Portulaca oleracea L. exhibits increased memory ability in rats

Alzheimer disease (AD) is a complex mental illness, which is characterized by an age-dependent loss of memory. Natural products are one of the most probable sources for discovering effective treatments for neurodegenerative disorders (ND). Many studies have shown that natural antioxidants from plant sources can effectively reduce the risk of ND. Portulaca oleracea L. is used in traditional Persian medicine to support the brain. The protective effect of P. oleracea was tested already in vitro and considerable results were obtained from the oxidative stress test on PC12 nerve cells (MTT cell viability assay (p < 0.0005)) [1]. The aim of our study was to investigate potential activity for pretreatment of ND.

Aerial parts of P. oleracea were collected in Iran and air dried under shade for 4 weeks. Crushed drug was extracted by maceration (20 °C) using 70% aqueous ethanol for 48 hours. The dried semisolid POEE (Portulaca oleracea ethanolic extract, yield 11.4%) was then prepared for gavage feeding.

Wistar rats were divided into five groups and were treated daily for 14 days as follows: Group-1 was nourished with normal water (control). Four other groups received EEPO orally at the doses of 100-, 200-, 400- and 800 mg/kg, respectively. The spatial memory and the learning ability were tested by using the Morris Water Maze method (MWM). POEE showed significant dose dependent effects at the dose of 400 mg/kg (p = 0.004) and 800 mg/kg (p = 0.03) by improving the memory capability. This extract may be an option for pretreatment of AD because of the already known ability to reduce oxidative stress on nerves cells plus the finding that it shows efficacy on memory ability in rats.

Fig. 1

Tab. 1: Multiple Comparisons

Dependent Variable: prob
			Mean Difference			95% Confidence Interval
	(I) group	(J) group	(I-J)	Std. Error	Sig.	Lower Bound	Upper Bound
	4	1	7.92571*	2.50754	.004	2.7385	13.1130
LSD
		2	560800*	2.68372	.048	.0563	11 1597
		3	4.96000	2.58241	.067	-.3821	10.3021
		5	2 78667	2.58241	292	-2 5555	8 1288
	5	1	513905"	2 22576	.030	.5347	9 7434
		2	2 82133	242252	256	-2 1900	7.8327
		3	2 17333	2.30978	357	-2 6048	6 9515
		4	-2 78667	2 58241	292	-8 1288	2 5555
Group 1: cont. Group 2: 100 mg/kg Group 3: 200 mg/kg Group 4: 400 mg/kg Group 5: 800 mg/kg

Reference:

[1] Shabnam Sarshar and Hasan Rafati, Neuroprotective effects of portulaca total extract and its major fractions, 15th International Congress "PHYTOPHARM 2011" abstracts book, 95 – 96