Differential neuroprotective effect of curcuminoid formulations in aluminum chloride-induced Alzheimer's disease.

Alzheimer's disease (AD) is a slowly progressive brain degenerative disorder which gradually impairs memory, thinking, and ability to perform easy routine tasks. This degenerative disorder mainly targets the elderly people and has imposed an endemic burden on society. Hence, there is a crucial need to investigate the efficacious herbal pharmacotherapies that can effectively mitigate and prevent the pathological hallmarks of AD. The current study aims to explore the potential efficacy of curcuminoid-rich extract (CRE) and its ternary complex (TC). Experimental rodents were administered with AlCl3 (300 mg/kg) to induce AD and treated with rivastigmine, curcuminoid crude extract, CRE, and TC orally for three consecutive weeks. Neurobehavioral, biochemical, and histopathological studies were performed from the last week of the study period. The mRNA expression of different pathological biomarkers was estimated by RT-qPCR analysis. The results of the study suggested that CRE and TC significantly improved the behavioral, biochemical parameters and acetylcholinesterase inhibitory activity in treatment groups. Histological analysis was also carried out indicating that the neurodegenerative changes and neuronal loss were stabilized by CRE and TC supplementation. CRE and TC supplementation remarkably downregulated the interleukin-1α, tumor necrosis factor-α, interleukin-1ß, acetylcholinesterase, and ß-secretase pathological gene expression. Hence, it was concluded that CRE and TC may act as promising candidates in the prevention of AD via numerous underlying signaling pathways.

Demethoxycurcumin Suppresses Human Brain Glioblastoma Multiforme GBM 8401 Cell Xenograft Tumor in Nude Mice In Vivo.

Demethoxycurcumin (DMC), a derivate of curcumin, has been shown to induce apoptotic cell death in human glioblastoma multiforme GBM 8401 cells via cell cycle arrest and induction of cell apoptosis. However, there is no report showing DMC suppresses glioblastoma multiforme cells in vivo. In the present study, we investigated the effects of DMC on GBM8401 cells in vivo. At first, we established a luciferase-expressing stable clone named GBM 8401/luc2. Second, mice were inoculated subcutaneously with GBM 8401/luc2 cells to generate a xenograft tumor mice model. After inoculation, tumor volume reached 100-120 mm3, and all mice were randomly divided into three groups: Group I was treated with 110 µL phosphate-buffered solution (PBS) containing 0.1% dimethyl sulfoxide, Group II with 30 mg/kg of DMC, and Group III with 60 mg/kg of DMC. Mice from each group were given the oral treatment of DMC by gavage for 21 days. The body weight and tumor volume were recorded every 3 days. DMC significantly decreased the tumor volumes, and 60 mg/kg treatment showed a higher decrease in tumor volumes than that of 30 mg/kg, However, DMC did not affect the body weights. The photons emitted from mice tumors were detected with Xenogen IVIS imaging system, DMC at both doses decreased the total photon flux and 60 mg/kg treatment of DMC has low total photon flux than that of 30 mg/kg. The tumor volumes and weights in 60 mg/kg treatment of DMC were lower than that of 30 mg/kg. Immunohistochemical analysis was used to measure protein expression of tumors and results showed that DMC treatment led to lightly staining with anti-Bcl-2 and -XIAP and 60 mg/kg treatment of DMC has lighter staining with anti-Bcl-2 and -XIAP than that of 30 mg/kg. The higher dose (60 mg/kg) of DMC has higher signals of cleaved-caspase-3 than that of the lower dose (30 mg/kg). Furthermore, the hematoxylin and eosin (H&E) staining of liver tissues showed no significant difference between DMC-treated and control-groups. Overall, these observations showed that DMC suppressed tumor properties in vivo and DMC may be used against human glioblastoma multiforme in the future.

Demethoxycurcumin analogue DMC-BH inhibits orthotopic growth of glioma stem cells by targeting JNK/ERK signaling.

Glioma stem cells (GSCs) play an important role in glioblastoma resistance to conventional therapies and disease recurrence. Here, we assessed the therapeutic effect of a demethoxycurcumin analogue, DMC-BH, on GSCs, and investigated the underlying mechanisms. Our in vitro data demonstrate that DMC-BH inhibits GSC proliferation, and induces apoptosis and autophagy in GSCs. In addition, our results show that DMC-BH effectively crosses the blood-brain barrier to inhibit the growth of intracranial GSC tumors in vivo. DMC-BH significantly increased phosphorylation levels of JNK, ERK and c-Jun in GSCs. Inhibition of JNK and ERK activities reversed the pro-apoptotic effect of DMC-BH in GSCs, indicating that the DMC-BH-induced apoptosis in GSCs is mediated via the JNK/ERK signaling pathway. These results suggest that DMC-BH could potentially serve as a effective therapy against GSCs that acts by targeting the JNK/ERK signaling pathway.

Bactericidal and cytotoxic activity of a diarylheptanoid (etlingerin) isolated from a ginger (Etlingera pubescens) endemic to Borneo.

AIMS: The aim of this study was to investigate the antimicrobial activities of Etlingera pubescens, and to isolate and identify the antimicrobial compound. METHODS AND RESULTS: The crude extracts of E. pubescens were obtained through methanol extraction, and evaluated for antimicrobial activities. From this extract, 1,7-bis(3,4-dihydroxyphenyl)heptan-3-yl acetate (etlingerin) was isolated. When compared to curcumin (a compound with a similar chemical structure), etlingerin showed twofold lower minimum inhibitory concentration values while also being bactericidal. Through time kill assay, etlingerin showed rapid killing effects (as fast as 60 min) against the Gram-positive bacteria (Staphylococcus aureus ATCC 43300 and Bacillus subtilis ATCC 8188). Further assessment revealed that etlingerin caused leakage of intracellular materials, therefore suggesting alteration in membrane permeability as its antimicrobial mechanism. Cytotoxicity study demonstrated that etlingerin exhibited approximately 5- to 12-fold higher IC50 values against several cell lines, as compared to curcumin. CONCLUSIONS: Etlingerin isolated from E. pubescens showed better antibacterial and cytotoxic activities when compared to curcumin. Etlingerin could be safe for human use, though further cytotoxicity study using animal models is needed. SIGNIFICANCE AND IMPACT OF THE STUDY: Etlingerin has a potential to be used in treating bacterial infections due to its good antimicrobial activity, while having potentially low cytotoxicity.

The mechanistic antitumor study of myricanol 5-fluorobenzyloxy ether in human leukemic cell HL-60.

AIM: The aim of the study was to explore the growth inhibitory effect of myricanol 5-fluorobenzyloxy ether (5FEM) and the underlying mechanism in human leukemic cells HL-60. MATERIALS & METHODS: 5FEM was obtained by chemical modification of myricanol with fluorobenzyloxy ether at the OH(5) position. The cytotoxicity, cell apoptosis, cell cycle and the expression of key apoptosis-related genes in HL-60 were evaluated. RESULTS & CONCLUSION: 5FEM can significantly inhibited growth of HL-60 cells, increased the G2/M population and upregulated the expression of Bax, Fas, FasL, caspase-9 and p21 and downregulated that of Bcl-2 and survivin. The results enhance our understanding of 5FEM and aid the discovery of novel myricanol derivatives as potential antitumor agents.

Diarylheptanoid from Curcuma comosa Roxb. suppresses RANKL-induced osteoclast differentiation by decreasing NFATc1 and c-Fos expression via MAPK pathway.

Osteoporosis is caused by a functional imbalance between osteoblasts and osteoclasts. The increased activation of osteoclasts that is a hallmark of osteoporosis results in the progressive loss of bone mass and therefore in an increased susceptibility to bone fractures. Diarylheptanoids are a group of phytoestrogens that have been isolated from a number of plant species, including the rhizomes of Curcuma comosa Roxb. In this study, the effect of one of diarylheptanoids, (3S)-1-(3,4-dihydroxyphenyl)-3-hydroxy-7-phenyl-(6E)-6-heptene (DHPH), was investigated for anti-inflammatory and anti-osteoclastogenic activity. DHPH significantly inhibited nitric oxide production in RAW264.7 cell line following their activation by lipopolysaccharide and interferon-γ, with no cytotoxicity. In primary mouse bone-marrow-derived macrophage precursors, DHPH suppressed osteoclastogenesis induced by receptor activator of nuclear factor-κB (RANK) ligand at an inhibitory concentration 50 of 325±1.37nM. DHPH treatment delayed and reduced the expression of master regulators of osteoclast differentiation, NFATc1 and c-Fos. Consistent with this result, the mRNA level of cathepsin K, associated with osteoclast differentiation, was decreased whereas the reduction in the mRNA of irf8, a negative regulator of osteoclast differentiation, was similar to that measured in the vehicle-treated control cells. DHPH reduced the phosphorylation of p38 MAPK, ERK (p44/42). Furthermore, DHPH suppressed the bone absorption activity of osteoclasts and enhanced osteoblast differentiation. Taken together, DHPH interrupts the immediate downstream signaling cascade of RANK and interferes with osteoclast differentiation and its function while enhances osteoblast differentiation. These results demonstrate the potential of this diarylheptanoid as a new therapeutic agent in osteoporosis.

Development of phenotypic and transcriptional biomarkers to evaluate relative activity of potentially estrogenic chemicals in ovariectomized mice.

BACKGROUND: Concerns regarding potential endocrine-disrupting chemicals (EDCs) have led to a need for methods to evaluate candidate estrogenic chemicals. Our previous evaluations of two such EDCs revealed a response similar to that of estradiol (E2) at 2 hr, but a less robust response at 24 hr, similar to the short-acting estrogen estriol (E3). OBJECTIVES: Microarray analysis using tools to recognize patterns of response have been utilized in the cancer field to develop biomarker panels of transcripts for diagnosis and selection of treatments most likely to be effective. Biological effects elicited by long- versus short-acting estrogens greatly affect the risks associated with exposures; therefore, we sought to develop tools to predict the ability of chemicals to maintain estrogenic responses. METHODS: We used biological end points in uterine tissue and a signature pattern-recognizing tool that identified coexpressed transcripts to develop and test a panel of transcripts in order to classify potentially estrogenic compounds using an in vivo system. The end points used are relevant to uterine tissue, but the resulting classification of the compounds is important for other sensitive tissues and species. RESULTS: We evaluated biological and transcriptional end points with proven short- and long-acting estrogens and verified the use of our approach using a phytoestrogen. With our model, we were able to classify the diarylheptanoid D3 as a short-acting estrogen. CONCLUSIONS: We have developed a panel of transcripts as biomarkers which, together with biological end points, might be used to screen and evaluate potentially estrogenic chemicals and infer mode of activity.

Diterpenoids and a diarylheptanoid from Hedychium coronarium with significant anti-angiogenic and cytotoxic activities.

Two new labdane diterpenoids, namely hedycoronals A and B (1 and 2, resp.), were isolated from the rhizomes of Hedychium coronarium, together with eight known diterpenoids, 4-11, and a known diarylheptanoid, 3. The structures of 1 and 2 were established by detailed interpretation of their 1D- and 2D-NMR spectra and HR-ESI-MS data. Inhibitory activities against human umbilical vein endothelial cells (HUMECs) proliferation and cytotoxic activities against four cancer cell lines were assessed for all the isolates. Most of these metabolites showed moderate or potent cytotoxic activities against four cancer cell lines. Moreover, compounds 3 and 8 exhibited promising inhibitory activities against HUMECs with the IC(50) values of 6.4 to 3.3 µM.

Anti-inflammatory activities, triterpenoids, and diarylheptanoids of Alnus acuminata ssp. arguta.

CONTEXT: The main use of stem bark infusions of Alnus acuminata ssp. arguta (Schlecht.) Furlow (Betulaceae) includes treatments for acute inflammation in Mexican traditional medicine. OBJECTIVE: n-Hexane (CHE), chloroform (CCE), and methanol (CME) extracts of the stem bark were investigated for anti-inflammatory activity and its safety. MATERIALS AND METHODS: The anti-inflammatory effects of the orally administered CME, CCE, and CHE extracts, using carrageenan-induced rat hind paw edema model, and acute oral toxicity in mice, using Lorke's method, were determined. RESULTS AND DISCUSSION: The column chromatographic fraction (CME-3) showed a higher anti-inflammatory activity (92.2%) (IC(50): 60.8 mg/mL) as compared with CME (76.9%); both were in the same order of magnitude as that of indomethacin, the positive control drug. Safety parameters for acute oral toxicity test showed that CME was not toxic (LD(50): >5000). Several triterpenoids (1-7) from hexane extracts and diarylheptanoids (10-14) from methanol extracts of A. acuminata ssp. arguta were isolated and characterized. CONCLUSIONS: These results confirm the traditional uses of A. acuminata in acute inflammatory conditions and its safety for consumption.

[Antioxidative and cytotoxic properties of diarylheptanoids isolated from Zingiber officinale].

OBJECTIVE: To investigate the antioxidant and cytotoxic properties of five diarylheptanoids (1-5) isolated from the rhizomes of Zingiber officinale. METHOD: Various models such as scavenging superoxide anions and 1,1-diphenyl-2- picrylhydrazyl (DPPH) radicals, inhibiting lipid peroxidation, as well as protecting of rat pheochromocytoma (PC12) cells induced by hydrogen peroxide (H2O2) were employed to assay the antioxidative effects of the diarylheptanoids. The cytotoxicities of compounds 1-5 were measured with MTT assays. RESULT: The test compounds (1-5) showed promising DPPH inhibitory activities, and compound 5 exhibited the strongest DPPH scavenging activity with an IC50 value of (22.6+/-2.4) micromol x L(-1). Compounds 1, 3 and 4 showed potential anti-peroxidative effects with inhibitory rates of (66.3+/-15.4)%, (68.7+/-15.8)% and (72.2+/-10.6)%, respectively, at 100 microg x mL(-1). It could be observed that compounds 1, 3 and 4 demonstrated significant neuroprotective activities in a dose-dependent manner. Moreover, compound 3 exhibited certain cytotoxicities against human chronic myelogenous leukemia cells (K562) and its adriamycin-resistant cells (K562/ADR) with IC50 values of (34.9+/-0.6), (50.6+/-23.5) micromol x L(-1), respectively. CONCLUSION: In vitro results demonstrated that five diarylheptanoids (1-5) isolated from the roots of Z. officinale were capable of scavenging radicals, inhibiting lipid peroxidation and protecting PC12 cells against the insult by H2O2. Additionally, compound 3 could inhibit the growth of K562 and K562/ADR cells.

An effective diaryl derivative against Leishmania amazonensis and its influence on the parasite X macrophage interaction.

The activity of several diarylheptanoid derivatives (curcuminoids) was previously evaluated against Leishmania amazonensis promastigotes and among them the most active compound was 5-hydroxy-7- (4-hydroxy-3-methoxyphenyl)-1-(4-methoxyphenyl)-1,4,6-heptatrien-3-one. This study was carried out to investigate the influence of this diaryl derivative on the infective promastigotes and Balb/c mice peritoneal macrophage interaction. The potential in vitro toxicity was also evaluated. Promastigotes pretreated for 24 hours with the compound had their infective capacity significantly decreased. When the infection of Balb/c macrophage by L. amazonensis promastigotes was already installed, addition of the drug resulted in a diminishing of the infection rate. It was demonstrated that the compound was not toxic to the host macrophage in a concentration equivalent to the LD50/24h from the previous in vitro experiment.

Estudo de compostos diarílicos como potenciais agentes leishmanicidas: avaliação do efeito na biossíntese de esteróides / Study of diarylic compounds as potents leishmanicidal agents: evaluation of the effect in biosynthesis of steroids

Compostos diarílicos derivados da curcumina vêm sendo estudados pelo nosso grupo contra algumas espécies de Leishmania com resultados bastante promissores. Dando continuidade a este projeto, no presente trabalho foram estudados in vitro e in vivo derivados diarílicos sintéticos: diarilheptanóides e diarilpentanóides, contra contra promastigotas de L. braziliensis, L. chagasi e L. amazonensis e amastigotas axênicas de L. amazonensis. Nossos resultados in vitro mostraram que de uma maneira geral, os diarilheptanóides foram mais ativos que os diarilheptanóides contra as três espécies de Leishmania estudadas, e que funções oxigenadas nos anéis e uma cadeia alifática de maior número de carbonos são importantes para a atividade leishmanicida. O diarilheptanóide l (5-hidroxi-7-(4-hidroxi-3-metoxifenil)-1-4-metoxifenil)-1,4,6-heptatrien-3-ona), que foi o mais ativo nos experimentos in vitro, foi escolhido para dar continuidades aos experimentos. Nos ensaios de toxicidade in vitro utilizando-se macrófagos peritoniais de camundongos Balb/c, este composto não se mostrou deletério paras as células do hospedeiro, mesmo em concentrações 10 vezes maior que o equivalente ao seu IC50/24h=0,514mM. O efeito sobre a infecção de macrófagos por L. amazonensis, sugere uma toxicidade seletiva contra as amastigotas intracelulares. Além disto, foi observado um efeito no processo de interiorização dos parasitas nos macrófagos, possivelmente indicando alterações em moléculas de superfície do parasita. O estudo in vivo, mostrou que o composto foi eficaz, diminuindo o tamanho das patas dos camundongos Balb/c tratados experimentalmente com até três doses, quando comparados aos animais que não receberam tratamento ou que foram tratados com a Pentamidina, que foi a droga de referência em todos os experimentos. A análise do efeito do composto no metabolismo de ergosterol de L. amazonensis, mostrou mudanças significativas na biossíntese deste esteLmetilados e a inibição completa de sua síntese, permitindo supor ser esta via metabólica um potencial alvo para os compostos diarílicos.