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Effects of metal-contaminated soils on the accumulation of heavy metals in gotu kola (Centella asiatica) and the potential health risks: a study in Peninsular Malaysia

Ong GH, Wong LS, Tan AL, Yap CK

Environ Monit Assess, 2016 Jan;188(1):40.
PMID: 26687083 DOI: 10.1007/s10661-015-5042-0

Centella asiatica is a commonly used medicinal plant in Malaysia. As heavy metal accumulation in medicinal plants which are highly consumed by human is a serious issue, thus the assessment of heavy metals in C. asiatica is important for the safety of consumers. In this study, the heavy metal accumulation in C. asiatica and the potential health risks were investigated. Samples of C. asiatica and surface soils were collected from nine different sites around Peninsular Malaysia. The concentration of six heavy metals namely Cd, Cu, Ni, Fe, Pb and Zn were determined by air-acetylene flame atomic absorption spectrophotometer (AAS). The degree of anthropogenic influence was assessed by calculating the enrichment factor (EF) and index of geoaccumulation (Igeo). The heavy metal uptake into the plant was estimated through the calculation of translocation factor (TF), bioconcentration factor (BCF) and correlation study. Estimated daily intakes (EDI) and target hazard quotients (THQ) were used to determine the potential health risk of consuming C. asiatica. The results showed that the overall surface soil was polluted by Cd, Cu and Pb, while the uptake of Zn and Ni by the plants was high. The value of EDI and THQ showed that the potential of Pb toxicity in C. asiatica was high as well. As heavy metal accumulation was confirmed in C. asiatica, daily consumption of the plant derived from polluted sites in Malaysia was not recommended.
An investigation of arsenic contamination in Peninsular Malaysia based on Centella asiatica and soil samples

Ong GH, Yap CK, Maziah M, Suhaimi H, Tan SG

Environ Monit Assess, 2013 Apr;185(4):3243-54.
PMID: 22821327 DOI: 10.1007/s10661-012-2787-6

The first objective of this study was to provide data of arsenic (As) levels in Peninsular Malaysia based on soil samples and accumulation of As in Centella asiatica collected from 12 sampling sites in Peninsular Malaysia. The second objective was to assess the accumulation of As in transplanted C. asiatica between control and semi-polluted or polluted sites. Four sites were selected which were UPM (clean site), Balakong (semi-polluted site), Seri Kembangan (semi-polluted site) and Juru (polluted site). The As concentrations of plant and soil samples were determined by Instrumental Neutron Activation Analysis. The As levels ranged from 9.38 to 57.05 μg/g dw in soils, 0.21 to 4.33 μg/g dw in leaves, 0.18 to 1.83 μg/g dw in stems and 1.32-20.76 μg/g dw in roots. All sampling sites had As levels exceeding the CCME guideline (12 μg/g dw) except for Kelantan, P. Pauh, and Senawang with P. Klang having the highest As in soil (57.05 μg/g dw). In C. asiatica, As accumulation was highest in roots followed by leaves and stems. When the As level in soils were higher, the uptake of As in plants would also be increased. After the transplantation of plants to semi-polluted and polluted sites for 3 weeks, all concentration factors were greater than 50 % of the initial As level. The elimination factor was around 39 % when the plants were transplanted back to the clean sites for 3 weeks. The findings of the present study indicated that the leaves, stems and roots of C. asiatica are ideal biomonitors of As contamination. The present data results the most comprehensive data obtained on As levels in Malaysia.
Potential human health risk assessment of heavy metals via the consumption of tilapia Oreochromis mossambicus collected from contaminated and uncontaminated ponds

Yap CK, Jusoh A, Leong WJ, Karami A, Ong GH

Environ Monit Assess, 2015 Sep;187(9):584.
PMID: 26298187 DOI: 10.1007/s10661-015-4812-z

Fish tilapia Oreochromis mossambicus were collected from a contaminated Seri Serdang (SS) pond potentially receiving domestic effluents and an uncontaminated pond from Universiti Putra Malaysia (UPM). The fish were dissected into four parts namely gills, muscles, intestines, and liver. All the fish parts were pooled and analyzed for the concentrations of Cd, Cu, Fe, Ni, Pb, and Zn. Generally, the concentrations of all metals were low in the edible muscle in comparison to the other parts of the fish. It was found that the levels of all the heavy metals in the different parts of fish collected from the SS were significantly (P<0.05) higher than those from UPM, indicating greater metal bioavailabilities in the SS pond. The sediment data also showed a similar pattern with significantly (P<0.05) higher metal concentrations in SS than in UPM, indicating higher metal contamination in SS. Potential health risk assessments based on provisional tolerable weekly intake (PTWI) and the amount of fish required to reach the PTWI values, estimated daily intake (EDI), and target hazard quotient (THQ) indicated that health risks associated with heavy metal exposure via consumption of the fish's muscles were insignificant to human. Therefore, the consumption of the edible muscles of tilapia from both ponds should pose no toxicological risk of heavy metals since their levels are also below the recommended safety guidelines. While it is advisable to discard the livers, gills, and intestines of the two tilapia fish populations before consumption, there were no potential human health risks of heavy metals to the consumers on the fish muscle part.
Barium Levels in Soils and Centella asiatica

Ong GH, Yap CK, Mahmood M, Tan SG, Hamzah S

Trop Life Sci Res, 2013 Aug;24(1):55-70.
PMID: 24575242

In this study, Centella asiatica and surface soils were collected from 12 sampling sites in Peninsular Malaysia, and the barium (Ba) concentrations were determined. The Ba concentration [μg/g dry weight (dw)] was 63.72 to 382.01 μg/g in soils while in C. asiatica, Ba concentrations ranged from 5.05 to 21.88 μg/g for roots, 3.31 to 11.22 μg/g for leaves and 2.37 to 6.14 μg/g for stems. In C. asiatica, Ba accumulation was found to be the highest in roots followed by leaves and stems. The correlation coefficients (r) of Ba between plants and soils were found to be significantly positively correlated, with the highest correlation being between roots-soils (r=0.922, p<005), followed by leaves-soils (r=0.890, p<005) and stems-soils (r=0.848, p<005). This indicates that these three parts of C. asiatica are good biomonitors of Ba pollution. For the transplantation study, four sites were selected as unpolluted [(Universiti Putra Malaysia (UPM)], semi-polluted (Seri Kembangan and Balakong) and polluted sites (Juru). Based on the transplantation study under experimental field and laboratory conditions, Ba concentrations in C. asiatica were significantly (p<0.05) higher after three weeks of exposure at Seri Kembangan, Balakong and Juru. Thus, these experimental findings confirm that the leaves, stems and roots of C. asiatica can reflect the Ba levels in the soils where this plant is found. Three weeks after back transplantation to clean soils, the Ba levels in C. asiatica were still higher than the initial Ba level even though Ba elimination occurred. In conclusion, the leaves, stems and roots of C. asiatica are good biomonitors of Ba pollution.
Fulltext Emergency laparoscopic resection of spontaneous rupture of hepatocellular carcinoma: A case report

Khairuddin A, Ong GH, Tan JS, Johan S, Hoe VC, Sharif MS, et al.

Int J Surg Case Rep, 2020;66:104-106.
PMID: 31830742 DOI: 10.1016/j.ijscr.2019.11.055

INTRODUCTION: Laparoscopic liver resection is currently performed as a therapeutic modality in hepatocellular carcinoma (HCC). In an emergency setting such as bleeding or rupture, however it has not been well documented.
PRESENTATION OF CASE: We describe a 55-year-old lady who presented to the emergency department with epigastric pain and symptoms of anaemia for one day duration. She was normotensive but tachycardic. Blood investigations revealed haemoglobin level of 6.5 g/dL and serum alpha-fetoprotein of 3136 g/dL. Contrast enhanced computed tomography scan revealed ruptured HCC of segment 2 and 3. She underwent emergency laparoscopic resection of the ruptured HCC. The postoperative recovery was uneventful and she was discharged well on postoperative day 7. Histology confirmed a 10 cm ruptured HCC with 3 mm tumour-free resection margin.
DISCUSSION: Ruptured HCC is associated with a high mortality rate of 25-75 %. Traditional treatment involves initial stabilization and hemostasis through transarterial embolization followed by staged hepatic resection. However, laparoscopic liver resection has been shown to be superior than open surgery in terms of postoperative outcomes.
CONCLUSION: Laparoscopic resection of bleeding HCC is achievable and can be considered in the treatment algorithm of selected patients.
Fulltext Burkholderia vaccines: are we moving forward?

Choh LC, Ong GH, Vellasamy KM, Kalaiselvam K, Kang WT, Al-Maleki AR, et al.

Front Cell Infect Microbiol, 2013;3:5.
PMID: 23386999 DOI: 10.3389/fcimb.2013.00005

The genus Burkholderia consists of diverse species which includes both "friends" and "foes." Some of the "friendly" Burkholderia spp. are extensively used in the biotechnological and agricultural industry for bioremediation and biocontrol. However, several members of the genus including B. pseudomallei, B. mallei, and B. cepacia, are known to cause fatal disease in both humans and animals. B. pseudomallei and B. mallei are the causative agents of melioidosis and glanders, respectively, while B. cepacia infection is lethal to cystic fibrosis (CF) patients. Due to the high rate of infectivity and intrinsic resistance to many commonly used antibiotics, together with high mortality rate, B. mallei and B. pseudomallei are considered to be potential biological warfare agents. Treatments of the infections caused by these bacteria are often unsuccessful with frequent relapse of the infection. Thus, we are at a crucial stage of the need for Burkholderia vaccines. Although the search for a prophylactic therapy candidate continues, to date development of vaccines has not advanced beyond research to human clinical trials. In this article, we review the current research on development of safe vaccines with high efficacy against B. pseudomallei, B. mallei, and B. cepacia. It can be concluded that further research will enable elucidation of the potential benefits and risks of Burkholderia vaccines.
Molecular Characterization of Avian Infectious Bronchitis Virus Isolated in Malaysia during 2014-2016

Leow BL, Syamsiah Aini S, Faizul Fikri MY, Muhammad Redzwan S, Khoo CK, Ong GH, et al.

Trop Biomed, 2018 Dec 01;35(4):1092-1106.
PMID: 33601856

Avian Infectious Bronchitis (IB) is a highly contagious disease which can cause huge economic losses to the poultry industry. Forty five IB viruses (IBV) were isolated from poultry in Malaysia during 2014-2016. Phylogenetic analysis of the spike glycoprotein 1 (S1) gene revealed that all isolates were clustered into five distinct groups. The predominant type of IBV isolated was QX strains (47%), second was 4/91 type (27%), followed by Malaysian strain MH5365/95 (13%), Massachusetts type (11%) and finally Taiwanese strains (2%). Four types of S1 protein cleavage recognition motifs were found among the isolates which includes HRRRR, RRSRR, RRFRR and RRVRR. To our knowledge, this is the first report describing the motif RRVRR and are unique to Malaysian strains. Six IBVs were grouped in Malaysian MH5365/95 strains. Among these, one isolate was different from others where it only shared 82% identity with MH5365/95 and to others. It formed its own branch in the Malaysian cluster suggesting it may be a variant unique to Malaysia. Alignment analysis of the S1 amino acid sequences indicated that point mutations, insertions and deletions contribute to the divergence of IB variants. This study indicated at least five groups of IBV are circulating in Malaysia with most of the isolates belonged to QX strains. As new IBV variants continue to emerge, further study need to be carried out to determine whether the current available vaccine is able to give protection against the circulating virus.