Hydroxychavicol as a potential anticancer agent (Review)

Hydroxychavicol derivatives from Piper betle Linn. as natural PDE4 inhibitors with anti-inflammatory effects

PDE4 inhibitors have been developed as anti-inflammatory medications primarily used in the clinical treatment of pulmonary inflammations such as asthma, chronic obstructive pulmonary disease, and idiopathic pulmonary fibrosis. However, the application of these drugs is usually restricted by obvious side effects, such as nausea and vomiting. Our previous study found that several natural PDE4 inhibitors or their modified derivatives showed minimal side effects, particularly reduced incidence of nausea and vomiting, which aroused our interest in searching for natural PDE4 inhibitors. In this study, a chemical investigation of an active fraction of Piper betle L. leaves led to the characterization of 23 hydroxychavicol derivatives, including 18 hydroxychavicol-type lignans. Compounds 1-9 were new lignans, with three of them being racemates that were eventually resolved into isolated (+)- and (-)-enantiomers. Compounds 1-5 and 10, neolignans characterized by a dioxane moiety, were unique to this species within the genus Piper. Compounds 5 and 10 were the sole sesquineolignans found in the genus Piper. Compounds 5, 7-14, 16, 17, and 21 exhibited considerable inhibition towards PDE4 with IC50 values ranging from 1.8 to 10 μM, with hit 7 exhibiting remarkable activity (1.8 μM). Further anti-inflammatory assays revealed that compounds 5, 7, 9, and 16 decreased the expression of several key inflammatory mediators in LPS-stimulated RAW 264.7 cells. Notably, 16 was comparable to the positive control rolipram at the same concentration of 10 μM. A primary study of the mechanism of action revealed that 16 may exert anti-inflammatory effect by inhibiting the NF-κB signaling pathway, displaying significant inhibition of the phosphorylation of IκB-α and p65 at concentrations of 5 and 10 μM. These findings suggest that hydroxychavicol derivatives from P. betle L. leaves may serve as new PDE4 inhibitors, offering promising leads for the development of anti-inflammatory medications.

Identification of Therapeutic Potential of Hydroxychavicol Against Alzheimer's Disease: An Integrated Network Pharmacology, Molecular Docking, and Dynamic Simulation Study

Alzheimer's disease (AD) is a commonly occurring neurodegenerative disease in elderly and it is a leading cause of dementia worldwide. Hydroxychavicol (HC), a major phenolic component of Piper betle, has prominent anti-inflammatory and antioxidant properties, and studies have found its role in cognition improvement. Here is a systematic approach to deciphering the potential protein targets of HC in AD through network pharmacology and validation from molecular docking and dynamics simulation study. First, the druglikeliness of HC was predicted using the SwissADME analysis, which showed significant druglikeliness. A total of 88 possible target genes between HC and AD were obtained from the Swiss Target Prediction, HIT Version 2, DisGeNET, and GeneCards database. The pathway analysis was carried out using the STRING database which showed several genes including COMT, HSP90AA1, and GAPDH as the top hub genes on the basis of degree. GO and KEGG analyses demonstrated that the core targets were mainly involved in cAMP, PI3K/AkT, HIF1, Rap1, and Calcium signaling pathways. The molecular docking of HC with top hub genes resulted in the highest binding of HC with COMT (-8.9 kcal/mol), GAPDH (-6.7 kcal/mol), and HSP90AA1 (-6.5 kcal/mol) that showed stable binding in the molecular dynamics simulation study. COMT regulates the dopamine levels in the prefrontal cortex and impairment of the COMT is associated with the rapid progression of AD. HSP90, a ubiquitous molecular chaperone, is involved in regulating tau metabolism and Aβ processing and found to be downregulated in AD. GAPDH has been reported as the disease-susceptible gene in AD and its interaction with amyloid precursor protein and NFTs has also been reported. These findings suggest that HC is a promising therapeutic candidate, targeting multiple AD-related pathways, warranting further investigation into its molecular mechanisms and potential for clinical application.

Chemopreventive Effects of Piper betle (Sirih) on High-Fat Diet-Induced and Azoxymethane-Induced Colon Cancer in Male Sprague-Dawley Rats

A high-fat diet could lead to obesity, increasing colorectal cancer risk due to dyslipidemia and chronic inflammation, while Piper betle (PB) exhibits anti-tumor, anti-inflammation, and anti-oxidant benefits. This study aimed to determine whether PB possesses chemopreventive effects on high-fat diet (HFD)-induced and azoxymethane (AOM)-induced colon cancer. Male Sprague-Dawley rats receiving either a normal diet or HFD were divided into control, PB, AOM, and AOM+PB subgroups which were then sacrificed after 24 weeks. The lipid profile, leptin, and inflammatory markers were measured from serum, and aberrant crypt foci (ACF) in the colon were detected by methylene blue staining. Cellular proliferation was identified through immunohistochemical staining of antigen Kiel 67 (Ki67) and beta-catenin. There were significant differences in serum total cholesterol, low-density lipoprotein, triglycerides, and high-density lipoprotein in the HFD compared to the normal diet group. The AOM group for normal diet and HFD exhibited significantly increased serum leptin, interleukin-6, IL-12p70, tumor necrosis factor-α, and nuclear factor-κB, with overexpression of Ki67 and beta-catenin. These changes were reversed by PB supplementation. In conclusion, PB demonstrated lipid-modifying and chemopreventive effects against HFD and AOM-induced colon cancer in rats.

Mechanism of fibroblast growth factor 1 regulating fatty liver disorder in mule ducks

Mule ducks tend to accumulate abundant fat in their livers via feeding, which leads to the formation of a fatty liver that is several times larger than a normal liver. However, the mechanism underlying fatty liver formation has not yet been elucidated. Fibroblast growth factor 1 (FGF1), a member of the FGF superfamily, is involved in cellular lipid metabolism and mitosis. This study aims to investigate the regulatory effect of FGF1 on lipid metabolism disorders induced by complex fatty acids in primary mule duck liver cells and elucidate the underlying molecular mechanism. Hepatocytes were induced by adding 1,500:750 µmol/L oleic and palmitic acid concentrations for 36 h, which were stimulated with FGF1 concentrations of 0, 10, 100, and 1000 ng/mL for 12 h. The results showed that FGF1 significantly reduced the hepatic lipid droplet deposition and triglyceride content induced by complex fatty acids; it also reduced oxidative stress; decreased reactive oxygen species fluorescence intensity and malondialdehyde content; upregulated the expression of antioxidant factors nuclear factor erythroid 2 related factor 2 (Nrf2), HO-1, and NQO-1; significantly enhanced liver cell activity; promoted cell cycle progression; inhibited cell apoptosis; upregulated cyclin-dependent kinase 1 (CDK1) and BCL-2 mRNA expression; and downregulated Bax and Caspase-3 expression. In addition, FGF1 promoted AMPK phosphorylation, activated the AMPK pathway, upregulated AMPK gene expression, and downregulated the expression of SREBP1 and ACC1 genes, thereby alleviating excessive fat accumulation in liver cells induced by complex fatty acids. In summary, FGF1 may alleviate lipid metabolism disorders induced by complex fatty acids in primary mule duck liver cells by activating the AMPK signaling pathway.

Molecular Docking Analysis of Hydroxyclavicol and Eugenol From Betel Leaves Against Outer Membrane Protein (OmpH) of Dialister pneumosintes

Introduction Dialister pneumosintes is an obligate anaerobic non-spore-forming Gram-negative bacilli. As a part of polymicrobial film, the activated virulence factor causes oral diseases like gingivitis and periodontitis. Decreased susceptibility of clinical strains of D. pneumosintes to different antibiotics including piperacillin and metronidazole raises concerns. There has been significant interest in the utility of plant phytocompounds as potent antibacterial agents.  Aim The study aimed to look at the potential of two phytocompounds, eugenol and hydroxychavicol, for their ability to inhibit outer membrane protein (OmpH) of D. pneumosintes using computational tools. Results The study showed effective inhibition of the OmpH of D. pneumosintes by both eugenol and hydroxychavicol. The high probability to be active (Pa) value indicated the probability of true positive for the tested compounds for their predicted biological activity. There was strong reciprocity between the drug-likeliness and its binding affinity for the target protein, indicating an inhibitory nature. Conclusion The tested phytocompounds hydroxychavicol and eugenol showed potential inhibition of the OmpH protein of D. pneumosintes indicating its potential use as inhibitory compounds of the pathogen and future directions for the treatment of periodontitis and gingivitis.