1. To prepare an approximate 1 molar solution of sodium hydroxide -

dissolve 40 gm (1 mole) of NaOH (sodium hydroxide) in 1 L of distilled water. It is more convenient to prepare an approximate NaOH solution at approximately 1 M strength, as 40 g of NaOH is a convenient quantity to weigh.

Note: Only an approximate concentration of NaOH soln. can be prepared, which will then have to be standardised.

2. To prepare a 0.1M NaOH solution. -

· Dilute a standardised 1.0 M NaOH solution by a factor of 10

· or, Dilute a non standardised 1.0 M NaOH solution by a factor of 10 and then standardise.

· or, dissolve 4 gm NaOH in 1 L of distilled water (a less accurate option also requiring standardisation)

· It is more convenient to prepare and store an approximate NaOH solution at ~ 0.1 M strength, as -

· this is the concentration used in the determination of juice and wine's titratable acidity.

· M NaOH soln. is more stable then the weaker 0.01 M NaOH soln.

· the 0.1 M NaOH soln. can then be simply diluted down by a factor of ten to a 0.01 M NaOH solution and used in SO2 analysis.

To prepare a 0.01M NaOH solution -

o Dilute a standardised 0.1 M NaOH solution by a factor of 10

o or, Dilute a non standardised 0.1 M NaOH solution by a factor of 10 and then standardise.

o or, dissolve 0.4 gm NaOH in 1 L of distilled water (a less accurate option also requiring standardisation)

All prepared and standardised NaOH solutions should be protected from the air as much as possible by -

o pouring your 1L of 0.1M NaOH in four 250mL bottles.

o Sealing the bottles when not in use.

o Re-standardise your NaOH soln. once a month or more frequently depending on exposure.

o Alternatively, using a burette, reservoir combination fitted with soda lime tubes, requiring less frequent standardisation.

Note: the 0.01M NaOH solution used in the determination of SO2 should be prepared fresh, daily, as its low strength makes it subject to a higher percentage deterioration on air exposure

Neuroprotective effects of curdione against focal cerebral ischemia reperfusion injury in rats

Curdione is one of the most highly concentrated component of the active constituents in E-zhu, which has been reported to possess a variety of activities. However, the pharmacologic neuroprotective activity of curdione has not been evaluated. The present study aimed to investigate the protective effect of curdione on focal cerebral ischemia reperfusioninduced injury in rats and further exploring the underlying mechanisms. Materials and methods: Adult male Sprague Dawley rats were subjected to middle cerebral artery occlusion (MCAO) surgery for 2 h, followed by reperfusion stage. All animals received treatment once a day for 7 days before surgery and 14 days from 4 h after the reperfusion started. The neurological deficit test and Morris water maze test were performed at 1, 4, 7 and 14 days after MCAO. The infarct size of animals was determined by the 2,3,5-triphenyltetrazolium chloride staining, and pathological brain damage was estimated by hematoxylin–eosin staining. The malonaldehyde (MDA) levels and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-PX) were detected by enzyme-linked immunosorbent assay. Expression of apoptotic proteins was measured by Western blot. Results: Our results showed that curdione could significantly reduce the infarct size and neurological deficits, promote cognitive function recovery and recover neuronal morphologic damages in MCAO rats. It also blocked the increase of MDA content and elevated the activities of SOD, CAT and GSH-PX. Moreover, curdione attenuated the expression of Cyt-C, c-caspase-3 and c-caspase-9 increased the Bcl-2/Bax ratio and hence decreased the cellular apoptosis. Conclusion: Curdione possessed potential neuroprotective effect on rats in the MCAO model. The anti-oxidative and anti-apoptotic properties may be involved in the underlying mechanisms

References

Wang H, Li Y, Jiang N, et al. Protective effect of oxysophoridine on cerebral ischemia/reperfusion injury in mice. Neural Regeneration Research. 2013;8(15):1349-1359. doi:10.3969/j.issn.1673-5374.2013.15.001.

Zhang W, Zhang Q, Deng W, et al. Neuroprotective effect of pretreatment with ganoderma lucidum in cerebral ischemia/reperfusion injury in rat hippocampus. Neural Regeneration Research. 2014;9(15):1446-1452. doi:10.4103/1673-5374.139461.

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