Tournefortia paniculata Vent: a phytochemical and biological approach

Abstract

Tournefortia paniculata Vent. is a medicinal plant, traditionally known as marmelinho and used in the treatment of urinary tract disorders. There are incipient studies on the medicinal potential and phytochemistry of this plant. In this point of view, this study aimed to perform phytochemical and bioprospecting studies of antidiabetic, antimicrobial, antioxidant and chemopreventive activities of T. paniculata extractive preparations. Extractive preparation obtained from the exhaustive percolation of the powdered leaves of T. Paniculata with ethanol 92º INMP, provided the crude ethanolic extract (CE), which was resussuspended in water and sequentially partitioned with n-hexane (HEX), dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol (BuOH) to obtain the respective fractions. The present work generated two articles that contributed to the chemical-biological information of T. paniculata. In the first, these preparations were evaluated for their potential in the treatment and prevention of diabetes complications through in vitro inhibitory activities of α-amylase, α-glucosidase and lipoxidase enzymes, as well as the bactericidal and fungicides activities. In addition, the relationship between the chemical profile and these biological activities was established through chromatographic profiles by HPLC-DAD and principal components (PC) analyses. The DCM fraction showed the best inhibition results of α-amylase (0.038 ± 0. 021mg/mL) and lipoxidase (0.217 ± 0.006mg/mL) enzymes, while EtOAc fraction showed higher inhibitory activity for αglucosidase (0.035 ± 0.009mg/mL). No preparation of T. paniculata was active against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 9027, Klebsiela pneumoniae ATCC 25955, employing the broth microdilution technique. The DCM fraction showed activity against the Candida dubliniensis strain (CIM=1000μg/mL) and against the strain of Issatchenkia orientalis (CIM=500μg/mL). PC analysis between the biological activities and the areas of the 10 uncommon major peaks of the chromatographic profiles indicated a positive correlation and synergistic effect between the high and low polarities substances. We conclude that the DCM and EtOAc fractions were the most potential for further investigations in the area of prevention and treatment of diabetes complications. In the second article, the antioxidant and chemopreventive potential of CE and its fractions of T. paniculata were evaluated. The BuOH fraction was the most promising antioxidant activity for DPPH free radical scavenging (0.05 ± 0.00), total antioxidant capacity (4.14 ± 0.14), power reduction of Fe+3 ions (8.96 ± 0.20) and Oxygen Radical Absorbance Capacity (5.51 ± 0.05), as well as higher levels of total phenolic compounds (130.23 ± 1.95) and total flavones/flavonols (5.08 ± 0.07). BuOH fraction UPLCMS-ESI analysis allowed the partial identification of a glucoside derivative of the syringic acid. In chemoprevention assays, no preparation of T. paniculata was able to inhibit TNF-Kβ. However, the HEX (2 ± 0.16) and DCM (2 ± 0.11) fractions induced quinone reductase (QR) activity, without presenting cytotoxicity. Due to the greater mass recovery, HEX fraction was selected for further fractionation in the silica gel column providing the RH2 chemopreventive subfraction. UPLC-MS-ESI analysis of RH2 suggested the presence of a mixture of a heteroside-piperazine derivative and a heteroside-piperidine derivative of triterpenic nucleus. It is concluded that extractive preparations of T. paniculata have medicinal potential for the treatment and prevention of diabetes complications and as antioxidant and chemopreventive agents.