Changes

==Special Precautions of Syrian Rue==

==Health Benefits and Uses of Syrian Rue==

* CARDIOVASCULAR EFFECTS : P. harmala is one of the most frequently used medicinal plants to treat hypertension and cardiac disease worldwide.[9,85] It has also been shown in various pharmacological studies that P. harmala extract or its main active alkaloids, harmine, harmaline, Harman and harmalol, have different cardiovascular effects such as bradycardia, decreasing systemic arterial blood pressure and total peripheral vascular resistance, increasing pulse pressure, peak aortic flow and cardiac contractile force,[10] Vasorelaxant[11,12] and angiogenic inhibitory effects.[13]

**Effects on the heart : There have been a few studies conducted regarding the direct effects of P. harmala extract and its alkaloids on heart muscle. For example, in one study it was shown that three P. harmala isolated alkaloids (Harmine, Harmaline and Harmalol) have ionotropic effect and also decrease heart rate in normal anesthetized dogs. Since neither vagotomy nor atropinization affected the harmala-induced bradycardia it became evident that the decrease in heart rate was not due to a negative chronotropic effect of the alkaloids.[10]. In another in vivo study, harman dose-dependently produced transient hypotension and long-lasting bradycardia in anesthetized rats.[11] Harmaline inhibits both 45Ca2+ uptake and efflux in cardiac sarcolemal vesicles in a dose-dependent manner.[17]

**Angiogenic inhibitory effect : It was revealed in a study that harmine is a potent angiogenic inhibitor. This substance can significantly decrease the proliferation of vascular endothelial cells and reduce expression of different pro-angiogenic factors such as vascular endothelial growth factor, NO and pro-inflammatory cytokines. Nuclear factor-κB and other transcription factors like cAMP response element-binding (CREB) and Activating transcription factor 2 (ATF-2) involved in angiogenesis were also inhibited by harmine. Moreover, harmine decreased production of other factors by tumor cells, which play a significant role in angiogenesis like cyclooxygenase (COX-2), inducible nitric oxide synthase, and matrix metalloproteases.[13]

* EFFECTS ON NERVOUS SYSTEM : In traditional medicine, P. harmala has been used among societies to treat some nervous system disorders such as Parkinson's disease,[19] in psychiatric conditions[7] such as nervosity,[20] and to relieve rigorous pain.[21] The alkaloid content of P. harmala is shown to be psychoactive[22] and various in vitro and in vivo studies indicate a wide range of effects produced by P. harmala and its active alkaloids on both central and peripheral nervous system including, analgesia,[22,23] hallucination, excitation,[24] and anti-depressant effect.[25,26]. Some of these alkaloids such as harmaline, harmine, and norharmane are also endogenous compounds present in the body and since they have been found in high plasma concentrations in alcoholics,[27] drug addicts,[28] smokers,[29] and patients with Parkinson's disease,[30] they are thought to be crucially involved in various central nervous system (CNS) problems. It has been also proven that P. harmala-derived beta-carbolines interact with opioid,[21] dopamine,[24] GABA (Gamma-Aminobutyric acid),[31] 5-hydroxytryptamine, benzodiazepine, and imidazoline[32] receptors present in the nervous system and this way induce their many pharmacological effects. Moreover, these alkaloids are neuroprotective[31,33] and strong inhibitors of monoamine oxidase and this important feature makes them a preferable target in the treatment of some conditions like depression.[25]

**Relation with Parkinson's disease : The endogenous harmala alkaloids have been proven to be involved in Parkinson's disease.[31] One study on both endogenous and exogenous beta-carbolines showed that they all have general DAT-mediated (Dopamine active transporter-mediated) dopaminergic toxicity and therefore, are involved in the pathogenesis of Parkinson's disease.[36] Adversely, it was revealed in an in vitro study that two of these endogenous compounds, norharman and 9-methylnorharman, have good anti-parkinsonism effects via inhibition of MAO-B, an enzyme involved in the production of parkinsonism-related substances from the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. However, naturally occurring beta-carbolines had almost no such inhibitory effect.[33]. In contrast, several studies on the anti-parkinsonism effect of B. caapi revealed that its beta-carboline content (harmine and harmaline) has significant effect against this disease through the inhibition of MAO-B.[37,38] Although, these beta-carbolines with anti-parkinsonism effect are also present in P. harmala, there have been no studies conducted regarding the possible effect of P. harmala isolated alkaloids against Parkinson's disease, thus far.

**Other neuropsychological effects : There have been reports of other effects produced by P. harmala in the nervous system. In an in vitro study desoxypeganine, one of the P. harmala alkaloids, dose-dependently decreased ethanol consumption in female Alko alcohol rats with no effect on food and fluid consumption.[39] This may represent a safe way to decrease the consumption of alcohol in alcoholics. Harmane, another alkaloid isolated from P. harmala induced amnesia with a suggested mechanism of interaction with dopaminic (D1 and D2) receptors.[24] Harmaline and harmane have been shown to modulate voltage-activated calcium- ICa (V)-channels in vitro and in a reversible and use independent manner.[31]

*Antineoplasm, antiproliferative and antioxidant effects. Since ancient times, P. harmala has been used by traditional healers to make various preparations in the treatment of cancers and tumors in some parts of the world.[13,55] For example, it has been so common in traditional medicine of Morocco to use powdered seeds of P. harmala to treat skin and subcutaneous tumors.[56] The seed extract of P. harmala is the main component of a very common ethnobotanical preparation used against different cancers and neoplasms in Iran, namely Spinal-Z.[57,58] The antitumor activity of P. harmala and its active alkaloids (mainly beta-carbolines) have also drawn attentions of many researchers worldwide that has led to various pharmacological studies regarding this important effect of P. harmala.[23,56] Various authors have reported cytotoxicity of P. harmala on tumor cell lines in vitro and in vivo. In one study, the methanolic extract of P. harmala reduced significantly proliferation of three tested tumor cell lines (UCP-Med (a tumor cell line), Med-mek carcinoma, and UCP-Med sarcoma) in all concentrations. This anti-proliferative effect was produced by the alkaloid fraction of the extract in the first 24 h of the treatment. A cell lysis effect was observed in the next 24 h and thus, resulted in complete cell death within 48 to 72 h.[56] The same results were observed with the total extract of the plant in another study. The extract also showed cytotoxicity against artificially grafted subcutaneous Sp2/O cell-line in BALB-c (Albino) mice.[56] Administration of different beta-carboline alkaloids isolated from P. harmala showed inhibitory effect against Lewis Lung cancer sarcoma-180 or HepA tumor in mice at rates of 15.3-49.5%. Substitution of formate at R3 and aryl at R9 of the tricyclic skeleton respectively decreased neurotoxicity and increased the inhibitory effects of the alkaloids that made them ideal agents to be used as novel antitumor drugs with lesser side effects.[55] Several in vitro and in vivo studies have revealed that these cytotoxicity and antitumor effects of P. harmala are related to its interaction with RNA,[59] DNA and its synthesis,[56,60] and inhibition of human Topoisomerase.[58] In a study conducted in Iran, it was shown using the DNA relaxation assay that the extract of P. harmala inhibits human DNA Topoisomerase I. This effect was attributed to the beta-carboline content of the extract and potency of the alkaloids were determined as harmine >harmane >harmaline in a way that treatment with the total extract showed weaker inhibitory effect than treatment with every individual alkaloid.[58] Another study indicated that harmine and its derivatives have inhibitory effect on human Topoisomerase I activity but no effect on Topoisomerase II. Intercalation of several carbolines into eukaryotic DNA has also been reported by many authors.[58,61] This intraction of beta-carbolines cause significant structural changes in DNA and interfere with its synthesis.[56,61] The alkaloid-DNA binding affinity was ordered as harmine >harmalol >harmaline >harmane >tryptoline. There are also other suggested mechanisms for the anti-tumor activity of P. harmala alkaloids. In an in vitro study by Li et al., budding yeast was used as a model to investigate the anti-tumor activity of P. harmala. Results showed that DH334, a beta-carboline derivative and an anticancer drug, specifically inhibits cyclin dependent kinases (CDKs) and blocks the initiation of cell cycle at the G1 phase. It also inhibited the kinase activity of Cdk2/CyclinA (a member of the cyclin family) in vitro. This could be another possible mechanism for the antitumor activity of the drug.[56,93]

*Many pharmacological studies suggest an antioxidant and free radical scavenging effect of P. harmala. This effect has been attributed to the increasing effect of P. harmala extract on E2 (17β-estradiol) level as an important antioxidant and reactive oxygen species (ROS) scavenger.[12,62,63] In another study, the effects of harmaline and harmalol were tested on Digoxin-induced cytochrome P450 1A1 (CYP1A1), a carcinogen-activating enzyme, in human hepatoma HepG2 cells. These alkaloids significantly inhibited the enzyme via both transcriptional and posttranslational mechanisms in a concentration-dependent manner.[3] Ethanol and chloroform extracts of P. harmala showed protective effects against thiourea-induced carcinogenicity by normalization of neuron-specific enolase and thyroglobulin levels in animal models.[64] Other effects of the plant extract such as anti-proliferative effect on Leukemic cell lines,[65] inhibitory action on the metastasis of melanoma cells, inducing apoptosis in melanoma cells,[66] tumor angiogenesis inhibition,[13] and binding to RNA[61] have also been reported by various authors. In some cases, P. harmala showed a higher selectivity towards malignant cells than common anticancer drugs like doxorubicin.[57] All of these data suggest that P. harmala and its alkaloids possess the potential to be used as novel antioxidant and anti-tumor agents in anti-cancer therapy.

* OSTEOGENIC ACTIVITY : Two different studies conducted by Yonezawa et al. showed bone anabolic effects of harmine, in vivo and in vitro.[73,74] It was revealed that administration of 10 mg/kg/day of harmine inhibits formation and differentiation of osteoclasts in mice via down-regulation of c-Fos (A cellular proto-oncogene) and NFATc1 (Nuclear factor of activated T-cells, cytoplasmic 1) and thus, prevents osteoclast-mediated resorption. Adversly, it enhances osteoblast differentiation probably via inducing the expression of BMPs and activation of bone morphogenetic protein (BMP) and Runx2 pathways. It was also found that carbon C3C4 double-bond and 7-methoxy group of harmine plays an important role in these processes. These findings suggest that harmine, as the main alkaloid of P. harmala, may be useful for treatment of some bone diseases.

* IMMUNE SYSTEM EFFECTS : Beta-carboline alkaloids of P. harmala are shown to have immune-modulatory effects in several studies.[26,75] Extracts of this plant have significant anti-inflammatory effect via the inhibition of some inflammatory mediators including prostaglandin E2 (PGE2) (100 μg/mg) and tumor necrosis factor alpha (TNF-α) (10 μg/mg).[46]

[[Category:Treatments]]

[[Category:Herbal medicine]]