Glucose lowering effect of standardized extract of centella asiatica ECa233 in vitro and in vivo Thai silk worm model / Piyanuch Worachat = ฤทธิ์ลดระดับน้ำตาลของสารสกัดมาตรฐานบัวบก อีซีเอ 233 ในการศึกษาแบบนอกกายและแบบในกายหนอนไหมไทย / ปิยนุช วรฉัตร
This study aims to test the effect of ECa 233 and some compounds (asiaticoside and madecassoside) in lowering glucose by the mechanism of inhibition of α-glucosidase both in vitro and in vivo using Thai silkworm model. In vitro study was utilized to evaluate the inhibition of yeast and intestinal α-glucosidase from rat of the test compounds and determine the IC₅₀ value. Acarbose, ECa 233, asiaticoside and madecassoside showed the inhibition of yeast α-glucosidase with IC₅₀ value 0.0008, >500, 92.42 and 68.89 mg/ml, respectively and inhibition of intestinal α-glucosidase from rat with IC₅₀ value 0.005, 205.61, 21.81 and 50.52 mg/ml, respectively. In vivo study in Thai silkworm model was used to test the toxicity and determine the LD₅₀, the results showed that the LD₅₀ value of ECa 233, asiaticoside and madecassoside injected via intra-midgut in Thai silkworm was 178.51, >125 and >250 mg/ml, respectively and the LD₅₀ value of ECa 233, asiaticoside and madecassoside injected via intra-hemolymph in Thai silkworm was 46.92, >125 and 174.58 mg/ml, respectively. Then the hypoglycemic effect of the test compounds was determined using hyperglycemic Thai silkworm model induced by feeding diet mixed with 10% glucose or 10% sucrose or 10% maltose. It was found that sugar level in Thai silkworm hemolymph fed with 10% glucose, 10% sucrose and 10% maltose diet lowered with statistical significance using insulin comparing with the control group (P< 0.05). Acarbose also lowered the sugar level in diet mixed with 10% sucrose and 10% maltose diet with statistical significance comparing with the control group (P< 0.05). For intra-midgut administration, asiaticoside (50 mg/ml) and madecassoside (5, 50 mg/ml) lowered the sugar level in diet mixed with 10% sucrose whereas asiaticoside (0.05, 0.5, 5, 50 mg/ml) and madecassoside (0.05, 0.5, 5, 50 mg/ml) lowered the sugar level in diet mixed with 10% maltose with statistical significance comparing with the control group (P< 0.05). For intra-hemolymph administration, ECa 233 (0.05, 0.5, 5 mg/ml), asiaticoside (5, 50 mg/ml) and madecassoside (50 mg/ml) lowered the sugar level in diet mixed with 10% glucose whereas ECa 233 (5 mg/ml), asiaticoside (50 mg/ml) and madecassoside (50 mg/ml) lowered the sugar level in diet mixed with 10% sucrose. Moreover ECa 233 (0.5, 5 mg/ml), asiaticoside (0.05, 0.5, 5, 50 mg/ml) and madecassoside at (0.05, 0.5, 5, 50 mg/ml) lowered the sugar level in diet mixed with 10% maltose with statistical significance comparing with the control group (P< 0.05).
