Centella asiatica (CA) has been used as a nutritional plant as well as a traditional herbal medicine around the world. This study, quality component (proximate composition, total polyphenol, and triterpenoid compound), and antioxidant and anti-inflammatory activities of CA dried using various methods were investigated. Proximate compositions of CA with different drying methods included a large amount of carbohydrates, crude protein, crude ash, and crude fiber. Among the drying methods, cold drying provided the highest total polyphenol content and antioxidant activity, while hot-air drying at 75℃ provided the lowest total polyphenol content and antioxidant activity. In addition, when the major triterpenoid compounds of CA were analyzed, the highest content of asiaticoside of triterpenoid glycoside was obtained with all drying methods. With respect to the total triterpenoid, the highest content was obtained with cold drying (68.8 mg/g) whereas natural drying (31.4 mg/g) provided the lowest content. In anti-inflammatory activity of LPS-stimulated RAW 264.7 cells, EtOH extract of cold drying showed a significantly higher inhibitory activity in comparison to the other drying methods. In conclusion, it is considered that the cold drying method is suitable for industrial preparation of functional materials with high physiological ingredients, and antioxidant and anti-inflammatory activities from CA.

After ethanol (BM-E and RW-E) and hot-water (BM-HW and RW-HW) extracts were fractionated from two herbal mixtures (BM and RW), their physiological activities were investigated. All extracts consisted of more than 50% of neutral sugar, with their total polyphenol levels higher than flavonoid levels. Radical scavenging activities of EtOH extracts remained significantly higher compared to that of hot-water extracts, and in particular, RW-E showed consistently higher antioxidant activity than BM-E. When anti-inflammatory activities of the extracts were evaluated by LPS-stimulated RAW 264.7 cells at 10~500 μg/mL non-cytotoxicity doses, BM-E showed significantly higher levels of TNF-α, IL-1β, IL-6, and nitric oxide inhibitory activity than those of hot-water extracts and RW-E. Murine peritoneal macrophage cells were shown to be enhanced in crude polysaccharides (BM-CP and RW-CP fractionated from BM-HW and RW-HW) compared to hot-water extracts and polysaccharide K (PSK, positive control). Especially, RW-CP exhibited higher activity than BM-CP, and component sugar analysis showed that BM-CP mainly contained galacturonic acid, glucose, arabinose, galactose, and xylose (34.5%, 33.9%, 16.1%, 7.1%, and 6.3%, respectively), whereas RW-CP showed different measurements (29.5%, 59.2%, 5.0%, 4.5%, and 0.2%). In conclusion, two herbal mixtures could contain varying sets of physiological activities dependent on different extraction and fractionation methods.

Centella asiatica (CA) has been widely used as herbal plants. It is a valuable resources. The aim of the present study was to evaluate physiological activities of solvent extracts from CA cultivated in Chungju, Korea (Good tiger care). After preparing water (cold-water, CA-WE; hot-water, CA-HWE) and EtOH extracts (50% EtOH, CA-50E; 70% EtOH, CA-70E), their total polyphenol, flavonoid, and triterpenoid contents, and anti-oxidant activities, and anti-inflammatory activities were examined and compared. CA-70E showed the most potent anti-oxidant activity based on ABTS radical scavenging activity and reducing ability assays, while CA-50E and CA-70E showed the highest DPPH radical scavenging activity. Among major triterpenoid glycosides present in CA, madecassoside and asiaticoside contents were found to be the highest in CA-70E, and madecassic acid and asiatic acid were the highest in CA-50E. In LPS-stimulated RAW 264.7 cells, CA-70E showed the highest TNF-α inhibitory activity, although CA-50E and CA-70E similarly inhibited nitric oxide production. Ethanol extracts significantly inhibited IL-6 and IL-8 production more than water extracts using TNF-α/IFN-γ-stimulated HaCaT cells, indicating its better inhibitory against skin inflammation. Therefore, Chungju-CA EtOH extract, especially 70% EtOH extract, has high physiologically active ingredients and potent anti-oxidant and anti-inflammatory activities, suggesting its industrial application as a functional material.