Anti-inflammatory, free radical scavenging and alpha-glucosidase inhibitory activities of Hamelia patens and its chemical constituents

Abstract

Context Hamelia patens Jacq. (Rubiaceae) is traditionally used to treat wounds, inflammation and diabetes. However, there is still a lack of scientific evidence to support these applications. Objective The objective of this study is to evaluate the anti-inflammatory, antioxidant and antidiabetic activities of Hamelia patens, and identify its bioactive compounds. Materials and methods Four extracts were obtained by maceration and liquid-liquid extraction: HEX, DCM-EtOAc, MeOH-EtOAc and MeOH-Aq. The anti-inflammatory effect was evaluated orally on rat paw carrageenan-induced oedema over 6 h (50, 200 and 500 mg/kg), and topically in mouse ear oedema induced by 12-tetradecanoylphorbol-13-acetate (TPA) after 4 h (0.5 and 1 mg/ear). We also evaluated myeloperoxidase levels in ear tissue, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, and in vitro α-glucosidase inhibition. The chemical compounds were separated by column chromatography and identified by spectroscopic analysis. Results We found that the oral administration of the HEX extract at 500 and 200 mg/kg significantly decreased the carrageenan-induced inflammation after 1 and 3 h, respectively. The MeOH-EtOAc extract significantly inhibited myeloperoxidase activity (83.5%), followed by the DCM-EtOAc extract (76%), β-sitosterol/stigmasterol (72.7%) and the HEX extract (55%), which significantly decreased oedema induced by TPA at both doses, giving a similar effect to indomethacin. We also found that the MeOH-EtOAc, MeOH-Aq and DCM-EtOAc extracts showed good DPPH scavenging activity (IC50 values of 18.6, 93.9 and 158.2 μg/mL, respectively). The HEX extract showed the lowest α-glucosidase inhibition (an IC50 value of 26.07 μg/mL), followed by the MeOH-EtOAc extract (an IC50 value of 30.18 μg/mL), β-sitosterol/stigmasterol (IC50 34.6 μg/mL) and compound A ((6E,10E,14E,18E)-2,6,10,14,18,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, an IC50 value of 114.6 μg/mL), which were isolated for the first time from Hamelia patens. Discussion and conclusion Hamelia patens possesses anti-inflammatory, antioxidant and α-glucosidase inhibitory activities, which support its traditional use. These effects can be attributed to the identified compounds.

“Diabetes and Metabolism Disorders Medicinal Plants: A Glance at the Past and a Look to the Future 2018”: Antihyperglycemic Activity of Hamelia patens Jacq. Extracts

“…Biological studies have demonstrated radical scavenging [ 13 , 14 ] as well as anti-inflammatory [ 15 ], antibacterial [ 16 ], and cytotoxic [ 17 ] activity by H. patens . In an oral glucose tolerance test, this plant demonstrated inhibition of α -glucosidase [ 18 ] and a hypoglycemic effect [ 19 ]. Phytochemical analysis of the plant has established the presence of isopteropodin, rumberin, palmirin, maruquin, 24-methylenecicloartan-3ß-ol, 24-methylcicloart-24-en-3ß-ol, 2 E -3,7,11,15,19-pentamethyl-2-eicosaen-1-ol, stigmasterol, ß-sitosterol, ursolic acid, aricin, (+)-catechin, (-)-epicatechin, and (-)-hammelin [ 20 – 22 ].…”

Investigation of the Antioxidant, α-Glucosidase Inhibitory, Anti-inflammatory, and DNA Protective Properties of <i>Vaccinium arctostaphylos</i> L.

“…There are many reports that suggest that phenolic, anthocyanin, and flavonoid compounds included in medicinal herbs are responsible for α-glucosidase inhibition. 41,42 According to these results, the α-glucosidase inhibitory effect with total phenolic and total anthocyanin contents is more compatible than that between the α-glucosidase inhibitory effect with total flavonoid content. Feshani et al 43 reported that EE of V. arctostaphylos fruits showed antihyperglycemic activity against diabetic rats.…”

Hypoglycemic, Antitussive and Analgesic Effects of Nanoparticles of Cordia myxa Fruits Extract

“…Next, the extract was powdered with freeze dryer. 24 The yield (w/w) of extract was 34.7%. The extract was stored at refrigerator for future studies.…”