title: Alleviation of lead poisoning in the brain with aqueous leaf extract of the Thunbergia laurifolia (Linn.).
abstract: We used seven groups of 8-week-old male ICR mice, with 6 mice in each group, to test if aqueous leaf extract of the Thai medicinal plant Thunbergia laurifolia Linn. (TL) protects against lead poisoning. We found that co-treatment with aqueous TL leaf extract did not affect levels of lead in blood and brain of mice given lead in drinking water at 1 g/L for 8 weeks. However, co-treatment with aqueous TL leaf extract at 100mg/kg or 200mg/kg body weight was found to alleviate adverse effects of lead on learning deficit and memory loss, evaluated with water maze swimming test. Further, increased activity of the cell-death marker enzyme caspase-3 was observed in the brain of mice treated with lead, thereby suggesting that the memory loss could be caused by lead-induced loss of neurons in the brain. Co-treatment with aqueous TL leaf extract at 100 mg/kg or 200 mg/kg body weight was found to restore the levels of caspase-3 activity and maintain total anti-oxidant capacity and anti-oxidant enzymes in the brain. TL leaf extract thus reduced neuronal cell death and memory loss caused by lead uptake in mice, and the anti-oxidant activities of the TL leaf extract might account for these effects.
authors.affiliation: School of Allied Health Sciences and Public Health, Walailak University, Nakhon-Si-Thammarat 80160, Thailand. rjitbanj@wu.ac.th
authors.forename: Jitbanjong
authors.initials: J
authors.lastname: Tangpong
authors.forename: Soisungwan
authors.initials: S
authors.lastname: Satarug
mesh_terms: D027901:Acanthaceae; D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D007854:Lead / Q000097:blood / Q000378:metabolism / Q000633:toxicity; D020263:Lead Poisoning, Nervous System / Q000188:drug therapy*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D018782:Maze Learning; D008568:Memory / Q000187:drug effects; D051379:Mice; D008813:Mice, Inbred ICR; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D018515:Plant Leaves
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D007854:Lead; D008315:Malondialdehyde