Therapeutic effects and molecular mechanisms of natural products in thrombosis.

Thrombotic disorders, such as myocardial infarction and stroke, are the leading cause of death in the global population and have become a health problem worldwide. Drug therapy is one of the main antithrombotic strategies, but antithrombotic drugs are not completely safe, especially the risk of bleeding at therapeutic doses. Recently, natural products have received widespread interest due to their significant efficacy and high safety, and an increasing number of studies have demonstrated their antithrombotic activity. In this review, articles from databases, such as Web of Science, PubMed, and China National Knowledge Infrastructure, were filtered and the relevant information was extracted according to predefined criteria. As a result, more than 100 natural products with significant antithrombotic activity were identified, including flavonoids, phenylpropanoids, quinones, terpenoids, steroids, and alkaloids. These compounds exert antithrombotic effects by inhibiting platelet activation, suppressing the coagulation cascade, and promoting fibrinolysis. In addition, several natural products also inhibit thrombosis by regulating miRNA expression, anti-inflammatory, and other pathways. This review systematically summarizes the natural products with antithrombotic activity, including their therapeutic effects, mechanisms, and clinical applications, aiming to provide a reference for the development of new antithrombotic drugs.

Dual Drug-Loaded Nanoliposomes Encapsulating Curcumin and 5-Fluorouracil with Advanced Medicinal Applications: Self-Monitoring and Antitumor Therapy.

Due to the presence of physiological barriers, it is difficult to achieve the desired therapeutic efficacy of drugs; thus, it is necessary to develop an efficient drug delivery system that enables advanced functions such as self-monitoring. Curcumin (CUR) is a naturally functional polyphenol whose effectiveness is limited by poor solubility and low bioavailability, and its natural fluorescent properties are often overlooked. Therefore, we aimed to improve the antitumor activity and drug uptake monitoring by simultaneously delivering CUR and 5-Fluorouracil (5-FU) in the form of liposomes. In this study, dual drug-loaded liposomes (FC-DP-Lip) encapsulating CUR and 5-FU were prepared by the thin-film hydration method; their physicochemical properties were characterized; and their biosafety, drug uptake distribution in vivo, and tumor cell toxicity were evaluated. The results showed that the nanoliposome FC-DP-Lip showed good morphology, stability, and drug encapsulation efficiency. It showed good biocompatibility, with no side effects on zebrafish embryonic development. In vivo uptake in zebrafish showed that FC-DP-Lip has a long circulation time and presents gastrointestinal accumulation. In addition, FC-DP-Lip was cytotoxic against a variety of cancer cells. This work showed that FC-DP-Lip nanoliposomes can enhance the toxicity of 5-FU to cancer cells, demonstrating safety and efficiency, and enabling real-time self-monitoring functions.

Nano-Liposomes Double Loaded with Curcumin and Tetrandrine: Preparation, Characterization, Hepatotoxicity and Anti-Tumor Effects.

(1) Background: Curcumin (CUR) and tetrandrine (TET) are natural compounds with various bioactivities, but have problems with low solubility, stability, and absorption rate, resulting in low bioavailability, and limited applications in food, medicine, and other fields. It is very important to improve the solubility while maintaining the high activity of drugs. Liposomes are micro-vesicles synthesized from cholesterol and lecithin. With high biocompatibility and biodegradability, liposomes can significantly improve drug solubility, efficacy, and bioavailability. (2) Methods: In this work, CUR and TET were encapsulated with nano-liposomes and g DSPE-MPEG 2000 (DP)was added as a stabilizer to achieve better physicochemical properties, biosafety, and anti-tumor effects. (3) Results: The nano-liposome (CT-DP-Lip) showed stable particle size (under 100 nm) under different conditions, high solubility, drug encapsulation efficiency (EE), loading capacity (LC), release rate in vitro, and stability. In addition, in vivo studies demonstrated CT-DP-Lip had no significant toxicity on zebrafish. Tumor cytotoxicity test showed that CT-DP-Lip had a strong inhibitory effect on a variety of cancer cells. (4) Conclusions: This work showed that nano-liposomes can significantly improve the physical and chemical properties of CUR and TET and make them safer and more efficient.

Ventral tegmental area GABAergic neurons induce anxiety-like behaviors and promote palatable food intake.

The obesity epidemic is a global problem and a great challenge for public health. Overconsumption of food, especially palatable food, is the leading cause of obesity. The precise neural circuits underlying food overconsumption remain unclear and require further characterization. In the present study, we showed that Ca2+ signals of GABAergic neurons within the ventral tegmental area (VTA) increased after the onset of food intake, especially high-fat or high-sugar chow. Optogenetic activation of VTA GABAergic neurons evoked immediate eating of palatable food and significantly increased palatable food intake in satiated mice. Photoinhibition of VTA GABAergic neurons suppressed palatable food intake. Surprisingly, photoactivation of VTA GABAergic neurons suppressed the intake of standard chow in fasted mice, but did not reduce the duration of eating of standard chow. Moreover, we found that photoactivation of these neurons drove a series of anxiety-like behaviors in the open field, elevated plus maze, and marble-burying test. Additionally, we found that VTA GABAergic neurons sent abundant projections to the lateral hypothalamus and photoactivation of GABAergic VTA terminals in the lateral hypothalamus induced overconsumption of palatable food, but not anxiety-like behaviors. Taken together, our results illustrate that GABAergic VTA neurons are a key node in the neural circuitry underlying anxiety-like behavior and over-feeding of palatable food, and that over-excitation of GABAergic VTA neurons may underlie clinical diseases related to anxiety and obesity.

Basal forebrain GABAergic neurons promote arousal and predatory hunting.

Predatory hunting is an important approach for animals to obtain valuable nutrition and energy, which critically depends on heightened arousal. Yet the neural substrates underlying predatory hunting remain largely undefined. Here, we report that basal forebrain (BF) GABAergic neurons play an important role in regulating predatory hunting. Our results showed that BF GABAergic neurons were activated during the prey (cricket)-hunting and food feeding in mice. Optogenetic activation of BF GABAergic neurons evoked immediate predatory-like actions to both artificial and natural preys, significantly reducing the attack latency while increasing the attack probability and the number of killed natural prey (crickets). Similar to the effect of activating the soma of BF GABAergic neurons, photoactivation of their terminals in the ventral tegmental area (VTA) also strongly promotes predatory hunting. Moreover, photoactivation of GABAergic BF - VTA pathway significantly increases the intake of various food in mice. By synchronous recording of electroencephalogram and electromyogram, we showed that photoactivation of GABAergic BF - VTA pathway induces instant arousal and maintains long-term wakefulness. In summary, our results clearly demonstrated that the GABAergic BF is a key neural substrate for predatory hunting, and promotes this behavior through GABAergic BF - VTA pathway.

Glutamatergic lateral hypothalamus promotes defensive behaviors.

The glutamatergic lateral hypothalamus (LH) has been implicated in a variety of behaviors, such as evasion and feeding, while its role in defensive behaviors and relevant neurocircuits remains unclear. Here, we demonstrated that the glutamatergic LH is a critical structure regulating defensive behaviors. Trimethylthiazole (TMT), the odor of mice predator, significantly increased c-Fos expression in the LH. Using fiber photometry technology, we found that TMT exposure increased the activity of LH glutamatergic neurons. Selective activation of LH glutamatergic neurons with optogenetics and chemogenetics promoted a series of defense-related behaviors, including fleeing, avoidance, and hiding, while selective inhibition of LH glutamatergic neurons suppressed the avoidance provoked by TMT. Activation of both the glutamatergic LH terminals in the hypothalamic paraventricular nucleus (PVN) and the glutamatergic projection from the basolateral amygdala (BLA) to the LH elicited defensive behaviors. Finally, by combining the viral-mediated retrograde tracing with anterograde activation, we found that PVN-projecting glutamatergic neurons in the LH were activated by BLA glutamatergic inputs. Taken together, our results illustrate that the glutamatergic LH is a pivotal relay of defensive behaviors and possibly promotes these behaviors through the BLA→LH→PVN pathway.