1.Mitochondrial neurogastrointestinal encephalomyo pathy (MNGIE) in a Malaysian patient with a novel mutation in thymidine phosphorylase gene: A case report
Kay Sin Tan ; Heng Gee Lee ; Lay Hoong Lian ; Ying Shean Lu ; Bee Chin Chen ; Chee Woon Wang ; Jayaram Menon
Neurology Asia 2012;17(2):163-168
Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare neurodegenerative
multisystem disorder inherited in an autosomal recessive manner and characterized clinically by
gastrointestinal dysmotility, cachexia, ophthalmoparesis and/or ptosis, peripheral neuropathy and
leukoencephalopathy. Heterogenous causative mutations in the thymidine phosphorylase (TP) gene
located on chromosome 22q13 have been identifi ed. This is the fi rst reported case of a 25-year-old
Malaysian patient, of indigenous Bajau ethnicity who presented with recurrent abdominal pain before
developing other clinical features of classical MNGIE. Biochemical correlates include elevated plasma
levels of thymidine, deoxyuridine and lactate. The brain MRI showed diffuse leucoencephalopathy
while nerve conduction studies were consistent with demyelinating polyneuropathy. Direct DNA
sequencing of the nine coding exons of the TP gene showed both a novel and a previously described
mutation. The former is a point mutation in exon 5 (NG_011860.1:g.7387C>T) at amino acid position
179, resulting in a stop codon and premature truncation of thymidine phosphorylase(TP) protein
while the latter mutation occurred at exon 10 (NG_011860.1:g.9279C>T) resulting in a missense
homozygous mutation at amino acid position 471. Defi nite diagnosis was based on clinical features,
plasma and urinary nucleosides and the identifi cation of mutations in the TP gene. This case report
adds to the knowledge of genotype-phenotype relationship of TP mutations and its occurrence among
ethnic groups worldwide.
2.Peperomia pellucida (L.) Kunth and eye diseases: A review on phytochemistry, pharmacology and toxicology.
Keat Lam HO ; Phaik Har YONG ; Chee Woon WANG ; Umah Rani KUPPUSAMY ; Chek Tung NGO ; Festo MASSAWE ; Zhi Xiang NG
Journal of Integrative Medicine 2022;20(4):292-304
Peperomia pellucida (L.) Kunth is a medicinal plant used to manage inflammatory illnesses such as conjunctivitis, and gastrointestinal and respiratory tract disorders in tropical and subtropical regions. However, little is known about its pharmacological mechanism of action against eye diseases. This review aims to critically discuss the phytochemistry, pharmacology and toxicology of P. pellucida as well as its roles in the treatment of cataract, glaucoma and diabetic retinopathy. Recent developments in the uses of P. pellucida for healthcare and nutraceutical products by the pharmaceutical industry are also covered in this review. For this review, a literature search was performed with PubMed, ScienceDirect, SciFinder Scholar and Scopus databases, using relevant keywords. Among the various phytochemicals identified from P. pellucida, β-caryophyllene, carotol, dillapiole, ellagic acid, pellucidin A, phytol and vitexin exhibit strong pharmacological activities within the mitogen-activated protein kinase and nuclear factor-κB signalling pathways in inflammatory eye diseases. The antihypertensive, anti-inflammatory, antioxidant, antihyperglycemic and anti-angiogenic activities displayed by P. pellucida extracts in many in vitro, in vivo and clinical studies suggest its potential role in the management of inflammatory eye diseases. P. pellucida extract was non-toxic against normal cell lines but displayed mild toxicity in animal models. The growing public interest in P. pellucida has inspired the nutraceutical and pharmaceutical industries to process the plant into health products. Although the potential pharmacological mechanisms against eye diseases have been summarized, further studies of the interactions among constituent phytochemicals from P. pellucida within various signalling pathways shall support the use of the plant as an alternative therapeutic source.
Animals
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Ethnopharmacology
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Eye Diseases/drug therapy*
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Peperomia
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Phytochemicals/therapeutic use*
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Phytotherapy
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Plant Extracts/therapeutic use*
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Plants, Medicinal