Dibucaine inhibition of serum cholinesterase

Antioxidant and anti-cholinesterase activity of Sargassum wightii

CONTEXT

Sargassum has been used in traditional Chinese medicine since the eighth century AD to treat goiter. Sargassum wightii Greville (Sargassaceae) is a major source of alginic acid used widely in food and drug industries.

OBJECTIVE

To evaluate the anti-Alzheimer potential of S. wightii through evaluation of antioxidant and cholinesterase inhibitory activities.

MATERIALS AND METHODS

Successive extraction was done using solvents of varying polarity. Solvent extracts (100-500 µg/mL) were employed for all the antioxidant assays. Free radical scavenging activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl, OH•, H2O2 radical scavenging assay. The reducing power of the seaweed was evaluated by ferric reducing antioxidant power and reducing power assay. Cholinesterase (ChE) inhibitory activity was evaluated and the Km, Vmax and Ki were calculated. Further, compound characterization was done by GC-MS analysis.

RESULTS

The non-polar extracts were found to possess significant antioxidant activity. At 100 μg/mL, petroleum ether, hexane, benzene and dichloromethane extracts showed significant ChE inhibitory activity with IC50 values of 19.33 ± 0.56, 46.81 ± 1.62, 27.24 ± 0.90, 50.56 ± 0.90 µg/mL, respectively, for AChE, and 17.91 ± 0.65, 32.75 ± 1.00, 12.98 ± 0.31, 36.16 ± 0.64 µg/mL, respectively, for BuChE. GC-MS reveals that 1,2-benzenedicarboxylic acid, diisooctyl ester is the major compound present in dichloromethane extract of S. wightii. The mode of inhibition exhibited by dichloromethane extract against the cholinesterases was found to be competitive type.

DISCUSSION AND CONCLUSION

The presence of high amount of terpenoids could be the possible reason for its potential antioxidant and ChE inhibitory activity.

Relationship between butyrylcholinesterase activity and liver injury in mice acute infected with Toxoplasma gondii

This study aimed to investigate the butyrylcholinesterase (BChE) activity in mice experimentally infected with Toxoplasma gondii during the acute phase. Twenty mice were divided in two groups with 10 animals each: group A was composed of uninfected mice while group B was formed by rodents infected with T. gondii. Five days after infection, blood was collected and serum separated, and fragments of liver and brain were obtained. In serum and liver homogenate was noted a significant reduction (P<0.05) in BChE activity in infected mice when compared with uninfected ones. In serum was observed an increase in the activity of alanine aminotransferase and urea, associated with reduction in alkaline phosphatase activity and in the levels of total protein and albumin. Histologically, there were foci of necrosis and parasites in the forms of tachyzoites and cysts, with bradyzoites in liver samples of infected animals. Based on these results, we conclude that toxoplasmosis reduces BChE activity in mice, and this alteration is probably related to the liver damage caused by the parasitism. Therefore, this enzymatic alteration can directly contribute to the pathogenesis of the disease.

Plasma pseudo cholinesterase deficiency leading to seven hour apnoea in a child undergoing adeno-tonsillectomy

OBJECTIVE

We report a rare, silent, potentially fatal operative complication of seven hour apnoea in a patient undergoing adenotonsillectomy secondary to deficiency of plasma cholinesterase. Awareness of this hereditary disorder is important to otolaryngologist as; it is difficult to diagnose, can be unexpectedly alarming for parents and the surgeon.

METHODS

Case report and review of world literature.

RESULTS

A four-year male with obstructive sleep apnoea underwent a routine elective adenotonsillectomy; there was no spontaneous recovery of respiration following surgery. He was transferred to the intensive care unit and 7 h later was successfully weaned from the ventilator and extubated. A plasma cholinesterase level of 456 1U/L was discovered much later.

CONCLUSION

To our knowledge this is the first case report of pseudo cholinesterase deficiency reported in otolaryngology literature and first in Oman. The patient should receive information about the condition, the associated risks, inheritance and need for testing other family members.