Growing evidence suggests that exercise can provide neuroprotection by improving mitochondrial quality control (MQC) on the aged brain. Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling responsiveness declines with aging. However, whether AMPK plays a role in the exercise-mediated improvement of memory and MQC in the aged hippocampus remains to be established. AICAR (5-Aminoimidazole 4-carboxamide ribonucleoside), a pharmacological agonist of AMPK, has been proposed to be an exercise mimetic recently. However, it has not been clarified whether AICAR could mimic the effects of exercise on the aged hippocampus through improvement of MQC. In this study, AICAR (AMPK agonist) and Compound C (AMPK inhibitor) were used to investigate if AMPK plays a key role in exercise-induced improvement of MQC and if AICAR could act as an exercise mimetic through improvement of MQC in aged hippocampus. Both exercise and AICAR improved the memory of aged mice and increased AMPK phosphorylation in the aged hippocampus. Exercise, but not AICAR, improved mitochondrial respiratory function in the aged hippocampus and increased the Microtubule associated protein 1 light chain 3 (LC3) II/LC3 I ratio and the protein expression of LC3 II and Autophagy Related Protein 7 (ATG7) in the lysate of whole hippocampal tissue. Both exercise and AICAR increased the ratio of LC3 II/LC3 I and the protein expression of LC3 II in the mitochondrial fractions of the hippocampus. Regarding mitochondrial dynamics, neither exercise training nor AICAR changed the protein level of Mitofusin2 (Mfn2). Exercise, but not AICAR, increased the protein level of Dynamin-related protein 1 (Drp1). Furthermore, both exercise training and AICAR increased the protein level of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a modulator of mitochondrial biogenesis. Compound C abolished the exercise-induced effects on memory in aged mice (Fig. 1), AMPK phosphorylation, autophagy, mitophagy, and mitochondrial fission in the aged hippocampus. However, Compound C did not reverse the exercise-induced increase in PGC-1α protein levels in the aged hippocampus. Our data provide evidence that AMPK plays an important role in the exercise-induced improvement of memory and MQC in the hippocampus of aged mice. Importantly, we demonstrated for the first time that AICAR could partially mimetic the beneficial effects of endurance exercise on memory and MQC in the hippocampus of aged mice, and thus may be a promising exercise mimetic for counteracting brain aging. 

Patrinia scabiosaefolia, is used as wild vegetable in China for more than 2 000 years, with a variety of pharmacological activities, including anti-inflammatory, anti-tumor and hypoglycemic. Based on our ongoing research on chemical constituents and hypoglycemic activity of P. scabiosaefolia, 4 lignan compounds, (+)-isolariciresinol (1), 7R,7′R,8S,8′S-(+)-neo-olivil-4-O-β-D-glucopyranoside (2), 4-O-methylcedrusin (3) and patrinian A (4), were isolated and identified. The hypoglycemic activity showed that compounds 2 and 3 could extremely significantly improve insulin resistance at 100 (P < 0.001), 50 (P < 0.001) and 25 µmol/L (P < 0.01) in IR 3T3-L1 cells. While compound 4 only promoted glucose uptake by IR 3T3-L1 cells at 100 µmol/L (P < 0.01). Western blotting experiments showed that compounds 2 and 4 up-regulated the protein expressions of p-IRS, PI-3K, p-AKT and glucose transporter 4 (GLUT4), and promoted the transcription of GLUT4 mRNA. Therefore, the mechanisms of compounds 2 and 4 were presumed to improve IR by activating PI-3K/AKT signaling pathway.

Flower plants are popular all over the world and important sources of ornamental plants, bioactive molecules and nutrients. Flowers have a wide range of biological activities and beneficial pharmacological effects. Flowers and their active ingredients are becoming more and more popular in the preparation of food, drugs and industrial products. This paper summarizes the active ingredients, pharmacological activities and applications in the pharmaceutical and food industries of flower plants in recent years. In addition, the possible molecular mechanism of pharmacological effects of flower plants were also discussed. 302 active constituents from 55 species of flower plants were summarized, including flavonoids (115), terpenoids (90), phenylpropanoids (20), alkaloids (13), organic acids (27) and others (37). The pharmacological effects of flower plants are very extensive, mainly including antioxidant, anti-inflammatory, anti-tumor, anti-virus, and hypoglycemic. The mechanisms of anti-inflammatory, anti-tumor and hypoglycemic activities present the characteristics of multi-way and multi-target. Because of its rich nutrients, bioactive ingredients and plant essential oils, and its wide sources, flower plants are widely used in food, beverage, cosmetics and drug research. Flower plants also play an important role in pharmaceutical industry, food industry and other fields.