Nutrient intake among elderly in southern Peninsular Malaysia

Studies were conducted in selected areas in three states namely Johor (n=117, male=55, female=62), Negeri Sembilan (n=130, male=52, female=78) and Malacca (n=97, male=33, female=64) involving free living elderly (age range from 60 to 93 years old). Respondents were divided into three age cohort groups that is 60 to 69 years, 70 to 79 years and above 80 years old. Assessment of macro and micronutrients were obtained from 24-hour diet recall for three consecutive days. Household measurements were used to estimate the amount of food consumed. Mean energy intake for both sexes were lower than the Malaysian RDA. Mean energy intake were also found to decline with age increment. The percentage of carbohydrate from total calories is higher compared to fat and protein. No respondents were found to consume less than 1/3 RDA for protein. Although no significant difference in nutrient intake was noted among age cohort groups, there was a decline in the intake of protein, fat and carbohydrate. Significantly (p <0.05) lower carbohydrate intake was noted in cohort group above 80 years. As for vitamins and minerals consumption, more than 50% of the elderly population studied consumed less than 2/3 RDA for vitamin A, thiamine, riboflavin, niacin and calcium. Very low intake of nutrient may lead to many health problems. Overall mean energy intake indicate the respondents consume less than the Malaysian RDA for all three age cohort groups. Total mean energy intake were also found to decline with age increment for both sexes. Due to the low energy intake, higher percentage of elderly were found consuming less than 2/3 RDA for thiamine (65%), riboflavin (63%) and niacin (90%). Other nutrients which were also being consumed less than 2/3 RDA by the respondents are vitamin A (67%) and calcium (65%). The intake of calcium which was found to be extremely low (ranged from 277 to 303 mg) could lead to problems like osteoporosis.     

Effect of eurycomanone on cytochrome P450 isoforms CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2E1 and CYP3A4 in vitro

Eurycomanone, an active constituent isolated from Eurycoma longifolia Jack, was examined for modulatory effects on cytochrome P450 (CYP) isoforms CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2E1 and CYP3A4 using in vitro assays. The IC₅₀ value was determined to assess the potencies of modulation for each CYP isoform. Our results indicated that eurycomanone did not potently inhibit any of the CYP isoforms investigated, with IC₅₀ values greater than 250 μg/ml. Hence there appears to be little likelihood of drug–herb interaction between eurycomanone or herbal products with high content of this compound and CYP drug substrates via CYP inhibition.     

Antiplasmodial studies of Eurycoma longifolia Jack using the lactate dehydrogenase assay of Plasmodium falciparum

The roots of Eurycoma longifolia Jack have been used as traditional medicine to treat malaria. A systematic bioactivity-guided fractionation of this plant was conducted involving the determination of the effect of its various extracts and their chemical constituents on the lactate dehydrogenase activity of in vitro chloroquine-resistant Gombak A isolate and chloroquine-sensitive D10 strain of Plasmodium falciparum parasites. Their antiplasmodial activity was also compared with their known in vitro cytotoxicity against KB cells. Four quassinoids, eurycomanone (1), 13,21-dihydroeurycomanone (3), 13 alpha(21)-epoxyeurycomanone (4), eurycomalactone (6) and an alkaloid, 9-methoxycanthin-6-one (7), displayed higher antiplasmodial activity against Gombak A isolate but were less active against the D10 strain when compared with chloroquine. Amongst the compounds tested, 1 and 3 showed higher selectivity indices obtained for the cytotoxicity to antiplasmodial activity ratio than 14,15 beta-dihydroxyklaineanone (2), eurycomanol (5), 6 and 7.     

Inhibitory effects of cytochrome P450 enzymes CYP2C8, CYP2C9, CYP2C19 and CYP3A4 by Labisia pumila extracts

Ethnopharmacological relevance

Labisa pumila (LP), popularly known with its local name, Kacip Fatimah, is a well known herb grown in Indochina and Southeast Asia and is traditionally used to regain energy after giving birth in women. The propensity of LP to cause drug–herb interaction via cytochrome P450 (CYP) enzyme system has not been investigated.

Aim of the study

To evaluate the in vitro inhibitory effects of various LP extracts (aqueous, ethanol, dichloromethane (DCM) and hexane) on cytochrome P450 2C8 (CYP2C8), CYP2C9, CYP2C19 and CYP3A4 activities.

Materials and methods

Probe substrate-based high performance liquid chromatography (HPLC) methods were established for CYP2C9, CYP2C19 and CYP3A4 whereas a fluorescence-based enzyme assay was established for CYP2C8. The metabolite formations were examined after incubation of probe substrate with respective CYP isoform in the present or absent of LP extracts. The inhibitory effect of LP was characterized with kinetic parameters IC₅₀ and K_i values.

Results

LP extracts showed differential effect of CYP activities with the order of inhibitory potency as follows: dichloromethane>hexane>ethanol>aqueous. This differential effect was only observed in CYP2C isoforms but not CYP3A4. Both the hexane and DCM extracts exhibited moderate to potent inhibition towards CYP2C activities in different modes including non-competitive, competive and mixed-type. The DCM effect was notably strong for CYP2C8 and CYP2C9 showing K_i values of below 1 μg/ml. The selectivity of LP for CYP2C isoforms rather than CYP3A4 may be attributed to the presence of relatively small, lipophilic yet slightly polar compounds within the LP extracts.

Conclusions

The results of our study revealed that phytoconstituents contained in LP, particularly in hexane and dichloromethane extracts, were able to selectively inhibit CYP2C isoforms. The inactivation was characterized by low K_i values, in particular, in CYP2C8 and CYP2C9. These in vitro data indicate that LB preparations contain constituents that can potently inhibit CYP2C activities and suggest that this herb should be examined for potential pharmacokinetic drug interactions in vivo.     

Antropometric measurements of elderly

Body composition was assessed in a group of 344 free-living elderly between 60 and 89 years by means of anthropometry. The height, weight and body mass indexes of the elderly were reduced with advancing age in both the males and females. Skinfold thickness measurements also declined with age. Overall, the female elderly had a greater tricep skinfold thickness but smaller mid-arm circumferences, mid-arm muscle circumference and mid-arm muscle area compared to the male.     

Structural,optical and dielectric properties of tellurium-based double perovskite Sr2Ni1−xZnxTeO6

In this paper, Sr₂Ni_1−xZn_xTeO₆ (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) double perovskite compounds were synthesised by the conventional solid-state method, and the structural, optical and dielectric properties were investigated. The Rietveld refinement of X-ray diffraction data shows that all compounds were crystallised in monoclinic symmetry with the I2/m space group. Morphological scanning electron microscopy reported that the grain sizes decreased as the dopant increased. The UV-vis diffuse reflectance spectroscopy conducted for all samples found that the optical band gap energy, E_g, increased from 3.71 eV to 4.14 eV. The dielectric permittivity ε′ values increased for the highest Zn-doped composition, Sr₂Ni_0.2Zn_0.8TeO₆, being ∼1000 and ∼60 in the low- and high-frequency range, respectively. All samples exhibited low dielectric loss (tan δ ≤ 0.20) in the range of 10⁴–10⁵ Hz frequency. Impedance measurement revealed that grain resistance decreased with enhancement in Zn content in the Sr₂NiTeO₆ crystal lattice.

In this paper, Sr₂Ni_1−xZn_xTeO₆ (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) double perovskite compounds were synthesised by the conventional solid-state method, and the structural, optical and dielectric properties were investigated.     

Attitudes of medical students towards euthanasia in a multicultural setting

A cross-sectional survey of 400 medical students of multicultural backgrounds at the University of Malaya was conducted to understand their attitudes towards euthanasia and factors related to medical decisions and ethical reasoning concerning the prolongation of life, the right to die and euthanasia. The student respondents completed self-administered questionnaires that comprised of twelve questions with multiple stems addressing personal perceptions, knowledge, attitudes, and decisions about euthanasia and the relief of suffering. The majority of respondents (52%) were for the withdrawal of active therapy in a patient suffering from a terminal painful disease while 48% of them were against it. Seventy-one percent of the students involved in the study were against the idea of active euthanasia i.e. the administration of a lethal injection. However, 27% of the respondents felt that there was a moral justification to assist patients to die. Thirty-two percent of the respondents favoured the legalization of euthanasia in Malaysia while 67% of them were strongly against it. The majority (61%) of respondents would not practice euthanasia as a doctor nor would they have performed on themselves if or when it became legal. The main issue surrounding euthanasia that concerned the respondents was the misuse of it by unethical practitioners and they felt that further debate on the matter was essential, both within the local and international communities.     

Effects of Vanadium on the Structural and Optical Properties of Borate Glasses Containing Er3+ and Silver Nanoparticles

The erbium-vanadium co-doped borate glasses, embedded with silver nanoparticles (Ag NPs), were prepared to improve their optical properties for potential optical fiber and glass laser application. The borate glasses with composition (59.5–x) B₂O₃–20Na₂O–20CaO–xV₂O₅–Er₂O₃–0.5AgCl (x = 0–2.5 mol%) were successfully prepared by conventional melt-quenching method. The structural properties of glass samples were investigated by XRD, TEM and by Fourier transform infrared (FTIR) spectroscopy while optical properties were carried out by UV–Vis spectroscopy by measuring optical absorption and the emission properties were investigated by photoluminescence spectroscopy. The XRD patterns confirmed the amorphous nature of the prepared glass samples whilst the FTIR confirmed the presence of VO₄, VO₅, BO₃ and BO₄ vibrations. UV–Vis–NIR absorption spectra reveal eight bands which were located at 450, 490, 519, 540, 660, 780, 980, and 1550 nm corresponding to transition of ⁴F_5/2, ⁴F_7/2, ²H_11/2, ⁴S_3/2, ⁴F_9/2, ⁴I_9/2, ⁴I_11/2, and ⁴I_13/2, respectively. The optical band gap (E_opt), Urbach energy and refractive index were observed to decrease, increase and increase, respectively, to the addition of vanadium. Under 800 nm excitation, three emission bands were observed at 516, 580 and 673 nm, which are represented by ²H_11/2–⁴I_15/2, ⁴S_3/2–⁴I_15/2 and ⁴F_15/2–⁴I_15/2, respectively. The excellent features of achieved results suggest that our findings may provide useful information toward the development of functional glasses.     

Effect of Mn Doping on the Optical and Electrical Properties of Double Perovskite Sr2TiCoO6

A new series of Sr₂TiCo_1−xMn_xO₆ (0.0 ≤ x ≤ 0.7) materials has been synthesized using the conventional solid-state method. In this research, X-ray diffraction (XRD) results showed that Mn was successfully doped at the Co site in a cubic structure with monoclinic P2₁/n space group. The effect of Mn cation substitution on the structural, optical and electrical performance of Sr₂TiCo_1−xMn_xO₆ double perovskite was investigated. The optical study revealed a nonlinearity pattern of the band gap that is referred to as the band gap bowing trend. Results from optical and Rietveld refinement supports that the band gap bowing trend is correlated with the charge distribution that produces unique effects on structural and size changes due to the Co-Mn compositions. The morphological scanning electron microscopy studies also showed that larger crystallite sizes were developed when dopant was added. Furthermore, increases in the conductivities support the lowering band gap of Mn-doped samples. Here, the intermixing of the atomic orbitals of Co-Mn provides an efficient interlink electrical pathway to improve conductivity and exhibits a high dielectric property at room temperature. These values are strong evidence that STCM material will be suitable for applications in the semiconductor industry.