ABSTRACT
BACKGROUND@#Centella asiatica (L.) is a plant with neuroprotective and neuroregenerative properties; however, its effects on the neurodifferentiation of mesenchymal stem cells (MSCs) and on peripheral nerve injury are poorly explored. This study aimed to investigate the effects of C. asiatica (L.)-neurodifferentiated MSCs on the regeneration of peripheral nerve in a critical-size defect animal model. @*METHODS@#Nerve conduit was developed using decellularised artery seeded with C. asiatica-neurodifferentiated MSCs (ndMSCs). A 1.5 cm sciatic nerve injury in Sprague–Dawley rat was bridged with reversed autograft (RA) (n = 3, the gold standard treatment), MSC-seeded conduit (MC) (n = 4) or ndMSC-seeded conduit (NC) (n> = 4). Pinch test and nerve conduction study were performed every 2 weeks for a total of 12 weeks. At the 12th week, the conduits were examined by histology and transmission electron microscopy. @*RESULTS@#NC implantation improved the rats’ sensory sensitivity in a similar manner to RA. At the 12th week, nerve conduction velocity was the highest in NC compared with that of RA and MC. Axonal regeneration was enhanced in NC and RA as shown by the expression of myelin basic protein (MBP). The average number of myelinated axons was significantly higher in NC than in MC but significantly lower than in RA. The myelin sheath thickness was higher in NC than in MC but lower than in RA. @*CONCLUSION@#NC showed promising effects on nerve regeneration and functional restoration similar to those of RA. These findings revealed the neuroregenerative properties of C. asiatica and its potential as an alternative strategy for the treatment of critical size nerve defect.
ABSTRACT
Introduction: Collagen type I is widely used as a biomaterial for tissue-engineered substitutes. This study aimed to fabricate different three-dimensional (3D) scaffolds using ovine tendon collagen type I (OTC-I), and compare the attachment, proliferation and morphological features of human dermal fibroblasts (HDF) on the scaffolds. Methods: This study was conducted between the years 2014 to 2016 at the Tissue Engineering Centre, UKM Medical Centre. OTC-I was extracted from ovine tendon, and fabricated into 3D scaffolds in the form of sponge, hydrogel and film. A polystyrene surface coated with OTC-I was used as the 2D culture condition. Genipin was used to crosslink the OTC-I. A noncoated polystyrene surface was used as a control. The mechanical strength of OTC-I scaffolds was evaluated. Attachment, proliferation and morphological features of HDF were assessed and compared between conditions. Results: The mechanical strength of OTC-I sponge was significantly higher than that of the other scaffolds. OTC-I scaffolds and the coated surface significantly enhanced HDF attachment and proliferation compared to the control, but no differences were observed between the scaffolds and coated surface. In contrast, the morphological features of HDF including spreading, filopodia, lamellipodia and actin cytoskeletal formation differed between conditions. Conclusion: OTC-I can be moulded into various scaffolds that are biocompatible and thus could be suitable as scaffolds for developing tissue substitutes for clinical applications and in vitro tissue models. However, further study is required to determine the effect of morphological properties on the functional and molecular properties of HDF.
ABSTRACT
Centella asiatica, locally well known in Malaysia as pegaga, is a traditional herb that has been used widely in Ayurvedic medicine, traditional Chinese medicine, and in the traditional medicine of other Southeast Asian countries including Malaysia. Although consumption of the plant is indicated for various illnesses, its potential neuroprotective properties have been well studied and documented. In addition to past studies, recent studies also discovered and/or reconfirmed that C. asiatica acts as an antioxidant, reducing the effect of oxidative stress in vitro and in vivo. At the in vitro level, C. asiatica promotes dendrite arborisation and elongation, and also protects the neurons from apoptosis. In vivo studies have shown that the whole extract and also individual compounds of C. asiatica have a protective effect against various neurological diseases. Most of the in vivo studies on neuroprotective effects have focused on Alzheimer’s disease, Parkinson’s disease, learning and memory enhancement, neurotoxicity and other mental illnesses such as depression and anxiety, and epilepsy. Recent studies have embarked on finding the molecular mechanism of neuroprotection by C. asiatica extract. However, the capability of C. asiatica in enhancing neuroregeneration has not been studied much and is limited to the regeneration of crushed sciatic nerves and protection from neuronal injury in hypoxia conditions. More studies are still needed to identify the compounds and the mechanism of action of C. asiatica that are particularly involved in neuroprotection and neuroregeneration. Furthermore, the extraction method, biochemical profile and dosage information of the C. asiatica extract need to be standardised to enhance the economic value of this traditional herb and to accelerate the entry of C. asiatica extracts into modern medicine.