In the Beginning, Lipoproteins Cross the Endothelial Barrier.

Atherosclerosis begins with the infiltration of cholesterol-containing lipoproteins into the arterial wall. White blood cell (WBC)-associated inflammation follows. Despite decades of research using genetic and pharmacologic methods to alter WBC function, in humans, the most effective method to prevent the initiation and progression of disease remains low-density lipoprotein (LDL) reduction. However, additional approaches to reducing cardiovascular disease would be useful as residual risk of events continues even with currently effective LDL-reducing treatments. Some of this residual risk may be due to vascular toxicity of triglyceride-rich lipoproteins (TRLs). Another option is that LDL transcytosis continues, albeit at reduced rates due to lower circulating levels of this lipoprotein. This review will address these two topics. The evidence that TRLs promote atherosclerosis and the processes that allow LDL and TRLs to be taken up by endothelial cells leading to their accumulation with the subendothelial space.

Diuretic Potential of Fenchyl Acetate with Its Mechanism of Action: Toxicity Study.

Hypertension has become a global threat and is one of the greatest risk factors for chronic kidney disease. Fenchyl acetate is a monoterpene that has been assessed for its various pharmacological activities in the past, but no study has evaluated its diuretic potential and the mechanism involved in the diuretic activity after prolonged administration in rats. Therefore, this study aimed to measure the safety and diuretic profile of fenchyl acetate in rats. For evaluating the acute toxicity, a single dose of 2000 mg/kg was administered as per the OECD guideline no. 425, and the rats were observed for 14 days. After 14 days, blood samples were assessed for biochemical, hematological, and oxidative stress parameters. For the acute diuretic study, fenchyl acetate was given in doses of 100, 200, and 400 mg/kg, and urine samples after 8 h were assessed for sodium, potassium, creatinine, uric acid excretion, and urinary output. A single dose of fenchyl acetate (F.A) was selected for prolonged diuretic activity, and furosemide was taken as the standard drug in a repeated dose administration for 7 days. Rats' urine was assessed for pH, sodium, potassium, creatinine, and uric acid excretion along with urinary volume excretion. Furthermore, blood was withdrawn by cardiac puncture, and selected organs like the heart, liver, kidney, and spleen were analyzed for oxidative stress biomarkers. Using pharmacological antagonists or inhibitors, the involvement of L-NAME, acetylcholine, or prostaglandin in F.A.-induced diuresis was determined. Mitochondrial respiratory chain enzyme complexes were also assessed in the kidney homogenates. The acute toxicity results showed F.A to be safe as its LD50 was greater than 2000 mg/kg and there were no signs of mortality or toxicity. The acute diuretic study showed that F.A resulted in a significant and dose-dependent increase in sodium, potassium, creatinine, and uric acid excretion along with urinary output, and these results were comparable to the standard drug furosemide. Prolonged administration with F.A (400 mg/kg) resulted in a comparable excretion of sodium, potassium, creatinine, uric acid, and urine output with furosemide (15 mg/kg). The oxidative stress parameters revealed that F.A (400 mg/kg) resulted in reducing the formation of free radicals. The results from the mechanism-based studies showed the involvement of NO in inducing diuresis. Furthermore, F.A (400 mg/kg) significantly increased the mitochondrial complexes I, II, III, IV, I + III, and II + III in the kidney homogenates, thus restoring the mitochondrial enzymes and improving the renal function. The current study suggests that F.A is safe with a significant diuretic potential with the involvement of NO in its mechanism of action.

The Protective Effect of Citronellol against Doxorubicin-Induced Cardiotoxicity in Rats.

Citronellol has been reported to have anti-inflammatory, anti-cancer, and antihypertensive activities, but its effect on myocardial ischemia is still unclear. The aim of this study was to investigate the therapeutic effects and pharmacological mechanisms of citronellol on ischemia. Therefore, a rat model of myocardial ischemia was established using the doxorubicin (DOX) model. To induce cardiotoxicity, the rats were given DOX (2.5 mg/kg) intraperitoneally over a 14-day period. Group I served as the control and received tween 80 (0.2%), group II received the vehicle and DOX, group III received the standard drug dexrazoxane and DOX, whereas groups IV, V, and VI were treated orally with citronellol (25, 50, and 100 mg/kg) and DOX, respectively. After treatment, the rats were euthanized, and blood samples were collected to assess the levels of serum cardiac markers, lipid profiles, and tissue antioxidant enzymes. The gene expressions of eNOS, PPAR-g, IL-10, VEGF, and NFkB-1 were also determined using real-time polymerase chain reactions. Simultaneous treatment with DOX and citronellol reduced cardiac antioxidant enzymes and lipid biomarkers in a dose-dependent manner. Citronellol also increased the expression of anti-inflammatory cytokines while reducing the expression of pro-inflammatory cytokines. Therefore, it can be concluded that citronellol may have potential cardioprotective effects in preventing DOX-induced cardiotoxicity.

Imine Derivatives of Benzoxazole Attenuate High-Fat Diet-Induced Hyperlipidemia by Modulation of Lipid-Regulating Genes.

Purpose: Hyperlipidemia being the prominent risk factor of cardiovascular diseases and side effects associated with the current lipid-lowering drugs have attracted the interest of scientists in the quest for new alternatives. In view of the diverse pharmacological potentials of benzoxazole (BZX) compounds, this study was designed to evaluate the antihyperlipidemic activity of imine derivatives of BZX in high-fat diet (HFD)-fed rats. Methods: Hyperlipidemia was induced in Sprague-Dawley rats by using HFD for 28 days. On the 28th day, blood samples were collected, and animals having serum triglycerides (TG) greater than 400 mg/dL and total cholesterol (TC) greater than 280 mg/dL were selected for further study. Hyperlipidemic rats were daily treated with either a vehicle or simvastatin (SIM; 20 mg/kg) or BZX compounds (10, 20, and 30 mg/kg), for 12 consecutive days. After the specified time duration, hyperlipidemic biomarkers were evaluated in the blood samples of sacrificed rats. Liver samples were collected for histopathological and mRNA analyses. Binding affinities of BZX derivatives with different targets were assessed by molecular docking. Results: The present study revealed that the BZX derivatives dose-dependently reduced the serum levels of TC, TG, low-density lipoprotein, and very low-density lipoprotein along with improvement in high-density lipoprotein levels. Similarly, all the compounds reduced HFD-induced alanine transaminase and aspartate aminotransferase levels except BZX-4. Histopathology of liver samples demonstrated mild to moderate fatty changes upon treatment with BZX-1, BZX-2, and BZX-4. The hepatic architecture of the BZX-3-treated samples was close to normal, and only mild inflammation was witnessed in these samples. Moreover, all the compounds significantly increased superoxide dismutase and glutathione levels, indicating their antioxidant potentials. Gene expression data showed that BZX-1 and BZX-3 reduced lipid levels by inhibiting HMGCR, APOB, PCSK9, SRB1, and VCAM1 and via improving PPAR-α and APOE mRNA levels. BZX-2 demonstrated its antihyperlipidemic effects mainly due to inhibition of APOB, while BZX-4-mediated effects appeared to be due to attenuation of APOB, PCSK9, and SRB1. BZX derivatives displayed strong binding affinities with HMGCR, APOB, and VCAM1, which suggested that some of the interactions might be required for inhibition of these target proteins. Conclusions: Based on the current findings, it can be concluded that BZX derivatives exert their antihyperlipidemic effects via modulation of multiple lipid-regulating genes.

Pulegone Prevents Hypertension through Activation of Muscarinic Receptors and Cyclooxygenase Pathway in L-NAME-Induced Hypertensive Rats.

The current study was designed to determine pulegone's antihypertensive and vasoprotective activity in L-NAME-induced hypertensive rats. Firstly, the hypotensive dose-response relationship of pulegone was evaluated in normotensive anesthetized rats using the invasive method. Secondly, the mechanism involved in hypotensive activity was determined in the presence of pharmacological drugs such as atropine/muscarinic receptor blocker (1 mg/kg), L-NAME/NOS inhibitor (20 mg/kg), and indomethacin/COX inhibitor (5 mg/kg) in anesthetized rats. Furthermore, studies were carried out to assess the preventive effect of pulegone in L-NAME-induced hypertensive rats. Hypertension was induced in rats by administering L-NAME (40 mg/kg) orally for 28 days. Rats were divided into six groups which were treated orally with tween 80 (placebo), captopril (10 mg/kg), and different doses of pulegone (20 mg/kg, 40 mg/kg, and 80 mg/kg). Blood pressure, urine volume, sodium, and body weight were monitored weekly. After 28 days, the effect of pulegone on lipid profile, hepatic markers, antioxidant enzymes, and nitric oxide was estimated from the serum of treated rats. Moreover, plasma mRNA expression of eNOS, ACE, ICAM1, and EDN1 was measured using real-time PCR. Results show that pulegone dose-dependently decreased blood pressure and heart rate in normotensive rats, with the highest effect at 30 mg/kg/i.v. The hypotensive effect of pulegone was reduced in the presence of atropine and indomethacin, whereas L-NAME did not change its hypotensive effect. Concurrent treatment with pulegone for four weeks in L-NAME-treated rats caused a reduction in both systolic blood pressure and heart rate, reversed the reduced levels of serum nitric oxide (NO), and ameliorated lipid profile and oxidative stress markers. Treatment with pulegone also improved the vascular response to acetylcholine. Plasma mRNA expression of eNOS was reduced, whereas ACE, ICAM1, and EDN1 levels were high in the L-NAME group, which was facilitated by pulegone treatment. To conclude, pulegone prevented L-NAME-induced hypertension by demonstrating a hypotensive effect through muscarinic receptors and cyclooxygenase pathway, indicating its use as a potential candidate in managing hypertension.

Inhibitory Peptide of Soluble Guanylyl Cyclase/Trx1 Interface Blunts the Dual Redox Signaling Functions of the Complex.

Soluble guanylyl cyclase (GC1) and oxido-reductase thioredoxin (Trx1) form a complex that mediates two NO signaling pathways as a function of the redox state of cells. Under physiological conditions, reduced Trx1 (rTrx1) supports the canonical NO-GC1-cGMP pathway by protecting GC1 activity from thiol oxidation. Under oxidative stress, the NO-cGMP pathway is disrupted by the S-nitrosation of GC1 (addition of a NO group to a cysteine). In turn, SNO-GC1 initiates transnitrosation cascades, using oxidized thioredoxin (oTrx1) as a nitrosothiol relay. We designed an inhibitory peptide that blocked the interaction between GC1 and Trx1. This inhibition resulted in the loss of a) the rTrx1 enhancing effect of GC1 cGMP-forming activity in vitro and in cells and its ability to reduce the multimeric oxidized GC1 and b) GC1's ability to fully reduce oTrx1, thus identifying GC1 novel reductase activity. Moreover, an inhibitory peptide blocked the transfer of S-nitrosothiols from SNO-GC1 to oTrx1. In Jurkat T cells, oTrx1 transnitrosates procaspase-3, thereby inhibiting caspase-3 activity. Using the inhibitory peptide, we demonstrated that S-nitrosation of caspase-3 is the result of a transnitrosation cascade initiated by SNO-GC1 and mediated by oTrx1. Consequently, the peptide significantly increased caspase-3 activity in Jurkat cells, providing a promising therapy for some cancers.

Fenchone, a monoterpene: Toxicity and diuretic profiling in rats.

Fenchone is a monoterpene present in the essential oils of various plants, including Foeniculum vulgare and Peumus boldus. Previous studies confirmed the anti-inflammatory, antioxidant, wound-healing, antidiarrheal, antifungal, antinociceptive, and bronchodilator activities of fenchone. Owing to various pharmacological activities of Fenchone, the current research was designed to evaluate its diuretic activity along with toxicity profiling. For evaluating acute toxicity, OECD guideline 425 was followed in which a single dose of 2000 mg/kg was orally administered to rats. For evaluating the diuretic potential in rats, three doses of Fenchone (100, 200, and 400 mg/kg) were assayed in comparison to furosemide (15 mg/kg) as the standard drug, followed by measurements of urinary volume, urinary electrolytes, uric acid, and urinary creatinine in saline-loaded rats for 8 h. The acute toxicity study showed a significant increase in hemoglobin (Hb), red blood cells (RBCs), alkaline phosphatase (ALP), and alkaline transaminase (ALT) along with a significant decrease in serum triglycerides, cholesterol, and uric acid levels when compared with the control group. The oxidative stress parameter, superoxide dismutase (SOD), was increased in the heart and spleen. Nitrite (NO) and glutathione were significantly increased in the kidney. The acute diuretic effect of Fenchone (400 mg/kg) significantly increased the urinary output, electrolytes (Na+, K+, and Ca++), urinary creatinine, and urinary uric acid in a dose-dependent manner. The Na+/K+ ratio was remarkably higher in the treatment group than that of the control group. The diuretic index, saluretic index, and Lipschitz value were also calculated from electrolyte concentration and urinary volume measurements, and the values were significantly increased in rats administered with fenchone at 400 mg/kg dose. The current study concluded that fenchone is safe and has remarkable diuretic action.

Novel mannich-based derivative of 2-mercaptobenzimidazole (AK7): a new candidate for the treatment of inflammatory arthritis owing to its NF-κB1 inhibitory potential.

This study investigated the anti-arthritic potential of novel mannich-based derivatives of 2-mercaptobenzimidazole (AK7 and AK9) in rats. The compounds were characterized by NMR and FTIR spectroscopies and their acute anti-inflammatory effects were measured by carrageenan (CRG)-induced paw edema model. The most potent doses of AK7 and AK9 were subsequently evaluated in the complete Freund's adjuvant (CFA)-induced inflammatory arthritis model. AK7 and AK9 inhibited CRG-induced inflammation in a dose-dependent fashion and a similar reduction in CFA-induced paw inflammation was observed. Moreover, X-ray and histopathological analyses of AK7-treated animals displayed normal joint structure whereas AK9, despite of its anti-inflammatory effects, failed to protect against cartilage destruction. Interestingly, biochemical analysis revealed a better safety profile for AK7 than for AK9 and methotrexate. Both compounds suppressed mRNA levels of pro-inflammatory mediators (IRAK1, NF-κB1, TNF-α, IL1B) while only AK7 reduced the transcript levels of interstitial collagenase (MMP1). Molecular docking analysis of AK7 and AK9 with TNF-α and MMP1 also supported the experimental data. These findings clearly highlight the beneficial effects of AK7 in the prevention and/or treatment of inflammatory arthritis.

Ex vivo, in vitro, and in silico approaches to unveil the mechanisms underlying vasorelaxation effect of Mentha Longifolia (L.) in porcine coronary artery.

OBJECTIVE: Mentha (M.) longifolia (L.) is traditionally used for various ailments. The current study was intended to explore the underlying vasorelaxation mechanisms of M. longifolia. MATERIAL AND METHODS: Aqueous-methanol extract from the aerial parts of M. longifolia was prepared and subjected to activity-guided fractionation. The vasorelaxant activity was performed using porcine coronary arteries with intact and denuded endothelium. In-vitro PDE inhibitory activity of the active fraction was carried out using the radio-enzymatic assay. The active fraction was also subjected to GCMS. Docking and molecular dynamic simulation studies were also performed RESULT: We had observed that aqueous-methanolic extract induced relaxation in the coronary artery in a dose-dependent manner when the endothelium was intact and denuded. n-butanol fraction (MLB) has produced a maximum effect, and it was selected for mechanistic studies. MLB has significantly enhanced the relaxation produced by cAMP and cGMP, elevating atrial natriuretic peptide, sodium nitroprusside, isoproterenol, and forskolin. The pre-treatment with MLB inhibited the contractile response produced by KCl, U46619, and CaCl2 in without endothelium rings. MLB has non-selectively inhibited the PDE isoforms. GCMS analysis of MLB has revealed the presence of menthol, thymol, and carvacrol in the active fraction. Docking and molecular dynamic simulation studies have indicated that thymol can be a competitive inhibitor for PDE1. CONCLUSION: It is postulated that an n-butanol fraction of Mentha longifolia produced endothelium-independent relaxation due to increased levels of cAMP and cGMP caused by the inhibition of various PDEs.

Novel acetamide derivatives of 2-aminobenzimidazole prevent inflammatory arthritis in rats via suppression of pro-inflammatory mediators.

Benzimidazole ring system is an important pharmacophore with diverse pharmacological activities. In this study, we explored the anti-arthritic effects of newly synthesized acetamide derivatives of 2-aminobenzimidazole (N1 and N2) in rats. FTIR and NMR spectroscopies were used to characterize these compounds. Carrageenan (CRG) induced paw edema model was used to test the acute anti-inflammatory activity of various doses (10, 20 and 30 mg/kg) of N1 and N2 compounds. Based on acute anti-inflammatory effects, the most potent dose of each compound was selected and investigated in complete freund's adjuvant (CFA) induced inflammatory arthritis (RA) model (n = 4 in each group). Histopathological, hematological, radiographic, and RT-qPCR analyses were performed to assess the progression or resolution of inflammatory arthritis. The tested compounds produced a dose-dependent anti-inflammatory activity against CRG induced paw inflammation and similarly reduced edema in CFA induced inflammatory arthritis model. Histopathological and X-ray analyses of ankle joints revealed minimal inflammation and normal joint structures in N1 and N2 treated groups. The tested compounds also reduced the levels of autoantibodies and restored hematological parameters. Interestingly, the tested compounds did not elevate aspartate aminotransferase and alanine transaminase levels and displayed a better safety profile than methotrexate. N1 and N2 compounds also attenuated the transcript levels of IRAK1, NF-kB1, TNF-α, IL-1ß, IL17 and MMP1. In addition, N1 displayed a greater inhibition of mRNA levels of COX1, COX2, mPGES1 and PTGDS as compared to N2. Our findings demonstrate that N1 and N2 compounds possess strong anti-arthritic activity which can be attributed to the suppression of pro-inflammatory mediators.

Pharmacological evaluation of anti-arthritic potential of terpinen-4-ol using in vitro and in vivo assays.

Terpinen 4-ol, a phytochemical is a monoterpene which has been reported for its anti-inflammatory effect. Present research was planned to check its effect against arthritis through in vitro and in vivo models. Terpinen 4-ol was evaluated through in-vitro procedures including blocking of protein (BSA and egg albumin) denaturation and human RBC membrane stabilization. In in vivo study, terpinen 4-ol (15, 30 and 60 mg/kg) was evaluated using formaldehyde and CFA arthritic models. Terpinen 4-ol significantly inhibited increase in paw and joint swelling as compared to diseased group. Terpinen 4-ol showed remarkable antioxidant effect (SOD, reducing power) and also improved body weight, haematological, histopathological and radiological parameters in CFA model. Also, moreover, the excess production of IL-1ß, TNF-α, IRAK, and NF-kB were noticeably attenuated in all terpinen 4-ol treated rats, however, IL-17 and IL-10 were distinctly increased compared to arthritic control rats in RT-PCR. Also, terpinen 4-ol showed promising antioxidant effect in DPPH assay. Henceforth, it might be concluded that terpinen 4-ol has anti-arthritic effect which can be attributed to the downregulation of pro-inflammatory cytokines.

Appraisal of hypotensive effect of natural monoterpene: Bornyl acetate and in-silico molecular docking analysis.

The modern trend of research is highly focused on finding new bioactive molecules from medicinal plants. As a functional bicyclic monoterpene, Bornyl acetate (BA) has displayed antioxidant and anti-inflammatory properties in different types of cells and tissues. The purpose of this research was to evaluate the probable hypotensive effect of BA, an underlying mechanism(s) backboned by in-silico studies. Mean arterial pressure and heart rate were recorded via invasive blood pressure measuring technique in normotensive Sprague-Dawley rats following the administration of BA (1-80mg/kg). Docking studies were carried out with various targets involved in the pathophysiology of hypertension.RO5 and ADMET properties were also evaluated. In the current study dose-dependent reduction in systolic, diastolic and mean arterial pressure was observed. Pretreatment with atropine and captopril significantly (p<0.001) reduced the hypotensive effect produced by BA. On the other hand docking studies showed pronounced interactions with M2 mAch receptor in an agonistic way and ACE protein in an antagonistic way. BA justified all cut-off limits of RO5 and had an acceptable predicted computational toxicity profile. Results postulate that dose-dependent hypotensive effect of BA is mediated through the muscarinic pathway and ACE inhibitory activity corresponding well with findings of in-silico studies.

Involvement of Muscarinic Receptors in Hypotensive and Diuretic Effects of Aqueous Soluble Fraction from Asphodelus tenuifolius Cav.

Background. Asphodelus tenuifolius Cav. (Asphodelaceae) is widely used in Pakistan traditional medicine as a hypotensive and diuretic agent. Despite the cardioprotective effects described for A. tenuifolius, the mechanisms involved in its probable hypotensive and diuretic effects have never been evaluated. Firstly, different extracts from A. tenuifolius seeds were obtained, and their antioxidant profiles and chemical constituents by LC-DAD-were determined, including molecular networking by the GNPS platform. Then, to evaluate changes in blood pressure, different groups of anesthetized normotensive rats were intravenously treated with the crude extract (AT-Cr, 1-50 mg/kg), aqueous (AS-AT, 1-25 mg/kg), n-butanol (BS-AT, 1-50 mg/kg), and dichloromethane fraction (DS-AT, 1-80 mg/kg). The diuretic effects of AT-Cr, AS-AT, BS-AT, and DS-AT at 100, 200, and 300 mg/kg, p.o. doses, were also evaluated in comparison with hydrochlorothiazide (HCTZ, 10 mg/kg, p.o). The urinary volume, sodium, potassium, and pH were estimated in the sample collected for 6 h from saline-loaded rats. Using pharmacological antagonists or inhibitors, we determine the involvement of acetylcholine, prostaglandins, and nitric oxide in A. tenuifolius-induced hypotensive and diuresis action. In addition, the activities of angiotensin-converting enzyme, erythrocyte carbonic anhydrase, and renal Na+/K+/ATPase were evaluated in vitro. Acute treatment with crude extract and fractions of A. tenuifolius exhibited significant hypotensive and diuretic potential in normotensive rats. However, AS-AT produced the most potent and significant dose-dependent hypotension and diuretic effects in normotensive rats. Previous treatment with atropine significantly reduced the hypotensive and diuretic action of AS-AT, but pretreatment with indomethacin or L-NAME did not affect these effects. Moreover, the 7-day treatment with AS-AT did not reduce activities of serum angiotensin-converting enzyme, erythrocyte carbonic anhydrase, and renal Na+/K+/ATPase. AS-AT showed four major compound node clusters, which included sugars, alkaloids, nucleoside, amino acid, and glycosylated flavonoids. This research supports and extends the traditional use of A. tenuifolius as a hypotensive and diuretic agent. The results showed that AS-AT from A. tenuifolius could present compounds responsible for hypotensive and diuretic activities through the activation of muscarinic receptors.

Endothelium-independent vasorelaxant effect of Asphodelus tenuifolius Cav. via inhibition of myosin light chain kinase activity in the porcine coronary artery.

ETHNOPHARMACOLOGICAL RELEVANCE: Asphodelus tenuifolius Cav. (Asphodelaceae), a wild, terrestrial, annual stemless herb, is widely used in traditional medicine for the treatment of hypertension, diabetes, atherosclerosis and circulatory problems. A previous research study from our laboratory revealed that A. tenuifolius has beneficial effects in reducing blood pressure and improves aortic endothelial dysfunction in chronically glucose fed rats. Despite the fact that A. tenuifolius reduces blood pressure and improves endothelial function in vivo, there are no detailed studies about its possible mechanism of action. AIM OF THE STUDY: This study was designed to provide pharmacological basis and mechanism of action for the traditional use of A. tenuifolius in hypertension and circulatory problems. We explored the vasorelaxant effect of A. tenuifolius and its underlying vasorelaxation mechanism in porcine coronary artery rings. MATERIALS AND METHODS: Aqueous methanolic crude extract of A. tenuifolius was prepared by maceration process and then activity guided fractionation was carried out by using different polarity based solvents. Phytochemical studies were carried out using LC-DAD-MS. Segments of porcine distal coronary artery were set up in a wire myograph for isometric force measurements. Extract/fractions of A. tenuifolius seeds were tested for vasodilator activity by measurement of changes in tone after pre-contraction with the thromboxane mimetic U46619 in the presence or absence of inhibitors of intracellular signaling cascades. RESULTS: Crude extract/fractions of A. tenuifolius produced dose dependent endothelium independent vasorelaxant response in coronary rings, whereas, the butanol fraction of A. tenuifolius (BS-AT) produced the largest relaxation response with 100% relaxation at 1 mg/ml, therefore the mechanism of relaxation of this fraction was determined. The relaxation to BS-AT was unaffected by removal of the endothelium, pre-contraction with KCl, or the presence of the non-selective potassium channel blocker tetraethylammonium, indicating that the relaxation was endothelium-independent, and does not involve activation of potassium channels. BS-AT (1 mg/ml) inhibited the contractile response to calcium,the L-type calcium channel activator BAY K8664,and ionomycin, indicating that it inhibits calcium-induced contractions. The relaxation response to BS-AT was attenuated in the absence of extracellular calcium. However, relaxations to BS-AT were also reduced after deletion of calcium from intracellular stores with cyclopiazonic acid. Incubation with 1 mg/ml BS-AT also inhibited phosphorylation of myosin light chains in homogenates of coronary artery. CONCLUSION: The butanol extract of Asphodelus tenuifolius produces a large endothelium-independent relaxation of the porcine coronary artery through inhibition of calcium-induced contractions. The effect appears to be downstream of calcium influx, possibly through inhibition of myosin light chain kinase. This study supports previous studies demonstrating that A. tenuifolius reduces blood pressure. Future studies will aim to determine the active compounds underlying this response.

Evaluation of anti-inflammatory and analgesic activities of aqueous methanolic extract of Ranunculus muricatus in albino mice.

Ranunculus muricatus (Ranunculaceae) is commonly used by inhabitants of Pakistan for the treatment of gout and rheumatism, both of which are inflammatory disorders. The present study attempts to evaluate the anti-inflammatory and analgesic activities of aqueous methanolic extract of R. muricatus in mice. The plant extract at doses of 50, 100 and 150 mg/kg was tested for anti-inflammatory activity against carrageenan and egg albumin induced paw edema in mice and analgesic activity was appraised against acetic acid induced writhing and formalin induced paw licking in mice models. The results designate that extract at the highest dose of 150 mg/kg significantly (p<0.001) and dose dependently inhibited carrageenan induced and egg albumin induced paw edema. Similarly, extract at the same dose of 150 mg/kg showed potent and dose dependent (p<0.001) suppression of formalin induced paw licking and abdominal constrictions / stretching of hind limbs induced by acetic acid. The anti-inflammatory and analgesic activity of plant extract was comparable to standard drug ibuprofen in all models. This study thus supports the use of R. muricatus in traditional medicine for conditions associated with inflammation and analgesia which might be attributed to its previously proven high alkaloid, flavonoids, phenol, tannins content and free radical scavenging activity.

Study on vascular mechanisms underlying the hypotensive effect of Sorghum halepense (L.) Pers.

Sorghum halepense L (Poaceae), ordinarily it is known as Johnson grass and locally as baru. This study was designed to find the vascular mechanisms underlying the hypotensive activity of S. halepense. In this study, effect of S. halepense seed extract/fractions on various blood pressure parameters were evaluated in normal and fructose induced hypertensive rats by invasive technique. Possible underlying hypotensive mechanism of active fraction was determined by using various pharmacological inhibitors. S. halepense extract/fractions vasorelaxant effect were also evaluated on rat aorta rings in organ bath and various intracellular signaling pathway inhibitors were used for determination of underlying mechanisms. S. halepense extract/fractions produced blood pressure lowering effect with most significant effect by its aqueous soluble fraction at dose of 10mg/kg. This effect was attenuated by pretreatment of atropine. Aqueous soluble fraction produced endothelium dependent vasorelaxation in rat aortic rings that was inhibited by pretreatment of atropine after phenylephrine induced contraction. The vasorelaxant effect of aqueous soluble fraction was attenuated by potassium channel blockers and also produced inhibitory effect on calcium entry through calcium channels. It also suppressed phenylephrine induced contraction like verapamil. By HPLC analysis found vanillic acid and naringinin in it. In conclusion, aqueous soluble fraction of S.halepense possess phytoconstituents which may be responsible for hypotensive and vasorelaxant effect of Sorghum halepense.

Blood pressure lowering effects of Ranunculus scleratus Linn. in normal and fructose induced hypertensive rats and estimation of underlying mechanisms.

Ranunculus scleratus Linn. is used in folk medicine to treat hypertension. This study was aimed at providing validation to its traditional use and to explore underlying mechanisms of action. Effects of hydro-ethanolic crude extract of the plant and its fractions on blood pressure was evaluated using direct surgical method in normotensive and in fructose induced hypertensive rats. Various doses of crude extract, RSC, (5, 10, 20, 30mg/kg) and all fractions (3, 5, 10, 20mg/kg) were studied. Results suggested that aqueous fraction of R. scleratus (RSA) produced most pronounced effects at 10mg/kg in normotensive and at 20mg/kg in hypertensive animals. Underlying mechanisms, using various pharmacological antagonists were also elucidated. Results suggested the involvement of muscarinic receptor, angiotensin converting enzyme (ACE) inhibition, ganglionic block and nitric oxide (NO) release in presenting hypotensive response.

Role of the NO/cGMP pathway and renin-angiotensin system in the hypotensive and diuretic effects of aqueous soluble fraction from Crataegus songarica K. Koch.

ETHNO-PHARMACOLOGICAL RELEVANCE: Fruits of Crataegus songarica K. Koch. (Rosaceae) are commonly used in folk medicine for their diuretic properties to treat hypertension and congestive heart failure. To date, no scientific data has been published to support the diuretic potential. AIM OF THE STUDY: The purpose of this study was to evaluate efficacy and mechanism underlying the hypotensive and diuretic action of C. songarica in normotensive rats and to determine the constituents from the extracts by LC-DAD-MS. MATERIALS AND METHODS: Firstly, phytochemical profiling and antioxidant potential of C. songarica extracts was determined. Then, to evaluate changes in blood pressure, different groups of anesthetized normotensive rats were intravenously treated with crude extract (CS-Cr, 10-80 mg/kg), aqueous soluble (AS-CS, 0.1-20 mg/kg), and n-butanol soluble fractions of C. songarica (BS-CS, 1-80 mg/kg). The diuretic effects of CS-Cr (100-500 mg/kg, p.o), AS-CS (100-300 mg/kg, p.o) and BS-CS (100-300 mg/kg, p.o) were evaluated in comparison with hydrochlorothiazide (HCTZ, 10 mg/kg, p.o). The urinary volume, sodium, potassium and pH were estimated in the sample collected for 6 h from saline-loaded rats. Using pharmacological antagonists or inhibitors, we determine the involvement of acetylcholine, prostaglandins, and nitric oxide in C. songarica induced hypotensive and diuresis action. In addition, the activities of angiotensin converting enzyme, erythrocytary carbonic anhydrase and renal Na+/K+/ATPase were evaluated in vitro. RESULTS: From the LC-DAD-MS analyses, thirty-nine compounds were detected, showing a complex chemical profile and an expressive antioxidant activity "in vitro". Acute treatment with CS-Cr, AS-CS, and BS-CS exhibited significant hypotensive and diuretic potential in normotensive rats. However, AS-CS produced most potent and significant dose-dependent hypotension in normotensive rats, and also produced highly significant diuretic and saluretic effects. Despite the changes in urinary excretion of electrolytes, the plasmatic levels of sodium and potassium were not changed. Previous treatment with atropine and L-NAME significantly reduced the hypotensive and diuretic action of AS-CS in normotensive rats. Moreover, the 7-day treatment with AS-CS also resulted in significant ACE inhibitory activity. CONCLUSION: This research supports and extends the ethnomedicinal use of C. songarica as diuretic and hypotensive agent. The results showed that AS-CS from C. songarica could present compounds responsible for hypotensive and diuretic activities with no signs of toxicity, and these effects could involve nitric oxide pathway activated by muscarinic receptors or/and inhibition of angiotensin converting enzyme.

Indigenous medicinal plants of Pakistan used to treat skin diseases: a review.

ETHNO-PHARMACOLOGICAL RELEVANCE: Plants are providing reliable therapy since time immemorial. Pakistan has a great diversity in medicinal flora and people use these ethno-medicines to deal with many skin problems. This review explores the fundamental knowledge on various dermatological properties of medicinal plants of Pakistan and is aimed to provide a baseline for the discovery of new plants having activities against skin issues. MATERIAL AND METHOD: A total of 244 published articles were studied using different research engines like PubMed, Google, Google-scholar and science direct. RESULTS: Review of literature revealed ethno-pharmacological use of 545 plant species, belonging to 118 families and 355 genera, to combat various skin ailments. Out of these, ten most commonly used plant species belonging to ten different families are documented in this review. It was also found out that ehno-medicines are prepared using various parts of the plants including leaves (28.32%), whole plant and roots 13.17% and 10.97% respectively, in the form of powder (23.5%) and paste (22.75%). A total of 13 endangered plant species and ten commercially important plants were recorded. CONCLUSION: Medicinal plants of Pakistan have therapeutic effects against several skin problems; however most of medicinal plants are still not evaluated scientifically to support their ethno-pharmacological claim on skin. Dermatological pathogens are recommended to study. Further, the conservational programs should be established for endangered species.