Potentiation of decursinol angelate on pentobarbital-induced sleeping behaviors via the activation of GABAA-ergic systems in rodents

Anti-insomnia Effect of a Polyherbal Formulation on P-chlorophenyalanine Induced Experimental Animal Model

Sleep is a dynamic and controlled set of physiological and behavioural practices during which the stabilisation and restoration processes of the body take place properly. Therefore, sleep disorders, especially chronic insomnia, can harm an individual's physical and mental health. However, the therapeutic alternatives are limited and possess severe side effects. Thus, in this study, we aimed to investigate the anti-insomnia effect of a polyherbal formulation (Sleep) (SLP) on p-chlorophenyalanine (PCPA) induced insomnia in rats. Intraperitoneal injection of PCPA induced the experimental condition, and the therapeutic effect of SLP was evaluated by studying the sleep pattern and expression of various neurotransmitters and receptors, along with neurotrophins. Moreover, insomnia-associated oxidative stress and inflammation were also studied. From the findings, we found that the SLP-supplemented animals improved their sleeping behaviour and that the major neurotransmitters, hormones, and receptors were maintained at an equilibrium level. Furthermore, the neurotrophin level was increased and pro-inflammatory cytokines were reduced. The evaluation of oxidative stress markers shows that the antioxidants were significantly boosted, and as a result, lipid peroxidation was prevented. The overall findings suggest that SLP can be used as an effective medication for the treatment of sleep disorders like insomnia as it triggers the major neurotransmitter system.

Decursinol-mediated antinociception and anti-allodynia in acute and neuropathic pain models in male mice: Tolerance and receptor profiling

Korean scientists have shown that oral administration of Angelica gigas Nakai (AGN) root alcoholic extract and the metabolite of its pyranocoumarins, decursinol, have antinociceptive properties across various thermal and acute inflammatory pain models. The objectives of this study were 1) to assess whether tolerance develops to the antinociceptive effects of once-daily intraperitoneally administered decursinol (50 mg/kg) in acute thermal pain models, 2) to establish its anti-allodynic efficacy and potential tolerance development in a model of chemotherapy-evoked neuropathic pain (CENP) and 3) to probe the involvement of select receptors in mediating the pain-relieving effects with antagonists. The results show that decursinol induced antinociception in both the hot plate and tail-flick assays and reversed mechanical allodynia in mice with cisplatin-evoked neuropathic pain. Tolerance was detected to the antinociceptive effects of decursinol in the hot plate and tail-flick assays and to the anti-allodynic effects of decursinol in neuropathic mice. Pretreatment with either the 5-HT2 antagonist methysergide, the 5-HT2A antagonist volinanserin, or the 5-HT2C antagonist SB-242084 failed to attenuate decursinol-induced antinociception in the tail-flick assay. While pretreatment with the cannabinoid inverse agonists rimonabant and SR144528 failed to modify decursinol-induced anti-allodynia, pretreatment with the opioid antagonist naloxone partially attenuated the anti-allodynic effects of decursinol. In conclusion, our data support decursinol as an active phytochemical of AGN having both antinociceptive and anti-allodynic properties. Future work warrants a more critical investigation of potential receptor mechanisms as they are likely more complicated than initially reported.

Angelica gigas: Signature Compounds, In Vivo Anticancer, Analgesic, Neuroprotective and Other Activities, and the Clinical Translation Challenges

Angelica gigas Nakai (AGN) root is a medicinal herbal widely used in traditional medicine in Korea. AGN root ethanolic extract dietary supplements are marketed in the United States for memory health and pain management. We comprehensively reviewed the anticancer, analgesic, pro-memory and other bio-activities of AGN extract and its signature phytochemicals decursin, decursinol angelate, and decursinol a decade ago in 2012 and updated their anticancer activities in 2015. In the last decade, significant progress has been made for understanding the pharmacokinetics (PK) and metabolism of these compounds in animal models and single dose human PK studies have been published by us and others. In addition to increased knowledge of the known bioactivities, new bioactivities with potential novel health benefits have been reported in animal models of cerebral ischemia/stroke, anxiety, sleep disorder, epilepsy, inflammatory bowel disease, sepsis, metabolic disorders, osteoporosis, osteoarthritis, and even male infertility. Herein, we will update PK and metabolism of pyranocoumarins, review in vivo bioactivities from animal models and human studies, and critically appraise the relevant active compounds, the cellular and molecular pharmacodynamic targets, and pertinent mechanisms of action. Knowledge gaps include whether human pyranocoumarin PK metrics are AGN dose dependent and subjected to metabolic ceiling, or metabolic adaptation after repeated use. Critical clinical translation challenges include sourcing of AGN extracts, product consistency and quality control, and AGN dose optimization for different health conditions and disease indications. Future research directions are articulated to fill knowledge gaps and address these challenges.

Establishment of a rat model with ageing insomnia induced by D-galactosef and para-chlorophenylalanine

The current study aimed to establish a rat model of ageing insomnia induced by D-galactose and/or para-chlorophenylalanine. Following establishment of the model, body weights were measured, and Morris water maze and pentobarbital-induced sleep tests were performed. The serum levels of inflammatory mediators and the neural levels of neurotransmitters were detected. The results demonstrated that the body weights of PCPA+D-gal-induced ageing insomnia rats decreased significantly. Ageing insomnia rats exhibited longer latencies to the platform in the Morris water maze tests and fewer target crossings. The sleep latency of the model rats was longer and sleep time was shorter by contrast. The relative expression of hippocampal IL-6, TNF-α, NF-κB and mGluR2 mRNA of the PCPA+D-gal-induced ageing insomnia group was higher, while the relative expression of 5-HT_1AR and GABA_AR_a1 mRNA were lower. The serum levels of IL-1β, IL-6, TNF-α and brain level of glutamate increased in the PCPA+D-gal-induced ageing insomnia group, while the levels of 5-HT and GABA decreased. In conclusion, memory function, sleep time, expression of inflammatory factors and neurotransmitters are altered in ageing insomnia rats induced by D-galactose and para-chlorophenylalanine, indicating the successful establishment of a murine model of ageing insomnia.

A Sargassum fluitans Borgesen Ethanol Extract Exhibits a Hepatoprotective Effect In Vivo in Acute and Chronic Liver Damage Models

One of the leading causes of death worldwide, cirrhosis, is a liver condition characterized by chronic necrosis, inflammation, and fibrosis. Hepatoprotective compounds, such as antioxidants, can prevent fibrosis. Macroalgae (seaweed) contain high amounts of antioxidant compounds and are plentiful; indeed, species such as Sargassum fluitans Borgesen (Phaeophyceae) carpet many beaches in the Caribbean Basin. An in vivo assay was done evaluating the possible hepatoprotective effect of a Sargassum fluitans ethanol extract. Two murine liver damage models were employed: acetaminophen (APAP) in Balb/c mice to induce acute damage; carbon tetrachloride (CCl4) in Wistar rats to induce chronic damage. Serum liver enzyme levels and relative liver weight were measured, and histopathological and immunohistochemical analyses of liver tissue sections were done. Both APAP and CCl4 significantly raised serum enzyme marker enzymes. Administration of 50 mg/kg S. Fluitans ethanol extract reduced this APAP- and CCl4-induced elevation to normal levels. This effect was corroborated by the extract's inhibition of inflammation and fibrosis in liver tissue observed in the histopathological analysis. The analyzed S. fluitans ethanol extract exhibited an in vivo hepatoprotective effect in acute and chronic liver injury models.

Aloysia citriodora Palau (lemon verbena) for insomnia patients: A randomized, double-blind, placebo-controlled clinical trial of efficacy and safety

Aloysia citriodora (A. citriodora) has a long history of traditional use for sedation and treatment of insomnia in different societies. This study was carried out to assess the efficacy of A. citriodora in patients with insomnia. One hundred patients were randomly divided into two groups of A. citriodora (total essential oil 1.66 mg/10 ml and total amount of flavonoid in terms of quercetin 3.22 mg/10 ml of the syrup) and placebo. They were advised to use 10 cc of the syrups; an hour before the bedtime for a period of 4 weeks. Participants were assessed using Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) questionnaires at the baseline and then 2 and 4 weeks after the enrollment. Mean scores of global PSQI and its four components including sleep latency, habitual sleep efficiency, daytime dysfunction, and subjective sleep quality and also ISI score in the A. citriodora group improved significantly after 4 weeks of treatment when compared with the placebo group (p < 0.001, for all of them). Also, improvement of global score of PSQI and ISI was observed in the intervention group as compared with the placebo group, 2 weeks after the enrollment (p < 0.001). The results of this study showed that oral intake of A. citriodora can be suggested as a complementary treatment for patients with insomnia.

Sleep-Aids Derived from Natural Products

Although drugs such as barbiturates and benzodiazepines are often used for the treatment of insomnia, they are associated with various side effects such as habituations, tolerance and addiction. Alternatively, natural products with minimal unwanted effects have been preferred for the treatment of acute and/or mild insomnia, with additional benefits of overall health-promotion. Basic and clinical researches on the mechanisms of action of natural products have been carried out so far in insomnia treatments. Recent studies have been focusing on diverse chemical components available in natural products, with an interest of developing drugs that can improve sleep duration and quality. In the last 15 years, our co-workers have been actively looking for candidate substances from natural products that can relieve insomnia. This review is, therefore, intended to bring pharmacological data regarding to the effects of natural products on sleep duration and quality, mainly through the activation of GABA_A receptors. It is imperative that phytochemicals will provide useful information during electroencephalography (EEG) analysis and serve as an alternative medications for insomnia patients who are reluctant to use conventional drugs.