oxygen species (ROS)-dependent anti-inflammatory properties.