The production of nitric oxide and TNF-alpha in peritoneal macrophages is inhibited by Dichroa febrifuga Lour

Dichroa febrifuga Lour.: A review of its botany, traditional use, phytochemistry, pharmacological activities, toxicology, and progress in reducing toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Dichroa febrifuga Lour., a toxic but extensively used traditional Chinese medicine with a remarkable effect, is commonly called "Changshan" in China. It has been used to treat malaria and many other parasitic diseases.

AIM OF THE REVIEW

The study aims to provide a current overview of the progress in the research on traditional use, phytochemistry, pharmacological activities, toxicology, and methods of toxicity reduction of D. febrifuga. Additionally, further research directions and development prospects for the plant were put forward.

MATERIALS AND METHODS

The article uses "Dichroa febrifuga Lour." "D. febrifuga" as the keyword and all relevant information on D. febrifuga was collected from electronic searches (Elsevier, PubMed, ACS, CNKI, Google Scholar, and Baidu Scholar), doctoral and master's dissertations and classic books about Chinese herbs.

RESULTS

30 chemical compounds, including alkaloids, terpenoids, flavonoids and other kinds, were isolated and identified from D. febrifuga. Modern pharmacological studies have shown that these components have a variety of pharmacological activities, including anti-malarial activities, anti-inflammatory activities, anti-tumor activities, anti-parasitic activities and anti-oomycete activities. Meanwhile, alkaloids, as the material basis of its efficacy, are also the source of its toxicity. It can cause multiple organ damage, including liver, kidney and heart, and cause adverse reactions such as nausea and vomiting, abdominal pain and diarrhea. In the current study, the toxicity can be reduced by modifying the structure of the compound, processing and changing the dosage forms.

CONCLUSIONS

There are few studies on the chemical constituents of D. febrifuga, so the components and their structure characterization contained in it can become the focus of future research. In view of the toxicity of D. febrifuga, there are many methods to reduce it, but the safety and rationality of these methods need further study.

The anti-inflammatory activity of the compounds isolated from Dichroa febrifuga leaves

Dichroa febrifuga Lour. is a traditional medicinal herb that has been applied in the treatment of malaria and some other infectious diseases. Studies recently have focused on the anti-inflammation of the extracts of Dichroa febrifuga Lour. although there have not many reports about which compounds play the essential role. Therefore, in this study, we isolated hydrangenoside C (1), isoarborinol (2), and methyl 1,3,4,6-tetra-O-acetyl-fructofuranoside (3) from the leaves of Dichroa febrifuga. Subsequently, the anti-inflammatory property of 1-3 was assessed using an in vivo assay of edema mouse model which was induced by carrageenan. Out of the three, 2 inhibited the edema effectively and dose-dependently, similarly to diclofenac while there was no obvious activity observed in 1 and 3. The in silico results demonstrated that 2 enables binding to 5-LOX and PLA2 via generating h-bonds. This is the first study to mention the anti-inflammation of 2 in Dichroa febrifuga Lour., and would be a contribution to further studies to elucidate the promising bioactivities of this compound.

Protective Role of Natural Products in Glioblastoma Multiforme: A Focus on Nitric Oxide Pathway

In spite of therapeutic modalities such as surgical resection, chemotherapy, and radiotherapy, Glioblastoma Multiforme (GBM) remains an incurable fatal disease. This necessitates further therapeutic options that could enhance the efficacy of existing modalities. Nitric Oxide (NO), a short-lived small molecule, has been revealed to play a crucial role in the pathophysiology of GBM. Several studies have demonstrated that NO is involved in apoptosis, metastasis, cellular proliferation, angiogenesis, invasion, and many other processes implicated in GBM pathobiology. Herein, we elaborate on the role of NO as a therapeutic target in GBM and discuss some natural products affecting the NO signaling pathway.

Toxicological evaluation of the ultrasonic extract from Dichroae radix in mice and wistar rats

This study was aimed at evaluating the acute and subchronic toxicity of ultrasonic extract of Dichroae radix (UEDR) in mice and rats. High performance liquid chromatography (HPLC) and thin layer chromatogrephy (TLC) were used to detect β-dichroine and α-dichroine in UEDR for quality control. The levels of β-dichroine and α-dichroine in UEDR were 1.46 and 1.53 mg/g, respectively. An oral LD₅₀ of 2.43 g/kg BW was observed in acute toxicity test. After 28-day repeated oral administration, compared with the control group, treatment-related changes in body weight (BW) and body weight gain (BWG), lymphocyte counts and ratios, as well as in the relative organ weights (ROWs) of liver, kidney, lung, and heart, were detected in the middle- and high-dose groups (P < 0.05, P < 0.01), no differences were noted in the serum biochemical parameters and necropsy examinations in both sexes at all doses. Histopathological examinations exhibited UEDR-associated signs of toxicity or abnormalities. After 14 days withdrawal, no statistically significant or toxicologically relevant differences were observed in any of the UEDR-treated groups, and the hispathological lesions in the high-dose group were alleviated. Findings showed that long-course and high-dose of UEDR administration was toxic, and showed dose-dependence, the toxic damage was reversible.

Inhibitory Effect ofSpirodela polyrhixaon the Secretion of NO in LPS-stimulated Macrophages

Spirodela polyrhixa Schleid has been used in folk medicine to treat inflammatory diseases. Since nitric oxide (NO) is one of the major inflammatory parameters, we studied the effect of aqueous extracts of Spirodela polyrhixa (AESP) on NO production in lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages. AESP inhibited the secretion of NO in macrophages, without affecting cell viability. The protein level of inducible nitric oxide synthase (iNOS) in peritoneal macrophages was also decreased by AESP. Transient transfection assay of reporter plasmid and gel shift assay indicated that AESP blocked the activation of nuclear factor-kappa B (NF-κB), which was considered to be a potential transcription factor for iNOS expression. AESP also blocked the phosphorylation and degradation of inhibitory protein I kappa B-alpha (IκB-α). These results suggest that AESP could exert its anti-inflammatory actions by suppressing the synthesis of NO through inhibition of NF-κB activity.

Involvement of the nitric oxide/soluble guanylate cyclase pathway in the anti-oedematogenic action of Pfaffia glomerata (Spreng) Pedersen in mice

Pfaffia glomerata is used in southern American countries against inflammatory diseases. We have explored the ability of a crude hydroalcoholic extract of P. glomerata root (HEPG) to prevent the oedematogenic action of several inflammatory agents in mice. We have examined also the duration of its effects and the mechanisms involved. The oral or intraperitoneal treatment of mice with HEPG (1, 10, 30, 100 or 300 mg kg−1) reduced, in a dose-dependent manner, carrageenan-induced paw oedema in the early (1–4 h) and late (48 h) periods. In the early period, the ID50 value (the median dose that caused 50% inhibition) of HEPG was 60.5 (28.5–128.71) and 20.4 (14.8–28.3) mg kg−1 after oral and intraperitoneal administration, respectively. This effect was still evident when HEPG was administered up to 6 h before carrageenan. HEPG inhibited also paw oedema induced by histamine, serotonin, bradykinin, substance P and bacterial lipopolysaccharide. In addition, oral administration of HEPG increased the levels of nitrate and nitrite in the blood of mice. Further, its anti-oedematogenic action against carrageenan was prevented fully by NG nitro-L-arginine-methyl-ester (10 mg kg−1, s.c.), as well as by methylene blue (20 mg kg−1, s.c.) or 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one (2 mg kg−1, s.c.). The results indicated that stimulation of endogenous production of nitric oxide, followed by soluble guanylate cyclase activation, was implicated in the anti-oedematogenic action of HEPG.

Dichroa febrifuga Lour. inhibits the production of IL-1beta and IL-6 through blocking NF-kappaB, MAPK and Akt activation in macrophages

AIM OF THE STUDY

The roots of Dichroa febrifuga Lour. have been used as a traditional antimalarial drug and also used in the treatment of productive cough and unstable fever caused by infection in China and Korea. In this study, we evaluated the anti-inflammatory effect and underlying molecular mechanism of aqueous extract of Dichroa febrifuga (AEDF) in C57BL/6 mouse peritoneal macrophages.

MATERIALS AND METHODS

The effect of AEDF on proinflammatory cytokine (IL-1beta and IL-6) production was analyzed by ELISA and real-time RT-PCR. The effects of AEDF on NF-kappaB/IkappaB-alpha/IKK were measured by reporter assay (in RAW 264.7 cells), EMSA, Western blotting and kinase assay. The effects of AEDF on Akt and MAPKs activity were assayed by Western blotting.

RESULTS

AEDF inhibited the production of IL-1beta and IL-6, NF-kappaB activation, IkappaB-alpha degradation, and IKK, Akt, ERK1/2 and JNK activities in LPS-stimulated mouse peritoneal macrophages.

CONCLUSIONS

These results suggest that AEDF inhibits proinflammatory cytokine (IL-1beta and IL-6) production in LPS-stimulated mouse peritoneal macrophages, and that these effects are mediated by the inhibition of the activity of IKK/IkappaB/NF-kappaB and the phosphorylation of Akt, ERK1/2, and JNK. Our results provide a molecular basis for understanding the inhibitory effects of Dichroa febrifuga roots on endotoxin-mediated inflammation.

Gleditsia sinensis thorns inhibit the production of NO through NF-kappaB suppression in LPS-stimulated macrophages

The thorns of Gleditsia sinensis LAM. (Leguminosae) have been used in traditional medicine for the treatment of inflammatory diseases including swelling, suppuration, carbuncle and skin diseases in China and Korea. In this study, we investigated the mechanism responsible for anti-inflammatory effects of Gleditsia sinensis thorns in RAW 264.7 macrophages. The aqueous extract of Gleditsia sinensis thorns (AEGS) inhibited LPS-induced NO secretion as well as inducible nitric oxide synthase (iNOS) expression, without affecting cell viability. Furthermore, AEGS suppressed LPS-induced NF-kappaB activation, phosphorylation and degradation of IkappaB-alpha, phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). These results suggest that AEGS has the inhibitory effects on LPS-induced NO production and iNOS expression in macrophages through blockade in the phosphorylation of MAPKs, following IkappaB-alpha degradation and NF-kappaB activation.

Effects of lotus plumule supplementation before and following systemic administration of lipopolysaccharide on the splenocyte responses of BALB/c mice

To determine whether lotus plumule supplementation alleviates acute systemic inflammation in vivo, the BALB/c mice were continuously supplemented with lotus plumule for 3 weeks, following administration with an intraperitoneal (i.p.) injection of lipopolysaccharide (LPS) at a concentration of 10mg/kg body weight (BW) to induce acute systemic inflammation. At 24h after injection of LPS, the mice were sacrificed and the visceral organ weight and splenocyte responses were measured. The results showed that lotus plumule supplementation did not significantly affect body weights and IL-6 secretion of splenocyte cultures from BALB/c mice. LPS challenge significantly increased the relative organ weights of the lungs, liver, and spleen, however low dose supplementation (40 mg/kg BW/day) with lotus plumule significantly decreased the relative organ weights of the inflammatory liver, spleen and kidney. Low dose supplementation with lotus plumule significantly increased IL-10 production of splenocyte cultures, however high dose supplementation (800 mg/kg BW/day) significantly decreased IL-10 production. These results suggest that low dose and 3-week supplementation of lotus plumule might alleviate acute systemic inflammation in vivo via decreasing the visceral organ inflammation and increasing the production of anti-inflammatory cytokine IL-10 from splenocytes. These results are valuable for developing future nutraceuticals and anti-inflammatory agents from traditional medicinal foods.

Ca2+/calmodulin-dependent protein phosphatase calcineurin mediates the expression of iNOS through IKK and NF-kappaB activity in LPS-stimulated mouse peritoneal macrophages and RAW 264.7 cells

Ca(2+) and Ca(2+)/calmodulin-dependent protein phosphatase calcineurin (CN) have been known to play crucial roles in immune response and inflammation. Using mouse peritoneal macrophages and RAW 264.7 macrophage cells, we demonstrated that LPS mobilized intracellular free Ca(2+) and induced CN phosphatase activity. iNOS expression and NO secretion in response to LPS were suppressed by Ca(2+) antagonists (TMB-8, BAPTA/AM, and nifedipine) and CN inhibitor (cyclosporin A). Transient expression of constitutively active CN in mouse peritoneal macrophages and RAW 264.7 macrophages strongly activated NF-kappaB, a key mediator of iNOS expression. We also found that CN mediates NF-kappaB activation via IkappaB-alpha hyperphosphorylation and degradation. Overexpression of dominant negative mutant of IKKalpha and -beta demonstrates that only IKKbeta is the target for CN. These results indicate that CN is required for full iNOS expression and the effective activation of NF-kappaB in RAW 264.7 and peritoneal macrophages.

Nitric oxide, human diseases and the herbal products that affect the nitric oxide signalling pathway

1. Nitric oxide (NO) is formed enzymatically from l-arginine in the presence of nitric oxide synthase (NOS). Nitric oxide is generated constitutively in endothelial cells via sheer stress and blood-borne substances. Nitric oxide is also generated constitutively in neuronal cells and serves as a neurotransmitter and neuromodulator in non-adrenergic, non-cholinergic nerve endings. Furthermore, NO can also be formed via enzyme induction in many tissues in the presence of cytokines. 2. The ubiquitous presence of NO in the living body suggests that NO plays an important role in the maintenance of health. Being a free radical with vasodilatory properties, NO exerts dual effects on tissues and cells in various biological systems. At low concentrations, NO can dilate the blood vessels and improve the circulation, but at high concentrations it can cause circulatory shock and induce cell death. Thus, diseases can arise in the presence of the extreme ends of the physiological concentrations of NO. 3. The NO signalling pathway has, in recent years, become a target for new drug development. The high level of flavonoids, catechins, tannins and other polyphenolic compounds present in vegetables, fruits, soy, tea and even red wine (from grapes) is believed to contribute to their beneficial health effects. Some of these compounds induce NO formation from the endothelial cells to improve circulation and some suppress the induction of inducible NOS in inflammation and infection. 4. Many botanical medicinal herbs and drugs derived from these herbs have been shown to have effects on the NO signalling pathway. For example, the saponins from ginseng, ginsenosides, have been shown to relax blood vessels (probably contributing to the antifatigue and blood pressure-lowering effects of ginseng) and corpus cavernosum (thus, for the treatment of men suffering from erectile dysfunction; however, the legendary aphrodisiac effect of ginseng may be an overstatement). Many plant extracts or purified drugs derived from Chinese medicinal herbs with proposed actions on NO pathways are also reviewed.

Sporothrix schenckii lipid inhibits macrophage phagocytosis: involvement of nitric oxide and tumour necrosis factor-alpha

The role of cell-wall compounds in the immune response to sporotrichosis is unknown. The effect of cell-wall compounds and exoantigen obtained from Sporothrix schenckii in macrophage/fungus interaction was analysed with respect to nitric oxide (NO) and tumour necrosis factor-alpha (TNF-alpha). The lipid compound of the cell wall plays an important role in the pathogenesis of this mycosis and was found to inhibit the phagocytic process and to induce high liberation of NO and TNF-alpha in macrophage cultures in the present study. This is a very interesting result because it is the first report about one compound of the fungus S. schenckii that presents this activity.