In order to develop fermented silkworm “Dongchunghacho” (Paecilomyces tenuipes) with improved absorption and increased effectiveness, we fermented Dongchunghacho using four kinds of microorganisms, viz., lactic acid bacteria, Bacillus subtilis, Natto bacillus, and yeast. A total of 15 samples were fermented using a combination of microbial inoculation culture and conditions to produce fermentation products. The contents of basic components such as sugar, reducing sugar, protein, total polyphenol, and total flavonoid were examined as well as the antioxidant, tyrosinase inhibitory, and thrombolytic activities of the fermented products were analyzed. We observed that reducing sugar and protein contents decreased in most of the fermented products, but the products fermented using yeast exhibited higher sugar content and, thus, higher sweetness. Total polyphenol content and antioxidant activity did not increase in fermented products compared to non-fermented Dongchunghachos, but total flavonoid content and tyrosinase inhibitory and thrombolytic activities increased by fermentation. In particular, total flavonoid content and tyrosinase inhibitory and thrombolytic activities primarily increased in the products fermented using yeast and lactic acid bacteria. However, it was not possible to confirm the increase in these activities in samples fermented by single fermentation using only yeast. Therefore, we propose that it will be possible to develop fermented food from silkworm Dongchunghacho (P. tenuipes) with excellent health benefits through additional study of multiple fermentation conditions using lactic acid bacteria and yeast.

Steamed and freeze-dried mature silkworm powders (SMSP) have various health improvement effects. However, westill do not know which substances are reponsible for varius health improvement effect yet. In this study, we comparedcontents of phytochemicals in SMSP to mulberry leaves and other silkworm powders. We found that SMSP have certainlevels of phyttochemicals and silk proteins. Our data suggested that various substances in SMSP are responsible for healthimprovements effect. (Project title: Elucidation the health improvement effects of boiled silk worm larvae, Project No:PJ010828012017)

Hepatocellular carcinoma (HCC) is a representative inflammation-associated cancer and known to be the most frequent tumor. However, the preventive agents for hepatocarcinogenesis are unsatisfactorily identified. We investigated the protective effect of steamed and freeze-dried mature silkworm larval powder (SMSP) on diethylnitrosamine (DEN)-induced hepatotoxicity in mice and compared the effect of three silkworm varieties: white-jade, golden-silk, and light-green strains. The mice were fed with diet containing 0.1, 1, and 10 g/kg of three types of SMSP for two weeks while DEN (100 mg/kg, i.p.) was injected 18 h before the end of this experiment. Liver toxicity was determined as serum indicator, histopathological examination, and expression of inflammatory enzyme. Pretreatment with SMSP reduced necrotic and histopathological changes induced by DEN in the liver. The measurement of serum biochemical indicators showed that pretreatment with SMSP also decreased DEN-induced hepatotoxicity, the levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). In addition, SMSP inhibited the expressions of inflammatory enzymes, cyclooxygenase-2 and inducible nitric oxide synthase. White-jade SMSP showed the most effective hepatoprotective results against hepatotoxicity among the three silkworm strains used in this study. SMSP may have a protective effect against acute liver injury by inhibiting necrosis and inflammatory response in DEN-treated mice.