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Fulltext In vitro porcine blood-brain barrier model for permeability studies: pCEL-X software pKa(FLUX) method for aqueous boundary layer correction and detailed data analysis

Yusof SR, Avdeef A, Abbott NJ

Eur J Pharm Sci, 2014 Dec 18;65:98-111.
PMID: 25239510 DOI: 10.1016/j.ejps.2014.09.009

In vitro blood-brain barrier (BBB) models from primary brain endothelial cells can closely resemble the in vivo BBB, offering valuable models to assay BBB functions and to screen potential central nervous system drugs. We have recently developed an in vitro BBB model using primary porcine brain endothelial cells. The model shows expression of tight junction proteins and high transendothelial electrical resistance, evidence for a restrictive paracellular pathway. Validation studies using small drug-like compounds demonstrated functional uptake and efflux transporters, showing the suitability of the model to assay drug permeability. However, one limitation of in vitro model permeability measurement is the presence of the aqueous boundary layer (ABL) resulting from inefficient stirring during the permeability assay. The ABL can be a rate-limiting step in permeation, particularly for lipophilic compounds, causing underestimation of the permeability. If the ABL effect is ignored, the permeability measured in vitro will not reflect the permeability in vivo. To address the issue, we explored the combination of in vitro permeability measurement using our porcine model with the pKa(FLUX) method in pCEL-X software to correct for the ABL effect and allow a detailed analysis of in vitro (transendothelial) permeability data, Papp. Published Papp using porcine models generated by our group and other groups are also analyzed. From the Papp, intrinsic transcellular permeability (P0) is derived by simultaneous refinement using a weighted nonlinear regression, taking into account permeability through the ABL, paracellular permeability and filter restrictions on permeation. The in vitro P0 derived for 22 compounds (35 measurements) showed good correlation with P0 derived from in situ brain perfusion data (r(2)=0.61). The analysis also gave evidence for carrier-mediated uptake of naloxone, propranolol and vinblastine. The combination of the in vitro porcine model and the software analysis provides a useful tool to better predict BBB permeability in vivo and gain better mechanistic information about BBB permeation.

Matched MeSH terms: In Vitro Techniques
Augmentation of angiogenic and endothelial associated gene expression by EDM50 in human chorion-derived stem cells

Manzor NF, Chua KH, Tan GC, Tan AE, Abdul Rahman H

Med J Malaysia, 2008 Jul;63 Suppl A:11-2.
PMID: 19024960

The objective of this study was to investigate the angiogenic potential of human chorion-derived stem cells (CDSC) cultured in medium containing bFGF and VEGF (EDM50). Total RNA was extracted from cells cultured in FD+10% FBS and EDM50. Quantitative RT-PCR was carried out to score the differential mRNA expression of genes involve in angiogenesis and endothelial differentiation. Our finding demonstrated that all angiogenic and endothelial associated genes were expressed higher in EDM50. Expression level of ANG-1, eNOS and VEGFR2 were significantly higher in EDM50 compared to FD+10% FBS. Our results suggested that human CDSC cultured in EDM50 can be used for angiogenesis purpose in regenerative medicine.

Matched MeSH terms: In Vitro Techniques
An in vitro study on the anti-adherence effect of Brucea javanica and Piper betle extracts towards oral Candida

Nordin MA, Wan Harun WH, Abdul Razak F

Arch Oral Biol, 2013 Oct;58(10):1335-42.
PMID: 23915676 DOI: 10.1016/j.archoralbio.2013.07.001

The adherence of Candida to mucosal surfaces is the initial step for successful invasive process of the oral cavity. The study aimed to investigate the effect of two plant extracts on the non-specific and specific bindings of oral candida.

Matched MeSH terms: In Vitro Techniques
Identification and Quantification of Quercetin, A Major Constituent of Artocarpus altilis by Targeting Related Genes of Apoptosis and Cell Cycle: In Vitro Cytotoxic Activity Against Human Lung Carcinoma Cell Lines

Jalal TK, Khan AYF, Natto HA, Abdull Rasad MSB, Arifin Kaderi M, Mohammad M, et al.

Nutr Cancer, 2019;71(5):792-805.
PMID: 30614285 DOI: 10.1080/01635581.2018.1516790

Nine phenolic compounds were identified and quantified in Artocarpus altilia fruit. One of the main compounds was quercetin, which is the major class of flavonoids has been identified and quantified in pulp part of A. altilis fruit of methanol extract. The aim of this study was to evaluate in vitro cytotoxic assay. Inhibitory concentration 50% concentration was determined using trypan blue exclusion assay. Apoptosis induction and cell cycle regulation were studied by flow cytometric analysis. The expression of apoptosis and cell cycle-related regulatory genes were assessed by RT-qPCR study of the methanol extract of pulp part on human lung carcinoma (A549) cell line. A significant increase of cells at G2/M phases was detected (P

Matched MeSH terms: In Vitro Techniques
Fulltext Heavy Metal in Paddy Soil and its Bioavailability in Rice Using In Vitro Digestion Model for Health Risk Assessment

Zulkafflee NS, Mohd Redzuan NA, Hanafi Z, Selamat J, Ismail MR, Praveena SM, et al.

Int J Environ Res Public Health, 2019 11 28;16(23).
PMID: 31795132 DOI: 10.3390/ijerph16234769

Rice ingestion is one of the major pathways for heavy metal bioaccumulation in human. This study aimed to measure the heavy metal content of paddy soils and its bioavailability in paddy grain in order to assess the health risk. In total, 10 rice samples (50 g each) of paddy plants were harvested from the Selangor and Terengganu areas of Malaysia to assess the bioavailability of heavy metal (As, Cd, Cu, Cr, and Pb) using the in vitro digestion model of Rijksinstituut voor Volksgezondheid en Milieu. The bioavailability of heavy metal concentrations in rice samples were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The findings showed the bioavailability of heavy metal concentrations was decreased in the order Cr > Cu > Pb > As > Cd. Chromium was found to be the most abundant bioavailable heavy metal in cooked rice, which was the result of its high content in paddy soil. Hazard Quotient values for the bioavailability of the heavy metal studied were less than one indicating no non-carcinogenic health risks for adults and children. Meanwhile, the total Lifetime Cancer Risk exceeded the acceptable value showing a potential of carcinogenic health risk for both adults and children. The application of in vitro digestion model in assessing bioavailability of heavy metal produces a more realistic estimation of human health risks exposure. However, a regular monitoring of pollution in Selangor and Terengganu areas is crucial since the exposure of heavy metals through rice consumption poses the potential non-carcinogenic and carcinogenic health risk to the local residents.

Matched MeSH terms: In Vitro Techniques
Transgene expression from CpG-reduced lentiviral gene delivery vectors in vitro

Low PT, Lai MI, Ngai SC, Abdullah S

Gene, 2014 Jan 1;533(1):451-5.
PMID: 24120896 DOI: 10.1016/j.gene.2013.09.075

Current viral gene delivery vectors for gene therapy are inefficient due to short-lived transgene expression attributed to the cytosine-phosphate-guanine (CpG) motifs in the transgene. Here we assessed the effects of CpG motif reduction in lentiviral (LV) gene delivery context on the level and duration of reporter gene expression in Chinese Hamster Ovary (CHO) cells, Human Immortalized Myelogenous Leukemia (K562) cells and hematopoietic stem cells (HSCs). The cells were transduced with LV carrying Zero-CpG green fluorescent protein (ZGFP) reporter gene, LV/CMV/ZGFP. The GFP expression was compared to its non CpG-depleted GFP reporter gene LV (LV/CMV/GFP) counterpart. The LV/CMV/ZGFP exhibited prolonged transgene expression in CHO cells and HSCs up to 10 days and 14 days, in the respective cells. This effect was not seen in the transduced K562 cells, which may be due to the DNA hypomethylation status of the cancer cell line. Transgene copy number analysis verified that the GFP expression was not from pseudo-transduction and the transgene remained in the genome of the cells throughout the period of the study. The modest positive effects from the LV/CMV/ZGFP suggest that the reduction of CpG in the LV construct was not substantial to generate higher and more prolonged transgene expression.

Matched MeSH terms: In Vitro Techniques
Fulltext An efficient in vitro plantlet regeneration from shoot tip cultures of Curculigo latifolia, a medicinal plant

Babaei N, Abdullah NA, Saleh G, Abdullah TL

ScientificWorldJournal, 2014;2014:275028.
PMID: 24723799 DOI: 10.1155/2014/275028

A procedure was developed for in vitro propagation of Curculigo latifolia through shoot tip culture. Direct regeneration and indirect scalp induction of Curculigo latifolia were obtained from shoot tip grown on MS medium supplemented with different concentrations and combinations of thidiazuron and indole-3-butyric acid. Maximum response for direct regeneration in terms of percentage of explants producing shoot, shoot number, and shoot length was obtained on MS medium supplemented with combination of thidiazuron (0.5 mg L(-1)) and indole-3-butyric acid (0.25 mg L(-1)) after both 10 and 14 weeks of cultures. Indole-3-butyric acid in combination with thidiazuron exhibited a synergistic effect on shoot regeneration. The shoot tips were able to induce maximum scalp from basal end of explants on the medium with 2 mg L(-1) thidiazuron. Cultures showed that shoot number, shoot length, and scalp size increased significantly after 14 weeks of culture. Transferring of the shoots onto the MS medium devoid of growth regulators resulted in the highest percentage of root induction and longer roots, while medium supplemented with 0.25 mg L(-1) IBA produced more numbers of roots.

Matched MeSH terms: In Vitro Techniques
Vasorelaxation induced by common edible tropical plant extracts in isolated rat aorta and mesenteric vascular bed

Runnie I, Salleh MN, Mohamed S, Head RJ, Abeywardena MY

J Ethnopharmacol, 2004 Jun;92(2-3):311-6.
PMID: 15138017

In this study, the vasodilatory actions of nine edible tropical plant extracts were investigated. Ipomoea batatas (sweet potato leaf), Piper betle (betel leaf), Anacardium occidentale (cashew leaf), Gynandropsis gynandra (maman leaf), Carica papaya (papaya leaf), and Mentha arvensis (mint leaf) extracts exhibited more than 50% relaxing effect on aortic ring preparations, while Piper betle and Cymbopogon citratus (lemongrass stalk) showed comparable vasorelaxation on isolated perfused mesenteric artery preparation. The vascular effect on the aortic ring preparations were mainly endothelium-dependent, and mediated by nitric oxide (NO) as supported by the inhibition of action in the presence of N(omega)-nitro-L-arginine (NOLA), an nitric oxide synthase (NOS) inhibitor, or by the removal of endothelium. In contrast, vasodilatory actions in resistance vessels (perfused mesenteric vascular beds) appear to involve several biochemical mediators, including NO, prostanoids, and endothelium-dependent hyperpolarizing factors (EDHFs). Total phenolic contents and antioxidant capacities varied among different extracts and found to be independent of vascular relaxation effects. This study demonstrates that many edible plants common in Asian diets to possess potential health benefits, affording protection at the vascular endothelium level.

Matched MeSH terms: In Vitro Techniques
Fulltext Chemical Constituents of Malaysian U. cordata var. ferruginea and Their in Vitro α-Glucosidase Inhibitory Activities

Abdullah NH, Salim F, Ahmad R

Molecules, 2016 Apr 27;21(5).
PMID: 27128898 DOI: 10.3390/molecules21050525

Continuing our interest in the Uncaria genus, the phytochemistry and the in-vitro α-glucosidase inhibitory activities of Malaysian Uncaria cordata var. ferruginea were investigated. The phytochemical study of this plant, which employed various chromatographic techniques including recycling preparative HPLC, led to the isolation of ten compounds with diverse structures comprising three phenolic acids, two coumarins, three flavonoids, a terpene and an iridoid glycoside. These constituents were identified as 2-hydroxybenzoic acid or salicylic acid (1), 2,4-dihydroxybenzoic acid (2), 3,4-dihydroxybenzoic acid (3), scopoletin or 7-hydroxy-6-methoxy-coumarin (4), 3,4-dihydroxy-7-methoxycoumarin (5), quercetin (6), kaempferol (7), taxifolin (8), loganin (9) and β-sitosterol (10). Structure elucidation of the compounds was accomplished with the aid of 1D and 2D Nuclear Magnetic Resonance (NMR) spectral data and Ultraviolet-Visible (UV-Vis), Fourier Transform Infrared (FTIR) spectroscopy and mass spectrometry (MS). In the α-glucosidase inhibitory assay, the crude methanolic extract of the stems of the plant and its acetone fraction exhibited strong α-glucosidase inhibition activity of 87.7% and 89.2%, respectively, while its DCM fraction exhibited only moderate inhibition (75.3%) at a concentration of 1 mg/mL. The IC50 values of both fractions were found to be significantly lower than the standard acarbose suggesting the presence of potential α-glucosidase inhibitors. Selected compounds isolated from the active fractions were then subjected to α-glucosidase assay in which 2,4-dihydroxybenzoic acid and quercetin showed strong inhibitory effects against the enzyme with IC50 values of 549 and 556 μg/mL compared to acarbose (IC50 580 μg/mL) while loganin and scopoletin only showed weak α-glucosidase inhibition of 44.9% and 34.5%, respectively. This is the first report of the isolation of 2-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid and loganin from the genus and the first report of the α-glucosidase inhibitory potential of 2,4-dihydroxybenzoic acid.

Matched MeSH terms: In Vitro Techniques
Fulltext In vitro sustained release study of gallic acid coated with magnetite-PEG and magnetite-PVA for drug delivery system

Dorniani D, Kura AU, Hussein-Al-Ali SH, Bin Hussein MZ, Fakurazi S, Shaari AH, et al.

ScientificWorldJournal, 2014;2014:416354.
PMID: 24737969 DOI: 10.1155/2014/416354

The efficacy of two nanocarriers polyethylene glycol and polyvinyl alcohol magnetic nanoparticles coated with gallic acid (GA) was accomplished via X-ray diffraction, infrared spectroscopy, magnetic measurements, thermal analysis, and TEM. X-ray diffraction and TEM results showed that Fe3O4 nanoparticles were pure iron oxide having spherical shape with the average diameter of 9 nm, compared with 31 nm and 35 nm after coating with polyethylene glycol-GA (FPEGG) and polyvinyl alcohol-GA (FPVAG), respectively. Thermogravimetric analyses proved that after coating the thermal stability was markedly enhanced. Magnetic measurements and Fourier transform infrared (FTIR) revealed that superparamagnetic iron oxide nanoparticles could be successfully coated with two polymers (PEG and PVA) and gallic acid as an active drug. Release behavior of gallic acid from two nanocomposites showed that FPEGG and FPVAG nanocomposites were found to be sustained and governed by pseudo-second-order kinetics. Anticancer activity of the two nanocomposites shows that the FPEGG demonstrated higher anticancer effect on the breast cancer cell lines in almost all concentrations tested compared to FPVAG.

Matched MeSH terms: In Vitro Techniques
Root and canal morphology of maxillary premolar teeth in an Egyptian subpopulation using two classification systems: a cone beam computed tomography study

Saber SEDM, Ahmed MHM, Obeid M, Ahmed HMA

Int Endod J, 2019 Mar;52(3):267-278.
PMID: 30225932 DOI: 10.1111/iej.13016

AIM: To investigate the number of roots and root canal configurations using two coding systems and the root canal diverging and merging levels in extracted maxillary premolars in an Egyptian subpopulation using cone beam computed tomography (CBCT).
METHODOLOGY: A total of 700 maxillary premolars were examined using CBCT in an Egyptian subpopulation. The number of roots was identified, and root canal configurations were classified according to Vertucci's classification and a new system for classifying root and canal morphology. In addition, the position where roots bifurcated and the levels where canals merged or diverged were identified. Fisher's exact test and independent t-test were used for statistical analysis, and the level of significance was set at 0.05 (P = 0.05).
RESULTS: More than half of maxillary first premolars were double-rooted, and the majority of maxillary second premolars were single-rooted (P

Matched MeSH terms: In Vitro Techniques
Antimalarial activity of extracts of Malaysian medicinal plants

Najib Nik A Rahman N, Furuta T, Kojima S, Takane K, Ali Mohd M

J Ethnopharmacol, 1999 Mar;64(3):249-54.
PMID: 10363840

In vitro and in vivo studies revealed that Malaysian medicinal plants, Piper sarmentosum, Andrographis paniculata and Tinospora crispa produced considerable antimalarial effects. Chloroform extract in vitro did show better effect than the methanol extract. The chloroform extract showed complete parasite growth inhibition as low as 0.05 mg/ml drug dose within 24 h incubation period (Andrographis paniculata) as compared to methanol extract of drug dose of 2.5 mg/ml but under incubation time of 48 h of the same plant spesies. In vivo activity of Andrographis paniculata also demonstrated higher antimalarial effect than other two plant species.

Matched MeSH terms: In Vitro Techniques
Impact of bovine and human serum albumin on Curcumin in vitro activity against Staphylococcus aureus

Teow SY, Ali SA

Pak J Pharm Sci, 2017 May;30(3):891-895.
PMID: 28653935

This study evaluated the impact of pH (7.4 and 6.5), bovine serum albumin (BSA), and human serum albumin (HSA) on Curcumin activity against 2 reference, 1 clinical, and 10 environmental strains of Staphylococcus aureus (S. aureus). Minimal inhibitory concentrations (MICs) of Curcumin against S. aureus were statistically indifferent (p>0.05) at pH7.4 and pH6.5. Activity of Curcumin against S. aureus was reduced by two folds in the presence of 1.25-5% BSA/HSA.

Matched MeSH terms: In Vitro Techniques
Fulltext An Overview of In Vitro, In Vivo, and Computational Techniques for Cancer-Associated Angiogenesis Studies

Rahman HS, Tan BL, Othman HH, Chartrand MS, Pathak Y, Mohan S, et al.

Biomed Res Int, 2020;2020:8857428.
PMID: 33381591 DOI: 10.1155/2020/8857428

Angiogenesis is a crucial area in scientific research because it involves many important physiological and pathological processes. Indeed, angiogenesis is critical for normal physiological processes, including wound healing and embryonic development, as well as being a component of many disorders, such as rheumatoid arthritis, obesity, and diabetic retinopathies. Investigations of angiogenic mechanisms require assays that can activate the critical steps of angiogenesis as well as provide a tool for assessing the efficacy of therapeutic agents. Thus, angiogenesis assays are key tools for studying the mechanisms of angiogenesis and identifying the potential therapeutic strategies to modulate neovascularization. However, the regulation of angiogenesis is highly complex and not fully understood. Difficulties in assessing the regulators of angiogenic response have necessitated the development of an alternative approach. In this paper, we review the standard models for the study of tumor angiogenesis on the macroscopic scale that include in vitro, in vivo, and computational models. We also highlight the differences in several modeling approaches and describe key advances in understanding the computational models that contributed to the knowledge base of the field.

Matched MeSH terms: In Vitro Techniques
Apoptosis induction, cell cycle arrest and in vitro anticancer activity of gonothalamin in a cancer cell lines

Alabsi AM, Ali R, Ali AM, Al-Dubai SA, Harun H, Abu Kasim NH, et al.

Asian Pac J Cancer Prev, 2012;13(10):5131-6.
PMID: 23244123

Cancer is one of the major health problems worldwide and its current treatments have a number of undesired adverse side effects. Natural compounds may reduce these. Currently, a few plant products are being used to treat cancer. In this study, goniothalamin, a natural occurring styryl-lactone extracted from Goniothalamus macrophyllus, was investigated for cytotoxic properties against cervical cancer (HeLa), breast carcinoma (MCF-7) and colon cancer (HT29) cells as well as normal mouse fibroblast (3T3) using MTT assay. Fluorescence microscopy showed that GTN is able to induce apoptosis in HeLa cells in a time dependent manner. Flow cytometry further revealed HeLa cells treated with GTN to be arrested in the S phase. Phosphatidyl serine properties present during apoptosis enable early detection of the apoptosis in the cells. Using annexin V/PI double staining it could be shown that GTN induces early apoptosis on HeLa cells after 24, 48 and 72 h. It could be concluded that goniothalamin showing a promising cytotoxicity effect against several cancer cell lines including cervical cancer cells (HeLa) with apoptosis as the mode of cell death induced on HeLa cells by Goniothalamin was.

Matched MeSH terms: In Vitro Techniques
Fulltext Antifungal effectiveness of various intracanal medicaments against Candida albicans: an ex-vivo study

Chua EG, Parolia A, Ahlawat P, Pau A, Amalraj FD

BMC Oral Health, 2014;14:53.
PMID: 24886335 DOI: 10.1186/1472-6831-14-53

To investigate the antifungal activity of propolis, triple antibiotic paste (TAP), 2% chlorhexidine gel and calcium hydroxide with propylene glycol on Candida albicans-infected root canal dentinal tubules at two different depths (200 μm and 400 μm) and two time intervals (day 1 and 7).

Matched MeSH terms: In Vitro Techniques
Iliotibial band tension affects patellofemoral and tibiofemoral kinematics

Merican AM, Amis AA

J Biomech, 2009 Jul 22;42(10):1539-1546.
PMID: 19481211 DOI: 10.1016/j.jbiomech.2009.03.041

The iliotibial band (ITB) has an important role in knee mechanics and tightness can cause patellofemoral maltracking. This study investigated the effects of increasing ITB tension on knee kinematics. Nine fresh-frozen cadaveric knees had the components of the quadriceps loaded with 175 N. A Polaris optical tracking system was used to acquire joint kinematics during extension from 100 degrees to 0 degrees flexion. This was repeated after the following ITB loads: 30, 60 and 90 N. There was no change with 30 N load for patellar translation. On average, at 60 and 90 N, the patella translated laterally by 0.8 and 1.4mm in the mid flexion range compared to the ITB unloaded condition. The patella became more laterally tilted with increasing ITB loads by 0.7 degrees, 1.2 degrees and 1.5 degrees for 30, 60 and 90 N, respectively. There were comparable increases in patellar lateral rotation (distal patella moves laterally) towards the end of the flexion cycle. Increased external rotation of the tibia occurred from early flexion onwards and was maximal between 60 degrees and 75 degrees flexion. The increase was 5.2 degrees, 9.5 degrees and 13 degrees in this range for 30, 60 and 90 N, respectively. Increased tibial abduction with ITB loads was not observed. The combination of increased patellar lateral translation and tilt suggests increased lateral cartilage pressure. Additionally, the increased tibial external rotation would increase the Q angle. The clinical consequences and their relationship to lateral retinacular releases may be examined, now that the effects of a tight ITB are known.

Matched MeSH terms: In Vitro Techniques
Polypeptides associated with in vitro cyst formation of Blastocystis hominis

Init I, Mak JW, Top S, Zulhainan Z, Prummongkol S, Nissapatorn V, et al.

Southeast Asian J. Trop. Med. Public Health, 2003 Dec;34(4):727-32.
PMID: 15115079

The objective of this study was to characterize the polypeptides associated with cysts of Blastocystis hominis. This form is believed to be infective and plays a role in parasite resistance to anti-B. hominis drugs currently used for treatment of Blastocystis associated diarrhea. Cysts were induced through in vitro culture of the parasite in complete medium supplemented with bacterial extract with trypticase, metronidazole or doxycycline. SDS-PAGE analysis showed almost similar polypeptide patterns of parasite extracts obtained from in vitro cultured parasites before and after exposure with the three supplements. Polypeptide bands at 76, 58.5, 48, 45, 40, 38, 32, 25 and 22 kDa were constantly seen in all antigenic preparations and no specific cyst-associated polypeptide was present. However, on immunoblot analysis, 3 out of 16 blastocystosis human sera identified a cyst-associated polypeptide at 60 kDa in all parasite extracts prepared from cultures with the three supplements. In addition, there were associated morphological changes detected in these parasites stained with acridine orange and observed under fluorescence microscopy. Metronidazole induced cyst forms (reddish cells) as early as 12 hours post-exposure; more cyst production (with stronger immunoblot bands) occurred after 24 hours exposure. However, cysts rupture with release and destruction of B. hominis daughters cells occurred after 48 hours exposure. Doxycycline induced less cyst-like forms at 24 hours (weaker 60 kDa band) and less destruction of the cysts (60 kDa band still present at 72 hours post exposure). Bacterial extract and trypticase also induced cysts at 12 hours with increasing numbers up to 72 hours exposure (corresponding increase in intensity of 60 kDa band from samples harvested at 12 to 72 hours post exposure) without any sign of deleterious effect on the parasite.

Matched MeSH terms: In Vitro Techniques
Fulltext In vitro pharmacodynamic profile of Loranthus ferrugineus: evidence for noncompetitive antagonism of norepinephrine-induced vascular contraction

Ameer OZ, Salman IM, Najim HS, Abdullah GZ, Abdulkarim MF, Yam MF, et al.

J Acupunct Meridian Stud, 2010 Dec;3(4):272-82.
PMID: 21185543 DOI: 10.1016/S2005-2901(10)60048-9

The mode by which Loranthus ferrugineus methanol extract antagonizes and/or modulates norepinephrine-induced vasoconstriction was investigated in rat aortic rings. The vascular effects of three different concentrations of this extract were challenged against cumulative additions of norepinephrine. Phentolamine, a nonselective α-adrenoceptor antagonist, verapamil, an L-type calcium channel blocker, and papaverine, a phosphodiesterase inhibitor, were used in three different concentrations as positive controls. Log concentration-response curves and double-reciprocal plots were constructed for the extract and each vasorelaxant. To characterize antagonism reversibility, the norepinephrine maximum contractile effect was examined before extract addition to the aortic ring chamber and after its removal. Phentolamine shifted the norepinephrine log concentration-response curve to the right with no significant depression in the maximum response. Similar to verapamil and papaverine, the extract produced a rightward shift in norepinephrine log concentration-response curve and a significant drop in maximum response. The double-reciprocal plots showed comparable y-intercept values for all phentolamine concentrations, a characteristic of competitive antagonism. In contrast, different y-intercept values on double-reciprocal plots were obtained for each concentration of extract, verapamil, and papaverine, typical of noncompetitive antagonism. The norepinephrine maximum contractile response was approximately similar before the addition of extract and after its removal. The data collectively showed that L. ferrugineus methanol extract exerted its vascular effect by reversible noncompetitive antagonism of norepinephrine-induced vasoconstriction. These findings add to the understanding of the cardiovascular mechanisms by which L. ferrugineus, a plant traditionally used for the management of hypertension, elicits its action.

Matched MeSH terms: In Vitro Techniques
Fulltext In vitro cholinomimetic effect of Loranthus ferrugineus in isolated guinea pig ileum

Ameer OZ, Salman IM, Siddiqui MJ, Yam MF, Sriramaneni RN, Sadikun A, et al.

J Acupunct Meridian Stud, 2009 Dec;2(4):288-93.
PMID: 20633504 DOI: 10.1016/S2005-2901(09)60070-4

This study aimed to elucidate the mechanism(s) of the spasmogenic action of Loranthus ferrugineus in isolated guinea pig ileum. Thus the contractile responses of guinea pig ileum to graded additions of either L. ferrugineus methanol extract or its n-butanol fraction were tested in the presence and absence of various pharmacological interventions. The data showed that L. ferrugineus methanol extract and the n-butanol fraction produced a concentration-dependent spasmogenic effect in isolated guinea pig ileum segments. These effects were significantly inhibited in the presence of 1 microM atropine. In contrast, the response to the lowest concentrations of L. ferrugineus methanol extract (0.25, 0.5 and 1 mg/mL) and n-butanol fraction of L. ferrugineus (0.125, 0.25 and 0.5 mg/mL) were considerably enhanced in the presence of 0.05 microM neostigmine. Neither L. ferrugineus methanol extract nor n-butanol fraction contractile responses were affected upon the incubation of the ileal segments with 100 microM hexamethonium. The results of this study show that the spasmogenic effect of L. ferrugineus is possibly mediated through a direct action on intestinal muscarinic receptors. It is suggested that the bioactive constituents of L. ferrugineus serve as a substrate for acetylcholinesterase.

Matched MeSH terms: In Vitro Techniques

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