Tautomerism and bioactivities of curcumenol, a common sesquiterpenoid widely existing in edible plants

The Extraction, Determination, and Bioactivity of Curcumenol: A Comprehensive Review

Curcuma wenyujin is a member of the Curcuma zedoaria (zedoary, Zingiberaceae) family, which has a long history in traditional Chinese medicine (TCM) due to its abundant biologically active constituents. Curcumenol, a component of Curcuma wenyujin, has several biological activities. At present, despite different pharmacological activities being reported, the clinical usage of curcumenol remains under investigation. To further determine the characteristics of curcumenol, the extraction, determination, and bioactivity of the compound are summarized in this review. Existing research has reported that curcumenol exerts different pharmacological effects in regard to a variety of diseases, including anti-inflammatory, anti-oxidant, anti-bactericidal, anti-diabetic, and anti-cancer activity, and also ameliorates osteoporosis. This review of curcumenol provides a theoretical basis for further research and clinical applications.

Curcumenol improves renal function in 5/6 nephrectomy-induced chronic renal failure rats via the SIRT1/NF-κB pathway

The present work aimed to explore the protective effects of curcumenol and evaluate its pharmacological mechanisms in 5/6 nephrectomy-induced chronic renal failure (CRF). Rats with CRF were administrated curcumenol and the effects on renal functions were investigated. Renal function examinations were carried out, whereas serum levels of inflammatory mediators, including NF-κB, MCP-1 and IL-1β were analyzed by ELISA. The mRNA expression levels of SIRT1, p65 and IκBα were measured by qRT-PCR, and the SIRT1 protein levels were analyzed by western blot and immunohistochemistry. Our results indicated that curcumenol significantly improved the renal functions in the CRF rats. Compared to the sham group, serum levels of NF-κB, MCP-1, IL-1β, and the mRNA expression levels of p65 were significantly increased (p < 0.01), whereas the mRNA expression level of IκBα was significantly decreased (p < 0.01) and the SIRT1 levels were dramatically down-regulated (p < 0.05) in the CRF groups. Treatment with curcumenol remarkably inhibited inflammatory responses as reflected by the reduced levels of inflammatory mediators (p < 0.01) and SIRT1 up-regulation (p < 0.05). Our findings suggested that curcumenol could improve the renal function in 5/6 nephrectomy-induced CRF rats, and the mechanisms might involve suppressing the associated inflammation and modulating the SIRT1 and NF-κB signaling pathways.

Tautomeric phytosterols from Vernonia amygdalina Delile and their anti-cervical cancer activity

Vernonia amygdalina Delile is generally used as green vegetables for cuisine in Nigeria and health tea or products in southeast of china. It was also used as folk medicine for the treatment of anti-helminth, febrifuge, digestive tonic and wounds. In this study, eleven undescribed phytosterols (1-2, 4-12) and six known analogues (3, 13-17) were isolated from the stems of V. amygdalina. Their structures including absolute configurations were elucidated by comprehensive spectroscopic methods (1D and 2D NMR, HRESIMS), X-ray diffraction and comparison of their ECD spectra. Besides, the tautomerism of phytosterols (1, 3-6, 12-17) with hemiacetal moiety were analyzed by solution NMR with different deuterated solvent and variable-temperature experiments. In addition, the cytotoxic activities of isolates against HeLa cells were evaluated. As a result, compound 10 exhibited the most potent anti-cervical cancer activity with the IC₅₀ of 22.44 μM. Mechanism studies indicated that 10 triggered HeLa cells apoptosis through activating caspase signaling pathway. Furthermore, 10 could arrest the cell cycle in S phase and suppress the activation of the PI3K/AKT/mTOR pathway, leading to the inhibition of HeLa cells proliferation.

Bisacurone suppresses hepatic lipid accumulation through inhibiting lipogenesis and promoting lipolysis

Turmeric and its components have various health beneficial functions. However, little is known about function of bisacurone, which is one of the sesquiterpenes in turmeric, at the compound level. In this study, we investigated the preventive effect of bisacurone on hepatic lipid accumulation and its mechanism in HepG2 cells and ICR mice. In HepG2 cells, bisacurone significantly inhibited fatty acid-induced intracellular lipid accumulation in a dose-dependent manner. Bisacurone at 10 µM increased protein expression of peroxisome proliferator-activated receptor α and carnitine palmitoyltransferase-1A accompanied by phosphorylation of AMP-activated protein kinase. In the liver of ICR mice, bisacurone decreased total lipids, triglyceride, and cholesterol contents. Bisacurone at 10 mg/kg body weight increased phosphorylation of AMP-activated protein kinase, and its downstream acetyl-CoA carboxylase as a rate-limiting enzyme for lipogenesis, while it decreased the nuclear translocation level of sterol regulatory element-binding protein 1 and carbohydrate-responsive element-binding protein as the major transcription factors for lipogenesis. On the other hand, bisacurone promoted lipolysis by up-expression of peroxisome proliferator-activated receptor α and carnitine palmitoyltransferase-1A. Thus, bisacurone might be a valuable food factor for preventing hepatic lipid accumulation by inhibiting lipogenesis and promoting lipolysis through phosphorylation of AMP-activated protein kinase.