Fructus Ligustrum lucidi inhibits inflammatory mediator release through inhibition of nuclear factor-kappaB in mouse peritoneal macrophages

Anti-Neuroinflammatory Effects and Mechanism of Action of Fructus ligustri lucidi Extract in BV2 Microglia

For centuries, Fructus ligustri lucidi (FLL; the fruit of Ligustrum lucidum Aiton or Ligustrum japonicum Thunb.) has been commonly used in traditional Chinese medicine for treating hepatitis and aging-related symptoms and in traditional Korean medicine to detoxify kidneys and the liver. Pharmacological research has shown FLL has antioxidant, anti-inflammatory, anticancer, anti-osteoporosis, and hepatoprotective activities. This study was undertaken to investigate the effects of FLL extract (FLLE) on neuroinflammation. After setting a non-toxic concentration using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] assay data, we investigated the effects of FLLE using Western blotting, cell migration, enzyme-linked immunosorbent assay, a nitric oxide (NO) assay, and immunofluorescence staining in lipopolysaccharide (LPS)-stimulated murine BV2 microglial cells. FLLE was non-toxic to BV2 cells up to a concentration of 500 μg/mL and concentration-dependently inhibited the production of NO and prostaglandin E₂ and the protein levels of inducible nitric oxide synthase and cyclooxygenase-2 under LPS-induced inflammatory conditions. It also inhibited the secretion of the inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Furthermore, FLLE pretreatment attenuated LPS-induced increases of CD68 (a marker of microglia activation) and suppressed the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) signaling pathways in LPS-stimulated BV2 cells, and significantly increased heme oxygenase (HO)-1 levels. FLLE also reduced the LPS-induced increase in the migratory ability of BV2 cells and the phosphorylation of vascular endothelial growth factor receptor 1. Collectively, FLLE effectively inhibited inflammatory response by suppressing the MAPK and NF-κB signaling pathways and inducing HO-1 in LPS-stimulated BV2 microglial cells. Our findings provide a scientific basis for further study of FLL as a candidate for preventing or alleviating neuroinflammation.

Oleanolic Acid Protects the Skin from Particulate Matter-Induced Aging

The role of particulate matter (PM) in health problems including cardiovascular diseases (CVD) and pneumonia is becoming increasingly clear. Polycyclic aromatic hydrocarbons, major components of PM, bind to aryl hydrocarbon receptor (AhRs) and promote the expression of CYP1A1 through the AhR pathway in keratinocytes. Activation of AhRs in skin cells is associated with cell differentiation in keratinocytes and inflammation, resulting in dermatological lesions. Oleanolic acid, a natural component of L. lucidum, also has anti-inflammation, anticancer, and antioxidant characteristics. Previously, we found that PM₁₀ induced the AhR signaling pathway and autophagy process in keratinocytes. Here, we investigated the effects of oleanolic acid on PM₁₀-induced skin aging. We observed that oleanolic acid inhibits PM₁₀-induced CYP1A1 and decreases the increase of tumor necrosis factor–alpha and interleukin 6 induced by PM₁₀. A supernatant derived from keratinocytes cotreated with oleanolic acid and PM₁₀ inhibited the release of matrix metalloproteinase 1 in dermal fibroblasts. Also, the AhR-mediated autophagy disruption was recovered by oleanolic acid. Thus, oleanolic acid may be a potential treatment for addressing PM₁₀-induced skin aging.

Phenol glycosides extract of Fructus Ligustri Lucidi attenuated depressive-like behaviors by suppressing neuroinflammation in hypothalamus of mice

Depression is partially caused by inflammation in central nervous system. This study investigated the ameliorative effects of phenol glycosides (PG) from Ligustrum lucidum Ait. (Oleaceae) on neuroinflammation and depressive-like behavior in mice hypothalamus as well as the molecular mechanism. Mice were administered with PG extract for 2 weeks prior to treatment with LPS. The mice treated with PG extract showed resistance to LPS-induced reduction in body weight and LPS-induced depressive-like behaviors shown by sucrose preference, tail suspension test, forced swimming test and open field test. LPS-induced activation of microglial cells and elevation in protein expression of inflammatory cytokines including IL-1β, RANTES and MCP-1 in hypothalamus of mice were abrogated by pre-treatment with PG extract. This extract down-regulated expression of TLR4, MyD88, NLRP3, renin and angiotensin II and decreased proportional area of Iba-1⁺ microglias in hypothalamus. Pre-treatment with PG extract inhibited LPS-triggered activation of CaSR/G_α11 signaling, stimulated 1-OHase expression in hypothalamus, and enhanced circulating 1,25(OH)₂ D₃ level. Overall, pre-treatment with PG extract ameliorated LPS-induced depressive-like behaviors by repressing neuroinflammation in mice hypothalamus which was attributed to its suppression on activation of microglia and production of inflammatory cytokines via acting on TLR4 pathway, CaSR and RAS cascade associated with improving vitamin D metabolism.

Oleanolic acid mitigates interleukin-1β-induced chondrocyte dysfunction by regulating miR-148-3p-modulated FGF2 expression

BACKGROUND

microRNA (miR)-mediated post-transcriptional repression has been reported in the process of chondrocyte dysfunction. The present study aimed to investigate the molecular mechanisms underlying in oleanolic acid (OLA)-prevented interleukin (IL)-1β-induced chondrocyte dysfunction via the miR-148-3p/fibroblast growth factor-2 (FGF-2) signaling pathway.

METHODS

Candidate miRs were filtrated using miR microarray assays in chondrocytes with or without IL-1β stimulation. Gene expression of candidate miRs and protein expression of FGF2 were analyzed using a quantitative reverse transcriptase-polymerase chain reaction and western blotting, respectively. Cell growth was evaluated using cell counting kit-8 assays. Cell apoptosis was detected using Annexin V-fluorescein isothiocyanate double staining.

RESULTS

Treatment with OLA counteracted IL-1β-evoked chondrocyte growth inhibition, apoptosis, caspase3 production, and release of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine. Additionally, FGF2 protein expression levels elevated by IL-1β were down-regulated by OLA and transfection with miR-148-3p mimics. IL-1β-induced down-regulation of miR-148-3p in chondrocytes was evaluated by OLA administration. Bioinformatics algorithms and experimental measurements indicated that FGF2 might be a direct target of miR-148-3p. miR-148-3p mimics exhibited equal authenticity of OLA to protect against IL-1β-induced chondrocyte dysfunction.

CONCLUSIONS

Our present findings highlight a protective effect of OLA on IL-1β-induced chondrocyte dysfunction, and a novel signal cascade comprising the miR-148-3p/FGF2 signaling pathway might be a potential therapeutic target of OLA with respect to preventing the progression of osteoarthritis.

Four spices prevent mice from contracting Salmonella enterica serovar Typhimurium

Ligustrum lucidum Ait (LL), Lysimachia christinae Hance (LC), Mentha piperita Linn (MP), and Cinnamomum cassia Presl (CC) are common spices used in Asia. The present study investigated the anti-Salmonella effects of the four spices using aqueous extracts. The amount of phenolic acids and flavonoids in each spice aqueous extract was determined as indicators of purity. Mice were pretreated with LL, LC, MP or CC aqueous extract for 7 days. Following infection with Salmonella enterica serovar Typhimurium strain ST21 (ST21), the aqueous extract of each spice was subsequently administered for 4 days. ST21 infected mice had lower body weight compared with the control group. The administration of spice aqueous extracts significantly increased body weight following infection. ST21 infection increased the fecal ST21 counts compared with the control group; however, following spice aqueous extract treatments, ST21 counts significantly decreased. The spice treatments also significantly reduced ST21 count in blood and the organs. Notably, ST21 infection increased interferon (IFN)-γ and interleukin (IL)-6 levels in serum whilst spice treatments reduced these cytokines. In the spleen, spice treatment significantly lowered IFN-γ, IL-6, IL-1β, and tumor necrosis factor (TNF)-α levels, but increased IL-12 levels. ST21 infection stimulated the production of immunoglobulin (Ig)A and IgM in serum whilst spice aqueous extract treatment significantly decreased these levels. In summary, LL and MP aqueous extract treatments had the most significant effect in protecting against ST21 infection. Results of the RAW 264.7 cell infection model suggested that the mechanisms involved in the anti-ST21 effect of each spice were individually different. All four aqueous extracts demonstrated different mechanisms in attenuating ST21 invasion with the protective effect of LC aqueous extract potentially involving TNF-α expression. The present findings suggested that the four spices may be considered as potent functional foods due to their anti-Salmonella effects.

New secoiridoids from the fruits of Ligustrum lucidum

Three new secoiridoids, nuezhenelenoliciside (1), isojaslanceoside B (2), 6'-O-trans-cinnamoyl-secologanoside (3), were isolated from the dried fruits of Ligustrum lucidum. Their structures were elucidated by comprehensive spectroscopic analysis. Among them, 1 featured a rare rearrangement product of secoiridoid, which underwent the cleavage of chemical bond between C-1 and O-2, and the reformation of a new iridoid ring between C-8 and O-2. In addition, all compounds were tested for their osteogenic activity on pre-osteoblastic MC3T3-E1 cells. As a result, 1 and 3 exhibited potent effects on promoting cell proliferation of pre-osteoblast cells.

Antioxidant Effect of Fructus Ligustri Lucidi Aqueous Extract in Ovariectomized Rats Is Mediated through Nox4-ROS-NF-κB Pathway

Purpose: This study is designed to explore whether Fructus ligustri lucidi (FLL) exhibits antioxidant effect in ovariectomized (OVX) rats, and to identify the signaling pathway involved in this process.

Methods: OVX rats were treated with FLL aqueous extract (3.5 g/kg) for 12 weeks. Serum, uteri, and tibias were harvested from the rats and the levels of total antioxidant capacity (TAC), nitric oxide (NO), malondialdehyde (MDA), 8-hydroxy-desoxyguanosine (8-OHdG), and superoxide dismutase (SOD) were determined. Changes in the levels of NF-κB-p65, phosphorylation of NF-κB-p65 (NF-κB-pp65), NF-κB inhibitor alpha (IκBα), phosphorylation of IκBα (p-IκBα), and NADPH oxidase 4 (Nox4) in uteri and tibias were determined by western blot, immunofluorescent and immunohistochemical analysis, respectively. In addition, the expression of cytochrome C (Cyto-C) and B-cell lymphoma-2 (Bcl-2) were determined in the tibias of rats. Histopathological changes in the bones were evaluated by hematoxylin-eosin staining. Bone mineral density (BMD) was determined in rat femurs by dual X-ray absorptiometry.

Results: Treatment of OVX rats with FLL aqueous extract improved redox homeostasis by increasing the levels of TAC and NO as well as decreasing the levels of MDA and 8-OHdG in serum, tibias, and uteri. Further, FLL extract also downregulated the expression of Nox4, NF-κB-p65, NF-κB-pp65, and p-IκBα in the uteri and tibias. Furthermore, administration of FLL–OVX rats increased Bcl-2 expression and prevented cytoplasmic release of mitochondrial Cyto-C in the tibias. In addition, FLL treatment also improved bone microstructure and increased cortical bone thickness as well as increased BMD values in the femurs of OVX rats.

Conclusions: FLL treatment may suppress oxidative stress response in OVX rats via regulating the Nox4/ROS/NF-κB signaling pathway. These results suggest the potential of using FLL as a natural antioxidant agent in preventing the development of osteoporosis.

Effects of Kuan-Sin-Yin decoction on immunomodulation and tumorigenesis in mouse tumor models

Background

Complementary therapies are widely used among cancer patients. Kuan-Sin-Yin (KSY) decoction, a popular qi-promoting herbal medicine, was constituted with several herbs known to exhibit immunomodulating or anticancer activity. After combining these herbs as a compound formula, it is necessary to reassess the immunomodulation effects, the effects on tumor growth, and possible toxicity of KSY.

Methods

The anti-cancer effects of KSY in vivo were determined by measuring the tumor volumes, anticancer-associated cytokines (IFN-gamma, TNF-alpha, IL-2, and IL-12), accumulation of tumor infiltrating leukocytes (TILs), proliferation and apoptosis-related molecular markers (Ki-67, p53, p21, activated caspase 3, and cleaved PARP), and an in situ TUNEL assay. The body weight and serum chemistry of treated mice were also assessed. In vitro, the effects of KSY were evaluated using MTT assay, BrdU incorporation assay and cell growth curve.

Results

In vivo, KSY suppressed bladder or lung cancer growth but did not promote the production of cytokines nor increase the accumulation of TILs. The expression of p53 and p21 in KSY-treated mice were increased. The numbers of apoptotic tumor cells and the expression of apoptosis marker proteins (Caspase 3 and cleaved PARP) were not significantly elevated after KSY treatment. In vitro, the viability and proliferation of tumor cells, but not normal cells, were suppressed by KSY treatment. No significant toxicity was found in KSY-treated mice.

Conclusions

KSY suppressed the tumor growth in vivo and in vitro, which resulted from its cytostatic effects on cancer cells, rather than the induction of anti-cancer immunity. Under these experimental conditions, no apparent toxicity was observed.

Electronic supplementary material

The online version of this article (doi:10.1186/1472-6882-14-488) contains supplementary material, which is available to authorized users.

Analgesic and Anti-Inflammatory Property of the Methanol Extract from Ligustrum morrisonense Leaves in Rodents

Ligustrum morrisonense Kaneh and Sasaki (abbreviated as LM), an endemic Ligustrum plant in Taiwan, is similar to Ligustrum lucidum, which is usually used for curing hepatic and inflammatory disorders. The aim of this study was to evaluate the analgesic and anti-inflammatory properties of LM by chemical-induced algesia and carrageenan-induced inflammation in rodents. Its triterpenoid contents were measured by using high performance liquid chromatography-photodiode array detector. LM leaf extracts effectively inhibited writhing responses induced by 1% acetic acid and biphasic-licking responses caused by 1% formalin. LM leaf extract also reduced the edema induced by 1% carrageenan. Furthermore, LM leaf extract reduced the abdominal Evan's blue extravasations caused by lipopolysaccharide (LPS), serotonin, histamine and bradykinin. LM leaf extract has higher contents of amyrin and lupeol among six assayed triterpenoid compounds. In conclusion, LM is a potential analgesic and anti-inflammatory Ligustrum plant, and its anti-inflammatory effects are partially related to decreasing microvascular permeability via inflammatory mediators and inhibiting cyclooxygenase-2 activity.

Triterpenoid contents and anti-inflammatory properties of the methanol extracts of ligustrum species leaves

Ligustrum (privet) plants are used by Chinese physicians to prevent and cure hepatitis and chronic bronchitis. Three common Ligustrum plant spp., namely Ligustrum lucidum Ait. (LL), L. pricei Hayata (LP) and L. sinensis Lour. (LS) were collected to assess their analgesic/anti-inflammatory properties on chemical-induced nociception and carrageenan-induced inflammation in rodents. The methanol extracts from Ligustrum plants leaves effectively inhibited nociceptive responses induced by 1% acetic acid and 1% formalin. LP and LL reduced the edema induced by 1% carrageenan. LP exhibited the best potency of the Ligustrum plants. Furthermore, LP reduced the abdominal Evan's blue extravasations caused by lipopolysaccharide, lipoteichoic acid, autocrines and sodium nitroprusside. The triterpenoid content of the three Ligustrum spp. was measured by high performance liquid chromatography using a photodiode array detector. LP contained the highest content of amyrin, betulinic acid and lupeol. LL had the highest content of oleanolic acid and ursolic acid. The various degrees of analgesic/anti-inflammatory effects among three Ligustrum plants may be related to their different triterpenoid contents. LP is a potential analgesic and anti-inflammatory Ligustrum plant. The effects of LP are partially related to the inhibition of cyclooxygenase-2 activity and a decrease in microvascular permeability via the actions of autocrines and kinins.

Dual inhibition of metallopeptidases ACE and NEP by extracts, and iridoids from Ligustrum vulgare L

AIM OF THE STUDY

In order to confirm the traditional use of Ligustrum vulgare L. (common privet, Oleaceae) we investigated the inhibitory activity of different extracts from leaves (LlE), flowers (LflE) and fruits (LfrE) on metallopeptidases ACE and NEP.

MATERIALS AND METHODS

Powdered plant materials were first extracted with water and then with ethyl acetate and n-butanol saturated with water. The metallopeptidases activity was determined using in vitro fluorimetric assays.

RESULTS

At a concentration of 100microg/ml the ethyl acetate extracts showed the highest activity. The bio-guided fractionation of the leaves extract led to the isolation of two iridoids which were identified by (1)H, (13)C and HETCOR NMR spectroscopy as oleuropein and ligstroside aglycones. Both compounds are dual ACE/NEP inhibitors with IC(50) of 20 and 25microM for ACE and IC(50) of 35 and 75microM for NEP, respectively. Secoirydoids glycosides, tyrozol and hydroxytyrozol, as well as, flavonoids present in the ethyl acetate extracts showed little or no inhibitory activity.

CONCLUSIONS

Our results partially support the diuretic and hypotensive activities of common privet.