BackgroundThe efficacy of Centella asiatica for incision and burn wounds are not fully understood. Here, we report the wound healing activities of sequential hexane, ethyl acetate, methanol, and water extracts of Centella asiatica in incision and partial-thickness burn wound models in rats.MethodsMale Sprague–Dawley rats weighing 250–300 g were randomly divided into incision and burn wound groups. Each group was stratified into seven subgroups: (1) untreated; (2) NSS-; (3) Tween 20®- (vehicle control); (4) hexane extract-; (5) ethyl acetate extract-; (6) methanol extract-; and (7) aqueous extract-treated groups. The test substances were applied topically once daily. The tensile strength of the incision wound was measured on the seventh day after wound infliction. The general appearance and degree of wound healing of the burn wound were assessed on Days 3, 7, 10 and 14 after burn injury and prior to histopathological evaluation.ResultsOn the seventh day after wound infliction, the tensile strength of incision wound in all extract-treated groups was significantly higher than that of the vehicle control (Tween 20®), but comparable to the NSS-treated group. The degrees of healing in the burn wound with the four extracts were significantly higher than that of the control on Days 3, 10 and 14. Histopathological findings on Day 14 after burn injury revealed prominent fibrinoid necrosis and incomplete epithelialization in the control and untreated groups, whereas fully developed epithelialization and keratinization were observed in all extract-treated groups. Analysis by thin layer chromatography demonstrated that the phyto-constituents β-sitosterol, asiatic acid, and asiaticoside and madecassocide were present in the hexane, ethyl acetate and methanol extracts, respectively.ConclusionsAll extracts of Centella asiatica facilitate the wound healing process in both incision and burn wounds. Asiatic acid in the ethyl acetate extract seemed to be the most active component for healing the wound.

ECa 233, a standardized extract of , has been found to exhibit various positive neurological effects and to have a good safety profile. The present study aimed to explore the disposition kinetics of ECa 233, containing madecassoside (53.1 %) and asiaticoside (32.3 %), in rats. The extract was intravenously or orally administered at doses from 50 to 200 mg/kg. Plasma, tissues, urine, and feces were collected at time points from 0 to 48 h after dosing. The levels of madecassoside and asiaticoside, as well as their postulated triterpenic metabolites, madecassic acid and asiatic acid, in biological samples, were simultaneously measured by liquid chromatography-tandem mass spectrometry. The results showed that all animals had a good tolerability for ECa 233, whereas madecassic and asiatic acids were found in negligible amounts after pharmacokinetic assessment. Madecassoside and asiaticoside demonstrated rather similar absorption and tissue distribution profiles. They were rapidly absorbed, reaching maximum levels within 5-15 min after oral administration, but they had poor oral bioavailability, less than 1 %. Both triterpenoids were extensively distributed in the brain, stomach, and skin within 1 h and remained there for at least 4 h after dosing. Madecassoside and asiaticoside in ECa 233 were mainly excreted as an unchanged form after being injected, and exclusively as triterpenic acid metabolites in feces after oral administration. The pharmacokinetic results obtained could provide some guidance for an appropriate dosing regimen of ECa 233 in future studies. This study also provided the first evidence demonstrating the presence of madecassoside and asiaticoside in their target tissues.

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BackgroundIn order to gain insight into neuroprotective effects of ECa 233, a standardized extract of Centella asiatica, previously demonstrated in animal models of memory impairment induced by transient global ischemia or intracerebroventricular injection of β-amyloid, the effect of ECa 233 on neurite outgrowth of human IMR-32 neuroblastoma cell line was investigated.MethodsCells were seeded and incubated with various concentrations of ECa 233. Morphometric analysis was carried out by a measurement of the longest neurite growth of cells at 24 and 48 h. Contributing signaling pathways possibly involved were subsequently elucidated by western blot analysis.ResultsWhile ECa 233 had only limited effects on cell viability, it significantly enhanced neurite outgrowth of IMR-32 cells at the concentrations of 1–100 μg/ml. Western blot analysis revealed that ECa 233 significantly upregulated the level of activated ERK1/2 and Akt of the treated cells suggesting their involvement in the neuritogenic effect observed, which was subsequently verified by the finding that an addition of their respective inhibitors could reverse the effect of ECa 233 on these cells.ConclusionsThe present study clearly demonstrated neurite outgrowth promoting activity of ECa 233. ERK1/2 and Akt signaling pathways seemed to account for the neurotrophic effect observed. In conjunction with in vivo neuroprotective effect of ECa 233 previously reported, the results obtained support further development of ECa 233 for clinical use in neuronal injury or neurodegenerative diseases.

Centella asiatica is widely considered the most important medicinal plant for treating and relieving skin diseases. Recently developed standardized extract of Centella asiatica ECa 233 has demonstrated positive effects on wound healing of incision and burn wound in rats. However, knowledge associated with wound healing mechanism of ECa 233 was scare. Therefore, this study aimed to investigate the effect and underlying molecular mechanisms of ECa 233 on the migration of a human keratinocyte cell line (HaCaT) using scratch wound healing assay. Formation of filopodia, a key protein in cell migration as well as signaling pathways possibly involved were subsequently assessed. It was found that HaCaT cell migration was significantly enhanced by ECa 233 in a concentration- and time-dependent manner. The filopodia formations were accordingly increased in exposure to ECa 233 at concentrations of 0.1-100 μg/ml. Furthermore, ECa 233 was found to significantly upregulate the expression of Rac1 and RhoA and to induce phosphorylation of FAK and Akt as well as ERK and p38 MAPK. Taken all together, it is suggestive that ECa 233 induces cell migration and subsequently promotes wound healing activity, through the activation of FAK, Akt, and MAPK signaling pathways thereby supporting the role of ECa 233 to be further developed for the clinical treatment of wound.

The aim of this study was to investigate the safety and pharmacokinetic profiles of a newly developed, standardized extract of Centella asiatica (ECa 233) capsule in healthy Thai volunteers. This study was designed as an open-labeled, 2-sequence dosage, single- and repeated-dose study investigated under fasting conditions. Plasma concentrations of the parent compounds and their relative acid metabolites were measured and pharmacokinetic parameters were calculated using noncompartmental analysis. Tolerability was assessed based on physical examinations, monitoring of vital signs, clinical laboratory tests, and any observed adverse events. A key finding of this study was that the pharmacokinetics of ECa 233 in healthy volunteers did not correspond with its pharmacokinetics in animal studies. As indicated in human pharmacokinetic parameters, maximum plasma concentration and area under the curve of the parent compounds (madecassoside and asiaticoside) were very low, while their respective metabolites (madecassic acid and asiatic acid) demonstrated higher values. Based on the pharmacokinetic results observed in the dose comparison, accumulation of active metabolites after repeated dose is highly suggestive. In addition, the asiatic acid profile showed 2-fold increase in Cmax and AUC(0–t) after increasing dose from 250 to 500 mg of ECa 233. Lastly, the safety and tolerability evaluation illustrated that single and multiple doses in both 250 and 500 mg oral administration of ECa 233 were well tolerated, and none of the volunteers discontinued their participation due to adverse effects during the study.

1. ECa 233, the standardised extract of Centella asiatica, contains not less than 80% triterpenoid glycosides, in a madecassoside:asiaticoside ratio of 1.5 (±0.5):1. 2. The pharmacokinetic comparison of madecassoside and asiaticoside was performed in rats following intravenous and oral administration of ECa 233, or an equivalent dose of the individual compounds. Blood, tissues, urine and faeces were collected after dosing to determine drug and metabolite levels using liquid chromatography-tandem mass spectrometry. 3. Our study demonstrated that plasma levels of madecassoside, and to a lesser extent asiaticoside, were higher after administration of ECa 233 than the corresponding values for the pure compounds. There was a bidirectional interconversion between asiaticoside and madecassoside consistent with the increased exposure of madecassoside and asiaticoside in ECa 233. 4. Both madecassoside and asiaticoside appeared to be widely distributed in several organs and metabolized extensively; following intravenous administration of either compound, approximately 80-90% of the dose was recovered as madecassic acid and asiatic acid in the faeces.

The herb Centella asiatica has long been considered a memory tonic. A recent review found no strong evidence for improvement of cognitive function, suggesting negative results were due to limitations in dose, standardization and product variation. We used a standardized extract of C. asiatica (ECa 233) to study behavioral, cellular and molecular effects on learning and memory enhancement. ECa 233 (10, 30, and 100 mg/kg) was given orally to normal rats twice a day for 30 days. We used the Morris water maze to test spatial learning and performed acute brain slice recording to measure changes of synaptic plasticity in the hippocampus, a core brain region for memory formation. Plasticity-related protein expressions (NR2A, NR2B, PSD-95, BDNF and TrkB) in hippocampus was also measured. Rats receiving 10 and 30 mg/kg doses showed significantly enhanced memory retention, and hippocampal long-term potentiation; however, only the 30 mg/kg dose showed increased plasticity-related proteins. There was an inverted U-shaped response of ECa 233 on memory enhancement; 30 mg/kg maximally enhanced memory retention with an increase of synaptic plasticity and plasticity-related proteins in hippocampus. Our data clearly support the beneficial effect on memory retention of a standardized extract of Centella asiatica within a specific therapeutic range.