Garlic Oil Suppressed Nitrosodiethylamine-Induced Hepatocarcinoma in Rats by Inhibiting PI3K-AKT-NF-κB Pathway

Garlic oil supplementation blocks inflammatory pyroptosis-related acute lung injury by suppressing the NF-κB/NLRP3 signaling pathway via H2S generation

Acute lung injury (ALI) is a major cause of acute respiratory failure with a high morbidity and mortality rate, and effective therapeutic strategies for ALI remain limited. Inflammatory response is considered crucial for the pathogenesis of ALI. Garlic, a globally used cooking spice, reportedly exhibits excellent anti-inflammatory bioactivity. However, protective effects of garlic against ALI have never been reported. This study aimed to investigate the protective effects of garlic oil (GO) supplementation on lipopolysaccharide (LPS)-induced ALI models. Hematoxylin and eosin staining, pathology scores, lung myeloperoxidase (MPO) activity measurement, lung wet/dry (W/D) ratio detection, and bronchoalveolar lavage fluid (BALF) analysis were performed to investigate ALI histopathology. Real-time polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were conducted to evaluate the expression levels of inflammatory factors, nuclear factor-κB (NF-κB), NLRP3, pyroptosis-related proteins, and H2S-producing enzymes. GO attenuated LPS-induced pulmonary pathological changes, lung W/D ratio, MPO activity, and inflammatory cytokines in the lungs and BALF. Additionally, GO suppressed LPS-induced NF-κB activation, NLRP3 inflammasome expression, and inflammatory-related pyroptosis. Mechanistically, GO promoted increased H2S production in lung tissues by enhancing the conversion of GO-rich polysulfide compounds or by increasing the expression of H2S-producing enzymes in vivo. Inhibition of endogenous or exogenous H2S production reversed the protective effects of GO on ALI and eliminated the inhibitory effects of GO on NF-κB, NLRP3, and pyroptotic signaling pathways. Overall, these findings indicate that GO has a critical anti-inflammatory effect and protects against LPS-induced ALI by suppressing the NF-κB/NLRP3 signaling pathway via H2S generation.

Hepatoprotective effect of diallyl trisulfide against lipopolysaccharide and D-galactosamine induced acute liver failure in mice via suppressing inflammation and apoptosis

Acute liver failure (ALF), characterized by the quick occurrence of disorder in liver, is a serious liver injury with extremely high mortality. Therefore, we investigated whether diallyl trisulfide (DATS), a natural product from garlic, protected against ALF in mice and studied underlying mechanisms. In the present study, lipopolysaccharide (LPS) (10 μg·kg^-1)/D-galactosamine (D-gal) (500 mg·kg^-1) was intraperitoneally injected to ICR mice to induce ALF. The mice were orally administered 20-, 40-, or 80-mg·kg^-1 DATS) 1 h before LPS/D-gal exposure. Serum biochemical analyses and pathological study found that DATS pretreatment effectively prevented the ALF in LPS/D-gal-treated mice. Mechanistically, pretreatment of DATS inhibited the increase of the numbers of CD11b⁺ Kupffer cells and other macrophages in the liver, the release of tumor necrosis factor-α into the blood, and Caspase-1 activation induced by LPS/D-gal treatment in mice. Furthermore, DATS inhibited the activation of Caspase-3, downregulation of Bcl-2/Bax ratio, and increase of TUNEL positive staining. Altogether, our findings suggest that DATS exhibits hepatoprotective effects against ALF elicited by LPS/D-gal challenge, which probably associated with anti-inflammation and anti-apoptosis.

Estrogen receptor-α36 is involved in diallyl sulfide-induced inhibition of malignant growth of HepG2 and Huh7 hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is a highly malignant disease that currently lacks effective treatment. Epidemiological studies have suggested the preventive role of raw garlic intake in different tumors, such as HCC. Although diallyl sulfide (DAS), the main component of garlic extracts, has been reported to inhibit the growth of HCC cells, the underlying mechanism remains elusive. This study aimed to investigate the inhibitory effect of DAS on the growth of HepG2 and Huh7 hepatocellular carcinoma cells and its underlying mechanism. HepG2 and Huh7 cells were treated with DAS and nude mice were intrahepatically injected with human HCC HepG2 cells and maintained with or without DAS administration for 28 days. MTS and clonogenic assays revealed that DAS inhibited the growth and clonogenicity of HepG2 and Huh7 hepatocellular carcinoma cells. Furthermore, DAS inhibited the growth of xenograft tumors accompanied by a decreased rate of pathological karyomitosis as observed by H&E staining. The expression levels of estrogen receptor-α36 (ER-α36) and epidermal growth factor receptor (EGFR) in HepG2 and Huh7 cells and in xenograft tumors derived from HepG2 cells after DAS treatment were detected by immunohistochemistry and western blotting. We found that DAS disrupted the positive regulatory loop between ER-α36 and EGFR, and decreased the phosphorylation of AKT at Ser 473 both in vivo and in vitro. DAS also induced cell apoptosis, as evidenced by Hoechst and TUNEL staining. Western blotting revealed activation of caspase3, increased BAX and decreased Bcl-2 expression. However, the ER-α36 expression knockdown attenuated DAS-induced ERK and AKT phosphorylation in HCC cells. DAS was also able to inhibit ER-α36-mediated activation of the MAPK/ERK signaling induced by estrogen. Thus, our results indicate that ER-α36 signaling is involved in DAS-induced inhibition of HCC cell growth both in vitro and in vivo.

Morin attenuates osteoclast formation and function by suppressing the NF-κB, MAPK and calcium signalling pathways

Morin is a natural compound isolated from moraceae family members and has been reported to possess a range of pharmacological activities. However, the effects of morin on bone-associated disorders and the potential mechanism remain unknown. In this study, we investigated the anti-osteoclastogenic effect of morin in vitro and the potential therapeutic effects on ovariectomy (OVX)-induced osteoporosis in vivo. In vitro, by using a bone marrow macrophage-derived osteoclast culture system, we determined that morin attenuated receptor activator of nuclear factor (NF)-κB ligand (RANKL)-induced osteoclast formation via the inhibition of the mitogen-activated protein kinase (MAPK), NF-κB and calcium pathways. In addition, the subsequent expression of nuclear factor of activated T cells c1 (NFATc1) and c-fos was significantly suppressed by morin. In addition, NFATc1 downregulation led to the reduced expression of osteoclastogenesis-related marker genes, such as V-ATPase-d2 and Integrin β3. In vivo, results provided that morin could effectively attenuate OVX-induced bone loss in C57BL/6 mice. In conclusion, our results demonstrated that morin suppressed RANKL-induced osteoclastogenesis via the NF-κB, MAPK and calcium pathways, in addition, its function of preventing OVX-induced bone loss in vivo, which suggested that morin may be a potential therapeutic agent for postmenopausal osteoporosis treatment.

Protective Effects of Garlic and Cinnamon Oils on Hepatocellular Carcinoma in Albino Rats

Natural oils are traditional medicinal herbs, which have attracted interests for its potential anti-inflammatory and anticancer activities. The present work is aimed at evaluating the protective effect of garlic oil and cinnamon oil on diethylnitrosamine- (DENA-) and 2-acetylaminofluorene- (2-AAF-) induced p53 gene mutation and hepatocarcinogenesis in rats. Forty male albino rats were divided into 4 equal groups: control, hepatocellular carcinoma (HCC), garlic oil-HCC, and cinnamon oil-HCC. The HCC-induced group showed a significant decrease in the body mass and a significant elevation in the liver weight, alpha-fetoprotein (AFP), liver enzymes, hepatic malondialdehyde (MDA), and p53 protein expression levels as well as genetic mutations in intron 5 of p53 gene in the form of Single-Nucleotide Polymorphisms (SNPs) and insertions. In addition, the glutathione (GSH) level and superoxide dismutase (SOD) activities were increased. While HCC rats pretreated with garlic oil or cinnamon oil were significantly reversed, these destructive actions increased GSH and SOD levels. The HCC-induced group showed histopathological features of liver cancer including hypercellularity, nuclear hyperchromasia, mitotic figures, and preneoplastic foci. On the other hand, HCC rats pretreated with garlic oil or cinnamon oil revealed partial reversal of normal liver architecture. The present findings proposed that these natural oils have the ability to improve liver function, significantly reduced the liver toxicity and HCC development. However, further sophisticated studies are recommended before their use as conventional therapeutics for HCC treatment.

Potent effects of dioscin against hepatocellular carcinoma through regulating TP53-induced glycolysis and apoptosis regulator (TIGAR)-mediated apoptosis, autophagy, and DNA damage

BACKGROUND AND PURPOSE

Dioscin shows potent effects against cancers. We aimed to elucidate its pharmacological effects and mechanisms of action on hepatocellular carcinoma (HCC) in vivo and in vitro.

EXPERIMENTAL APPROACH

Effects of dioscin were investigated in SMMC7721 and HepG2 cells, diethylnitrosamine-induced primary liver cancer in rats, and cell xenografts in nude mice. Isobaric tags for relative and absolution quantitation (iTRAQ)-based proteomics was used to find dioscin's targets and investigate its mechanism.

KEY RESULTS

In SMMC7721 and HepG2 cells dioscin markedly inhibited cell proliferation and migration, induced apoptosis, autophagy, and DNA damage. It inhibited DEN-induced primary liver cancer in rats, markedly changed body weights and restored levels of α fetoprotein, alanine transaminase, aspartate transaminase, γ-glutamyltransferase, alkaline phosphatase, and Ki67. It also inhibited growth of xenografts in mice. In SMMC7721 cells, 191 differentially expressed proteins were found after dioscin, based on iTRAQ-based assay. TP53-inducible glycolysis and apoptosis regulator (TIGAR) was identified as being significantly down-regulated by dioscin. Dioscin induced cell apoptosis, autophagy, and DNA damage via increasing expression levels of p53, cleaved PARP, Bax, cleaved caspase-3/9, Beclin-1, and LC3 and suppressing those of Bcl-2, p-Akt, p-mammalian target of rapamycin (mTOR), CDK5, p-ataxia telangiectasia-mutated gene (ATM). The transfection of TIGAR siRNA into SMMC7721 cells and xenografts in nude mice further confirmed that the potent activity of dioscin against HCC is evoked by adjusting TIGAR-mediated inhibition of p53, Akt/mTOR, and CDK5/ATM pathways.

CONCLUSIONS AND IMPLICATIONS

The data suggest that dioscin has potential as a therapeutic, and TIGAR as a drug target for treating HCC.

Preventive Effect of Garlic Oil and Its Organosulfur Component Diallyl-Disulfide on Cigarette Smoke-Induced Airway Inflammation in Mice

Garlic (Allium sativum) has traditionally been used as a medicinal food and exhibits various beneficial activities, such as antitumor, antimicrobial, hypolipidemic, antiarthritic, and hypoglycemic activities. The aim of this study was to explore the preventive effect of garlic oil (GO) and its organosulfur component diallyl disulfide (DADS) on cigarette smoke (CS)-induced airway inflammation. Mice were exposed to CS daily for 1 h (equivalent to eight cigarettes per day) for two weeks, and intranasally instilled with lipopolysaccharide (LPS) on day 12 after the initiation of CS exposure. GO and DADS were administered to mice by oral gavage, both at rates of 20 and 40 mg/kg, for 1 h before CS exposure for two weeks. In the bronchoalveolar lavage fluid, GO and DADS inhibited the elevation in the counts of inflammatory cells, particularly neutrophils, which were induced in the CS and LPS (CS + LPS) group. This was accompanied by the lowered production (relative to the CS + LPS group) of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α. Histologically, GO and DADS inhibited the CS- and LPS-induced infiltration of inflammatory cells into lung tissues. Additionally, GO and DADS inhibited the phosphorylation of extracellular signal-regulated kinase and the expression of matrix metalloproteinase-9 in the lung tissues. Taken together, these findings indicate that GO and DADS could be a potential preventive agent in CS-induced airway inflammation.

Ellagic Acid Holds Promise Against Hepatocellular Carcinoma in an Experimental Model: Mechanisms of Action

This research work was initiated to explore the efficacy of ellagic acid in mitigation of hepatocarcinogenesis in rats. Rats were distributed into 4 groups; negative control, hepatocellular carcinoma (HCC), doxorubicin and ellagic acid. Serum alpha-fetoprotein (AFP), glypican-3 (GPC-3), signal transducer and activator of transcription 3 (STAT3) and suppressors of cytokine signaling 3 (SOCS3) levels were assayed by ELISA. Immunohistochemical examination of hepatic VEGF expression was also conducted, along with histological procedures for examination of liver tissue sections. Significant elevation in serum AFP, GPC-3 and STAT3 levels with a significant drop in SOCS3 were observed in the HCC group. In contrast, the treated groups showed significant decline in serum AFP, GPC-3 and STAT3 levels and significant increase in SOCS3. Additionally, the HCC group declared mild positive immunoreaction for VEGF in hepatocytes while treatment with doxorubicin or ellagic acid was associated with a negative immunoreaction for VEGF. These results were supported by histological examination of liver tissue. The obtained findings suggested that ellagic acid may have beneficial chemopreventive role against hepatocarcinogenesis through its apoptotic, antiangiogenic and antiproliferative activities.

The protective effect of diallyl trisulfide on cytopenia induced by benzene through modulating benzene metabolism

It has been known that metabolism of benzene is necessary for its toxicity. The purpose of our study is to investigate the effect of diallyl trisulfide (DATS) on attenuating cytopenia in peripheral blood introduced by benzene through regulating benzene metabolism in rats. We established benzene poisoning model with benzene (1.3 g/kg), while the DATS treatment groups were treated with DATS plus benzene (15 or 30 mg/kg) for 28 days, respectively. The results of blood parameters and concentration of metabolites of benzene (t, t-MA and SPMA) determination in urine showed that DATS could effectively attenuate the cytopenia induced by benzene through regulating benzene metabolism. Western blot and chemical method were used to detect the activities and protein expression levels of enzymes CYP2E1 and GSTT1 in liver and enzymes MPO and NQO1 in bone marrow were tested. The results suggested that the inhibition of bioactivation in liver and bone marrow catalyzed by CYP2E1 and MPO and the activation of detoxification catalyzed by GSTT1 and NQO1 might be the critical mechanism, through which DATS modulated benzene metabolism to prevent benzene-induced cytopenia.