Cell-based assays and molecular simulation reveal that the anti-cancer harmine is a specific matrix metalloproteinase-3 (MMP-3) inhibitor.

The biological activities of harmine have been a much clearer picture in recent years, which include anti-tumor, anti-inflammation and cytotoxic properties. Numerous in vitro and in vivo animal models have confirmed its activities, but its mode of action remains a relative unsolved issue. We therefore investigated harmine for its effects on MMP-3 and the molecular interaction was also simulated. The human glioma cancer cell line, U-87 MG cells, was subjected to different concentrations (1-10 µM) of harmine for 24 h. Methylthiazol tetrazolium (MTT) test, half maximal inhibitory concentration (IC50), western blot analysis, enzyme-linked immunosorbent assay and molecular docking through BIOVIA DiscoveryStudio™ were performed. These results showed that although harmine stimulation in vitro has very little or no effects on MMP-3 expression by U-87 MG cells, the treatment of harmine decreases MMP-3 activity in a dose dependent manner. It was further calculated that 7.9 µM is the IC50 towards MMP-3. Using a molecular dynamic simulation approach, we identified the N2, methyl of C1 and benzene ring of harmine interact with Zn2+ (2.4 Å), His205 (2.4 Å) and His211 (2.4 Å) as well as Val163 (2.7 Å) at the active site of MMP-3, respectively, and thus conferred a striking specific binding advantage. Taken altogether, the present study evidences that harmine acts as an MMP-3 inhibitor specially targeting the enzymatic active site and possibly efficiently ameliorates MMP-3-driven malignant and inflammatory diseases.

Pharmacological effects of harmine and its derivatives: a review.

Harmine is isolated from the seeds of the medicinal plant, Peganum harmala L., and has been used for thousands of years in the Middle East and China. Harmine has many pharmacological activities including anti-inflammatory, neuroprotective, antidiabetic, and antitumor activities. Moreover, harmine exhibits insecticidal, antiviral, and antibacterial effects. Harmine derivatives exhibit pharmacological effects similar to those of harmine, but with better antitumor activity and low neurotoxicity. Many studies have been conducted on the pharmacological activities of harmine and harmine derivatives. This article reviews the pharmacological effects and associated mechanisms of harmine. In addition, the structure-activity relationship of harmine derivatives has been summarized.

Microwave-assisted extraction of three bioactive alkaloids from Peganum harmala L. and their acaricidal activity against Psoroptes cuniculi in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: Peganum harmala L. is a perennial herbaceous, glabrous plant that grows in semi-arid conditions, steppe areas and sandy soils. It is used to treat fever, diarrhoea, subcutaneous tumours, arthralgia, rheumatism, cough, amnesia and parasitic diseases in folk medicines. In this paper, we aimed to develop a simpler and faster method for the extraction of three alkaloids from Peganum harmala L. than other conventional methods by optimizing the parameters of a microwave-assisted extraction (MAE) method, and to investigate the acaricidal activities of three compounds against Psoroptes cuniculi. MATERIALS AND METHODS: After optimizing the operating parameters with the single factor experiment and a Box-Behnken design combined with a response-surface methodology, a MAE method was developed for extracting the alkaloids from the seeds, and a high-performance liquid chromatography was used to quantify these compounds. An in vitro experiments were used to study the acaricidal activities. RESULTS: The optimal conditions of MAE method were as follows: liquid-to-solid ratio 31.3:1mL/g, ethanol concentration 75.5%, extraction time 10.1min, temperature 80.7°C, and microwave power 600W. Compared to the heat reflux extraction (HRE, 60min) and the ultrasonic-assisted extraction (UAE, 30min) methods, MAE method require the shortest time (10min) and obtain the highest yield of three compounds (61.9mg/g). Meanwhile, the LT50 values for the vasicine (1.25 and 2.5mg/mL), harmaline (1.25 and 2.5mg/mL), harmine (1.25 and 2.5mg/mL) and MAE extract (100mg/mL) against Psoroptes cuniculi were 12.188h, 9.791h, 11.994h, 10.095h, 11.293h, 9.273h and 17.322h, respectively. CONCLUSIONS: The MAE method developed exhibited the highest extraction yield within the shortest time and thus could be used to extract the active compounds from Peganum harmala L. on an industrial basis. As the active compounds of Peganum harmala L., vasicine, harmalin and harmine presented the marked acaricidal activities against Psoroptes cuniculi, and could be widely applied for the treatments of acariasis in animals.

Cerebroprotective effect of isolated harmine alkaloids extracts of seeds of Peganum harmala L. on sodium nitrite-induced hypoxia and ethanol-induced neurodegeneration in young mice.

The aim of the study was to isolate the harmine alkaloids from the seeds of Peganum harmala (TAPH) and its cerebroprotective effect on cognitive deficit mice. The tested doses of TAPH were screened for Sodium nitrite induced hypoxia and Ethanol induced neurodegeneration using behavioral models. The TAPH was found to be non-neurotoxic and Psychoactive by preventing the motor impairment and increasing the locomotion activity of animals in Rota rod and Actophotometer respectively. TAPH (5, 2.5 and 1.25 mg kg(-1) p.o.) significantly (p < 0.001) protected the Sodium nitrite induced memory impairment by decreasing the time require to find the water bottle in special water bottle case model. In Elevated Plus Maze (EPM) and Passive Shock Avoidance paradigm (PSA) the TAPH shown improved acquisition and retention memory significantly (p < 0.001) by decreasing the Transverse Latency Time (TLT) and increasing the Step Down Latency (SDL), respectively in dose dependent manner. The results were well supported by biochemical parameters, by inhibiting the Acetylcholinestrase (p < 0.01) activity, increasing the GSH (p < 0.001) level and decreasing the TBARS (p < 0.001) level of whole brain. Moreover TAPH has shown the significant Monoamine oxidase-A (MAO-A) inhibition action (p < 0.001), hence it reduces the metabolism of epinephrine, 5-HT and other monoamines and enhances the action of these neurotransmitters indirectly; this adrenergic system plays an important role in learning and memory. Further, TAPH (5 mg kg(-1)) protect the DNA fragmentation of frontotemporal cortex of the brain from hypoxic effect induced by Sodium nitrite in Gel Electrophoresis studies. The results were comparable to their respective standards. Hence, harmine alkaloids are potential enough to utilize in the management of Neurodegenerative disorders of the type Alzheimer's diseases.

A study on the antitumoral and differentiation effects of peganum harmala derivatives in combination with ATRA on leukaemic cells.

Plant derived agents may exert a new approach to the treatment of leukaemia. The present study was an evaluation of proliferation, cytotoxicity and differentiation of harmine and harmaline on HL60 cells, alone or in combination with ATRA and G-CSF. Counting of cells, viability, MTT assay, morphology, NBT reduction and flow cytometry analysis were performed using CD11b and CD 14 monoclonal antibodies. The data showed that harmine and harmaline reduced proliferation in dose and time dependent manner. Optimal antiproliferative concentration of these agents was chosen. However, both agents in higher doses were cytotoxic. Combination of ATRA, G-CSF and each agent alone, particularly harmaline in optimal dose, resulted in partially additive decrease in cell proliferation. Cells treated with both harmaline and ATRA demonstrated some morphological changes and NBT positivity, but the extent of changes observed following treatment with harmaline was less than ATRA. Flow cytometric analysis showed that ATRA induced a neutrophilic differentiation, while harmaline led to a predominantly monocytic differentiation. Combination of harmine and harmaline with ATRA and G-CSF did not change the extent of differentiation, and the cells differentiated into the neutrophilic lineage. This shows that the direction of differentiation is dominantly determined by ATRA. These preliminary data implies a new approach in treatment of leukemia.

Human monoamine oxidase enzyme inhibition by coffee and beta-carbolines norharman and harman isolated from coffee.

Monoamine oxidase (MAO) is a mitochondrial outer-membrane flavoenzyme involved in brain and peripheral oxidative catabolism of neurotransmitters and xenobiotic amines, including neurotoxic amines, and a well-known target for antidepressant and neuroprotective drugs. Recent epidemiological studies have consistently shown that coffee drinkers have an apparently lower incidence of Parkinson's disease (PD), suggesting that coffee might somehow act as a purported neuroprotectant. In this paper, "ready to drink" coffee brews exhibited inhibitory properties on recombinant human MAO A and B isozymes catalyzing the oxidative deamination of kynuramine, suggesting that coffee contains compounds acting as MAO inhibitors. MAO inhibition was reversible and competitive for MAO A and MAO B. Subsequently, the pyrido-indole (beta-carboline) alkaloids, norharman and harman, were identified and isolated from MAO-inhibiting coffee, and were good inhibitors on MAO A (harman and norharman) and MAO B (norharman) isozymes. beta-carbolines isolated from ready-to-drink coffee were competitive and reversible inhibitors and appeared up to 210 microg/L, confirming that coffee is the most important exogenous source of these alkaloids in addition to cigarette smoking. Inhibition of MAO enzymes by coffee and the presence of MAO inhibitors that are also neuroactive, such as beta-carbolines and eventually others, might play a role in the neuroactive actions including a purported neuroprotection associated with coffee consumption.

Xanthomicrol is the main cytotoxic component of Dracocephalum kotschyii and a potential anti-cancer agent.

Spinal-Z, a methanolic mixture of dried powdered seeds of Peganum harmala Linn. and leaf of Dracocephalum kotschyii Boiss. is an Iranian ethno-medical remedy. It has been used for the treatment of various types of cancer for many years. To evaluate the use of Spinal-Z in treatment of cancer, we examined its effects against a panel of malignant cell lines and tumors induced in mice. The in vitro antiproliferative activities of Spinal-Z, the seed extract of P. harmala and the leaf extract of D. kotschyii were determined using the MTT assay. The concentration of the agent required to inhibit cell growth by 50% (IC50) was estimated. In addition, the anti-tumor activities of the remedy and its constituents were investigated. Viability of cells treated with Spinal-Z and its components decreased in a dose dependent manner. Spinal-Z and its components showed cytotoxic effects against all cell lines tested. The leaf extract of D. kotschyii showed a greater preferential cytotoxic effect than the seed extract of P. harmala and Spinal-Z, on all cell lines tested. Harmine showed cytotoxicity against HL60 and K562 cell lines. This could explain the cytotoxic effect of P. harmala on these cells. The leaf extract of D. kotschyii was able to inhibit tumor proliferation in mice. The active ingredient in the leaf extract of D. kotschyii appears to be a flavone identified as xanthomicrol. Xanthomicrol was able to inhibit proliferation of a number of malignant cells. The cytotoxic effects of xanthomicrol were more selective towards malignant cells than doxorubicin.

Affinitive separation and on-line identification of antitumor components from Peganum nigellastrum by coupling a chromatographic column of target analogue imprinted polymer with mass spectrometry.

A coupled LC-MS (liquid-phase chromatography and mass spectrometry) system consisting of a combination of a column of molecularly imprinted polymer (MIP) and a MS detector was used for affinitive separation and on-line identification of the antitumor components, harmine and harmaline, from the methanol extract of Peganum nigellastrum seeds. Three molecularly imprinted polymers were synthesized with porogens bearing different hydrogen bonding capacities with harman, the structural analogue of harmaline, and harmine as the template. The affinity and selectivity of the anti-harman MIPs for the targets, harmine and harmaline, were investigated chromatographically, and the influences of the porogens and sample loads on the retention of the target compounds were also discussed. In addition, the target binding capacities of the MIPs were evaluated by frontal chromatography. When the MIPs were further used in a LC-MS system to separate the extract of herb, it was observed that imprinting with different porogens would cause the MIPs to exhibit different tendencies to adsorb the matrix components from the herb. Though the MIP prepared with a porogen of less hydrogen bonding capacity possessed higher selectivity and stronger affinity for the targets, matrix components in the herb extract interfered with the chromatographic performance more seriously when it was used as the LC solid phase in the LC-MS system for selective extraction of harmaline and harmine from the crude herb extract. Positively, the MIPs were stable and reproducible in the separation test, and the imprinting columns could efficiently separate the antitumor components from the herb extract after the sample was simply pretreated. The work in this paper would be helpful for the further extraction and identification of certain pharmacophoric compounds in herbs by a LC-MS system using MIPs as the HPLC solid phase.

Antiplatelet activity of soy sauce as functional seasoning.

In seeking the functionality of foodstuffs applicable to medicine, soy sauce was found to show antiplatelet activity. Therefore, the active components in soy sauce were purified, structurally identified, and studied for their inhibitory effects on the aggregation of human platelets. Aqueous 2-fold diluents of soy sauce inhibited platelet aggregation induced by collagen and epinephrine depending on the dilution factor. Since a basic extract with diethyl ether completely inhibited collagen-induced aggregation, it was subjected to serial extractions and multistep HPLC fractionations for purifying antiplatelet components. The finally obtained isolates were identified as 1-methyl-1,2,3,4-tetrahydro-beta-carboline and 1-methyl-beta-carboline on the basis of EI-MS, (1)H NMR, diode array, and fluorescence spectra. Their spectral data and chromatographic behaviors were the same as those of synthetic ones. 1-Methyl-1,2,3, 4-tetrahydro-beta-carboline showed mean concentrations (n = 5-6) of 4.6, 4.2, 28.6, 11.6, and 65.8 microgram/mL to produce 50% inhibition of the maximal aggregation response induced by epinephrine, platelet-activating factor, collagen, adenosine 5'-diphosphate, and thrombin, respectively. Its inhibitory effect was much greater than that of 1-methyl-beta-carboline on platelet aggregation by all the tested inducers. The quantitative HPLC analysis revealed that the significant amounts of both antiplatelet compounds were uniformly contained in commercially available soy sauce. From these results, soy sauce may be referred to as functional seasoning containing alkaloidal components with the potent preventive effect on thrombus formation.