Maclura cochinchinensis (Lour.) Corner (MC) heartwood extracts have been used for the treatment of gout, hyperuricemia, and inflammation in Thai traditional medicine. Despite their traditional use, their mechanisms of action remain unknown. The aim of this study was to determine the mechanisms of MC heartwood extract activity using both in vitro and in vivo models . The extraction methods were optimized to yield the highest contents of biochemical compounds and antioxidant activities. The effects of MC heartwood extract on xanthine oxidase and its enzyme kinetics were determined in vitro and the antihyperuricemic effect was evaluated in potassium oxonate (PO)-induced hyperuricemic mice. The anti-inflammatory effect of MC heartwood extract was also tested against lipopolysaccharide-induced proinflammatory mRNA upregulation in RAW 264.7 mouse macrophage cells. Soxhlet extraction of MC heartwood with 70% ethanol produced stronger antioxidant activity, and higher total phenolic and flavonoid contents than conventional methods did (maceration or decoction). By using HPLC, we found that MC contains morin as a major constituent, which may account for its pharmacological activities. Moreover, administration of MC heartwood extract (500 mg/kg) markedly decreased uric acid levels in PO-induced hyperuricemic mice (p < 0.05). MC heartwood extract inhibited the hepatic activity of xanthine oxidase ex vivo by approximately 53%. In addition, MC heartwood extract markedly downregulated mRNA expression of inflammatory mediators (TNF-α, TGF-β, iNOS, and COX-2) and this inhibition was comparable with that of dexamethasone. Therefore, MC heartwood extract is a promising candidate as a natural treatment for inflammation and the hyperuricemia that causes gout.

Stingless bees (Apoidea) are widely distributed and commercially cultivated in artificial hives in fruit gardens. Their propolis are commonly used in traditional medicine to treat various diseases (e.g., abscesses, inflammations, and toothaches) and as a constituent of numerous health products. Thus, this study aimed to (i) develop and validate a high-performance thin layer chromatography method for the quantitation of major active constituents (α- and γ-mangostins) in propolis produced by five stingless bee species (Tetragonula fuscobalteata Cameron, T. laeviceps Smith, T. pagdeni Schwarz, Lepidotrigona terminata Smith, and L. ventralis Smith) cultivated in Thai mangosteen orchards and (ii) determine an optimal extraction solvent. Separation was performed on a silica gel 60 F₂₅₄ plate using toluene/ethyl acetate/formic acid (8:2:0.1, v/v/v) as a mobile phase, and the developed method was validated to assure its linearity, precision, accuracy, and limits of detection/quantitation. Propolis extract from T. fuscobalteata exhibited the highest mangostin content, and acetone was shown to be more a more effective extraction solvent than dichloromethane, ethanol, or methanol. Thus, the simplicity and reliability of the developed method make it well suited for the routine analysis (e.g., for quality control) of commercial products containing stingless bee propolis.

Salak seed extract (Salacca zalacca) is known for its high antioxidant content and low caffeine levels, making it a promising candidate for the development of value-added health products. However, there is a lack of scientific evidence for its anti-hyperglycemic effects. To address this, we investigated the in vitro and in vivo anti-hyperglycemic and antioxidant effects of salak seed extract. The HPLC chromatogram of salak seed extract shows a prominent peak that corresponds to chlorogenic acid. In vitro studies revealed that salak seeds inhibited α-glucosidase activity and glucose uptake in Caco-2 cells in a concentration-dependent manner, while also exhibiting antioxidant properties. The extract exhibits a non-competitive inhibition on α-glucosidase activity, with an IC₅₀ and K_i of 16.28 ± 7.22 and 24.81 μg/mL, respectively. In vivo studies utilizing streptozotocin-nicotinamide-induced diabetic mice showed that the extract significantly reduced fasting blood glucose (FBG) levels in the oral glucose tolerance test. Continuous administration of the salak seed extract resulted in lower FBG levels by 13.8% as compared with untreated diabetic mice, although this change was not statistically significant. The estimated LD₅₀ value of salak seed extract exceeds 2000 mg/kg, and no toxicity symptoms have been detected. Our research supports that salak seed extract has the potential to serve as a functional food or supplement that may be beneficial in reducing postprandial hyperglycemia among people with type 2 diabetes. This effect was explained by the salak’s inhibitory mechanisms of glucose absorption due to inhibition of both α-glucosidase activity and intestinal glucose uptake, coupled with its antioxidant effects.

Maclura cochinchinensis (Lour.) Corner., of the Moraceae family, is a medical shrub commonly found in Thailand, and for which a wide variety of pharmacological activities have been reported, including antiviral, anti-inflammatory, antioxidant, and anticancer activities. The main bioactive compounds, oxyresveratrol and morin, are known to be found in M. cochinchinensis heartwood. In this study, we quantitatively analyzed the levels of these two active substances in M. cochinchinensis extracted with various solvents, including in various cosmetic formulations and herbs sourced from various parts of Thailand. High-performance liquid chromatography (HPLC) was performed on a C₁₈ column with an isocratic elution using 1.5% formic acid and acetonitrile at a flow rate of 1 ml/min, and detected at 352 nm. This method was validated for accuracy, precision, linearity, limits of detection, and quantification. The average percent recovery for oxyresveratrol and morin in the extracts was 100.01 ± 0.62% and 99.31 ± 2.56%, and in gel formulation was 99.65 ± 3.54% and 118.41 ± 4.70%, respectively. The relative standard deviation of intra- and inter-day precision was less than 2.0% and 2.8%, respectively. Limits of detection and quantification were 0.06 and 0.2 μg/ml, respectively. The amounts of oxyresveratrol and morin extracted from different solvents, such as acetone, 80% ethanol, 50% ethanol, methanol, and distilled water were in the range of 37.75–68.16 and 54.63–144.83 mg/g, respectively, while five samples of M. cochinchinensis heartwood collected from different regions of traditional drug stores contained in the range of 26.85–60.37 and 110.26–157.44 mg/g, respectively. Additionally, the percentage label amounts of oxyresveratrol and morin were analyzed in gel preparations, and found at 82.88% and 120.99%, respectively. This technique is convenient, simple, and reliable to effectively analyze the content of these active compounds in extracts and cosmetic products.