AGL9: A Novel Hepatoprotective Peptide from the Larvae of Edible Insects Alleviates Obesity-Induced Hepatic Inflammation by Regulating AMPK/Nrf2 Signaling

In this study, we investigated the anti-obesity properties of the novel peptide Ala-Gly-Leu-Gln-Phe-Pro-Val-Gly-Arg (AGL9), isolated from the enzymatic hydrolysate of Allomyrinadichotoma larvae. To investigate the preventive effects of AGL9 against hepatic steatosis and its possible mechanisms of action, we established an nonalcoholic fatty liver disease (NAFLD) model by feeding C57BL/6 mice a high-fat diet. NAFLD mice were administered 100 mg/kg AGL9 and 60 mg/kg orlistat via gavage (10 mL/kg) for 5 weeks, followed by the collection of blood and liver tissues. We found that AGL9 normalized the levels of serum alanine aminotransferase, aspartate aminotransferase, triglyceride, total cholesterol, high-density lipoprotein, very low-density lipoprotein (LDL)/LDL, adiponectin, and leptin in these mice. Additionally, AGL9 activated the protein-level expression of 5′ AMP-activated protein kinase and acetyl-CoA carboxylase phosphorylation and the transcript-level expression of sterol regulatory element-binding protein-1c, fatty acid synthase, superoxide dismutase, glutathione peroxidase, glucocorticoid receptor, nuclear respiratory factor 2, tumor necrosis factor-α, interleukin-1β, interleukin-6, and monocyte chemoattractant protein-1 in hepatocytes. These results showed that AGL9 exhibited hepatoprotective effects by attenuating lipid deposition, oxidative stress, and inflammation via inhibition of AMPK/Nrf2 signaling, thereby reducing the production of hepatic proinflammatory mediators and indicating AGL9 as a potential therapeutic strategy for NAFLD.

Molecular Cloning and Expression Profile of Class E Genes Related to Sepal Development in Nelumbo nucifera

The lotus (Nelumbo Adans.) is an important aquatic plant with ornamental, medicinal and edible values and cultural connotations. It has single-, semi-double-, double- and thousand-petalled types of flower shape and is an ideal material for developmental research of flower doubling. The lotus is a basal eudicot species without a morphological difference between the sepals and petals and occupies a critical phylogenetic position in flowering plants. In order to investigate the genetic relationship between the sepals and petals in the lotus, the class E genes which affect sepal formation were focused on and analyzed. Here, SEPALLATA 1(NnSEP1) and its homologous genes AGAMOUS-LIKE MADS-BOXAGL9 (NnAGL9) and MADS-BOX TRANSCRIPTION FACTOR 6-like (NnMADS6-like) of the class E gene family were isolated from the flower buds of the Asian lotus (Nelumbo nucifera Gaertn.). The protein structure, subcellular localization and expression patterns of these three genes were investigated. All three genes were verified to locate in the nucleus and had typical MADS-box characteristics. NnSEP1 and NnMADS6-like were specifically expressed in the sepals, while NnAGL9 was highly expressed in the petals, suggesting that different developmental mechanisms exist in the formation of the sepals and petals in the lotus. The significant functional differences between NnSEP1, NnMADS6-like and NnAGL9 were also confirmed by a yeast two-hybrid assay. These results expand our knowledge on the class E gene family in sepal formation and will benefit fundamental research on the development of floral organs in Nelumbo.