Lay Kek Teh

Hepatoprotective Activity of Dried- and Fermented-Processed Virgin Coconut Oil

The present study aims to determine the hepatoprotective effect of MARDI-produced virgin coconut oils, prepared by dried- or fermented-processed methods, using the paracetamol-induced liver damage in rats. Liver injury induced by 3 g/kg paracetamol increased the liver weight per 100 g bodyweight indicating liver damage. Histological observation also confirms liver damage indicated by the presence of inflammations and necrosis on the respective liver section. Interestingly, pretreatment of the rats with 10, but not 1 and 5, mL/kg of both VCOs significantly (P < .05) reduced the liver damage caused by the administration of paracetamol, which is further confirmed by the histological findings. In conclusion, VCO possessed hepatoprotective effect that requires further in-depth study.

The relevance of CYP2D6 genetic polymorphism on chronic metoprolol therapy in cardiovascular patients.

Background and objective:  CYP2D6 polymorphisms are well described in normal populations but there are few data on its clinical significance. We therefore investigated the influence of CYP2D6 polymorphism on steady‐state plasma concentrations and apparent oral clearance of metoprolol in patients with cardiovascular diseases.

Heterogeneity of the CYP2D6 gene among Malays in Malaysia.

Background: Although Malays shared an origin with Chinese, their evolution saw substantial divergences. Phenotyping studies suggested that they differed in CYP2D6 polymorphism, with higher PM prevalence but lesser right‐shift for debrisoquine MRs.

In vitro antiproliferative and antioxidant activities of the extracts of Muntingia calabura leaves.

The in vitro antiproliferative and antioxidant activities of the aqueous, chloroform and methanol extracts of Muntingia calabura leaves were determined in the present study. Assessed using the 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay, the aqueous and methanol extracts of M. calabura inhibited the proliferation of MCF-7, HeLa, HT-29, HL-60 and K-562 cancer cells while the chloroform extract only inhibited the proliferation of MCF-7, HeLa, HL-60 and K-562 cancer cells. Interestingly, all extracts of M. calabura, which failed to inhibit the MDA-MB-231 cells proliferation, did not inhibit the proliferation of 3T3 (normal) cells, indicating its safety. All extracts (20, 100 and 500 μg/ml) were found to possess antioxidant activity when tested using the DPPH radical scavenging and superoxide scavenging assays with the methanol, followed by the aqueous and chloroform, extract exhibiting the highest antioxidant activity in both assays. The total phenolic content for the aqueous, methanol and chloroform extracts were 2970.4 ± 6.6, 1279.9 ± 6.1 and 2978.1 ± 4.3 mg/100 g gallic acid, respectively. In conclusion, the M. calabura leaves possess potential antiproliferative and antioxidant activities that could be attributed to its high content of phenolic compounds, and thus, needs to be further explored.

In Vitro Antiproliferative and Antioxidant Activities and Total Phenolic Contents of the Extracts of Melastoma malabathricum Leaves

The present study aims to determine the in vitro antiproliferative and antioxidant activities of various extracts from the leaves of Melastoma malabathricum using various established in vitro assays. The aqueous extract inhibited the proliferation of Caov-3 and HL-60 cell lines, while the chloroform extract exhibited antiproliferative activity against the Caov-3, HL-60, and CEM-SS cell lines. The methanol extract demonstrated antiproliferative activity against more cell lines, including the MCF-7, HeLa, Caov-3, HL-60, CEM-SS, and MDA-MB-231 cancer cell lines. Interestingly, all extracts did not inhibit the proliferation of 3T3 cells, thus indicating their noncytotoxic properties. Unlike the chloroform extracts, the aqueous and methanol extracts of M malabathricum (20, 100, and 500 μg/ml) produced high antioxidant activity for the superoxide scavenging assay with only the 500 μg/ml aqueous and methanol extracts exhibited high activity for the 2,2-diphenyl -1-picrylhydrazyl radical scavenging assay. The total phenolic content recorded for the aqueous, methanol, and chloroform extracts were 3344.2 ± 19.1, 3055.1 ± 8.7, and 92.5 ± 7.3 mg/100 g of gallic acid, respectively. The M malabathricum leaves possessed potential antiproliferative and antioxidant activities that could be attributed to its high content of phenolic compounds.

Polymorphism of ITPA 94C>A and risk of adverse effects among patients with acute lymphoblastic leukaemia treated with 6-mercaptopurine

What is known and Objective:  Genetic polymorphisms of thiopurine S‐methyltransferase (TPMT) and inosine triphosphate pyrophosphohydrolase (ITPA 94C>A) contribute to variable responses, including fatal adverse effects, among subjects treated with 6‐mercaptopurine (6‐MP). Our objectives were to investigate the distribution of specific TPMT and ITPA genotypes in healthy subjects and patients with acute lymphoblastic leukaemia (ALL) from the three main ethnic groups (Malays, Chinese and Indians) in Malaysia and the association of the polymorphisms with adverse effects of 6‐MP.

In vivo antiulcer activity of the aqueous extract of Bauhinia purpurea leaf

ETHNOPHARMACOLOGICAL RELEVANCE Bauhinia purpurea (Fabaceae) is a medicinal plant traditionally used to treat various ailments, including ulcers. In order to establish pharmacological properties of the leaf of Bauhinia purpurea, studies were performed on antiulcer activity of the plants aqueous extract. MATERIALS AND METHODS The Bauhinia purpurea aqueous extract (BPAE) was prepared in the doses of 100, 500 and 1,000 mg/kg. Antiulcer activity of BPAE was evaluated by absolute ethanol- and indomethacin-induced gastric ulcer, and pyloric ligation models. Acute toxicity was also carried out. RESULTS BPAE, at the dose of 5,000 mg/kg, did not cause any signs of toxicity to rats when given orally. Oral administration of BPAE exhibited antiulcer activity (p<0.05) in all models used. However, the dose-dependent activity was observed only in the absolute ethanol-induced gastric ulcer model. Histological studies supported the observed antiulcer activity of BPAE. In pyloric ligation assay, BPAE increased the gastric wall mucus secretion. CONCLUSIONS The BPAE exhibits antiulcer activity, which could be due to the presence of saponins or sugar-free polyphenols, and, thus, confirmed the traditional uses of Bauhinia purpurea in the treatment of ulcers.

Antinociceptive Activity of Methanol Extract of Muntingia calabura Leaves and the Mechanisms of Action Involved

Muntingia calabura L. (family Elaeocarpaceae) has been traditionally used to relieve various pain-related ailments. The present study aimed to determine the antinociceptive activity of methanol extract of M. calabura leaves (MEMC) and to elucidate the possible mechanism of antinociception involved. The in vivo chemicals (acetic acid-induced abdominal constriction and formalin-, capsaicin-, glutamate-, serotonin-induced paw licking test) and thermal (hot plate test) models of nociception were used to evaluate the extract antinociceptive activity. The extract (100, 250, and 500 mg/kg) was administered orally 60 min prior to subjection to the respective test. The results obtained demonstrated that MEMC produced significant (P < 0.05) antinociceptive response in all the chemical- and thermal-induced nociception models, which was reversed after pretreatment with 5 mg/kg naloxone, a non-selective opioid antagonist. Furthermore, pretreatment with L-arginine (a nitric oxide (NO) donor), NG-nitro-L-arginine methyl esters (L-NAME; an inhibitor of NO synthase (NOS)), methylene blue (MB; an inhibitor of cyclic-guanosine monophosphate (cGMP) pathway), or their combination also caused significant (P < 0.05) change in the intensity of the MEMC antinociception. In conclusion, the MEMC antinociceptive activity involves activation of the peripheral and central mechanisms, and modulation via, partly, the opioid receptors and NO/cGMP pathway.

In vivo Antinociceptive and Anti-inflammatory Activities of Dried and Fermented Processed Virgin Coconut Oil

Objective: The present study was carried out to investigate the antinociceptive and anti-inflammatory activities of virgin coconut oil (VCO) produced by theMalaysian Agriculture Research and Development Institute (MARDI) using various in vivo models. Materials and Methods: Two types of VCOs, produced via standard drying (VCOA) and fermentation (VCOB) processes were used in this study. Both VCOA and VCOB were serially diluted using 1% Tween 80 to concentrations (v/v) of 10, 50 and 100%. Antinociceptive and anti- inflammatory activities of both VCOs were examined using various in vivomodel systems. The antinociceptive activity of the VCOs were compared to those of 1% Tween 80 (used as a negative control), morphine (5 mg/kg) and/or acetylsalicylic acid (100 mg/kg). Results: Both VCOA and VCOB exhibited significant (p < 0.05) dose-dependent antinociceptive activity in the acetic acid-induced writhing test. Both VCOs also exerted significant (p < 0.05) antinociceptive activity in both phases of the formalin and hot-plate tests. Interestingly, the VCOs exhibited anti-inflammatory activity in an acute (carrageenan-induced paw edema test), but not in a chronic (cotton-pellet-induced granuloma test) model of inflammation. Conclusion: The MARDI-produced VCOs possessed antinociceptive and anti-inflammatory activities. Further studies are needed to confirm these observations.

Malaysian Indians are genetically similar to Caucasians: CYP2C9 polymorphism.

Background:  CYP2C9 is one of the major drug metabolizing enzymes for many drugs including warfarin, NSAIDs and losartan. It is polymorphic in many populations. Data on the distribution of CYP2C9 and the implication of CYP2C9 polymorphism in the Malaysian population is lacking. Our objectives were therefore to investigate the prevalence of CYP2C9 variants among unrelated healthy volunteers of Malays, Chinese and Indians in Malaysia.