Covalent drugs based on small molecules and peptides for disease theranostics.

Biomacromolecules, such as proteins, nucleic acids and polysaccharides, are widely distributed in the human body, and some of them have been recognized as the targets of drugs for disease theranostics. Drugs typically act on targets in two ways: non-covalent bond and covalent bond. Non-covalent bond-based drugs have some disadvantages, such as structural instability and environmental sensitivity. Covalent interactions between drugs and targets have a longer action time, higher affinity and controllability than non-covalent interactions of conventional drugs. With the development of artificial intelligence, covalent drugs have received more attention and have been developed rapidly in pharmaceutical research in recent years. From the perspective of covalent drugs, this review summarizes the design methods and the effects of covalent drugs. Finally, we discuss the application of covalent peptide drugs and expect to provide a new reference for cancer treatment.

The involvement of AMPA-ERK1/2-BDNF pathway in the mechanism of new antidepressant action of prokinetic meranzin hydrate.

It was recently discovered that ketamine can relieve depression in a matter of hours through an action on α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. This is much more rapid than the several weeks required for the available antidepressants to show therapeutic efficacy. However, ketamine has negative side effects. The aim of this study was to determine whether the natural prokinetic drug meranzin hydrate (MH) has a fast-acting antidepressant effect mediated by AMPA receptors. By means of in vivo and in vitro experiments, we found that (1) treatment of rats with MH at 9 mg/kg decreased immobility time in a forced swimming test (FST), as did the popular antidepressant fluoxetine and the AMPA receptor positive modulator aniracetam. Pretreatment of rats with NBQX (10 mg/kg), an antagonist of AMPA receptors, blocked this effect of MH. (2) MH increased number of crossings of forced swimming rats in the open field test. (3) FST enhanced hippocampal ERK1/2, p-ERK1/2 and BDNF expression levels. MH (9 mg/kg) treatment further up-regulated hippocampal p-ERK1/2 and BDNF expression levels, and this effect was prevented by NBQX. (4) MH-increased BDNF expression corresponded with MH-decreased immobility time in the FST. (5) In vitro experiments, we found that incubation of rats hippocampus slices with MH (10, 20 µM respectively) increased concentrations of BDNF and p-ERK1/2. This effect of MH (20 µM) were prevented by NBQX. In conclusion, in animals subjected to acute stress, the natural prokinetic drug MH produced a rapid effect mediated by AMPA receptors and involving BDNF modulation through the ERK1/2 pathway.

Meranzin hydrate exhibits anti-depressive and prokinetic-like effects through regulation of the shared α2-adrenoceptor in the brain-gut axis of rats in the forced swimming test.

BACKGROUND: In recent years, the brain-gut axis theory has received increasing attention in studies of depression. However, most studies separately address potential antidepressant and prokinetic treatments. Investigations of drugs that could potentially treat comorbid depression and gastrointestinal (GI) dysfunction via a common mechanism of action have not yet been performed in detail. AIM: To find a common mechanism of action of our patented drug, meranzin hydrate (MH), in the antidepressant and prokinetic treatment. METHODS: The forced swimming test (FST) model of depression, plasma ghrelin measurement, and in vivo and in vitro measurements of GI motility were used. RESULTS: 1. Administration of MH (9 mg/kg) decreased the immobility time during the FST after acute treatment; this effect was inhibited by the alpha 2-adrenoceptor antagonist, yohimbine, but not by the alpha 1-adrenoceptor antagonist, prazosin. 2. After chronic treatment, the immobility time of rats during the FST was decreased significantly by MH (2.25 mg/kg). 3. MH (9 mg/kg) increased plasma ghrelin levels in rats subjected to the FST; this increase was enhanced by the ghrelin receptor agonist, GHRP-6. 4. MH (9 mg/kg) also promoted gastric emptying and intestinal transit in rats with or without FST. 5. In vitro, MH (10 µM) increased jejunal contractions in rats subjected to the FST; this effect was inhibited by yohimbine. Furthermore, the inhibitory effect of yohimbine was partly reversed by the ghrelin receptor agonist, GHRP-6. CONCLUSION: Our study revealed that MH from natural resources exhibits antidepressive and prokinetic-like effects through the regulation of the common mediator, the alpha 2-adrenoceptor.

Fructus Aurantii induced antidepressant effect via its monoaminergic mechanism and prokinetic action in rat.

Depression could hardly get a satisfactory effect from the currently available antidepressants. To get a more effective treatment, antidepressant effect and monoaminergic mechanism of Fructus Aurantii (FRA) in the rat forced swimming test (FST) and open field test (OFT), and its prokinetics were examined. FST and OFT were respectively used to evaluate the antidepressant effect and locomotor activity of FRA. We observed the effects of monoamine receptor antagonists on FRA-induced antidepressant effect in rat. The effects of FRA on intestinal transit, gastric emptying and in vitro jejunum contractile activity were assessed. FRA decreased significantly the immobility time (32.6±8.5, 30.3±5.2 vs 56.4±9.4, all p<0.01) in FST, dose-dependent increased the locomotor activity (102±17.5, 120±18.5 vs 89±9.8, p<0.05 or 0.01), significantly accelerated gastric emptying (GE: 48.1±6.3, 39.5±5.7 vs 19.5±3.8, p<0.01) and intestinal transit (IT: 67.3±9.1, 64.2±6.3 vs 49.1±8.2, p<0.01) of the semi-liquid meal, compared with vehicle. And FRA (1 µM, 10 µM) significantly increased the mean amplitude (0.24±0.021 and 0.281±0.015) of contraction in jejunum of rat compared with vehicle (0.149±0.011) in vitro. FRA (10 µM) could induce a largest amplitude (0.281±0.015) of contraction in jejunum. The anti-immobility effect of FRA in FST was prevented by pre-treatment of rat with p-chlorophenylalanine methyl ester, WAY100635, ketanserin, haloperidol, SCH233390, sulpiride, yohimbine, but not prazosin. FRA could simultaneously induce prokinetics and antidepressant effect, deserves further to investigate.

Ferulic acid-induced anti-depression and prokinetics similar to Chaihu-Shugan-San via polypharmacology.

Selective serotonin reuptake inhibitors (SSRIs), one of popular antidepressants as "one-compound-one-target" paradigm, cannot but discontinue because of inhibiting gut movement. Traditional Chinese medicine (TCM) Chaihu-Sugan-San (CSS) can simultaneously exert anti-depression and prokinetics. From this thread, we aimed to find a new antidepressant with polypharmacological mechanisms. In vivo antidepressive and prokinetic comparisons between CSS and its absorbed compound ferulic acid (FA) were made. And FA's action mechanisms involved in monoaminergic systems, HPA axis and gastrointestinal peptide ghrelin was then studied in forced swimming test (FST) of rat. Lastly, the jejunal contraction activity evoked by FA was measured in vitro. Compared with vehicle, FA reduced immobility time, increased locomotor activity, accelerated gastric emptying and intestinal transit similar to CSS whose absorbable component FA was identified in hippocampus and jejunum. FA's prokinetics in vivo was further supported by its jejunal contraction in vitro. FA-induced anti-immobility was prevented by pretreated with PCPA, WAY-100635, ketanserin, sulpiride, SCH233390, haloperidol and yohimbine, respectively. CRH, ACTH and 5-HT were significantly decreased, but ghrelin was apparently increased compared with vehicle. In summary, FA induced anti-depression and prokinetics similar to CSS via inhibiting serotonin, norepinephrine and dopamine reuptakes, regulating HPA axis, increasing ghrelin and stimulating jejunal contraction simultaneously.

[Observation on changes of the intragastric protein phosphorylation level involving electroacupuncture-induced improvement of the injured gastric mucosa in the rat].

OBJECTIVE: To study the effect of electroacupuncture (EA) of Stomach Meridian acupoints on changes o of the related protein phosphorylation in the gastric mucosa involving the repair of the injured gastric mucosa in the rat. METHODS: A total of 20 SD rats were divided into control, model, acupoint and non-acupoint groups, with 5 cases in each. Gastric mucosa injury model was established by intragastric perfusion of dehydrated alcohol (0.8 ml/100 g). EA (4 Hz/50 Hz, 1-3 mA) was applied to "Zusanli" (ST 36), "Liangmen" (ST 21) and "Sibai" (ST 2), and the corresponding non-acupoints, once daily for 7 days. Gastric mucosal ulcer index (UI) was measured, and the profiling of the protein phosphorylation of interest in gastric mucosa cells was detected by antibody microarrays. RESULTS: In comparison with control group, the gastric mucosal UI of model group was significantly higher than that of control group (P < 0.01), while the UI of EA group was significant lower than those of model group and non-acupoint group (P < 0.01), suggesting a recovery of the injured mucous membrane. Findings of protein array analysis indicated that a total of 720 kinds of phosphorylated proteins (> or = 1.5 folds) were found in the injured gastric mucosa. Compared to model group, the phosphorylation levels of 100 and 20 proteins were up-regulated, and 16 and 9 proteins down-regulated in acupoint and non-acupoint groups, respectively. The up-regulated proteins involve cell cycle mediation, cell proliferation, anti-apoptosis, and the regulation of the cell adhesion, cytoskeleton protein, inflammation, immune activities, etc. while the down-regulated proteins involve the down-regulation of the phosphorylation levels of the apoptosis proteins, adhesion proteins and cytoskeleton proteins, etc. In comparison to non-acupoint group, the phosphorylation levels of 100 proteins were up-regulated and 16 proteins down-regulated in acupoint group. CONCLUSION: EA of acupoints of the Stomach Meridian can promote repair of the injured gastric mucosa, which may be related to its effects in regulating the levels of phosphorylation of many signaling proteins.