MyMedR

Displaying all 6 publications

Abstract:

Sort:

Fulltext Antioxidant and LC-QToF-MS/MS analysis of polyphenols in polar and non-polar extracts from Strobilanthes crispus and Clinacanthus nutans

Tan, H. M., Leong, K. H., Song, J., Mohd Sufian, N. S. F., Mohd Hazli, U. H. A., Chew, L. Y., et al.

International Food Research Journal, 2020;27(5):903-914.
MyJurnal

Strobilanthes crispus and Clinacanthus nutans are popular herbal plants in the Southeast
Asian region. The present work was aimed at determining the antioxidant activities and the
associated components in the leaf extracts of both species using polar and non-polar solvents
namely water, methanol, ethyl acetate, and hexane. The total phenolic content (TPC) and total
flavonoid content (TFC) were higher in the leaf extracts of S. crispus as compared to C.
nutans. Among the solvents, methanol was the best solvent in extracting the antioxidant
components for S. crispus (TPC: 159.85 ± 0.89 mg GAE/g extract and TFC: 955.47 ± 2.66 mg
RE/g extract). However, for C. nutans, its methanolic extract yielded the highest TPC (36.39
± 0.17 mg GAE/g extract), whereas ethyl acetate yielded the highest TFC (229.61 ± 7.81 mg
RE/g extract). The high levels of both TPC and TFC contributed to the antioxidant activities
of S. crispus extract as reflected in the methanolic extract attaining the highest level of
antioxidant activities, measured by ferric reducing antioxidant power (FRAP) (6.84 ± 1.12
mmol Fe2+/g extract), DPPH radical scavenging (IC50: 203.60 ± 7.28 μg/mL), and Trolox
equivalent antioxidant capacity (TEAC) (1.01 ± 0.01 mmol TE/g extract) assays. This
contrasted with C. nutans which showed lower antioxidant activities owing to its lower TPC
and TFC. Correlation analysis revealed significant correlations (p < 0.05, r = 0.915 - 0.985)
between both TPC and TFC in S. crispus and antioxidant activities. However, only TPC of C.
nutans showed a significant correlation with FRAP values (r = 0.934). Further tentative
identification of the constituents in the extracts using HPLC-ESI-QToF-MS/MS revealed the
existence of 20 polyphenolic compounds in both S. crispus and C. nutans, which were likely
responsible for their antioxidant activities. In addition, 15 polyphenolic compounds classified
as chalcones, isoflavanoids, flavones, and flavonols have not been previously reported in both
species. The methanolic extracts of both species yielded a higher content of antioxidants, with
S. crispus offering a richer source of dietary antioxidants as compared to C. nutans. However,
further study is needed to identify their bioactivities in relation to their bioactive components.
SLE mortality in an oriental population

Koh ET, Seow A, Leong KH, Chng HH

Lupus, 1997;6(1):27-31.
PMID: 9116715 DOI: 10.1177/096120339700600104

We analysed the causes of 67 deaths, over a 4 y period, in our oriental population with systemic lupus erythematosus (SLE). The median disease duration was 48 +/- 60.5 months (range 1-250 months). The mean age at diagnosis and death were 30 and 35.1 y respectively. SLE alone accounted for death in 30 patients (44.8%), infection in 27 (40.3%), pulmonary embolism in 5 (7.5%), malignancy in 4 (5.9%) and rheumatic heart disease in 1 (1.5%). The major organ involvement in those with active disease at death were SLE related thrombocytopenia (n = 23/44, 52.3%), nephritis (n = 21/44), 47.7%), cerebral lupus (n = 16/44, 36.4%), and pulmonary haemorrhage (n = 12/44, 27.3%). As in other series, SLE and infection were the principal causes of death in our population. During this 4 y period, there was no late death due to atherosclerosis.
Study site: Tan Tock Seng Hospital (TTSH), Singapore
Validation of the medical outcomes study family and marital functioning measures in SLE patients in Singapore

Thumboo J, Fong KY, Chan SP, Leong KH, Feng PH, Thio ST, et al.

Lupus, 1999;8(7):514-20.
PMID: 10483028 DOI: 10.1191/096120399678840747

OBJECTIVE: To validate the Medical Outcomes Study Family and Marital Functioning Measures (FMM and MFM) in a multi-ethnic, urban Asian population in Singapore.
METHODS: English speaking Chinese, Malay or Indian SLE patients (n=120) completed a self-administered questionnaire containing the FFM and MFM at baseline, after 2 weeks and after 6 months. Lupus activity, disease-related damage and quality of life were assessed using the British Isles Lupus Assessment Group (BILAG), Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index and SF-36 Health Survey respectively. Scale psychometric properties were assessed through factor analysis, Cronbach's alpha, quantifying test-retest differences and known-groups construct validity.
RESULTS: Factor analysis of scores obtained at baseline and after 6 months identified 3 factors corresponding to the FFM (1 factor) and the MFM (2 factors). Both scales showed acceptable internal consistency, with Cronbach's alpha of 0.95 for the FFM and 0.70 for the MFM. Mean (s.d.) test-retest differences were -0.31 (3.82) points for the FFM and -0.70 (4.26) points for the MFM. Eleven out of 13 a priori hypotheses relating both the FFM and MFM to demographic, disease and quality of life variables were confirmed, supporting the construct validity of these scales.
CONCLUSION: The FFM and MFM are valid and reliable measures of family and marital functioning in a multi-ethnic cohort of Asian SLE patients in Singapore.
Hip fracture incidence rates in Singapore 1991-1998

Koh LK, Saw SM, Lee JJ, Leong KH, Lee J, National Working Committee on Osteoporosis

Osteoporos Int, 2001;12(4):311-8.
PMID: 11420781

In this population-based study, we determined the incidence rates of hip fracture among Singapore residents aged 50 years and above. Information was obtained from a centralized database system which captured admissions with the primary diagnosis of a closed hip fracture (ICD-9 codes 820, 820.0, 820.2 and 820.8, n = 12,927) from all health care establishments in the country from 1991 to 1998 inclusive. After removing duplicates, hospital transfers, readmissions and non-acute care admissions, the total number of hip fractures was 9406. Based on the national population census 1990 (n = 464,100) and yearly population estimates, the age-adjusted hip fracture rates for 1991-1998 (per 100,000) were 152 in men and 402 in women. This was 1.5 and over 5 times higher than corresponding rates in the 1960s. From 1991 to 1998, these hip fracture rates tended to increase by 0.7% annually in men and by 1.2% annually in women. Among the three major racial groups, in men, the Chinese had significantly higher age-adjusted hip fracture rates (per 100,000): 168 (95% confidence interval (CI) 158-178) compared with 128 (95% CI 105-152) for Indians and 71 (95% CI 54-88) for Malays. A similar pattern occurred in women: 410 (95% CI 395-425), for Chinese compared with 361 (95% CI 290-432) for Indians and 264 (95% CI 225-303) for Malays. Since the 1960s, the main increases in hip fracture rates have been seen in the Chinese and Malays, with the rates in Indians appearing to decrease. Hip fracture incidence rates in Singapore have risen rapidly over the past 30-40 years, particularly in women, and are now among the highest in Asia. Significant racial differences in hip fracture rates occur within the same community. Time trends in hip fracture rates differed between races.
Measuring health-related quality of life in Singapore: normal values for the English and Chinese SF-36 Health Survey

Thumboo J, Chan SP, Machin D, Soh CH, Feng PH, Boey ML, et al.

Ann Acad Med Singap, 2002 May;31(3):366-74.
PMID: 12061299

OBJECTIVE: To determine norms for assessing Health-related Quality of Life (HRQOL) in Singapore using the Short Form 36 Health Survey (SF-36).
MATERIALS AND METHODS: Mean SF-36 scores were calculated for 24 population subgroups (categorised by age, gender, ethnicity and questionnaire language) and for subjects with self-reported co-morbid conditions using data from a community-based survey in Singapore.
RESULTS: The English and Chinese SF-36 was completed by 4122 and 1381 subjects, respectively, 58% (n = 3188) of whom had self-reported co-morbid conditions. SF-36 scores varied in subgroups differing in age, gender and ethnicity. In general, subjects with self-reported co-morbid conditions had lower SF-36 scores than those without these conditions, the magnitude of which exceeded 20 points in several instances. A method for calculation of SF-36 scores adjusted for age, gender, ethnicity and questionnaire language is described.
CONCLUSION: We present norms for English and Chinese SF-36 versions in Singapore and describe potential uses for these data in assessing HRQOL in Singapore.
The effects of ethnicity on disease patterns in 472 Orientals with systemic lupus erythematosus

Thumboo J, Fong KY, Chng HH, Koh ET, Chia HP, Leong KH, et al.

J Rheumatol, 1998 Jul;25(7):1299-304.
PMID: 9676760

OBJECTIVE: To determine the effects of ethnicity on disease manifestations in Oriental patients with systemic lupus erythematosus (SLE) and to describe the risk of developing renal or central nervous system (CNS) involvement with time.
METHODS: A retrospective study of 472 patients with SLE seen at the only Rheumatology Unit in Singapore. The effect of ethnicity on selected disease manifestations at diagnosis was assessed after adjusting for demographic variables using multiple logistic regression. The probability of developing selected disease manifestations with time was determined using the Kaplan-Meier product limit method.
RESULTS: At diagnosis, Malays had a higher risk of renal or CNS involvement than Chinese (OR 2.26, 95% CI 1.21 to 4.21, and OR 3.07, 95% CI 1.01 to 9.34, respectively), and Indians a lower risk of malar rash and a higher risk of oral ulcers than Chinese (OR 0.30, 95% CI 0.13 to 0.68, and OR 2.90, 95% CI 1.45 to 7.34, respectively). The prevalence of renal or CNS involvement in the entire cohort increased with time, reaching 75.6% (95% CI 66.1% to 85.0%) and 16.7% (95% CI 11.7% to 21.6%), respectively, after 18 years of disease.
CONCLUSION: Ethnicity influenced disease manifestations at diagnosis in this cohort of Oriental patients with SLE. Renal or CNS involvement developed in previously unaffected patients up to 18 years after diagnosis, highlighting the need for continued vigilance in patients with lupus.