Antioxidative properties of 4-methylumbelliferone are related to antibacterial activity in the silkworm (Bombyx mori) digestive tract

In vitro analysis of 4-methylumbelliferone as a sole carbon source for Lactobacillus helveticus 2126

In the recent years, 4-methylumbelliferone (4-MU) has been gaining importance, both as an anti-cancer agent and as a dietary supplement. The aim of this study was to determine the effectiveness of 4-MU as a carbon source for potential probiotic bacteria Lactobacillus helveticus 2126. For this purpose, a series of plate assays and infrared spectroscopy (FTIR) were used for 4-MU before and after the treatment with L. helveticus 2126. The plate assays indicated an initial inhibition followed by utilization of 4-MU that stimulated bacterial growth. A significant shift was observed in the FTIR peaks, which also have suggested possible extracellular activity of the bacteria for 4-MU utilization.

SIGNIFICANCE AND IMPACT OF THE STUDY

4-Methylumbelliferone (4-MU) is a widely used chloretic and is currently under research for treating colon cancer. Preliminary studies suggest that it has the potential to be used as an effective and sustainable prebiotic for the human microbiome, as it can be naturally obtained from plants. This manuscript describes the effectiveness of 4-MU as a carbon source for the probiotic bacteria Lactobacillus helveticus. Our study also suggests the role of bacterial superoxide dismutase in transforming 4-MU as a possible prebiotic for the human microbiome.

Hematopoiesis toxicity induced by 4-methylumbelliferon determined in an invertebrate model organism

Umbelliferone has potential value as it has an inhibitory effect on tumor cells; however, its impact on an animal's circulatory system and hematopoietic function has not been reported. In this study, 4-methylumbelliferon (4-MU), an umbelliferone derivative, was used as a model drug, and its potential toxicity on hemocytes and hematopoietic organs (HOs) was investigated using an invertebrate animal model, the silkworm, Bombyx mori. The results showed that the level of reactive oxygen species in HOs increased when larvae (third day of the fifth instar) were orally exposed to 4 mM 4-MU for 8 min, followed by the induction of improved antioxidative metabolism of coenzymes in hemolymph. Exposure to 4-MU also significantly upregulated the expression levels of several genes in the hemolymph and fat body (a detoxification tissue similar to the liver in mammals) including antimicrobial peptide gene cecropinA and moricin, and a phagocytosis-related gene, tetraspanin E, suggesting an increased antioxidant level and antimicrobial ability of the circulatory system. However, the percentage of dead hemocytes increased and hematopoiesis significantly decreased in HOs, indicating the toxic effect of 4-MU on hemocytes and hematopoiesis, despite it inducing enhanced antioxidant and antimicrobial activity in the circulatory system.

Parental environmental exposure leads to glycometabolic disturbances that affect fertilization of eggs in the silkworm Bombyx mori: the parental transcript legacy

Parental transcript legacy plays an important role in fertilization and development of the early embryo. Parental environmental exposure affects the fertilization of eggs, but the underlying biochemical mechanism is largely unresolved. In this study, the parental environmental effects on fertilization of eggs were explored in the silkworm Bombyx mori (B. mori), an ideal lepidopteran animal model. The results showed that the rate of fertilization decreased after the parents were exposed to a poor environment at 32 °C with continuous illumination for 72 h on days 6-9 of the pupal stage, which is a key period for germ cell maturation. This was likely attributable to lower energy charge values, obstructed nicotinamide adenine dinucleotide (NAD(+)) regeneration and inactive tricarboxylic acid cycle (TCA), leading to accumulation of large amounts of pyruvic acid and lactic acid. This effect was related to energy metabolism via glycolysis; in particular disruption of pyruvate metabolism. In conclusion, this study showed parental exposure to an abnormal environment during germ cell maturation affected glycolysis and the subsequent fertilization of eggs via the parental transcript legacy in B. mori.