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The hatching rates and developmental durations of Eupolyphaga sinensis Walker eggs were studied under variable combinations of low temperatures (5 °C and 10 °C) and high temperatures (25 °C and 30 °C). Our findings were intended to provide new evidence on the effect of temperature on the hatching of insect eggs. The results showed that both low temperatures and high temperatures significantly affected the hatching rate and time of E. sinensis eggs. Further analysis revealed a significant interactive effect between low temperatures and high temperatures. The 5 °C + 30 °C treatment achieved the highest egg hatching rate (77.33%) and the shortest hatching time (44.11 ± 1.55 d), which was significant compared with three other temperature treatments. The effects of high temperatures treatments on the hatching rate and the hatching time were more significant than that in the low temperature treatments. Hatching began earlier at 5 °C + 30 °C and 10 °C+30 °C temperatures, and single-day hatching first increased rapidly before declining afterwards within a short period. Comparatively, the hatching of eggs under the (5 °C+25 °C) and (10 °C+25 °C) temperatures was initially significantly delayed, including the peak single-day hatching rate. Under these treatments, the hatching rate tended to be gradual in terms of the temporal dynamics without showing any prominent peak. These results showed that low and high temperatures significantly affect the hatching rates of E. sinensis eggs. This study provided basis for the large-scale breeding of E. sinensis. [ABSTRACT FROM AUTHOR]

The dysbiosis of gut flora and its metabolites plays important roles in the progression of hyperlipidemia (HL), and some bioactive peptides are available for HL treatment. In this study, we aimed to isolate an active peptide (AR-9) from active peptides of E. sinensis (APE) and determine whether AR-9 could improve many symptoms of a HL rat induced by a high-fat diet (HFD) by modulating gut flora and its metabolites. Above all, AR-9 was derived from APE using ion-exchange chromatography, and its structure was deconstructed by Fourier transform infrared spectrometer (FT-IR), circular dichroism (CD) spectroscopy, and UHPLC-Q-Exactive-Orbitrap MS. Then, an HFD-induced HL model in SD rats was established and used to clarify the regulatory effects of AR-9 (dose of 3 mg/kg) on HL. Normal diet--fed rats were taken as the control. The plasma samples and liver were harvested for biochemical and histopathological examinations. 16S rRNA gene sequencing and untargeted metabolomics were sequenced to assess changes in gut flora and its metabolites from rat fecal samples. Finally, Spearman's correlation analysis was used to assess the relationship between lipid-related factors, gut flora, and its metabolites so as to evaluate the mechanism of AR-9 against HL. The results of the separation experiments showed that the amino acid sequence of AR-9 was AVFPSIVGR, which was a fragment of the actin protein from Blattaria insects. Moreover, HFD rats developed exaltation of index factors, liver lipid accumulation, and simple fibrosis for 8 weeks, and the profiles of gut flora and its metabolites were significantly altered. After treatment, AR-9 decreased the levels of lipid factors in plasma and the extent of liver damage. 16S rRNA gene sequencing results indicated that AR-9 significantly increased the relative abundance of beneficial bacteria Bacteroidetes and reduced the relative abundance of the obesity-associated bacteria Firmicutes. Furthermore, AR-9 changed gut microbiota composition and increased the relative abundance of beneficial bacteria: Lactobacillus, Clostridium, Dehalobacterium, and Candidatus arthromitus. Fecal metabolomics showed that the pathway regulated by AR-9 was "arginine biosynthesis", in which the contents were citrulline and ornithine. Spearman's correlation analysis revealed that two metabolites (ornithine and citrulline) showed significantly negative correlations with obesity-related parameters and positive correlations with the gut genera (Clostridium) enriched by AR-9. Overall, our results suggested interactions between gut microbial shifts and fecal amino acid/lipid metabolism and revealed the mechanisms underlying the anti-HL effect of AR-9. The abovementioned results not only reveal the initial anti-HL mechanism of AR-9 but also provide a theoretical basis for the continued development of AR-9. [ABSTRACT FROM AUTHOR]

According to the Chinese Pharmacopoeia(2020 edition), Eupolyphaga Steleophaga is prepared from female Eupolyphaga sinensis. To explore the quality difference between male and female E. sinensis, the present study determined indexes in the Chinese Pharmacopoeia, anticoagulant activity, and content of primary metabolites, amino acids, and trace elements in male and female E. sinensis before and after sexual maturity. The results showed that the content of ash, water, extract, and aflatoxin of the larvae and female adults of E. sinensis met the Chinese Pharmacopoeia standards, while the content of ash and extract of male adults failed to meet the standards. After sexual maturity, the content of water-soluble proteins, crude fat, and extract of female E. sinensis was higher than that of the other three groups(P<0.05). Although the content of total protein, total amino acid(TAA), essential amino acid(EAA), non-essential amino acid(NEAA), branched-chain amino acid(BCAA), functional amino acid(FAA), and delicious amino acid(DAA) of male adults was higher than that of the other groups(P<0.05), the anticoagulant activity was the weakest(P<0.05). Before sexual maturity, the content of Fe in E. sinensis larvae was significantly higher than that in adults(P<0.05). The content of K and Mg in female larvae was the highest, while the content of Ca was the lowest(P<0.05). The content of Cu in male adults was higher than that in the other three groups(P<0.05). In conclusion, except for male adults, the larvae and female adults of E. sinensis meet the Chinese Pharmacopoeia standards. There is no difference in the internal quality of male and female E. sinensis larvae. It is recommended to collect female adults as much as possible. Male adults are rich in proteins and amino acids with high fibrinolytic activities, which can be developed in the future.