Determination of Elements in Gymnema inodorum Lour by Particle Induced X-Ray Emission (PIXE).

At present, Thailand uses medicinal plants to treat various diseases. Alternative medicine utilizes Gymnema inodorum Lour for antipyretic and anti-allergic purposes. There are also other research studies to treat diabetes mellitus, coronary artery disease, cataract, rheumatoid arthritis, gout, liver cancer, and stomach cancer. This study used particle-induced X-ray emission (PIXE) technique to analyze the elements in this plant. The advantage of this technique over other methods is the multi-elemental analysis and high sensitivity. The objective of this study was to determine the elemental compositions and to develop new standard methods for analyzing plant elemental compositions in Thailand. A 2-MeV proton beam was used to identify and characterize major and minor elements namely Mg, Al, Si, P, S, Cl, K, Ca, Ti, Mn, Fe, and Zn in Gymnema Inodorum Lour. Results have shown that these elements are present in varying concentrations in the selected parts: roots, stems, and leaves. The data of elemental analysis, applied in recommended quantities that are harmful to the body, describe the relationship between elements and efficacy of this plant in alternative medicine.

Low-Energy Ion-Species-Dependent Induction of DNA Double-Strand Breaks: Ion Energy and Fluence Thresholds.

The goal of this study was to determine the critical ion-radiation conditions under which heavy ion beams can induce DNA double-strand breaks. Helium, nitrogen and argon-ion beams in the energy range of 20 eV to 2 keV were used to irradiate naked DNA plasmid pGFP to fluences of 1, 2 and 4 × 1015 ions/cm2. The topological forms of DNA were subsequently analyzed using gel electrophoresis. The DNA forms were changed from the original supercoiled to damaged relaxed and linear forms, depending on the ion mass, energy, fluence and inertia. We found ion energy and fluence thresholds above which direct double-strand breaks can occur. The threshold is discussed in terms of the areal ion-energy density and the cross-section.