Oleamide in Ipomoea and Dillenia species and inflammatory activity investigated through ion channel inhibition

Background: Oleamide is an essential substance for human health. So, the plants with high oleamide content are great sources for health care products. Objective: This study is conducted to investigate the quality of oleamide in plants and test the bioactivity in the selected two studied species. Methods: The three Ipomoea and five Dillenia species including Ipomoea alba, Ipomoea aquatica and Ipomoea pes-caprae, and Dillenia indica, Dillenia obovata, Dillenia ovata, Dillenia parviflora and Dillenia pentagyna were investigated for the quantity of oleamide by high-performance liquid chromatography. The biological activity test was conducted on the powder formulation of the chosen plants, Dillenia ovata and Dillenia parviflora at a ratio of 30:70, for anti-inflammatory activity ex vivo on a panel of molecular targets through ion channel inhibition including voltage-gated sodium channel, voltage-gated potassium channel, and the cardiac ion as human ether-a-go-go related gene. Results: The results showed that the leaf extracts of I. aquatica and D. ovata gave the highest and subsequent oleamide quantity following 7.52 and 5.17 mg/g. Out of the Dillenia formulation which contained various compounds, oleamide showed the highest percentages of inhibition at 8.0-20.0%, and 6.2-14.2% in voltage-gated sodium channel, and voltage-gated potassium channel which had slightly lower values than the oleamide standard, and no effect as 0.0% value inhibition in the cardiac ion channel. Conclusion: The Dillenia formulation exhibits anti-inflammatory activity without affecting the heart. Accordingly, the three studied Ipomoea and three studied Dillenia species may be used for the same activity as a single component or formulation with effective solvent for disease treatments.

Download Full-text

Kinetic and thermodynamic modeling of a voltage-gated sodium channel

10.1101/2021.09.25.461780 ◽

2021 ◽

Author(s):

Mara Almog ◽

Nurit Degani-Katzav ◽

Alon Korngreen

Keyword(s):

Action Potential ◽

Ion Channel ◽

Sodium Channel ◽

Temperature Dependence ◽

Cortical Neurons ◽

Room Temperature ◽

Pyramidal Neurons ◽

Voltage Gated Sodium Channel ◽

Voltage Gated ◽

Voltage Gated Sodium Channels

Like all biological and chemical reactions, ion channel kinetics are highly sensitive to changes in temperature. Therefore, it is prudent to investigate channel dynamics at physiological temperatures. However, most ion channel investigations are performed at room temperature due to practical considerations, such as recording stability and technical limitations. This problem is especially severe for the fast voltage-gated sodium channel, whose activation kinetics are faster than the time constant of the standard patch-clamp amplifier at physiological temperatures. Thus, biologically detailed simulations of the action potential generation evenly scale the kinetic models of voltage-gated channels acquired at room temperature. To quantitatively study voltage-gated sodium channels' temperature sensitivity, we recorded sodium currents from nucleated patches extracted from the rat's layer five neocortical pyramidal neurons at several temperatures from 13.5 to 30°C. We use these recordings to model the kinetics of the voltage-gated sodium channel as a function of temperature. We show that the temperature dependence of activation differs from that of inactivation. Furthermore, we show that the sustained current has a different temperature dependence than the fast current. Our kinetic and thermodynamic analysis of the current provided a numerical model spanning the entire temperature range. This model reproduced vital features of channel activation and inactivation. Furthermore, the model also reproduced action potential dependence on temperature. Thus, we provide an essential building block for the generation of biologically detailed models of cortical neurons.

Download Full-text