Apirak Sakunpak

Quantitative analysis and formulation development of a traditional Thai antihypertensive herbal recipe

The health benefits of herbs and herbal products are gaining more attention in southeast Asia. The World Health Organization (WHO) has been supporting countries to promote application of traditional medicines so that this valuable resource is utilized safely and effectively. In Thailand, many traditional herbal recipes have been established since ancient times. Since then, they have been carefully modified, based on the wisdom of traditional Thai medicine practitioners. For this study, a traditional Thai antihypertensive herbal recipe (TTAH) was selected and studied in detail. According to WHO guidelines, both analysis of a sizeable chemical constituent, and formulation data of a product, are a requirement to support a clinical trial for an herbal recipe. Therefore, high-performance liquid chromatography–mass spectrometry (LC–MS) was used to investigate the chemical fingerprints, chemical constituents, and putative active ingredients of the TTAH. Eight chemical fingerprints were established. Metabolic profiling of 10 possible compounds was also identified and all were shown to be active pharmaceutical compounds. An attempt was also made to prepare a suitable formulation of the TTAH, to standardize the amount of active ingredients per dose, and to improve patient compliance. All evaluated parameters guided us to prepare the TTAH as a capsule. This informative data can be included in part of the chemistry–manufacturing–control guidance prior to phase 1/2 clinical trials.

Thin-layer chromatography–contact bioautography as a tool for bioassay-guided isolation of anti-Streptococcus mutans compounds from Pinus merkusii heartwood

In this study, thin-layer chromatography—contact bioautography (TLC—CB) was used for the bioassay-guided isolation of antibacterial compounds against Streptococcus mutans from ethanolic extract of Pinus merkusii heartwood. In the TLC—CB technique, clear inhibition zones at two major spots on the TLC plate were observed against S. mutans. The major separated anti-S. mutans compounds were isolated by a preparative TLC plate (silica gel) with the mobile phase composed of n-hexane and ethyl acetate (7:3 v/v). The isolated components were identified as dehydroabietic acid and resin acids. Resin acids were further purified by a pentafluorophenyl (PFP) high-performance liquid chromatography (HPLC) column using water and methanol as eluents. Isopimaric acid and abietic acid were obtained. The antibacterial properties of dehydroabietic acid, isopimaric acid, and abietic acid against four strains of S. mutans were evaluated using broth microdilution method. The results revealed that the isolated substances exhibited antibacterial activity against all bacterial strains.

Thin-Layer Chromatography—Densitometry and Thin-Layer Chromatography—Image Analysis for Screening Bile Acid-Binding Activities of Thai Edible Plants

Despite the fact that many researchers have developed different methods for the determination and detection of bile acid sequestrant, the analytical instruments are still quite costly, and expertise is usually required. In order to avoid the above-mentioned problems, simple, rapid, effective, and inexpensive methods to evaluate bile acid-binding are essential. The purpose of this study was to develop a simple and rapid thin-layer chromatography (TLC)—image analysis method to quantitatively determine the bile acid-binding activity of ten edible ethanolic plant extracts. The method was carried out by using TLC silica gel 60 F254 plate with the mobile phase composed of chloroform, methanol, and acetic acid (7:2:1 v/v). The chromatograms were analyzed with image analysis software (ImageJ). The method provided good linearity, accuracy, reproducibility, and selectivity for the determination of bile acid-binding activity. Litsea petiolata extract was found to show the most potent bile acid-binding activity compared to other extracts. Moreover, some extracts exhibited selective binding ability to bile acid; for example, extracts of Careya sphaerica and Polygonum odoratum could selectively bind rather to taurocholic acid than glycodeoxycholic acid. This study shows a simple method for the evaluation of potential edible plants to be used as cholesterol-reducing agents due to their bile acid-binding activity.