Lunasia amara Blanco bark belonging to the family Rutaceae. The research aimed to determine the effect of extraction method on yield value and phenolic content of bark extract of Lunasia amara Blanco by UV-Vis spectrophotometry. Sample was extracted by maceration, reflux, and soxhlet using methanol 70%. The extraction by maceration obtained the yield value of methanol extract of 2,352%; the reflux method of 1,611%; and the soxhlet method of 0,960%. Then the chemical content was identified by the addition of FeCl3 reagent and a blackish green color was formed positively indicating phenolic content. Afterward, phenolic identification was conducted by TLC with eluent n-hexane: ethyl acetate (2:8) containing phenolic because the Rf value was the same as the galic acid standard. The results showed that the extraction method producing the highest yield of bark extract of Lunasia amara Blanco was maceration. The phenolic content obtained by maceration was 66,548 mgGAE/g extract with 6.6548% GAE; the reflux was 73.645 mgGAE/g extract with 7.3645% GAE; and the soxhlet was 74.806 mgGAE/g extract with 7.4806% GAE.

Lunasia amara Blanco bark belonging to the family Rutaceae. The research aimed to determine the effect of extraction method on yield value and phenolic content of bark extract of Lunasia amara Blanco by UV-Vis spectrophotometry. Sample was extracted by maceration, reflux, and soxhlet using methanol 70%. The extraction by maceration obtained the yield value of methanol extract of 2,352%; the reflux method of 1,611%; and the soxhlet method of 0,960%. Then the chemical content was identified by the addition of FeCl3 reagent and a blackish green color was formed positively indicating phenolic content. Afterward, phenolic identification was conducted by TLC with eluent n-hexane: ethyl acetate (2:8) containing phenolic because the Rf value was the same as the galic acid standard. The results showed that the extraction method producing the highest yield of bark extract of Lunasia amara Blanco was maceration. The phenolic content obtained by maceration was 66,548 mgGAE/g extract with 6.6548% GAE; the reflux was 73.645 mgGAE/g extract with 7.3645% GAE; and the soxhlet was 74.806 mgGAE/g extract with 7.4806% GAE.

Kratom (Mitragyna speciosa (Korth.) Havil.) has been used to reduce blood sugar and lipid profiles in traditional medicine, and mitragynine is a major constituent in kratom leaves. Previous data on the blood sugar and lipid-altering effects of kratom are limited. In this study, phytochemical analyses of mitragynine, 7-hydroxymitragynine, quercetin, and rutin were performed in kratom extracts. The effects on α-glucosidase and pancreatic lipase activities were investigated in kratom extracts and mitragynine. The LC-MS/MS analysis showed that the mitragynine, quercetin, and rutin contents from kratom extracts were different. The ethanol extract exhibited the highest total phenolic content (TPC), total flavonoid content (TFC), and total alkaloid content (TAC). Additionally, compared to methanol and aqueous extracts, the ethanol extract showed the strongest inhibition activity against α-glucosidase and pancreatic lipase. Compared with the anti-diabetic agent acarbose, mitragynine showed the most potent α-glucosidase inhibition, with less potent activity of pancreatic lipase inhibition. Analysis of α-glucosidase and pancreatic lipase kinetics revealed that mitragynine inhibited noncompetitive and competitive effects, respectively. Combining mitragynine with acarbose resulted in a synergistic interaction with α-glucosidase inhibition. These results have established the potential of mitragynine from kratom as a herbal supplement for the treatment and prevention of diabetes mellitus.