Noppamas Soonthornchareonnon

Background/Objectives: Intestinal α-glucosidases, including maltase, sucrase, and trehalase, are key enzymes responsible for the final steps of carbohydrate digestion. Although Thai medicinal plants possess diverse bioactivities, most previous studies on plant-derived α-glucosidase inhibitors have focused on single-enzyme assays, primarily maltase, and lack systematic comparison of the three major intestinal disaccharidases—maltase, sucrase, and trehalase. This study aimed to determine the kinetic properties of rat intestinal α-glucosidases and evaluate the inhibitory potential of selected Thai plant extracts. Methods: Rat small-intestinal S9 fractions, post-mitochondrial supernatant obtained by centrifugation at 9000× g, containing soluble enzymes and microsomal components responsible for disaccharidase activity, were prepared and disaccharidase activities were quantified using the glucose oxidase–peroxidase method. Kinetic parameters were obtained from Eadie–Hofstee plots using maltose, sucrose, and trehalose as substrates. Fourteen Thai plant extracts (Oryza sativa, Cratoxylum formosum, Garcinia cawa, Aganosma marginata, Polyalthia evecta, Ellipeiopsis cherrevensis, Ancistrocladus tectorius, Micromelum minutum, and Microcos tomentosa) and isolated compounds (Bergapten, Eurycomalactone, Lupinifolin, Osthole) were assessed at 100 and 250 µg/mL for inhibition of maltase, sucrase, and trehalase. Results: Maltase exhibited the highest substrate affinity based on the lowest Km value. Among the tested samples, the 80% ethanol extract of Microcos tomentosa (MT80) inhibited maltase, sucrase, and trehalase activities by approximately 10–60% at 250 µg/mL, and was the only extract showing consistent inhibition across all three enzymes. Other extracts showed selective inhibition toward one or two enzymes. Conclusions: These findings indicate that MT80 possesses a broad-spectrum inhibitory profile against major intestinal α-glucosidases, suggesting a potential advantage for comprehensive regulation of postprandial glucose excursions and supporting its candidacy as a source of novel α-glucosidase inhibitors.

Maha Pigut Triphala is the herbal mixture of three fruits consisting of T. bellirica, T. chebula, and E. officinalis also known as P. emblica. Humans regularly eat the fresh fruits of these plants on a daily basis. Maha Pigut Triphala is one of the widely known herbal medicinal formulas used in traditional Thai medicine. Besides studying pharmacological properties, attention should also be paid to the safety and toxicity studies of herbal medicines. The objective of the present study was to evaluate the acute and chronic oral toxicity of Maha Pigut Triphala (2:1:3) in Sprague-Dawley rats. A single dose of Maha Pigut Triphala at a concentration of 5000 mg/kg body weight was administered orally to female rats in the acute oral toxicity study. In the chronic oral toxicity study, male and female rats were treated with various concentrations of Maha Pigut Triphala (600, 1200, and 2400 mg/kg body weight) once daily for 270 consecutive days. The presence of abnormalities in the symptoms and behavior of the rats were observed and recorded throughout the experiment. Additionally, body weight, organ weight, and mortality were recorded. At the end of the study, blood samples were collected for hematological and blood chemistry analysis, while the internal organs were evaluated for gross pathological and histopathological changes. The acute oral toxicity study revealed no mortality and abnormal symptoms or behavior in Maha Pigut Triphala-treated rats. Moreover, gross pathological and histopathological findings did not reveal any abnormalities in the internal organs. In the chronic oral toxicity evaluation, although there were negligible changes in body weight, organ weight, and hematological and blood chemistry parameters in rats treated with Maha Pigut Triphala for 270 days, no behavioral or gross pathological and histopathological abnormalities were observed. Overall, the results of this study demonstrate that Maha Pigut Triphala (2:1:3) neither causes acute nor chronic oral toxicity in rats, proposing the safety of this herbal formula in animals prior to human trials and use.

Tongkat ali (Eurycoma longifolia Jack) (ELJ) is a plant in the Simaroubaceae family. Its roots are used in traditional Thai medicine to treat inflammation, pain, and fever; however, the antiulcer abilities of its ethanolic extract have not been studied. This study examined the anti-inflammatory, antinociceptive, antipyretic, and gastroprotective effects of ethanolic ELJ extract in animal models and found that ELJ effectively reduced EPP-induced ear edema in a dose-dependent manner and that a high dose of ELJ inhibited carrageenan-induced hind paw edema formation. In cotton-pellet-induced granuloma formation, a high dose of ELJ suppressed the increases in wet granuloma weight but not dry or transudative weight. In the formalin-induced nociception study, ELJ had a significant dose-dependent inhibitory impact. Additionally, the study found that yeast-induced hyperthermia could be significantly reduced by antipyretic action at the highest dose of ELJ. In all the gastric ulcer models induced by chemical substances or physical activity, ELJ extracts at 150, 300, and 600 mg/kg also effectively prevented gastric ulcer formation. In the pyloric ligation model, however, the effects of ELJ extract on gastric volume, gastric pH, and total acidity were statistically insignificant. These findings support the current widespread use of Eurycoma longifolia Jack in traditional medicine, suggest the plant’s medicinal potential for development of phytomedicines with anti-inflammatory, antinociceptive, and antipyretic properties, and support its use in the treatment of gastric ulcers due to its gastroprotective properties.

Background: The Indian Ayurvedic herbal formula Triphala (TPL) is known for its pharmacological properties for immunomodulation, anti-inflammation, antioxidant, and anti-cancer. This study aimed to investigate the acute and chronic toxicities of the Triphala recipe in a rat model. Methods: To assess the acute toxicities, 5000 mg/kg of TPL was orally administered to Sprague-Dawley rats. For chronic toxicities, different dose levels of TPL at 600, 1200, and 2400 mg/kg/day were given daily for 270 days. General health and behaviors and the body and organ weights of the rats were monitored. At the end of the experiment, blood samples were evaluated for hematology and biochemistry profiles. The evaluation of the internal organs’ appurtenance and necropsy was performed to confirm the tissue histopathology. Results: The results showed that there was no sign of acute toxicity in the TPL group with a decrease in sex organ weights. No significant differences in the rats’ behaviors, physical health, body, or organ weights were found between the controls and the rats receiving the 270/day of oral Triphala at 600, 1200, and 2400 mg/kg/day. However, some alterations in blood chemistries and hematology, including glucose, BUN, red blood cells, Hb, HCT, and MCV, were observed without abnormalities in histopathology. Conclusions: It has been demonstrated that the long-term use of TPL in rat models is safe. No toxic effects were found, suggesting possible safety for long-term use in humans.

Salacia chinensis L. (SC) stems have been used as an ingredient in Thai traditional medicine for treating patients with hepatic fibrosis and liver cirrhosis. However, there is no scientific evidence supporting the antifibrotic effects of SC extract. Therefore, this study aimed to determine the antifibrotic activity of SC stem extract in human hepatic stellate cell-line called LX-2. We found that upon TGF-β1 stimulation, LX-2 cells transformed to a myofibroblast-like phenotype with a noticeable increase in α-SMA and collagen type I production. Interestingly, cells treated with SC extract significantly suppressed α-SMA and collagen type I production and reversed the myofibroblast-like characteristics back to normal. Additionally, TGF-β1 also influenced the development of fibrogenesis by upregulation of MMP-2, TIMP-1, and TIMP-2 and related cellular signaling, such as pSmad2/3, pErk1/2, and pJNK. Surprisingly, SC possesses antifibrotic activity through the suppression of TGF-β1-mediated production of collagen type 1, α-SMA, and the phosphorylation status of Smad2/3, Erk1/2, and JNK. Taken together, the present study provides accumulated information demonstrating the antifibrotic effects of SC stem extract and revealing its potential for development for hepatic fibrosis patients.

The ethanolic extract from the stem bark of Goniothalamus marcanii Craib was shown in preliminary brine shrimp lethality data having good cytotoxic activity. Further bioassay guided isolation was done by means of solvent partition, chromatography and precipitation to provide four isolated compounds: a novel compound 1 with the core structure of 1-azaanthraquinone moiety referred as marcanine G; as well as compounds 2–4 with known aristolactam structures namely, piperolactam C, cepharanone B and taliscanine. These compounds were characterised by spectroscopic techniques. The assessment of cytotoxicity was established on an SRB assay using doxorubicin as a positive control. Marcanine G (1) was considered the most active compound indicating the IC₅₀ values of 14.87 and 15.18 μM against human lung cancer cells (A549) and human breast cancer cells (MCF7), respectively. However, 2 showed mild activity with the IC₅₀ values of 83.72 and 82.32 μM against A549 and MCF7 cells, respectively.