Study on enhancing the inhibitory activity of pancreatic α-amylase and lipase enzymes of the mixture of Nelumbo nucifera leaves, Curcuma longa rhizomes and Coptis chinensis rhizomes

Abstract

     Obesity is the cause of many diseases. Synthetic drugs such as orlistat and acarbose support weight loss through the inhibition of α-amylase and lipase but cause many side effects. Based on the results of recent studies on the weight loss effects of plants, the ratio of the mixture of extracts from Nelumbo nucifera leaves,  Curcuma longa rhizomes, and Coptis chinensis rhizomes with the best inhibitory activity against pancreatic α-amylase and lipase was investigated by using Design-Expert 13 software and the D-Optimal model to design experiments with three independent variables: the percentage of the extracts: Nelumbo nucifera leaves (X₁), Curcuma longa rhizomes (X₂) and Coptis chinensis rhizomes (X₃). The objective functions Y₁ and Y₂ are the IC₅₀ values representing the inhibitory activity of α-amylase and pancreatic lipase enzymes, respectively. The results proposed the optimal extract mixture (X₁: 58.2 %, X₂: 36.6 %, and X₃: 5.2 %) and predicted Y₁ = 3 μg/mL and Y₂ = 8 μg/mL with α = 0.05. Validation experiments showed that the IC₅₀ inhibition of α - amylase and lipase enzymes of the optimal mixture was (3.043 ± 0.074) μg/mL and (8.183 ± 0.275) μg/mL, compared to acarbose (2.645 ± 0.138) μg/mL and orlistat (1.630 ±0.004) μg/mL. The proposed extract mixture had the best α-amylase and lipase inhibitory activity compared to the investigated mixtures.