Effect of tetrahydrocurcumin on erythromycin estolate-induced lipid peroxidation in rats

The role of tetrahydrocurcumin in disease prevention and treatment

In recent decades, natural compounds derived from herbal medicine or dietary sources have played important roles in prevention and treatment of various diseases and have attracted more and more attention. Curcumin, extracted from the Curcumae Longae Rhizoma and widely used as food spice and coloring agent, has been proven to possess high pharmacological value. However, the pharmacological application of curcumin is limited due to its poor systemic bioavailability. As a major active metabolite of curcumin, tetrahydrocurcumin (THC) has higher bioavailability and stability than curcumin. Increasing evidence confirmed that THC had a wide range of biological activities and significant treatment effects on diseases. In this paper, we reviewed the research progress on the biological activities and therapeutic potential of THC on different diseases such as neurological disorders, metabolic syndromes, cancers, and inflammatory diseases. The extensive pharmacological effects of THC involve the modulation of various signaling transduction pathways including MAPK, JAK/STAT, NF-κB, Nrf2, PI3K/Akt/mTOR, AMPK, Wnt/β-catenin. In addition, the pharmacokinetics, drug combination and toxicology of THC were discussed, thus providing scientific basis for the safe application of THC and the development of its dietary supplements and drugs.

Single and joint toxic effects of four antibiotics on some metabolic pathways of zebrafish (Danio rerio) larvae

In China, antibiotics are commonly used for human and veterinary medicine, and they are present in various environmental media. Thus, the toxic effects of antibiotics on organisms have attracted the attention of society and scientists alike. In this study, zebrafish embryos were used to test the single and joint toxicity of four antibiotics, sulfamonomethoxine (SMM), cefotaxime sodium (CFT), tetracycline (TC), enrofloxacin (ENR), and their combinations, combining the results of experimental and omics techniques. Following exposure to antibiotics for 120 h, the body lengths of zebrafish larvae in all 100 μg/L antibiotic groups were significantly shortened, and the reactive oxygen species (ROS) content in the 100 μg/L Mix group was significantly increased. Transcriptome sequencing (RNA-seq) showed that the mRNA level of numerous genes was significantly changed in the five antibiotic treatment groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the differentially expressed genes revealed a significant enrichment of the steroid biosynthesis and other metabolism pathways. Hub gene analysis highlighted dhcr24, acat1, aldh1a2, aldh8a1, suclg2, hadh, and hsdl2 as the key genes, and hub gene expression changes because of the antibiotic treatment suggested that the metabolic system of the zebrafish larvae was severely disrupted by the interaction with other genes. In conclusion, single or joint exposure to different antibiotics at environmental concentrations affected the early development and metabolic system of zebrafish larvae, and our results provide fundamental evidence for future studies of antibiotic toxicity in aquatic organisms.

Attenuation by Tetrahydrocurcumin of Adiposity and Hepatic Steatosis in Mice with High-Fat-Diet-Induced Obesity

Diet-induced obesity is strongly associated with nonalcoholic fatty-liver disease (NAFLD) and insulin resistance. We aimed to investigate the in vivo therapeutic value of tetrahydrocurcumin (THC) intervention in high-fat-diet (HFD)-induced obesity and hepatic steatosis. C57BL/6 mice were fed an HFD for 10 weeks, and then they received 20 or 100 mg/kg THC along with the HFD for another 10 weeks. Mice fed an HFD for 20 weeks experienced obesity, hepatic steatosis, hyperlipidemia, and insulin resistance. Tetrahydrocurcumin (THC) intervention for 10 weeks significantly reduced adiposity (epididymal-fat weights of 6.6 ± 0.4 g for the HFD-only group and 5.3 ± 0.8 and 5.6 ± 0.7 g for the HFD with 20 mg/kg THC and HFD with 100 mg/kg THC groups, respectively; p < 0.05) via downregulation of adipogenic factors. Inflammatory macrophage infiltration and polarization were decreased by THC in mouse epididymal adipose tissues. In the liver, THC markedly alleviated steatosis by approximately 28-37% ( p < 0.05) via the downregulation of lipogenesis, the activation of AMP-activated protein kinase (AMPK), and the increase of fatty acid oxidation. Elevated blood glucose and insulin resistance were also improved by THC, which might be caused by regulation of the hepatic insulin signaling cascade, gene transcription involved in glucose metabolism, and reduced macrophage infiltration in the liver and adipose tissue. Our results demonstrated the beneficial effects of THC-mediated intervention against obesity and NAFLD as well as other metabolic syndromes, revealing a novel therapeutic use of THC in obese populations.

Biological activities of curcumin and its analogues (Congeners) made by man and Mother Nature

Curcumin, a yellow pigment present in the Indian spice turmeric (associated with curry powder), has been linked with suppression of inflammation; angiogenesis; tumorigenesis; diabetes; diseases of the cardiovascular, pulmonary, and neurological systems, of skin, and of liver; loss of bone and muscle; depression; chronic fatigue; and neuropathic pain. The utility of curcumin is limited by its color, lack of water solubility, and relatively low in vivo bioavailability. Because of the multiple therapeutic activities attributed to curcumin, however, there is an intense search for a "super curcumin" without these problems. Multiple approaches are being sought to overcome these limitations. These include discovery of natural curcumin analogues from turmeric; discovery of natural curcumin analogues made by Mother Nature; synthesis of "man-made" curcumin analogues; reformulation of curcumin with various oils and with inhibitors of metabolism (e.g., piperine); development of liposomal and nanoparticle formulations of curcumin; conjugation of curcumin prodrugs; and linking curcumin with polyethylene glycol. Curcumin is a homodimer of feruloylmethane containing a methoxy group and a hydroxyl group, a heptadiene with two Michael acceptors, and an alpha,beta-diketone. Structural homologues involving modification of all these groups are being considered. This review focuses on the status of all these approaches in generating a "super curcumin.".

Potential therapeutic effects of curcumin, the anti-inflammatory agent, against neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases

Although safe in most cases, ancient treatments are ignored because neither their active component nor their molecular targets are well defined. This is not the case, however, with curcumin, a yellow-pigment substance and component of turmeric (Curcuma longa), which was identified more than a century ago. For centuries it has been known that turmeric exhibits anti-inflammatory activity, but extensive research performed within the past two decades has shown that this activity of turmeric is due to curcumin (diferuloylmethane). This agent has been shown to regulate numerous transcription factors, cytokines, protein kinases, adhesion molecules, redox status and enzymes that have been linked to inflammation. The process of inflammation has been shown to play a major role in most chronic illnesses, including neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases. In the current review, we provide evidence for the potential role of curcumin in the prevention and treatment of various proinflammatory chronic diseases. These features, combined with the pharmacological safety and negligible cost, render curcumin an attractive agent to explore further.

Tetrahydrocurcumin: effect on chloroquine-mediated oxidative damage in rat kidney

Tetrahydrocurcumin is an antioxidative substance, which is derived from curcumin, the component of turmeric. In the present investigation, the effect of tetrahydrocurcumin and curcumin against chloroquine-induced nephrotoxicity were studied in female wistar rats. Oral administration of tetrahydrocurcumin significantly prevented the occurrence of chloroquine (970 mg/kg body weight)-induced renal damage. Upon administration of tetrahydrocurcumin to chloroquine-treated rats, the level of lipid peroxidation was significantly decreased while the levels of non-enzymic and enzymic antioxidants were significantly increased in kidney. Oral administration (80 mg/kg body weight) attenuated the chloroquine-induced nephrotoxicity by significantly decreased levels of serum urea and creatinine with significant normalization of creatinine clearance. On administration of tetrahydrocurcumin, the depleted renal antioxidant defense system (enzymatic and non-enzymatic antioxidants) was significantly increased in rats treated with chloroquine. These biochemical observations were supplemented by histopathological examination of kidney section. These results suggest that administration of chloroquine imposes an oxidative stress to renal tissue and that tetrahydrocurcumin protects the oxidative damage associated with chloroquine.