Poria cocos ethanol extract and its active constituent, pachymic acid, modulate sleep architectures via activation of GABAA-ergic transmission in rats

Moringa oleifera seed ethanol extract and its active component kaempferol potentiate pentobarbital-induced sleeping behaviours in mice via a GABAergic mechanism

CONTEXT

Moringa oleifera Lam. (Moringaceae) (MO) is an important food plant that has high nutritional and medical value. However, there is limited information on whether its seeds can improve sleep.

OBJECTIVE

This study investigated the effects of MO seed ethanol extracts (EEMOS) on sleep activity improvement and examined the underlying mechanisms.

MATERIALS AND METHODS

Male ICR mice were placed into six groups (n = 12) and treated as follows: Control (sodium carboxymethyl cellulose, 20 mL/kg), estazolam tablets (2 mg/kg), EEMOS (1, 2 g/kg) and kaempferol (1, 2 mg/kg). These samples were successively given intragastric for 14 d. Locomotor activity assay, pentobarbital-induced sleeping and pentetrazol-induced seizures tests were utilized to examine the sedative-hypnotic effects (SHE) of EEMOS.

RESULTS

Compared with the control group, the results revealed that EEMOS (2 g/kg) and KA (2 mg/kg) possessed good SHE and could significantly elevate the levels of γ-aminobutyric acid and reduce the levels of glutamic acid in the mouse hypothalamus (p < 0.05). Moreover, SHE was blocked by picrotoxin, flumazenil and bicuculline (p < 0.05). EEMOS (2 g/kg) and KA (2 mg/kg) significantly upregulated the protein expression levels of glutamic acid decarboxylase-65 (GAD₆₅) and α₁-subunit of GABA_A receptors in the hypothalamus of mice (p < 0.05), not affecting glutamic acid decarboxylase-67 (GAD₆₇) and γ₂-subunit expression levels (p > 0.05). Additionally, they cause a significant increase in Cl^- influx in human cerebellar granule cells at a concentration of 8 µg/mL (p  <  0.05).

DISCUSSION AND CONCLUSIONS

These findings demonstrated that EEMOS could improve sleep by regulating GABA_A-ergic systems, and encourage further clinical trials to treat insomnia.

Pharmacological profiles and therapeutic applications of pachymic acid (Review)

Poria cocos is a saprophytic fungus that grows in diverse species of Pinus. Its sclerotium, called fu-ling or hoelen, has been used in various traditional Chinese medicines and health foods for thousands of years, and in several modern proprietary traditional Chinese medicinal products. It has extensive clinical indications, including sedative, diuretic, and tonic effects. Pachymic acid (PA) is the main lanostane-type triterpenoid in Poria cocos. Evidence suggests that PA has various biological properties such as cytotoxic, anti-inflammatory, antihyperglycemic, antiviral, antibacterial, sedative-hypnotic, and anti-ischemia/reperfusion activities. Although considerable advancements have been made, some fundamental and intricate issues remain unclear, such as the underlying mechanisms of PA. The present study aimed to summarize the biological properties and therapeutic potential of PA. The biosynthetic, pharmacokinetic, and metabolic pathways of PA, and its underlying mechanisms were also comprehensively summarized.

The Positive Effects of Poria cocos Extract on Quality of Sleep in Insomnia Rat Models

Sleep disorders may have various causes and can incur mental and/or physical symptoms, and affect an individual’s quality of life. In this study, we confirm that the Poria cocos extract (PCET) can improve sleep quality and structure by promoting inhibitory neurotransmission via the γ-aminobutyric acid (GABA) type A (GABAA) receptors based on the mechanisms revealed in the experiment with superior cervical ganglion neurons. Pentobarbital-induced sleep tests were conducted in order to determine whether the PCET extract improves the sleep quality and structure in normal ICR mice. Sleep latency and duration were checked with the righting reflex. To simulate the state of awakening as well as a normal sleep state, caffeine was administered orally before the PCET diet. After oral gavage of PCET, sleep latency was decreased, and total sleep duration was increased in normal and caffeine-induced sleep disturbance state. In the ACTH-induced sleep disturbed models, administration of PCET significantly reduced the sleep latency and increased the non-REM sleep duration, which was analyzed in real-time EEG by implanting wireless electrodes in SD rats. PCET was found to improve the sleep quality under a normal sleep state through the GABAA receptor; it also promoted and improved the sleep quality and sleep structure in both the arousal activation state and stress-based sleep disturbance.

The Lanostane Triterpenoids in Poria cocos Play Beneficial Roles in Immunoregulatory Activity

Poria cocos (Schwein) F.A. Wolf (syn. Wolfiporia cocos) dried sclerotium, called fuling, is an edible, saprophytic fungus commonly used as a tonic and anti-aging traditional Chinese medicine. It is traditionally used in combination with other traditional Chinese medicines to enhance immunity. This study showed that P. cocos extract (Lipucan^®) containing lanostane triterpenoids has no immunotoxicity and enhances non-specific (innate) immunity though activating natural killer cells and promotes interferon γ (IFN-γ) secretion by Type 1 T-helper (Th1) cells immune response. In addition, P. cocos extract significantly decreased interleukin (IL-4 and IL-5) secretion by Type 2 T-helper (Th2) cells immune response, which are related to the allergy response. The purified lanostane triterpenoids were first identified as active ingredients of P. cocos with enhanced non-specific immunity by promoting interferon γ (IFN-γ) secretion in a preliminary study. Our findings support that the P. cocos extract plays beneficial roles in immunoregulatory activity.