Research progress on the effects of 5-LOX and its inhibitors on tumors / 中国肿瘤生物治疗杂志

@#[摘 要] 脂氧合酶（LOX）家族蛋白在恶性肿瘤演进中发挥重要作用，其亚型5-LOX在多种肿瘤组织和细胞中呈高表达，且与淋巴结转移、患者的生存期有关，可通过诱导Src的磷酸化、选择性抑制p53依赖的促凋亡基因转录、促进肿瘤血管形成、刺激上皮-间质转化、形成转移前微环境等，促进肿瘤细胞增殖和转移、抑制凋亡，参与调控肿瘤的恶性演进过程。基于5-LOX及其激活蛋白ALOX5AP的促癌作用，已开发出直接、间接两类抑制剂及COX-2/5-LOX双重抑制剂，有望通过降低5-LOX活性或阻断5-LOX代谢途径发挥抗肿瘤作用。本文概述5-LOX在肿瘤中的调控作用以及5-LOX和其激活蛋白抑制剂的研究现状，以期为后续抗肿瘤药物的开发及临床应用提供参考及新的理论依据。

Screening of phytocompounds, molecular docking studies, and in vivo anti-inflammatory activity of heartwood aqueous extract of Pterocarpus santalinus L.f

Objective:To evaluate the anti-inflammatory potential of aqueous extract of Pterocarpus santalinus L.f. heartwood using molecular docking and in vivo experiment. Methods:An aqueous extract of Pterocarpus santalinus heartwood was prepared using a Soxhlet apparatus. Phytocompounds in the extract were tentatively identified using high-resolution mass spectrometry. Molecular docking experiments were carried out to evaluate the binding affinity of selected compounds, phloridzin to cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), prostaglandin E synthase-1 (PGES-1) and 5-lipoxygenase (5-LOX). Anti-inflammatory potential was evaluated by carageenan induced paw edema model in rats. Results:The presence of major component phloridzin along with quercetin, parthenin, ginkgolide B, picrotoxinin, usnic acid, octopine, and epigallocatechin was detected in the extract. Molecular docking study showed that phloridzin inhibited COX-1, COX-2, PGES-1 and 5-LOX with more affinity than ibuprofen and paracetamol. Pterocarpus santalinus heartwood extract at 200 and 400 mg/kg BW showed significant reduction in carageenan-induced hind paw edema in a dose-dependent manner, but the effect was slow when compared with the standard ibuprofen (30 mg/kg p.o.). Conclusions:The study indicated that after clinical trials, the aqueous extract of Pterocarpus santalinus heartwood can be effectively used in phytotherapy to treat inflammation.

Effects of baicalin-gardenoside pairing on 5-lox/CysLTs/CysLT pathway of cerebral ischemic injury rats / 中成药

AIM To study the effects of baicalin and gardenoside pairing on 5-lox/CysLTs/CysLT pathway of rats with cerebral ischemia injury.METHODS SD rats randomly assigned into control group,model group,baicalin and gardenoside pairing groups (7 ∶ 3,dosed at 30,45,60 mg/kg,respectively) in their cerebral ischemia recovery period were simulated with permanent middle cerebral artery occlusion (pMCAO) if necessary.After a week of natural recovery,the drugs' pharmacodynamic effects were evaluated by the neurofunctional scoring and HE staining,their impact on the content of CysLTs was determined by ELISA,and the influence on the expression of 5-lox,CysLT1 and CysLT2 was detected by western blot.RESULTS One-week consecutive administration of baicalin and gardenoside pairing contributed to a reduction in infiltration and tissue edema of ischemic cells.If compared with pMCAO group,the baicalin and gardenoside pairing groups were observed with significantly lowered scores of neurologic functioning,inhibited microglia activation,decreased content of CysLTs and down-regulated expression of 5-LOX,CysLT1 and CysLT2 (P ＜ 0.01).CONCLUSION Baicalin and gardenia pairing's alleviating effect to the damage of cerebral ischemia may be associated with its inhibition on microglia activation and 5-lox/CysLTs/CysLT signaling pathway,and thus an inflammatory impairment reduction.

Inhibition of cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) by D-005 (A lipid extract of Acrocomia crispa fruits) / [Inhibición de la ciclooxigenasa (COX) y la 5-lipooxigenasa (5-LOX) por el D-005 (extracto lipidico del fruto de la Acrocomia crispa)

This study was aimed to investigate whether the a lipid extract from Acrocomia crispa fruits (D-005) inhibits COX and 5-LOX enzyme activities in vitro. This study demonstrates that D-005 inhibits markedly and in a dose dependent manner COX-2 and 5-LOX activities. The dual inhibition of COX-2 and 5-LOX supports further research on the potential anti-inflammatory effect of D-005.

El objetivo de este estudio fue investigar si el extracto lipídico de los frutos de Acrocomia crispa (D-005) inhibe in vitro las actividades de las enzimas COX y 5-LOX. Este estudio demuestra que el D-005 inhibe marcadamente y de manera dosis dependiente las actividades de la COX-2 y 5-LOX. La inhibición dual de la COX-2 y 5-LOX soportan futuras investigaciones sobre el potencial efecto anti-inflamatorio del D-005.

5-LOX inhibitor MK886 suppresses the stemness of human colon cancer HT-29 cells / 医学研究生学报

Objective It remains a controversy whether 5-lipoxygenase (5-LOX) is associated with colon cancer stem cells.This study was to investigate the effect of the 5-LOX inhibitor MK886 in maintaining the stemness of the human colon cancer cell line HT-29.Methods Using CCK-8 assay, we examined the inhibitory effects of different concentrations of MK886 (12.5, 25, 50, 75, 100, and 200 μmol/L) on the colon cancer HT-29 cells cultured in vitro and calculated its half-inhibitory concentration (IC50).Then, we detected the effects of MK886 IC50 on the clone-and sphere-forming abilities of the cells, determined the mRNA expressions of the stemness markers CD133, Lgr5, Oct4 and Ascl2 by real-time PCR after 24 and 48 hours of MK886 IC50 intervention, and measured their protein expressions by Western blotting after 24, 48 and 72 hours of MK886 IC50 intervention.Results The inhibition rates of MK886 on the HT-29 cells at 24 and 48 hours were significantly increased in a time-and dose-dependent manner ([14.99±3.06] and [19.98±0.57]％ at 12.5 μmol/L, [20.46±1.14] and [34.97±6.02]％ at 25 μmol/L, [50.76±5.94] and [66.90±5.74]％ at 50 μmol/L, [66.84±1.77] and [73.11±2.48]％ at 75 μmol/L, [72.67±2.36] and [77.78±3.30]％ at 100 μmol/L, [83.67±0.24] and [84.69±2.24] ％ at 200 μmol/L) as compared with the blank control (0％ and 0％) (P<0.05).The clone-forming rate and number of spheres formed were remarkably lower in the MK886 intervention than in the control group ([10.60±1.71] vs [44.67±3.21]％, P<0.05;6.00±1.60 vs 19.07±2.89, P<0.05).After 24 and 48 hours of MK886 intervention, the mRNA expression of CD133 in the HT-29 cells was markedly up-regulated in comparison with that at 0 hour (0.72±0.10 and 0.39±0.07 vs 1.66±0.33, P<0.05), and so were those of Lgr5, Oct4 and Ascl2 (P<0.05).Conclusion The 5-LOX inhibitor MK886 can inhibit the proliferation and clone-and sphere-forming abilities of human colon cancer HT-29 cells by down-regulating the expressions of the stemness markers and thus suppressing the stemness of the colon cancer stem cells.

Structural optimization and biological evaluation of 1,5-disubstituted pyrazole-3-carboxamines as potent inhibitors of human 5-lipoxygenase

Human 5-lipoxygenase (5-LOX) is a well-validated drug target and its inhibitors are potential drugs for treating leukotriene-related disorders. Our previous work on structural optimization of the hit compound 2 from our in-house collection identified two lead compounds, 3a and 3b, exhibiting a potent inhibitory profile against 5-LOX with IC50 values less than 1 µmol/L in cell-based assays. Here, we further optimized these compounds to prepare a class of novel pyrazole derivatives by opening the fused-ring system. Several new compounds exhibited more potent inhibitory activity than the lead compounds against 5-LOX. In particular, compound 4e not only suppressed lipopolysaccharide-induced inflammation in brain inflammatory cells and protected neurons from oxidative toxicity, but also significantly decreased infarct damage in a mouse model of cerebral ischemia. Molecular docking analysis further confirmed the consistency of our theoretical results and experimental data. In conclusion, the excellent in vitro and in vivo inhibitory activities of these compounds against 5-LOX suggested that these novel chemical structures have a promising therapeutic potential to treat leukotriene-related disorders.

Efecto in vitro del policosanol (alcoholes de la cera de Saccharum officinarum L) sobre la enzima 5-lipooxigenasa / In vitro effects of policosanol (Saccharum officinarum L wax alcohols) on the 5-lipooxygenase enzyme

INTRODUCTION: policosanol, a mixture of high molecular weight aliphatic alcohols purified from sugarcane with octacosanol as the main component, shows cholesterol-lowering and antiplatelet effects in addition to an inhibitory effect on type I cicloxygenase. OBJECTIVE: to determine whether policosanol may inhibit 5-LOX enzyme activity in vitro. METHODS: effects on 5-LOX enzyme activities were assessed in rat blood polymorphonuclear leukocytes. Vehicle or Policosanol suspensions (0.6 to 6 000 µg/mL) were added to tubes containing the reaction mix and then absorbance changes at 234 nm were measured. RESULTS: added Policosanol inhibited in vitro 5-LOX activity by 30 percent, which was not a significant figure but depended on the concentration(r= 0.992; p< 0.05); it was 1 250 µg/mL. CONCLUSIONS: policosanol did not significantly inhibit 5-LOX enzyme activity in rat PMNL preparations, so that it does not seem to be a dual inhibitor of COX and-LOX enzymes. This result differs from that found for beeswax alcohols and underlines the different effects of the mixtures of long-chain fatty alcohols purified from the sugarcane and the beeswax(AU).

IINTRODUCCIÓN: el policosanol es una mezcla de alcoholes alifáticos aislados y purificados de la caña de azúcar cuyo componente mayoritario es el octacosanol, con efecto sobre la reducción de colesterol y antiagregante plaquetario, además inhibe la ciclooxigenasa (COX) tipo 1. OBJETIVO: determinar el poder de inhibición del policosanol en la actividad de la enzima 5-LOX in vitro. MÉTODOS: el efecto sobre la actividad de la enzima 5-LOX se determinó en leucocitos polimorfonucleares obtenidos de sangre de ratas. Se añadieron vehículo o suspensiones de policosanol (0,6 a 6 000 µg/mL) a tubos que contenían la mezcla de reacción y se medió el cambio de absorbancia a 234 nm. RESULTADOS: la adición de policosanol inhibió in vitro la actividad de la 5-LOX en un 30 por ciento que no fue significativo pero sí dependiente de la concentración (r= 0,992; p< 0,05), inhibición esta que alcanzó 1 250 µg/mL. CONCLUSIÓN: el policosanol no inhibió significativamente la actividad de la enzima 5-LOX en preparación de polimorfonucleares de ratas, por lo que no es un inhibidor dual de las enzimas. Este resultado difiere del encontrado para los alcoholes de la cera de abeja y subraya la diferencia de los efectos hallados entre las mezclas de alcoholes alifáticos de cadenas largas purificados de la caña de azúcar y la cera de abeja(AU)

Efecto in vitro del D-003 sobre la actividad enzimática de la 5-lipoxigenasa (5-LOX) / Effect in vitro of D-003 on 5-lipooxygenase (5-LOX) enzyme activity

Introducción: el D-003, mezcla de ácidos alifáticos primarios superiores purificada de la cera de la caña, inhibe la síntesis de colesterol. Trabajos recientes han demostrado que el D-003 resulta efectivo en modelos experimentales de osteoartritis y que inhibe la actividad de las enzimas COX1 y COX2, preferentemente la COX1, sin producir gastrotoxicidad. Ha sido referido que los inhibidores duales de las enzimas COX y 5-LOX presentan efectos antinflamatorios desprovistos de gastrotoxicidad o que incluso, pueden resultar gastroprotectores. De acuerdo con estos antecedentes, el D-003 podría ser un inhibidor dual de dichas enzimas. Objetivo: investigar el efecto in vitro del D-003 sobre la actividad enzimática de la 5-LOX, utilizando la fracción citosólica de leucocitos polimorfonucleares de ratas. Métodos: se utilizaron las condiciones de ensayo siguientes: fracción citosólica (50 µg de proteína) disuelta en solución reguladora borato 0,2 mol/L (pH 9) y ácido linoleico (7,8-250 mmol/L) como sustrato, ensayándose muestras paralelas incubadas con Tween-20/H2O (2 por ciento) (vehículo), D-003 (0,6-6 000 µg/mL) o extracto de Perna canaliculus (50 µg/mL) (sustancia de referencia). Se evaluó la actividad enzimática mediante el cambio de absorbancia a 234 nm producido por la formación de dienos conjugados y medido en espectrofotómetro UV-visible. Resultados: la adición de D-003 produjo una inhibición dosis dependiente de la actividad enzimática de la 5-LOX (r= 0,975; p< 0,05) (CI50= 23,06 µg/mL) in vitro. La magnitud de esta inhibición fue moderada, ya que la inhibición máxima, alcanzada a partir de 1 250 µg/mL, resultó de solo un 30 por ciento. Conclusiones: el estudio demuestra que el D-003 es capaz de inhibir la actividad enzimática de la 5-LOX in vitro, pero moderadamente(AU)

Introduction: D-003, a mix of higher primary aliphatic acids purified from sugarcane, inhibits cholesterol synthesis. Recent studies have demonstrated that D-003 is effective in experimental models of osteoarthritis and inhibits the enzymatic activities of COX1 and COX2, mainly that of COX1, without causing gastrotoxicity. It has been mentioned that the dual inhibitors of COX and 5-LOX enzymes present with anti-inflammatory effects and no gastrotoxicity or even they can have gastroprotective actions. According to this background, D-003 could be a dual inhibitor of COX and 5-LOX enzymes. Objective: to study the effects of D-003 on the enzymatic activity of 5-LOX in vitro, by using the cytosolic fraction of polymorphonuclear leukocytes of rats. Methods: the following testing conditions were used: cytosolic fraction (50 µg of protein) dissolved into 0,2 mol/L borate buffer solution (pH 9) and linoleic acid (7,8-250 mmol/L) as substrate. Parallel samples were incubated with Tween-20/H2O (2 percent) only (vehicle), D-003 (0,6-6 000 µg/mL) or green-lipped mussel (Perna canaliculus) extract (50 µg/mL) (reference substance). The enzymatic activity, evaluated by the conjugated diene formation, was assessed by the absorbance changes at 234 nm (5-LOX) measured in a UV-visible spectrophotometer. Results: by adding D-003, produced a dose dependent (r= 0,975; p< 0,05) (IC50= 23,06 µg/mL) in vitro inhibition of 5-LOX enzyme activity. The size of the inhibition was moderate, since the maximal inhibition, achieved from 1 250 µg/mL) on was only 30 percent. Conclusions: this study demonstrates that D-003 may inhibit in vitro the 5-LOX enzymatic activity, but in a moderate way(AU)

In-vitro and in-vivo anti-inflammatory activity of Andrographis serpyllifolia (Rottl. Ex Vahl.) Wt.

The study was aimed to evaluate the analgesic and anti-inflammatory activity (by both in-vitro and in-vivo) of both chloroform and methanol root extracts of Andrographis serpyllifolia (Rottl. Ex Vahl.) Wt. Methods used for the studies were In-vitro 5-Lipoxygenase inhibition assay and In-vivo measurement of rat paw edema and ear edema in rats, acetic acid induced writhing response and hot plate method in albino mice. Chloroform and methanolic extracts of A. serpyllifolia root have shown moderate potency in inhibiting 5-LOX and shown significant anti-inflammatory activity. Despite the IC50 values are little higher, anti-inflammatory efficacy of these extracts possibly due to other mechanisms apart of 5-LOX inhibition. However, In-vivo anti-inflammatory studies revealed that A. serpyllifolia methanolic extract has shown higher degree of efficacy when compared to the chloroform extract. In terms of analgesic activity in writhing test, methanolic extract has shown more efficacy than chloroform extract. Hence, it is important to isolate the active principles for further testing the anti-inflammatory efficacy.

In-vitro and in-vivo anti-inflammatory activity of Andrographis serpyllifolia (Rottl. Ex Vahl.) Wt.

The study was aimed to evaluate the analgesic and anti-inflammatory activity (by both in-vitro and in-vivo) of both chloroform and methanol root extracts of Andrographis serpyllifolia (Rottl. Ex Vahl.) Wt. Methods used for the studies were In-vitro 5-Lipoxygenase inhibition assay and In-vivo measurement of rat paw edema and ear edema in rats, acetic acid induced writhing response and hot plate method in albino mice. Chloroform and methanolic extracts of A. serpyllifolia root have shown moderate potency in inhibiting 5-LOX and shown significant anti-inflammatory activity. Despite the IC50 values are little higher, anti-inflammatory efficacy of these extracts possibly due to other mechanisms apart of 5-LOX inhibition. However, In-vivo anti-inflammatory studies revealed that A. serpyllifolia methanolic extract has shown higher degree of efficacy when compared to the chloroform extract. In terms of analgesic activity in writhing test, methanolic extract has shown more efficacy than chloroform extract. Hence, it is important to isolate the active principles for further testing the anti-inflammatory efficacy.