MyMedR

Displaying all 12 publications

Abstract:

Sort:

Polyphenols rich fraction of Dicranopteris linearis promotes fibroblast cell migration and proliferation in vitro

Ponnusamy Y, Chear NJ, Ramanathan S, Lai CS

J Ethnopharmacol, 2015 Jun 20;168:305-14.
PMID: 25858509 DOI: 10.1016/j.jep.2015.03.062

Dicranopteris linearis is a fern used traditionally for the treatment of skin afflictions such as external wounds, boils and ulcers. However, there are no scientific studies to date to demonstrate its ability to induce wound recovery. The objective of the present study was to explore the wound healing properties of an active fraction of D. linearis through several in vitro assays and to determine its chemical profile.
Fulltext Cholinesterase inhibitory activity and chemical constituents of Stenochlaena palustris fronds at two different stages of maturity

Chear NJ, Khaw KY, Murugaiyah V, Lai CS

J Food Drug Anal, 2016 04;24(2):358-366.
PMID: 28911590 DOI: 10.1016/j.jfda.2015.12.005

Stenochlaena palustris fronds are popular as a vegetable in Southeast Asia. The objectives of this study were to evaluate the anticholinesterase properties and phytochemical profiles of the young and mature fronds of this plant. Both types of fronds were found to have selective inhibitory effect against butyrylcholinesterase compared with acetylcholinesterase. However, different sets of compounds were responsible for their activity. In young fronds, an antibutyrylcholinesterase effect was observed in the hexane extract, which was comprised of a variety of aliphatic hydrocarbons, fatty acids, and phytosterols. In the mature fronds, inhibitory activity was observed in the methanol extract, which contained a series of kaempferol glycosides. Our results provided novel information concerning the ability of S. palustris to inhibit cholinesterase and its phytochemical profile. Further research to investigate the potential use of this plant against Alzheimer's disease is warranted, however, young and mature fronds should be distinguished due to their phytochemical differences.
An analytical method with a single extraction procedure and two separate high performance liquid chromatographic systems for the determination of artesunate, dihydroartemisinin and mefloquine in human plasma for application in clinical pharmacological studies of the drug combination

Lai CS, Nair NK, Mansor SM, Olliaro PL, Navaratnam V

J Chromatogr B Analyt Technol Biomed Life Sci, 2007 Oct 01;857(2):308-14.
PMID: 17719858

The combination of two sensitive, selective and reproducible reversed phase liquid chromatographic (RP-HPLC) methods was developed for the determination of artesunate (AS), its active metabolite dihydroartemisinin (DHA) and mefloquine (MQ) in human plasma. Solid phase extraction (SPE) of the plasma samples was carried out on Supelclean LC-18 extraction cartridges. Chromatographic separation of AS, DHA and the internal standard, artemisinin (QHS) was obtained on a Hypersil C4 column with mobile phase consisting of acetonitrile-0.05 M acetic acid adjusted to pH 5.2 with 1.0M NaOH (42:58, v/v) at the flow rate of 1.50 ml/min. The analytes were detected using an electrochemical detector operating in the reductive mode. Chromatography of MQ and the internal standard, chlorpromazine hydrochloride (CPM) was carried out on an Inertsil C8-3 column using methanol-acetonitrile-0.05 M potassium dihydrogen phosphate adjusted to pH 3.9 with 0.5% orthophosphoric acid (50:8:42, v/v/v) at a flow rate of 1.00 ml/min with ultraviolet detection at 284 nm. The mean recoveries of AS and DHA over a concentration range of 30-750 ng/0.5 ml plasma and MQ over a concentration of 75-1500 ng/0.5 ml plasma were above 80% and the accuracy ranged from 91.1 to 103.5%. The within-day coefficients of variation were 1.0-1.4% for AS, 0.4-3.4% for DHA and 0.7-1.5% for MQ. The day-to-day coefficients of variation were 1.3-7.6%, 1.8-7.8% and 2.0-3.4%, respectively. Both the lower limit of quantifications for AS and DHA were at 10 ng/0.5 ml and the lower limit of quantification for MQ was at 25 ng/0.5 ml. The limit of detections were 4 ng/0.5 ml for AS and DHA and 15 ng/0.5 ml for MQ. The method was found to be suitable for use in clinical pharmacological studies.
Chemical constituents and in vitro anticancer activity of Typhonium flagelliforme (Araceae)

Lai CS, Mas RH, Nair NK, Mansor SM, Navaratnam V

J Ethnopharmacol, 2010 Feb 3;127(2):486-94.
PMID: 19833183 DOI: 10.1016/j.jep.2009.10.009

Typhonium flagelliforme is an indigenous plant of Malaysia and is used by the local communities to treat cancer. This study aims to identify the chemical constituents of Typhonium flagelliforme particularly those which have antiproliferative properties towards human cancer cell lines.
Typhonium flagelliforme inhibits cancer cell growth in vitro and induces apoptosis: an evaluation by the bioactivity guided approach

Lai CS, Mas RH, Nair NK, Majid MI, Mansor SM, Navaratnam V

J Ethnopharmacol, 2008 Jun 19;118(1):14-20.
PMID: 18436400 DOI: 10.1016/j.jep.2008.02.034

Typhonium flagelliforme (Lodd.) Blume (Araceae) is a Malaysian plant used locally to combat cancer. In order to evaluate its antiproliferative activity in vitro and to possibly identify the active chemical constituents, a bioactivity guided study was conducted on the extracts of this plant.
A simple HPLC-DAD method for the detection and quantification of psychotropic mitragynine in Mitragyna speciosa (ketum) and its products for the application in forensic investigation

Parthasarathy S, Ramanathan S, Murugaiyah V, Hamdan MR, Said MI, Lai CS, et al.

Forensic Sci Int, 2013 Mar 10;226(1-3):183-7.
PMID: 23385139 DOI: 10.1016/j.forsciint.2013.01.014

Mitragyna speciosa, a native plant of Thailand and Malaysia known as 'ketum', is a plant of considerable interest. It exhibits strong antinociceptive effect and yet, acts like a psychostimulant. Due to the affordability and its ease of availability, the abuse of this plant as a substitute for other banned narcotics has become a major concern in many societies. In countries such as Thailand, Myanmar, Australia and Malaysia, the use of ketum is illegal. However, for a person to be charged for possessing or selling ketum, a reliable analytical method is needed in order to detect and identify the plant and its products. Mitragynine is the major alkaloid of ketum. This compound manifests its antinociceptive effects by acting on the opioid receptors. Since M. speciosa contain large quantity of mitragynine and it is exclusive to the species, the present analytical method is developed and validated for the purpose of screening ketum products based on this unique compound as the analytical marker. The method uses a HPLC-DAD system with Inertsil C8 (4.6 mm × 150 mm, 5 μm) as the column and a mixture of acetonitrile and formic acid, 50:50 (v/v), as the mobile phase. This method not only detects mitragynine, it can also be used to quantify the amount of mitragynine in the sample. The limit of detection is 0.25 μg/ml, while the limit of quantification is 0.50 μg/ml. The method is quick, simple and reliable with an accuracy of 97.27-101.74% and coefficient of variations of between 0.91 and 3.96%. The method has been tested and found suitable for the identification and quantification of mitragynine in dried plants, a variety of ketum extracts, as well as ketum drink obtained from the market.
Fulltext Anti-Tumor Action, Clinical Biochemistry Profile and Phytochemical Constituents of a Pharmacologically Active Fraction of S. crispus in NMU-Induced Rat Mammary Tumour Model

Yaacob NS, Yankuzo HM, Devaraj S, Wong JK, Lai CS

PLoS One, 2015;10(5):e0126426.
PMID: 26000968 DOI: 10.1371/journal.pone.0126426

Cancer patients seek alternative remedies such as traditional medicinal plants for safe and effective treatment and help overcome the side effects of conventional therapy. Current knowledge indicates that extracts of Strobilanthes crispus of the Acanthaceae family exhibit potent anticancer properties in vitro and are non-toxic in vivo. S. crispus was also reported to be protective against chemical hepatocarcinogenesis. We previously showed that a bioactive fraction of S. crispus leaves also synergized with tamoxifen to cause apoptosis of human breast cancer cell lines without damaging non-malignant epithelial cells. The present study aimed to evaluate the antitumor effect of S. crispus dichloromethane fraction (F3) using N-methyl-N-Nitrosourea (NMU)-induced rat mammary tumor model. Tumor regression was observed in 75% of the rats following 8-week oral administration of F3 with no secondary tumour formation and no signs of anemia or infection. However, no improvement in the liver and renal function profiles was observed. Major constituents of F3 were identified as lutein, 131-hydroxy-132-oxo-pheophytin a, campesterol, stigmasterol, β-sitosterol, pheophytin a and 132-hydroxy-pheophytin a. These compounds however, may not significantly contribute to the antitumor effect of F3.
Validation of high performance liquid chromatography-electrochemical detection methods with simultaneous extraction procedure for the determination of artesunate, dihydroartemisinin, amodiaquine and desethylamodiaquine in human plasma for application in clinical pharmacological studies of artesunate-amodiaquine drug combination

Lai CS, Nair NK, Muniandy A, Mansor SM, Olliaro PL, Navaratnam V

J Chromatogr B Analyt Technol Biomed Life Sci, 2009 Feb 15;877(5-6):558-62.
PMID: 19147417 DOI: 10.1016/j.jchromb.2008.12.037

With the expanded use of the combination of artesunate (AS) and amodiaquine (AQ) for the treatment of falciparum malaria and the abundance of products on the market, comes the need for rapid and reliable bioanalytical methods for the determination of the parent compounds and their metabolites. While the existing methods were developed for the determination of either AS or AQ in biological fluids, the current validated method allows simultaneous extraction and determination of AS and AQ in human plasma. Extraction is carried out on Supelclean LC-18 extraction cartridges where AS, its metabolite dihydroartemisinin (DHA) and the internal standard artemisinin (QHS) are separated from AQ, its metabolite desethylamodiaquine (DeAQ) and the internal standard, an isobutyl analogue of desethylamodiaquine (IB-DeAQ). AS, DHA and QHS are then analysed using Hypersil C4 column with acetonitrile-acetic acid (0.05M adjusted to pH 5.2 with 1.00M NaOH) (42:58, v/v) as mobile phase at flow rate 1.50ml/min. The analytes are detected with an electrochemical detector operating in the reductive mode. Chromatography of AQ, DeAQ and IB-DeAQ is carried out on an Inertsil C4 column with acetonitrile-KH(2)PO(4) (pH 4.0, 0.05M) (11:89, v/v) as mobile phase at flow rate 1.00ml/min. The analytes are detected by an electrochemical detector operating in the oxidative mode. The recoveries of AS, DHA, AQ and DeAQ vary between 79.1% and 104.0% over the concentration range of 50-1400ng/ml plasma. The accuracies of the determination of all the analytes are 96.8-103.9%, while the variation for within-day and day-to-day analysis are <15%. The lower limit of quantification for all the analytes is 20ng/ml and limit of detection is 8ng/ml. The method is sensitive, selective, accurate, reproducible and suited particularly for pharmacokinetic study of AS-AQ drug combination and can also be used to compare the bioavailability of different formulations, including a fixed-dose AS-AQ co-formulation.
Fulltext Anticancer activity of a sub-fraction of dichloromethane extract of Strobilanthes crispus on human breast and prostate cancer cells in vitro

Yaacob NS, Hamzah N, Nik Mohamed Kamal NN, Zainal Abidin SA, Lai CS, Navaratnam V, et al.

BMC Complement Altern Med, 2010;10:42.
PMID: 20684795 DOI: 10.1186/1472-6882-10-42

The leaves of Strobilanthes crispus (S. crispus) which is native to the regions of Madagascar to the Malay Archipelago, are used in folk medicine for their antidiabetic, diuretic, anticancer and blood pressure lowering properties. Crude extracts of this plant have been found to be cytotoxic to human cancer cell lines and protective against chemically-induced hepatocarcinogenesis in rats. In this study, the cytotoxicity of various sub-fractions of dichloromethane extract isolated from the leaves of S. crispus was determined and the anticancer activity of one of the bioactive sub-fractions, SC/D-F9, was further analysed in breast and prostate cancer cell lines.
The potentiation of beta-lactam and anti-bacterial activities of lipophilic constituents from Mesua ferrae leaves against methicillin-resistant Staphylococcus aureus

Alagasamy SV, Ramanathan S, Chear NJ, Tan WN, Ramachandram DS, Ching-Ga AT, et al.

J Complement Integr Med, 2021 Jan 01;18(2):339-345.
PMID: 34187118 DOI: 10.1515/jcim-2019-0316

OBJECTIVES: Mesua ferrae, from the family of Calophyllaceae, is traditionally used for the treatment of piles, fever and renal disorders. The present study was aimed to examine the antibacterial compounds from the leaves of M. ferrae and their β-lactam antibiotic potentiate activities against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA).
METHODS: Stigmasterol (1) and β-caryophyllene oxide (2) were isolated from the n-hexane fraction of the leaves of M. ferrae using a bioassay-guided fractionation approach.
RESULTS: The isolated compounds displayed anti-Staphylococcus and anti-MRSA activities. It is worth to note that both compounds demonstrated synergism with β-lactam antibiotics against S. aureus and MRSA. Gas chromatography-mass spectrometry (GC-MS) analysis indicated the n-hexane fraction was dominated by triterpenes and sesquiterpenes, suggesting the total antibacterial activity exhibited by the fraction.
CONCLUSION: Based on the findings, it could conclude that M. ferrae is a promising natural source for the discovery of new anti-MRSA lead compounds.
Fulltext Adrenal Insufficiency in Children With Nephrotic Syndrome on Corticosteroid Treatment

Abu Bakar K, Khalil K, Lim YN, Yap YC, Appadurai M, Sidhu S, et al.

Front Pediatr, 2020;8:164.
PMID: 32351921 DOI: 10.3389/fped.2020.00164

Background: Adrenal insufficiency can result from impaired functions at all levels of hypothalamic-pituitary-adrenal (HPA) axis. We here studied risk factors associated with adrenal insufficiency in children receiving prolonged exogenous steroid treatment for nephrotic syndrome. Method:We performed low-dose Synacthen tests (LDSTs, 0.5 μg/m2) in children with steroid-sensitive nephrotic syndrome 4-6 weeks after discontinuation of the corticosteroid therapy. We measured early morning serum cortisol levels at baseline and at intervals of 10, 20, 30, and 60 min following the stimulation test. We defined normal HPA axis stimulation responses as those with peak cortisol cut-off values >550 nmol/L. Result:We enrolled 37 children for this study research. All children enrolled had normal early morning cortisol levels. However, 13 (35.1%) demonstrated HPA axis suppression (by LDST) 4-+6 weeks after discontinuation of oral prednisolone. Nephrotic syndrome diagnosed before 5 years of age (OR, 0.75; 95% CI, 0.57-0.99; p = 0.043), and steroid-dependence [OR, 5.58; 95% confidence interval (CI), 1.06-29.34; p = 0.042] were associated with increased risk of developing adrenal suppression after steroid discontinuation. Conclusion:HPA axis suppression, may go unnoticed without proper screening. A normal early morning cortisol level (275-555 nmol/L) does not exclude adrenal insufficiency in children with steroid-sensitive nephrotic syndrome. Further screening with LDSTs, particularly in children younger than 5 years at diagnosis, may be warranted.
Effect of graphene oxide nanoparticles on in vitro growth of Fragaria x ananassa (Cameron Highlands white Strawberry) and evaluation of genetic stability using DAMD and ISSR markers

Pang WQ, Lai CS, Mad' Atari MF, Pandian BR, Mohamad Ibrahim MN, Tan ST, et al.

Plant Physiol Biochem, 2023 Nov;204:108104.
PMID: 37862933 DOI: 10.1016/j.plaphy.2023.108104

Graphene oxide (GO) is a novel nanomaterial with distinct physical properties and significant biological applications. The use of GO in plant tissue culture offers several new properties and potential applications. This research is vital due to the growing need for innovative techniques to promote plant growth, improve plant productivity and mitigate challenges posed by environmental stressors. This study focused on the rare Cameron Highlands white strawberry plants (Fragaria x ananassa) and addressed issues such as callus production during direct shoot induction and hyperhydricity. The research aimed to investigate the effects of GO on the regeneration process and genetic stability of white strawberry plants and to use molecular markers to ensure that plants propagated in vitro are true to type. For this purpose, shoot tip explants were used and different concentrations of GO (0, 2.5, 5.0, 7.5, 10 mg/L) were added to the Murashige and Skoog (MS) medium for six weeks. The results showed that the optimum concentration for promoting the development of white strawberry seedlings was 7.5 mg/L of GO. The study also revealed that the addition of 7.5 mg/L GO in combination with 8 μM TDZ to the MS medium facilitated the induction of multiple shoots. Moreover, the clonal fidelity of the in vitro plants treated with GO showed a genetic similarity of over 97%. These results confirm that lower GO concentrations improve plant development and stability. Consequently, this nanomaterial has a positive effect on the growth of strawberry plants and is therefore well suited for strawberry tissue culture.

Filters

Please provide feedback to Administrator ([email protected])

External Links