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

Abstract

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.

How Healthy Are Non-Traditional Dietary Proteins? The Effect of Diverse Protein Foods on Biomarkers of Human Health

“…Only one study has evaluated the health effect of freeze dried mature silkworm larvae powder ( Bombyx mori ; silkworm). Lee et al administered silkworm powder to rats, in parallel with oral ethanol gavage, to explore the effect on biomarkers of alcohol-induced fatty liver disease [ 63 , 64 ]. Rats treated with silkworm powder had lower hepatic triglycerides (by 35%), together with a reduced plasma triglycerides and inflammatory markers (tumor necrosis factor-alpha and interleukin-1 beta, cytochrome P450 2E1 generating oxidative stress) compared to those for which ethanol was administered alone.…”

“…Consistent with these changes, the expression of genes involved with lipogenesis and fatty acid oxidation were upregulated in rats administered with silkworm powder. These findings suggest that silkworm powder may have a protective effect; however, much more research is needed [ 63 ].…”

“…Studies in animals suggest a potential anti-obesity effect, improved lipid metabolism, cholesterol biosynthesis, and reduced plasma homocysteine [ 54 , 55 , 56 , 57 ]. Silkworm, likewise, shows a beneficial effect on hepatic steatosis and alcohol-induced fatty liver disease [ 63 ]. Termites are well-accepted in African communities, increasing the protein and mineral content of infant foods [ 47 ].…”

Insects Used as Food and Feed: Isn’t That What We All Need?

“…Da-Young Lee and colleagues [ 34 ], who investigated the extent to which freeze-dried mature larval silkworm powder (SMSP) affected ethanol-induced fatty liver disease in rats, found that mature larval silkworm powder reduced triglyceride levels by as much as 35% in the livers of the rats that had received daily doses of 25% ethanol (3 g/kg body weight) for 4 weeks. In ethanol-treated rats given SMSP, the serum levels of triglycerides and various other compounds were lower, suggesting that SMSP can protect against alcoholic liver disease.…”

Use of a Silkworm (Bombyx mori) Larvae By-Product for the Treatment of Atopic Dermatitis: Inhibition of NF-κB Nuclear Translocation and MAPK Signaling

“…Ji et al [ 14 ] showed that silkworm powder effectively alleviates hepatic steatosis and injury in ethanol-treated rats through several mechanisms, including the inhibition of oxidative stress and inflammatory response. Moreover, studies have reported the inhibitory effects of steamed and freeze-dried silkworm powder (SFSP) on hepatic fibrosis and hepatocellular carcinoma [ 16 ]. The anti-melanogenic activity of SFSP [ 17 ] and the ameliorative effect of mature silkworm powder on scopolamine-induced amnesia [ 18 ] have been well documented.…”