Protective Effect of Boiled and Freeze-dried Mature Silkworm Larval Powder Against Diethylnitrosamine-induced Hepatotoxicity in Mice

BPOZ-2-deficient mice exhibit aggravated inflammation-associated tissue damage after acute dextran sodium sulfate or diethylnitrosamine exposure

An excessive inflammatory response plays an important role in pathological tissue damage associated with pathogen infection and tumorigenesis. Blood POZ-containing gene type 2 (BPOZ-2), an adaptor protein for the E3 ubiquitin ligase scaffold protein CUL3, is a negative regulator of the inflammatory response. In this study, we investigated the pathophysiological functions of BPOZ-2 in dextran sodium sulfate (DSS)-induced colon injury and diethylnitrosamine (DEN)-induced liver damage. Our results indicated that BPOZ-2 deficiency increased IL-1β induction after DSS and DEN treatment. In addition, BPOZ-2-deficient mice were more susceptible to DSS-induced colitis. Notably, BPOZ-2 deficiency aggravated DEN-induced acute liver injury. These results revealed that BPOZ-2 protected against pathological tissue damage with a dysregulated inflammatory response.

Anti-Obesity Effects of the Larval Powder of Steamed and Lyophilized Mature Silkworms in a Newly Designed Adult Mouse Model

Recently, "mature" silkworms (MS) of Bombix mori have been considered a potential nutraceutical, with a number of health benefits reported for steamed and lyophilized MS powder (SMSP). However, no obesity-related effects have been reported for SMSP. In the present study, anti-obesity effects of SMSP were investigated in adult mice in vivo, aged 12 weeks at the onset of SMSP treatment, fed a normal diet (ND) and a high-fat diet (HFD), respectively, for 12 weeks. SMSP significantly suppressed body weight gain, intra-abdominal adipose tissue, and food efficiency in both ND-fed and HFD-fed adult mice. In addition, SMSP significantly decreased food intake and liver weight in HFD-fed mice, indicating that SMSP suppressed appetite and simultaneously reduced the conversion of feed into body weight in HFD-fed mice. SMSP also significantly lowered the serum levels of glucose, triglyceride, total cholesterol, low-density lipoprotein cholesterol, asparagine transaminase, alanine transaminase, and alkaline phosphatase. However, SMSP had no significant effect on the weights of the kidney, spleen, or thymus or the serum levels of blood urea nitrogen and creatinine. Taken together, the above results suggest that SMSP has potent anti-obesity effects and is safe for long-term use as a potential therapeutic and/or nutraceutical in both obese patients and non-obese individuals.

Artichoke (Cynara Scolymus) Methanolic Leaf Extract Alleviates Diethylnitrosamine-Induced Toxicity in BALB/c Mouse Brain: Involvement of Oxidative Stress and Apoptotically Related Klotho/PPARγ Signaling

(1) Background: Various epidemiological studies suggest that oxidative stress and disrupted neuronal function are mechanistically linked to neurodegenerative diseases (NDs), including Parkinson's disease (PD) and Alzheimer's disease (AD). DNA damage, oxidative stress, lipid peroxidation, and eventually, cell death such as NDs can be induced by nitrosamine-related compounds, leading to neurodegeneration. A limited number of studies have reported that exposure to diethylnitrosamine (DEN), which is commonly found in processed/preserved foods, causes biochemical abnormalities in the brain. Artichoke leaves have been used in traditional medicine as a beneficial source of bioactive components such as hydroxycinnamic acids, cynarine, chlorogenic acid, and flavonoids (luteolin and apigenin). The aim of this study is to investigate the favorable effects of exogenous artichoke (Cynara scolymus) methanolic leaf extract supplementation in ameliorating DEN-induced deleterious effects in BALB/c mouse brains. (2) Methods: This study was designed to evaluate DEN (toxicity induction by 100 mg/kg) and artichoke (protective effects of 0.8 and 1.6 g/kg treatment) for 14 days. All groups underwent a locomotor activity test to evaluate motor activity. In brain tissue, oxidative stress indicators (TAC, TOS, and MDA), Klotho and PPARγ levels, and apoptotic markers (Bax, Bcl-2, and caspase-3) were measured. Brain slices were also examined histopathologically. (3) Results: Artichoke effectively ameliorated DEN-induced toxicity with increasing artichoke dose. Impaired motor function and elevated oxidative stress markers (decreasing MDA and TOS levels and increasing TAC level) induced by DEN intoxication were markedly restored by high-dose artichoke treatment. Artichoke significantly improved the levels of Klotho and PPARγ, which are neuroprotective factors, in mouse brain tissue exposed to DEN. In addition, caspase-3 and Bax levels were reduced, whereas the Bcl-2 level was elevated with artichoke treatment. Furthermore, recovery was confirmed by histopathological analysis. (4) Conclusions: Artichoke exerted neuroprotective effects against DEN-induced brain toxicity by mitigating oxidant parameters and exerting antioxidant and antiapoptotic effects. Further research is needed to fully identify the favorable impact of artichoke supplementation on all aspects of DEN brain intoxication.

Sericulture and the edible-insect industry can help humanity survive: insects are more than just bugs, food, or feed

The most serious threat which humans face is rapid global climate change, as the Earth shifts rapidly into a regime less hospitable to humans. To address the crisis caused by severe global climate change, it will be necessary to modify humankind's way of life. Because livestock production accounts for more than 14.5% of all greenhouse gas (GHG) emissions, it is critical to reduce the dependence of humans on protein nutrients and calories obtained from livestock. One way to do so is to use insects as food. Compared with typical livestock, farming edible insects (or "mini-livestock") produce fewer GHG emissions, require less space and water, involve shorter life cycles, and have higher feed conversion rates. It has been recently reported that consumption of certain insects can prevent or treat human diseases. This review goes beyond entomophagy to entomotherapy and their application to the food industry.

Synergistic Neuroprotective Effects of Mature Silkworm and Angelica gigas Against Scopolamine-Induced Mild Cognitive Impairment in Mice and H2O2-Induced Cell Death in HT22 Mouse Hippocampal Neuronal Cells

We previously reported that mature Bombyx mori silkworm (SW) ameliorated scopolamine (Sco)-induced amnesia, and Angelica gigas (AG) prevented cognitive impairment. SW is known for its gastroprotective effects such as improving liver function and alleviating the effects of Parkinson's disease. AG is known for its neuroprotective effects and for lowering the effects of low-density lipoprotein cholesterol. However, the neuroprotective effect of combined SW and AG (SWA-1) treatment and the underlying molecular mechanism by which SWA-1 regulates neurodegenerative diseases remains unclear. We evaluated the neuroprotective effect of SWA-1 against Sco-induced mild cognitive impairment in mice and H₂O₂-induced cell death in HT22 mouse hippocampal neuronal cells and elucidated the underlying molecular mechanism. Morris water maze and Y-maze tests were performed to examine the learning and memory abilities of mice. The underlying molecular mechanism was investigated by using western blotting. We demonstrated that SWA-1 significantly protects against H₂O₂-induced cell death in HT22 mouse hippocampal neuronal cells. SWA-1 also significantly reversed Sco-induced spatial learning and memory impairment. Specifically, SWA-1 upregulates the protein levels of phosphorylated extracellular signal-related kinase (Erk1/2) and phosphorylated p38 MAP kinase (p38). SWA-1 remarkably decreased the apoptotic index Bax/Bcl2 expression in the hippocampus of Sco-treated mice. Our results suggest that SWA-1 may be administered as alternative therapy for cognitive impairment and neurodegenerative diseases and should be studied further in human trials.

Hepatoprotective Effects of Steamed and Freeze-Dried Mature Silkworm Larval Powder against Ethanol-Induced Fatty Liver Disease in Rats

Silkworm, Bombyx mori, contains high amounts of beneficial nutrients, including amino acids, proteins, essential minerals, and omega-3 fatty acids. We have previously reported a technique for producing steamed and freeze-dried mature silkworm larval powder (SMSP), which makes it easier to digest mature silkworm. In this study, we investigated the preventive effects of SMSP on alcoholic fatty liver disease and elucidated its mechanism of action. Male Sprague-Dawley rats treated with SMSP (50 mg/kg) or normal diet (AIN-76A) were administered 25% ethanol (3 g/kg body weight) by oral gavage for 4 weeks. SMSP administration for 4 weeks significantly decreased hepatic fat accumulation in ethanol-treated rats by modulating lipogenesis and fatty acid oxidation-related molecules such as sirtuin 1, AMP-activated protein kinase, and acetyl-CoA carboxylase 1. Moreover, SMSP administration significantly diminished the levels of triglyceride in liver tissues by as much as 35%, as well as lowering the serum levels of triglyceride, gamma glutamyl transpeptidase, alanine transaminase, and aspartate aminotransferase in ethanol-treated rats. SMSP supplementation also decreased the pro-inflammatory tumor necrosis factor-alpha and interleukin 1 beta levels and cytochrome P450 2E1 generating oxidative stress. These results suggest that SMSP administration may be possible for the prevention of alcoholic liver disease.

Administration of Steamed and Freeze-Dried Mature Silkworm Larval Powder Prevents Hepatic Fibrosis and Hepatocellular Carcinogenesis by Blocking TGF-β/STAT3 Signaling Cascades in Rats

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related deaths worldwide and the majority of HCC patients occur with a background of hepatic fibrosis and cirrhosis. We have previously reported the hepatoprotective effects of steamed and freeze-dried mature silkworm larval powder (SMSP) in a chronic ethanol-treated rat model. Here, we assessed the anti-fibrotic and anti-carcinogenic effects of SMSP on diethylnitrosamine (DEN)-treated rats. Wistar rats were intraperitoneally injected with DEN once a week for 12 or 16 weeks with or without SMSP administration (0.1 and 1 g/kg). SMSP administration significantly attenuated tumor foci formation and proliferation in the livers of the rats treated with DEN for 16 weeks. SMSP administration also inhibited hepatic fibrosis by decreasing the levels of collagen fiber and the expression of pro-collagen I and alpha-smooth muscle actin (α-SMA). Moreover, SMSP supplementation improved the major parameters of fibrosis such as transforming growth factor-β (TGF-β), connective tissue growth factor (CTGF), tumor necrosis factor-alpha (TNF-α), plasminogen activator inhibitor-1 (PAI-1), and collagen type I (Col1A1) in the livers from the rats treated with DEN for 16 weeks. As s possible mechanisms, we investigated the effects of SMSP on the TGF-β and signal transducer and activator of transcription 3 (STAT3)-mediated signaling cascades, which are known to promote hepatic fibrosis. We found that SMSP treatment inhibited the activation of TGF-β and the phosphorylation of STAT3 pathway in DEN-treated rats. Moreover, SMSP administration suppressed the expressions of the target genes of TGF-β and STAT3 induced by DEN treatment. Our findings provide experimental evidences that SMSP administration has inhibitory effects of hepatic fibrosis and HCC induced by DEN in vivo and could be a promising strategy for the prevention or treatment of hepatic fibrosis and hepatocellular carcinogenesis.