Inhibition of UVB-induced oxidative damage and apoptotic biochemical changes in human lymphocytes by 2,5-dihydroxy-3-undecyl-1,4-benzoquinone (embelin).
OBJECTIVE
The present study investigates the inhibition of Ultraviolet B (UVB, 290-320 nm) radiation-induced oxidative damage in peripheral blood human lymphocytes by embelin extracted from Embelia ribes.


METHODS
Embelin was extracted, purified and characterized. Prior to inhibitory assessment, a maximum concentration of embelin that was non-toxic was determined. Six experimental groups, including respective controls were made to assess the inhibitory effect of embelin for the selected concentrations of 10 and 20 μg/ml. For the experimental groups; lymphocytes (1 × 10(6) cells) were pre-treated with the chosen concentration of embelin for a period of 60 min and then exposed to UVB for 30 min. UVB radiation inhibitory effect of embelin assessed by measuring antioxidant and lipid peroxidation levels, deoxyribonucleic acid (DNA) damage, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) at scheduled time points after irradiation.


RESULTS
Pre-treatment of lymphocytes with embelin prevents UVB-induced oxidative damage. An increase in antioxidant levels in irradiated cells in the presence of embelin and UV absorbance of embelin could be the reason for the decrease in lipid peroxidation level and prevention of DNA damage by UVB radiation.


CONCLUSIONS
Embelin prevents oxidative stress induced by UVB irradiation via its antioxidant property.
Microbiology Division, Central Leather Research Institute, (CSIR, New Delhi), Adyar, Chennai, Tamil Nadu.
Narayanaswamy
N
Radhakrishnan
Arumugam
A
Gnanamani
Nagarajan Rajendra
NR
Prasad
Asit Baran
AB
Mandal
D000328:Adult; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects*; D016227:Benzoquinones / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D031645:Embelia / Q000737:chemistry; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D015227:Lipid Peroxidation / Q000187:drug effects; D008214:Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects* / Q000528:radiation effects*; D010936:Plant Extracts / Q000494:pharmacology; D011837:Radiation-Protective Agents / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D014466:Ultraviolet Rays / Q000009:adverse effects*
D000975:Antioxidants; D016227:Benzoquinones; D010936:Plant Extracts; D011837:Radiation-Protective Agents; D017382:Reactive Oxygen Species; D020782:Matrix Metalloproteinases; C010945:embelin