Costunolide is a naturally occurring sesquiterpene lactone that demonstrates various therapeutic actions such as anti-oxidative, anti-inflammatory, and anti-cancer properties. Costunolide has recently emerged as a potential anti-cancer agent in various types of cancer, including colon, lung, and breast cancer. However, its mode of action in skin cancer remains unclear. To determine the anti-cancer potential of costunolide in skin cancer, human epidermoid carcinoma cell line A431 was treated with costunolide. A lactate dehydrogenase assay showed that costunolide diminished the viability of A431 cells. Apoptotic cells were detected by annexin V/propidium iodide double staining and Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay assay, and costunolide induced cell apoptosis via activation of caspase-3 as well as induction of poly-ADP ribose polymerase cleavage in A431 cells. In addition, costunolide elevated the level of the pro-apoptotic protein Bax while lowering the levels of anti-apoptotic proteins, including Bcl-2 and Bcl-xL. To address the inhibitory effect of costunolide on cell proliferation and survival, various signaling pathways, including mitogen-activated protein kinases, signal transducer and activator of transcription 3 (STAT3), nuclear factor κB (NF-κB), and Akt, were investigated. Costunolide activated the p38 and c-Jun N-terminal kinase pathways while suppressing the extracellular signal-regulated kinase (ERK), STAT3, NF-κB, and Akt pathways in A431 cells. Consequently, it was inferred that costunolide suppresses cell proliferation and survival via these signaling pathways. Taken together, our data clearly indicated that costunolide exerts anti-cancer activity in A431 cells by suppressing cell growth via inhibition of proliferation and promotion of apoptosis. Therefore, it may be employed as a potentially tumor-specific candidate in skin cancer treatment.

Background: Cancer is a representative geriatric disease closely related to senescent cells and cell aging in tissues. Senescent cells that surround cancer tissues reduce the effects of various cancer treatments and induce cancer recurrence through senescence-associated secretory phenotype (SASP) secretion. Thus, for good therapeutic effect, candidate drugs should be selective for both cancer and senescent cells. In this study, we investigated the selective effect of piperine as a potential senostatic agent as well as an anticancer drug. Methods: The effect of piperine on cytotoxicity and cell proliferation was tested by lactate dehydrogenase (LDH) or water-soluble tetrazolium salt (WST) assay. The levels of p16INK4a and p21, mitogen-activated protein kinases (MAPKs), and mammalian target of rapamycin (mTOR) were analyzed by Western blot analysis. The rejuvenation effects of piperine on the senescent cells were investigated by senescence-associated beta-galactosidase (SA-β-Gal) stain, mitochondria membrane potential (MMP) and reactive oxygen species (ROS) levels, and senescence-associated secretory phenotype (SASP) secretion after treatment with piperine in senescent cells. Results: While piperine induced high cytotoxicity in various cancer cell lines, it led to proliferating of premature senescent cells similar with nicotinamide (NA), which is known as a rejuvenating drug of senescent cells. Piperine differently affected cancer cells and premature senescent cells due to the different responses of intracellular signaling pathways and also reversed premature senescence phenotypes and modulated SASP secretion in premature senescent cells. Conclusions: From these results, we propose piperine as an effective cancer treatment that can simultaneously induce senostatic effects and the removal of cancer cells, not as an adjuvant to the existing senostatics for cancer treatment.

Aucklandia lappa Decne., known as “Mok-hyang” in Korea, has been used for the alleviation of abdominal pain, vomiting, diarrhea, and stress gastric ulcers in traditional oriental medicine. We investigated the anti-inflammatory and antioxidative effects of the ethanol extract of Aucklandia lappa Decne. (ALDE) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. ALDE significantly inhibited the LPS-induced nitric oxide (NO) production and reduced inducible nitric oxide synthase (iNOS) expression in RAW 264.7 cells. The production of other proinflammatory mediators, including COX-2, interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α, was reduced by ALDE in LPS-stimulated RAW 264.7 cells. The mechanism underlying the anti-inflammatory effects of ALDE was elucidated to be the suppression of LPS-induced nuclear translocation of p65, followed by the degradation of IκB and the inhibition of the phosphorylation of mitogen-activated protein kinases (MAPK). In addition, ALDE showed enhanced radical scavenging activity. The antioxidant effect of ALDE was caused by the enhanced expression of heme oxygenase (HO-1) via stabilization of the expression of the nuclear transcription factor E2-related factor 2 (Nrf2) pathway. Collectively, these results indicated that ALDE not only exerts anti-inflammatory effects via the suppression of the NF-κB and MAPK pathways but also has an antioxidative effect through the activation of the Nrf2/HO-1 pathway.

Inflammation is a defense mechanism that protects the body from infections. However, chronic inflammation causes damage to body tissues. Thus, controlling inflammation and investigating anti-inflammatory mechanisms are keys to preventing and treating inflammatory diseases, such as sepsis and rheumatoid arthritis. In continuation with our work related to the discovery of bioactive natural products, a polyphenol, catechin-7,4′-O-digallate (CDG), was isolated from Woodfordia uniflora, which has been used as a sedative and remedy for skin infections in the Dhofar region of Oman. Thus far, no study has reported the anti-inflammatory compounds derived from W. uniflora and the mechanisms underlying their action. To investigate the effects of CDG on the regulation of inflammation, we measured the reduction in nitric oxide (NO) production following CDG treatment in immortalized mouse Kupffer cells (ImKCs). CDG treatment inhibited NO production through the downregulation of inducible nitric oxide synthase expression in lipopolysaccharide (LPS)-stimulated ImKCs. The anti-inflammatory effects of CDG were mediated via the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation, an important inflammatory-response-associated signaling pathway. Moreover, CDG treatment has regulated the expression of pro-inflammatory cytokines, such as IL-6 and IL-1β. These results suggested the anti-inflammatory action of CDG in LPS-stimulated ImKCs.

Filamentous fungi produce several beneficial secondary metabolites, including bioactive compounds, food additives, and biofuels. Trichoderma, which is a teleomorphic Hypocrea that falls under the taxonomic groups Ascomycota and Dikarya, is an extensively studied fungal genus. In an ongoing study that seeks to discover bioactive natural products, we investigated potential bioactive metabolites from the methanolic extract of cultured Trichoderma gamsii. Using liquid chromatography–mass spectrometry (LC–MS), one major compound was isolated and structurally identified as 6-pentyl-α-pyrone (6PP) based on nuclear magnetic resonance data and LC–MS analysis. To determine its antioxidant and anti-inflammatory activity, as well as the underlying mechanisms, we treated lipopolysaccharide (LPS)-stimulated Raw264.7 mouse macrophages with 6PP. We found that 6PP suppresses LPS-induced increase in the levels of nitric oxide, a mediator of oxidative stress and inflammation, and restores LPS-mediated depletion of total glutathione by stabilizing nuclear factor erythroid 2-related factor 2 (Nrf2), an antioxidative factor, and elevating heme oxygenase-1 levels. Furthermore, 6PP inhibited LPS-induced production of proinflammatory cytokines, which are, at least in part, regulated by heme oxygenase-1 (HO-1). 6PP suppressed proinflammatory responses by inhibiting the nuclear localization of nuclear factor kappa B (NF-κB), as well as by dephosphorylating the mitogen-activated protein kinases (MAPKs). These results indicate that 6PP can protect macrophages against oxidative stress and LPS-induced excessive inflammatory responses by activating the Nrf2/HO-1 pathway while inhibiting the proinflammatory, NF-κB, and MAPK pathways.

Although vaccines and antiviral drugs are available, influenza viruses continue to pose a significant threat to vulnerable populations globally. With the emergence of drug-resistant strains, there is a growing need for novel antiviral therapeutic approaches. We found that 18-hydroxyferruginol (1) and 18-oxoferruginol (2) isolated from Torreya nucifera exhibited strong anti-influenza activity, with 50% inhibitory concentration values of 13.6 and 18.3 μM against H1N1, 12.8 and 10.8 μM against H9N2, and 29.2 μM (only compound 2) against H3N2 in the post-treatment assay, respectively. During the viral replication stages, the two compounds demonstrated stronger inhibition of viral RNA and protein in the late stages (12–18 h) than in the early stages (3–6 h). Moreover, both compounds inhibited PI3K-Akt signaling, which participates in viral replication during the later stages of infection. The ERK signaling pathway is also related to viral replication and was substantially inhibited by the two compounds. In particular, the inhibition of PI3K-Akt signaling by these compounds inhibited viral replication by sabotaging influenza ribonucleoprotein nucleus-to-cytoplasm export. These data indicate that compounds 1 and 2 could potentially reduce viral RNA and viral protein levels by inhibiting the PI3K-Akt signaling pathway. Our results suggest that abietane diterpenoids isolated from T. nucifera may be potent antiviral candidates for new influenza therapies.