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Effect of Astragalus membranaceus in rats on peripheral nerve regeneration: in vitro and in vivo studies.Lu MC, Yao CH, Wang SH, Lai YL, Tsai CC, Chen YS.
School of Post Baccalaureate Chinese Medicine, Changhua Christian Hospital, Changhua. lumc@mail.cmu.edu.tw
BACKGROUND: This study provides in vitro and in vivo evaluation of Astragalus membranaceus (AM) on peripheral nerve regeneration. METHODS: In the in vitro study, we analyzed the effects of AM on cell differentiation and neurite outgrowth by using a PC12 cell model. In the in vivo study, silicone rubber chambers filled with the AM water extract were used to bridge a 10-mm sciatic nerve defect in rats. RESULTS: We found that the AM water extract caused a marked enhancement of the nerve growth factor-mediated neurite outgrowth and the expression of growth-associated protein 43 from PC12 cells. Animals from the groups treated with the AM for 8 weeks had a relatively more mature structure with larger mean values of myelinated axon number, endoneurial area, and total nerve area when compared with those in the controls receiving the saline only. CONCLUSION: These results suggest that the silicone rubber tubes present a good framework for the nerve fibers to regenerate across the gap, and the AM extract can be a potential nerve growth-promoting factor, being salutary in aiding the growth of axons in the peripheral nerve.
AM can also inhibit
AGe formation.
<h1 class="title">Centella asiatica accelerates nerve regeneration upon oral administration and contains multiple active fractions increasing neurite elongation in-vitro.</h1>Soumyanath A, Zhong YP, Gold SA, Yu X, Koop DR, Bourdette D, Gold BG.
Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland OR 97239, USA.
Axonal regeneration is important for functional recovery following nerve damage. Centella asiatica Urban herb, also known as Hydrocotyle asiatica L., has been used in Ayurvedic medicine for centuries as a nerve tonic. Here, we show that Centella asiatica ethanolic extract (100 microg mL-1) elicits a marked increase in neurite outgrowth in human SH-SY5Y cells in the presence of nerve growth factor (NGF). However, a water extract of Centella was ineffective at 100 microg mL-1. Sub-fractions of Centella ethanolic extract, obtained through silica-gel chromatography, were tested (100 microg mL-1) for neurite elongation in the presence of NGF. Greatest activity was found with a non-polar fraction (GKF4). Relatively polar fractions (GKF10 to GKF13) also showed activity, albeit less than GKF4. Thus, Centella contains more than one active component. Asiatic acid (AA), a triterpenoid compound found in Centella ethanolic extract and GKF4, showed marked activity at 1 microM (microg mL-1). AA was not present in GKF10 to GKF13, further indicating that other active components must be present. Neurite elongation by AA was completely blocked by the extracellular-signal-regulated kinase (ERK) pathway inhibitor PD 098059 (10 microM). Male Sprague-Dawley rats given Centella ethanolic extract in their drinking water (300-330 mg kg-1 daily) demonstrated more rapid functional recovery and increased axonal regeneration (larger calibre axons and greater numbers of myelinated axons) compared with controls, indicating that the axons grew at a faster rate. Taken together, our findings indicate that components in Centella ethanolic extract may be useful for accelerating repair of damaged neurons.
Edited by Lufega, 03 March 2010 - 04:36 PM.