Multidrug-loaded liposomes prevent ischemic stroke through intranasal administration.

Baicalin (BA), a multi-target neuroprotective agent, has poor solubility resulting in low bioavailability. In this study, multidrug-loaded liposomes were prepared by encapsulating BA, borneol (BO) and cholic acid (CA) to prevent ischemic stroke. BBC-LP were administered intranasally (i.n.) to deliver into the brain for neuroprotection. Finally, potential mechanism of BBC treating ischemic stroke (IS) was explored by network pharmacology. In this study, BBC-LP was prepared by reverse evaporation method, and the encapsulation efficiency (EE) of the optimized liposomes was 42.69% and the drug loading (DL) was 6.17%. The liposomes had low mean particle size (156.62 ± 2.96 nm), polydispersity index (PDI) (0.195) and zeta potential (-0.99 mv). Compared to BBC, pharmacodynamic studies revealed that BBC-LP significantly improved neurological deficits, brain infarct volume, and cerebral pathology in MCAO rats. Toxicity studies showed that BBC-LP was not irritating to the nasal mucosa. These results suggest that BBC-LP can safely and effectively ameliorate IS injury by i.n. administration. Moreover, it's neuroprotective function may be related to the anti-apoptotic and anti-inflammatory effects exerted by phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway and mitogen-activated protein kinase (MAPK) signaling pathway.

Preparation, characterization and safety evaluation of Ligusticum chuanxiong essential oils liposomes for treatment of cerebral ischemia-reperfusion injury.

The essential oils of Ligusticum chuanxiong Hort. (CXEO) are considered to be important parts of the pharmacological action of Ligusticum chuanxiong Hort. CXEO have a wide range of applications in various fields. Despite the interesting properties of CXEO, the volatility and low solubility have limited the application. Liposomes are vesicles composed of concentric bilayer lipids arranged around the water environment. Therefore, this study aimed to prepare stable CXEO liposomes (CXEO-LP) to improve the properties. Then, CXEO-LP were prepared by thin film dispersion method and optimized. The results showed that CXEO-LP were well dispersed. Subsequently, in vitro release and antioxidant properties of CXEO-LP were researched. CXEO-LP had slow release effect and oxidation resistance, indicating CXEO-LP may be a potential drug for treating cerebral ischemia-reperfusion injury (CIRI). The nasal mucosa toxicity test and acute toxicity test showed that CXEO-LP had no obvious toxicity to nasal cavity, heart, liver, spleen, lung and kidney tissues. Pharmacodynamic studies found that CXEO-LP significantly improved neurological deficits and brain pathology in a mouse model of CIRI compared to CXEO after intranasal administration. In general, this study showed that CXEO-LP were easy to prepare and continuously released, and had an important development prospect in the treatment of CIRI.

Rubbing Salt in the Wound: Molecular Evolutionary Analysis of Pain-Related Genes Reveals the Pain Adaptation of Cetaceans in Seawater.

Pain, usually caused by a strong or disruptive stimulus, is an unpleasant sensation that serves as a warning to organisms. To adapt to extreme environments, some terrestrial animals have evolved to be inherently insensitive to pain. Cetaceans are known as supposedly indifferent to pain from soft tissue injury representatives of marine mammals. However, the molecular mechanisms that explain how cetaceans are adapted to pain in response to seawater environment remain unclear. Here, we performed a molecular evolutionary analysis of pain-related genes in selected representatives of cetaceans. ASIC4 gene was identified to be pseudogenized in all odontocetes (toothed whales) except from Physeter macrocephalus (sperm whales), and relaxed selection of this gene was detected in toothed whales with pseudogenized ASIC4. In addition, positive selection was detected in pain perception (i.e., ASIC3, ANO1, CCK, and SCN9A) and analgesia (i.e., ASIC3, ANO1, CCK, and SCN9A) genes among the examined cetaceans. In this study, potential convergent amino acid substitutions within predicted proteins were found among the examined cetaceans and other terrestrial mammals, inhabiting extreme environments (e.g., V441I of TRPV1 in cetaceans and naked mole rats). Moreover, specific amino acid substitutions within predicted sequences of several proteins were found in the studied representatives of cetaceans (e.g., F56L and D163A of ASIC3, E88G of GRK2, and F159L of OPRD1). Most of the substitutions were located within important functional domains of proteins, affecting their protein functions. The above evidence suggests that cetaceans might have undergone adaptive molecular evolution in pain-related genes through different evolutionary patterns to adapt to pain, resulting in greater sensitivity to pain and more effective analgesia. This study could have implications for diagnosis and treatment of human pain.