The Neuroprotective Effect of Zingiber cassumunar Roxb. Extract on LPS-Induced Neuronal Cell Loss and Astroglial Activation within the Hippocampus

Antidepressant effect of PT-31, an α₂-adrenoceptor agonist, on lipopolysaccharide-induced depressive-like behavior in mice

Increasing evidence indicates that neuroinflammation, oxidative stress, and neurotrophic factors play a key role in the pathophysiology of major depressive disorder (MDD). In addition, the attenuation of inflammatory response has been considered a putative mechanism for MDD treatment. PT-31 is an imidazolidine derivative and a putative α₂-adrenoceptor agonist that has previously demonstrated antinociceptive activity. The present study aimed to investigate the effect of PT-31 on depressive-like behavior and lipopolysaccharide-induced neurochemical changes. To this end, mice received intraperitoneally saline or lipopolysaccharide (600 µg/kg), and 5 h postinjection animals were orally treated with saline, PT-31 (3, 10, and 30 mg/kg), or fluoxetine (30 mg/kg). Mice were subjected to the open field test (OFT) 6 and 24 h after lipopolysaccharide administration and to the tail suspension test (TST) 24 h postlipopolysaccharide. Subsequently, animals were euthanized, and brains were dissected for neurochemical analyses. The administration of lipopolysaccharide-induced sickness- and depressive-like behaviors, besides promoting an increase in myeloperoxidase activity and a reduction in brain-derived neurotrophic factor (BDNF) levels. Noteworthy, PT-31 3 mg/kg attenuated lipopolysaccharide-induced decreased locomotor activity 6 h after lipopolysaccharide in the OFT. All tested doses of PT-31 significantly reduced the immobility time of animals in the TST and attenuated lipopolysaccharide-induced increased myeloperoxidase activity in the cortex of mice. Our results demonstrate that PT-31 ameliorates behavioral changes promoted by lipopolysaccharide in OFT and TST, which is possibly mediated by attenuation of the inflammatory response.

Potential Role of Ginger (Zingiber officinale Roscoe) in the Prevention of Neurodegenerative Diseases

Ginger is composed of multiple bioactive compounds, including 6-gingerol, 6-shogaol, 10-gingerol, gingerdiones, gingerdiols, paradols, 6-dehydrogingerols, 5-acetoxy-6-gingerol, 3,5-diacetoxy-6-gingerdiol, and 12-gingerol, that contribute to its recognized biological activities. Among them, the major active compounds are 6-shogaol and 6-gingerol. Scientific evidence supports the beneficial properties of ginger, including antioxidant and anti-inflammatory capacities and in contrast, a specific and less studied bioactivity is the possible neuroprotective effect. The increase in life expectancy has raised the incidence of neurodegenerative diseases (NDs), which present common neuropathological features as increased oxidative stress, neuroinflammation and protein misfolding. The structure-activity relationships of ginger phytochemicals show that ginger can be a candidate to treat NDs by targeting different ligand sites. Its bioactive compounds may improve neurological symptoms and pathological conditions by modulating cell death or cell survival signaling molecules. The cognitive enhancing effects of ginger might be partly explained via alteration of both the monoamine and the cholinergic systems in various brain areas. Moreover, ginger decreases the production of inflammatory related factors. The aim of the present review is to summarize the effects of ginger in the prevention of major neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and multiple sclerosis.

Neurotensin agonist PD 149163 modulates the neuroinflammation induced by bacterial endotoxin lipopolysaccharide in mice model

OBJECTIVE

The disruption of bidirectional communication between neuroendocrine and immune components by stressors leads to mental problems. The immunomodulation therapy of neuroinflammation-led psychiatric illness is an emerging area of research. Therefore, the present study aimed to evaluate immune modulation efficacy of PD 149163 (PD) against the lipopolysaccharide (LPS)-induced neuroinflammation.

MATERIALS AND METHODS

The Swiss albino mice (female/12 weeks) were divided into six groups (6 mice/group): (I) Control: 0.9% NaCl; (II) LPS: 1 mg/kg BW, for 5 days; (III) LPS + PD Low: LPS 1 mg/kg BW (for 5 days) after that PD 100 µg/kg BW (for 21 days); (IV) LPS + PD High: LPS 1 mg/kg BW (for 5 days) after that PD 300 µg/kg BW (for 21 days); (V) PD Low: PD 100 µg/kg BW (for 21 days); (VI) PD High: PD 300 µg/kg BW (for 21 days). All treatments were given intraperitoneal.

RESULTS

The LPS-induced weight loss (body and brain) was normalized to control after PD treatment. The PD enhanced superoxide dismutase (SOD) activity while decreased lipid hydroperoxide (LOOH) level altered in LPS-exposed mice. The significantly increased pro-inflammatory cytokines (IL-6 and TNF-α) in LPS exposure were also decreased by PD. Likewise, the LPS-induced HPA axis activation was stabilized by PD. In the hippocampus, the pyramidal cell layer thickness, pyramidal neurons number and size of CA1 and CA3 regions were reduced along with misalignment, shrinkage, and impairment of cytoarchitecture. In the co-treated group, the LPS-induced hippocampus disruption was reversed after PD exposure.

CONCLUSION

We suggested that the PD modulates the LPS-induced neuroinflammation and psychiatric illness in a dose-dependent manner.

Medicine-Food Herbs against Alzheimer’s Disease: A Review of Their Traditional Functional Features, Substance Basis, Clinical Practices and Mechanisms of Action

Alzheimer’s disease (AD) is a progressive, neurodegenerative disorder that currently has reached epidemic proportions among elderly populations around the world. In China, available traditional Chinese medicines (TCMs) that organically combine functional foods with medicinal values are named “Medicine Food Homology (MFH)”. In this review, we focused on MFH varieties for their traditional functional features, substance bases, clinical uses, and mechanisms of action (MOAs) for AD prevention and treatment. We consider the antiAD active constituents from MFH species, their effects on in vitro/in vivo AD models, and their drug targets and signal pathways by summing up the literature via a systematic electronic search (SciFinder, PubMed, and Web of Science). In this paper, several MFH plant sources are discussed in detail from in vitro/in vivo models and methods, to MOAs. We found that most of the MFH varieties exert neuroprotective effects and ameliorate cognitive impairments by inhibiting neuropathological signs (Aβ-induced toxicity, amyloid precursor protein, and phosphorylated Tau immunoreactivity), including anti-inflammation, antioxidative stress, antiautophagy, and antiapoptosis, etc. Indeed, some MFH substances and their related phytochemicals have a broad spectrum of activities, so they are superior to simple single-target drugs in treating chronic diseases. This review can provide significant guidance for people’s healthy lifestyles and drug development for AD prevention and treatment.

Neuroprotective Effect of Clobenpropit against Lipopolysaccharide-Induced Cognitive Deficits via Attenuating Neuroinflammation and Enhancing Mitochondrial Functions in Mice

Clobenpropit (CLO), an antagonist on histamine H₃ receptors (HH3R), has been shown to protect NMDA-induced neuronal necrosis in cortical neuronal cell culture from rats. In this work, we explored its potential on lipopolysaccharide (LPS)-induced memory deficits, neuroinflammation, and mitochondrial dysfunction in mice. CLO (1 and 3 mg/kg, p.o.) was treated continually for 30 days, and neurotoxicity was induced by four doses of LPS (250 µg/kg, i.p.). The radial arm maze (RAM) was used to access memory behaviors. After the REM test, brain tissue was collected from each mouse to estimate pro-inflammatory cytokines (TNFα and IL6), anti-inflammatory cytokines (TGF-β1 and IL-10), cyclooxygenase-2 (COX 2), and mitochondrial respiratory chain complex (MRCC- I, II and IV) enzymes. CLO treatment reversed the LPS-induced behavioral deficits by a significant reduction in time taken to consume all five bites (TTB), working memory error (WME), and reference memory error (REM) in the REM test. Regarding neuroinflammation, it attenuated the release of COX, TNF-α, and IL-6, and augmented TGF-β1 and IL-10 levels in the brain. Reversal of LPS-induced brain MRCC (I, II, and IV) levels also resulted with CLO treatment. From these findings, CLO promises neuroprotection against LPS-induced cognitive deficits by ameliorating neuroinflammation and restoring the MRCC enzymes in mice.

Zingiber officinale (Ginger) hydroalcoholic extract improved avoidance memory in rat model of streptozotocin-induced diabetes by regulating brain oxidative stress

OBJECTIVES

Diabetes mellitus associated cognitive impairment is suggested to be due to oxidative stress. Considering the anti-diabetic, antioxidant, antihyperlipidemic, and anti-inflammatory effects of Zingiber officinale, the present study aimed to investigate its effect on memory and oxidative stress factors in streptozotocin (STZ)-induced diabetic rats.

METHODS

The rats were allocated into five groups: Control, Diabetic, Diabetic + Ginger 100, Diabetic + Ginger 200, and Diabetic + Ginger 400. Following diabetes induction by STZ (60 mg/kg), 100, 200, or 400 mg/kg Ginger was given for eight weeks. Passive avoidance test (PA) was done and thiol, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) measurements were carried out in the brain.

RESULTS

The latency into the dark compartment decreased (p<0.001) and the number of entries and time spent in the dark chamber increased in the Diabetic group compared to the Control (p<0.001 for all). All three doses of extract improved performance of the rats in the PA test (p<0.001 for all). The hippocampal and cortical MDA level was higher (p<0.001) while CAT, SOD, and total thiol were lower (p<0.01-p<0.001) in the Diabetic group than the Control. Treatment with 200 and 400 mg/kg Z. officinale extract reduced hippocampal and cortical MDA (p<0.001) and improved CAT (p<0.001) while, just the dose of 400 mg/kg of the extract increased SOD and total thiol in hippocampal and cortical tissues (p<0.001) compared with Diabetic group.

CONCLUSIONS

Z. officinale extract could improve memory by reducing the oxidative stress in STZ-induced diabetes model.

Phytochemicals and Bioactivities of Zingiber cassumunar Roxb

Zingiber cassumunar Roxb. (Zingiberaceae), is an important medicinal plant known as “Plai (Phlai)” in Thailand, “Bangle” in Indonesia, and “Bulei” in China. Traditionally, this plant has been used to treat inflammation, pain, and respiratory problems. The rhizomes are the primary part of the plant that has been used for medicinal purposes due to their constituents with therapeutic properties, including phenylbutenoids, curcuminoids, and essential oils. Since the 1970s, many studies have been conducted on the phytochemicals and bioactivities of Z. cassumunar to establish fundamental scientific evidence that supports its use in traditional medicine. The accumulated biological studies on the extracts, solvent fractions, and constituents of Z. cassumunar have described their diverse medicinal properties, including antioxidant, anti-inflammatory, anticancer, neuroprotective/neurotrophic, cosmeceutical, and antifungal/antimicrobial bioactivities. In this review, we summarize information on the phytochemicals of Z. cassumunar and the bioactivities of its extracts and constituents.