Experimental study of the anti-tumour activity and pharmacokinetics of arctigenin and its valine ester derivative

Arctigenin promotes mucosal healing in ulcerative colitis through facilitating focal adhesion assembly and colonic epithelial cell migration via targeting focal adhesion kinase

Colonic mucosal defect constitutes the major reason of recurrence and deterioration of ulcerative colitis (UC), and mucosal healing has become the therapeutic endpoint of UC. Unfortunately, specific promoter of mucosal healing is still absent. Our previous researches demonstrated that arctigenin could alleviate colitis symptoms in mice, but whether it has a positive impact on colonic mucosal healing remains unclear. This study explores whether and how arctigenin promotes mucosal healing. Orally administered arctigenin was shown to alleviate colitis in mice primarily by enhancing mucosal healing. In vitro, arctigenin was shown to promote the wound healing by accelerating colonic epithelial cell migration but not proliferation. Acceleration of the focal adhesion turnover, especially assembly, is crucial for arctigenin promoting the cell migration. Arctigenin was able to activate focal adhesion kinase (FAK) in colonic epithelial cells through directly binding with Tyr251 site of FAK, as evidenced by surface plasmon resonance assay and site-directed mutagenesis experiment. In the colonic epithelial cells of UC patients and colitis mice, FAK activation was significantly down-regulated compared with the controls. Arctigenin promoted colonic epithelial cell migration and mucosal healing in dextran sulphate sodium (DSS)-induced colitis mice dependent on activating FAK, as confirmed by combined use with FAK inhibitor. In summary, arctigenin can directly promote mucosal healing in colitis mice through facilitating focal adhesion turnover, especially assembly, and consequent migration of epithelial cells via targeting FAK. Arctigenin may be developed as a mucosal healing promoter, and FAK is a potential therapeutic target for UC and other mucosal defect-related diseases.

Lignans as multi-targeted natural products in neurodegenerative diseases and depression: Recent perspectives

As the global population ages, the treatment of neurodegenerative diseases is becoming more and more important. There is an urgent need to discover novel drugs that are effective in treating neurological diseases. In recent years, natural products and their biological activities have gained widespread attention. Lignans are a class of metabolites extensively present in Chinese herbal medicine and possess good pharmacological effects. Latest studies have demonstrated their neuroprotective pharmacological activity in preventing acute/chronic neurodegenerative diseases and depression. In this review, the pharmacological effects of these disorders, the pharmacokinetics, safety, and clinical trials of lignans were summarized according to the scientific literature. These results proved that lignans mainly exert antioxidant and anti-inflammatory activities. Anti-apoptosis, regulation of nervous system functions, and modulation of synaptic signals are also potential effects. Despite the substantial evidence of the neuroprotective potential of lignans, it is not sufficient to support their use in the clinical management. Our study suggests that lignans can be used as prospective agents for the treatment of neurodegenerative diseases and depression, with a view to informing their further development and utilization.

The antitumor activity and pharmacokinetics research of PPD-Arg (Tos) using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry

In this study, a new compound PPD-Arg (Tos) (PAT), an arginine derivative of 20(s)-PPD, was synthesized via Fmoc-Arg (Tos)-OH and 20(s)-PPD. The pharmacokinetic properties in rats, in vitro cytotoxicity, and cell apoptosis rates of protopanaxadiol (PPD) and PAT were determined. A sensitive bioanalytical method for pharmacokinetics using ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry was developed and validated. The result showed that the T_max and t_1/2 of PAT were significantly enhanced, indicating a long-lasting effect in vivo. Compared to the PPD group, the PAT group showed higher bioavailability. PAT also exhibited higher antitumor efficacy than PPD against three cancer cells, especially the strongest inhibitory activity against Huh-7, even more potent than the positive control of paclitaxel. Therefore, the apoptosis assay based on annexin V/propidium iodide-combined staining against Huh-7 further demonstrated that PAT could induce apoptosis of Huh-7 cells. Better pharmacokinetic properties and antitumor efficacy of the arginine derivative of 20(s)-PPD were important. These findings could provide references for further clinical research on amino acid derivatives of PPD as antitumor agents.

Arctigenin, an anti-tumor agent; a cutting-edge topic and up-to-the-minute approach in cancer treatment

Today, herbal-derived compounds are being increasingly studied in cancer treatment. Over the past decade, Arctigenin has been introduced as a bioactive dibenzylbutyrolactone lignan which is found in Chinese herbal medicines. In addition to anti-microbial, anti-inflammatory, immune-modulatory functions, Arctigenin has attracted growing attention due to its anti-tumor capabilities. It has been shown that Arctigenin can induce apoptosis and necrosis and abolish drug resistance in tumor cells by inducing apoptotic signaling pathways, caspases, cell cycle arrest, and the modulating proteasome. Moreover, Arctigenin mediates other anti-tumor functions through several mechanisms. It has been demonstrated that Arctigenin can act as an anti-inflammatory compound to inhibit inflammation in the tumor microenvironment. It also downregulates factors involved in tumor metastasis and angiogenesis, such as matrix metalloproteinases, N-cadherin, TGF-β, and VEGF. Additionally, Arctigenin, through modulation of MAPK signaling pathways and stress-related proteins, is able to abolish tumor cell growth in nutrient-deprived conditions. Due to the limited solubility of Arctigenin in water, it is suggested that modification of this compound through amino acid esterification can improve its pharmacogenetic properties. Collectively, it is hoped that using Arctigenin or its derivates might introduce new chemotherapeutic approaches in future treatment.

Influence of hepatic neoplasia on life expectancy in dogs

BACKGROUND AND AIM

The present study investigated the influence of liver tumor structure on life expectancy in dogs. Diseases of the liver comprise 5-25% of all non-communicable diseases in dogs, and primary hepatic tumors account for 0.6-1.3% of tumors. This research aimed to study the post-operative life span of animals with primary or metastatic tumors of the liver.

MATERIALS AND METHODS

During the study period, 7124 oncological operations were performed in our clinic. In total, 128 liver tumors were detected in live animals, while 323 were detected posthumously. Forty animals underwent surgery for various liver tumors. In dogs with primary liver tumors, the average age was 11.9 years and the average body weight was 15.5 kg, while in dogs with liver metastases, the mean age was 11.4 years and the average body weight was 24 kg.

RESULTS

The ratio of males to females among dogs with primary liver tumors was about 1:1 (ten females and nine males), while that among dogs with metastatic liver damage was clearly predominantly female (14 females and two males) because females often undergo surgery for cancerous mammary glands or ovaries.

CONCLUSION

The size of tumors and the number of affected lobes had a significant effect on the post-operative life span. With a tumor size of <5 cm and a lesion covering less than two lobes of the liver, life expectancy was significantly longer and the prognosis was more favorable. In cases of large tumors or those affecting more than two lobes, life expectancy was significantly reduced and the prognosis was cautious to unfavorable.

Pharmacokinetics of Arctigenin and Fructus Arctii Powder in Piglets

Fructus arctii, also known as great power seed, is the dried fruit of Arctium lappa of the family Compositae. It is a commonly used veterinary herbal medicine, and arctigenin is the main active ingredient. The aim of this study was to characterize the absorption, distribution, metabolism, and excretion of arctigenin and Fructus arctii powder in piglets. These data were used to provide a theoretical reference for the development and clinical use of new veterinary drugs. Sixteen healthy piglets (mean weight 30.0 ± 5.0 kg) were divided into two groups. One group was administered 2.0 mg/kg body weight (bw) arctigenin intravenously, and the other was administered 1.0 g/kg^.bw Fructus arctii powder by gavage. Blood samples were collected from the anterior vena cava at different time points, and the concentration of arctigenin in the plasma of the piglets was determined using high-performance liquid chromatography (HPLC). Arctigenin conformed to a two-compartment model with no absorption, and the main pharmacokinetic parameters were as follows: distribution half-life (t_1/2α)−0.166 ± 0.022 h; elimination half-life (t_1/2β)−3.161 ± 0.296 h; apparent volume of distribution (V_d)−0.231 ± 0.033 L/kg; clearance rate (CL_b)−0.057 ± 0.003 L/(h.kg); and area under the curve (AUC)−1.189 ± 0.057 g^.h/mL. The pharmacokinetic parameters of arctigenin following oral administration of the Fructus arctii powder were as follows: absorption half-life (t_1/2ka)−0.274 ± 0.102 h, t_1/2α−1.435 ± 0.725 h, t_1/2β−63.467 ± 29.115 h, V_d−1.680 ± 0.402 L/kg, CL_b−0.076 ± 0.028 L/(h kg), peak time (t_max)−0.853 ± 0.211 h, peak concentration (C_max)−0.430 ± 0.035 g/mL, and AUC−14.672 ± 4.813 g/mL. These results indicated that intravenous arctigenin was sparingly distributed in tissues. In contrast, orally administered Fructus arctii powder was rapidly absorbed, more widely distributed, and more slowly eliminated than the intravenous arctigenin, which may indicate its sustained pharmacological effects.

28-Day Oral Chronic Toxicity Study of Arctigenin in Rats

Arctium lappa (burdock) is the most popular daily edible vegetable in China and Japan because of its general health tonic effects. Previous studies focused on the beneficial role of Arctigenin but neglected its potential side-effects and toxicities. In the present study, the sub-chronic toxicity profile of Arctigenin following 28 days of consecutive exposure was investigated in rats. The results showed that during the drug exposure period, Arctigenin-12 mg/kg administration resulted in focal necrosis and lymphocytes infiltration of heart ventricular septal muscle cells. In the kidney cortical zone, the renal tubular epithelial cells were swollen, mineralized, and lymphocyte infiltrated. In the liver, the partial hepatocyte cytoplasm showed vacuolation and fatty changes, focal necrosis, and interstitial lymphocyte infiltration. In the rats that underwent 36 mg/kg/day administration, there was bilateral testis and epididymis atrophy. In the lung and primary bronchus, erythrocytes and edema fluid were observed. Changes of proestrus or estrus were observed in the uterus, cervix, and vagina intimal epithelial cells. Lymphocytic focal infiltration occurred in the prostate mesenchyme. The high dosage of Arctigenin only decreased the body weight at day 4. At the end of the recovery period, histopathological changes were irreversible, even after withdrawal of the drug for 28 days. Focal necrosis still existed in the heart ventricular septal muscle cells and hepatocytes. Lymphocyte infiltrations were observed in the heart, renal cortex, hepatocyte, and pancreas exocrine gland. Meanwhile, atrophy occurred in the testicles and pancreas. In addition, in the Arctigenin-12 mg/kg group, creatinine (CREA) and brain weight were both significantly increased. The toxicokinetical study demonstrated that Arctigenin accumulated in the organs of rats. The food consumption, hematological, and biochemical parameters were not associated with the above results. These contradictory results might result from the lesions induced by Arctigenin, which were not sufficiently serious to change the parameters. These results suggest that Arctium lappa should be consumed daily with caution because of the potential toxicity induced by Arctigenin. According to all results, the lowest observed adverse effect level (LOAEL) was induced by 12 mg/kg daily exposure to Arctigenin, and the No-observed-adverse-effect-level (NOAEL) should be lower than 12 mg/kg.

7-Isopenthenyloxycoumarin, Arctigenin, and Hesperidin Modify Myeloid Cell Leukemia Type-1 (Mcl-1) Gene Expression by Hormesis in K562 Cell Line

Hormesis is a new concept in dose–response relationship. Despite of traditional dose–response curves, there is a low-dose stimulation and a high-dose inhibition in this case. Hormesis effect in apoptosis induction/inhibition by natural compounds is reported previously. Here, we searched this effect for myeloid cell leukemia type-1 (Mcl-1) gene expression by phytochemicals 7-isopenthenyloxycoumarin (7-IP), arctigenin (Arg), and hesperidin (Hsp). For this purpose, first we tested the cytotoxicity of various doses of these compounds against K562 leukemia cell lines for different times by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. After that we explored the effect of various doses of these phytochemicals on Mcl-1 gene expression for different times by real-time polymerase chain reaction method. We found that these phytochemicals have cytotoxicity against K562 cell line. Hesperidin is the most cytotoxic agent. We also found that these natural compounds have hormetic effect on Mcl-1 gene expression. The hormetic model in Mcl-1 gene expression is overcompensation stimulation. This phenomenon is reported for the first time. We conclude that 7-IP, Arg, and Hsp are cytotoxic against K562 cancerous cells and induce/inhibit Mcl-1 gene expression by hormesis dose–response relationship.