Anti-oral streptococci and anti-biofilm properties of Etlingera pavieana essential oil and its bioactive compounds proposed for an alternative herbal mouthwash.

Oral streptococci are the major group of bacteria in the oral cavity. Some of their species cause oral diseases that may lead to tooth loss and quality-of-life reduction, such as dental caries. One of prevention techniques to promote oral health is rinsing mouthwash after toothbrushing. This study aimed to determine the potential uses of local food, also remedy, plant in Thailand called Reaw-Horm or Etlingera pavieana for alternative herbal mouthwash. The essential oil from E. pavieana rhizome (Eo) is used for anti-streptococci including Streptococcus mutans and Streptococcus sobrinus and anti-biofilm activities. The main components of Eo are methyl chavicol (MC) and trans-anethole (TA). The disk diffusion method showed the inhibition zone of Eo in a dose-dependent manner. The minimum inhibitory concentration (MIC) of Eo and TA was >1.6 % v/v, and 0.4 % v/v of MC. Regarding anti-biofilm activities, MC showed nearly equal anti-biofilm formation of S. mutans and S. sobrinus, whereas Eo and TA acted toward S. sobrinus more than S. mutans biofilm. Sub-MIC killing effects on cells under biofilm were observed in Eo and MC. Therefore, MC was recommended as an active compound for anti-streptococci activities. Biocompatibility of Eo and MC were shown to be safe for epidermal cell lines. Herbal mouthwashes containing Eo were developed and had antioxidant and antimicrobial actions with established for 3 months. This study provides in vitro support on the use of herbal mouthwash with antioxidant and antimicrobial activities for dental caries prevention and well-being of individuals.

Oral Glucose Tolerance Test (OGTT) Evidence for the Postprandial Anti-Hyperglycemic Property of Salacca zalacca (Gaertn.) Voss Seed Extract.

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 Ki 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.

Synergistic effect of Trikatuk, a traditional Thai formulation, on antioxidant and alpha-glucosidase inhibitory activities.

Oxidative stress and hyperglycemia are known to be responsible for several diseases, including diabetes. To prevent these diseases, efforts are ongoing to identify novel antioxidants with hypoglycemic effects. Trikatuk is a traditional Thai formulation composed of three herbs in equal quantities: the fruits of Piper nigrum and Piper retrofractum and the rhizomes of Zingiber officinale. This formulation has been reported to have antioxidant activity and the three individual herbs have been traditionally used for managing diabetes. Therefore, the present study aimed to investigate the phytochemical contents, antioxidant activity (DPPH and ABTS radical scavenging assays), and alpha-glucosidase inhibitory activity of Trikatuk. As Trikatuk is a combination of herbs, the synergistic effect and two different preparation methods from powder or extract mixtures were also explored. The results revealed that Trikatuk, particularly prepared from a mixture of extracts, exhibited high contents of piperine, total phenolics and total flavonoids, as well as significant antioxidant and alpha-glucosidase inhibitory activities. Trikatuk also exhibited additive or synergistic effects in all experiments. Overall, Trikatuk is potentially an alternative traditional medicine and dietary supplement offering antioxidant activity and diabetes management.

Antihyperglycemic effects of Lysiphyllum strychnifolium leaf extract in vitro and in vivo.

CONTEXT: Lysiphyllum strychnifolium (Craib) A. Schmitz (LS) (Fabaceae) has traditionally been used to treat diabetes mellitus. OBJECTIVE: This study demonstrates the antidiabetic and antioxidant effects of aqueous extract of LS leaves in vivo and in vitro. MATERIALS AND METHODS: The effects of aqueous LS leaf extract on glucose uptake, sodium-dependent glucose cotransporter 1 (SGLT1) and glucose transporter 2 (GLUT2) mRNA expression in Caco-2 cells, α-glucosidase, and lipid peroxidation were evaluated in vitro. The antidiabetic effects were evaluated using an oral glucose tolerance test (OGTT) and a 28-day consecutive administration to streptozotocin (STZ)-nicotinamide (NA)-induced type 2 diabetic mice. RESULTS: The extract significantly inhibited glucose uptake (IC50: 236.2 ± 36.05 µg/mL) and downregulated SGLT1 and GLUT2 mRNA expression by approximately 90% in Caco-2 cells. Furthermore, it non-competitively inhibited α-glucosidase in a concentration-dependent manner with the IC50 and Ki of 6.52 ± 0.42 and 1.32 µg/mL, respectively. The extract at 1000 mg/kg significantly reduced fasting blood glucose levels in both the OGTT and 28-day consecutive administration models as compared with untreated STZ-NA-induced diabetic mice (p < 0.05). Significant improvements of serum insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and GLUT4 levels were observed. Furthermore, the extract markedly decreased oxidative stress markers by 37-53% reduction of superoxide dismutase 1 (SOD1) in muscle and malondialdehyde (MDA) in muscle and pancreas, which correlated with the reduction of MDA production in vitro (IC50: 24.80 ± 7.24 µg/mL). CONCLUSION: The LS extract has potent antihyperglycemic activity to be used as alternative medicine to treat diabetes mellitus.

Inhibitory effects of Triphala on CYP isoforms in vitro and its pharmacokinetic interactions with phenacetin and midazolam in rats.

Context: Direct evidence of Triphala-drug interactions has not been provided to date. Objective: This study was aimed to determine the effects of Triphala on cytochrome P450 (CYP) isoforms and P-glycoprotein (P-gp) in vitro, and to investigate pharmacokinetic interactions of Triphala with CYP-probes in rats. Materials and methods: Effects of Triphala on the activities of CYP isoforms and P-gp were examined using human liver microsomes (HLMs) and Caco-2 cells, respectively. Pharmacokinetic interactions between Triphala and CYP-probes (i.e., phenacetin and midazolam) were further examined in rats. Results: Triphala extract inhibited the activities of CYP isoforms in the order of CYP1A2>3A4>2C9>2D6 with the IC50 values of 23.6 ± 9.2, 28.1 ± 9.8, 30.41 ± 16.7 and 93.9 ± 27.5 µg/mL, respectively in HLMs. It exhibited a non-competitive inhibition of CYP1A2 and 2C9 with the K i values of 23.6 and 30.4 µg/mL, respectively, while its inhibition on CYP3A4 was competitive manner with the Ki values of 64.9 µg/mL. The inhibitory effects of Triphala on CYP1A2 and 3A4 were not time-dependent. Moreover, Triphala did not affect the P-gp activity in Caco-2 cells. Triphala, after its oral co-administration at 500 mg/kg, increased the bioavailabilities of phenacetin and midazolam by about 61.2% and 40.7%, respectively, in rats. Discussion and conclusions: Increases observed in the bioavailabilities of phenacetin and midazolam after oral co-administration of Triphala in rats provided a direct line of evidence to show Triphala-drug interactions via inhibition of CYP1A and CYP3A activities, respectively. These results, together with the lack of time-dependency of CYP 1A2 and 3A4 inhibition in vitro, suggested that the inhibitory effect of Triphala is primarily reversible.

Antidiabetic effects of Maclura cochinchinensis (Lour.) corner heartwood extract.

BACKGROUND AND AIM: Maclura cochinchinensis (MC) (Lour.) heartwood extract have been used traditionally to treat diabetes in Thailand, but their mechanism of action has not been elucidated. EXPERIMENTAL PROCEDURE: This study investigated the effects of an aqueous heartwood extract of MC on α-glucosidase and α-amylase activities. Moreover, its antidiabetic effect was evaluated using an oral glucose tolerance test (OGTT) and a 28-day administration to streptozotocin (STZ)-nicotinamide (NA)-induced type 2 diabetic mice. RESULTS: In both OGTT and the daily oral administration for 28 days in STZ-NA-induced type 2 diabetic mice models, the extract (1,000 mg/kg) significantly decreased fasting blood glucose. This hypoglycemic effect was explained by increased insulin levels and α-glucosidase inhibition (IC50:1.53 ±â€¯0.03 µg/mL). CONCLUSION: This first study on the hypoglycemic activity of MC heartwood extract indicates that it could be a potential natural remedy for type 2 diabetes.

In vitro and in vivo evidence of hypouricemic and anti-inflammatory activities of Maclura cochinchinensis (Lour.) Corner heartwood extract.

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-ß, 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.

A validated HPTLC method for quantitative analysis of morin in Maclura cochinchinensis heartwood.

Objective: The study was conducted to develop and validate a high performance thin-layer chromatography (HPTLC)-densitometric method for the quantitative analysis of morin in Maclura cochinchinensis heartwood collected from different locations in Thailand. Methods: HPTLC analysis was performed on an aluminium sheet of silica gel 60 F254 using toluene: ethyl acetate: formic acid (36:12:7, volume percent) as a mobile phase. The densitometric scanning was performed at the wavelength 410 nm. HPTLC method was validated according to ICH guideline. Results: The proposed HPTLC method showed acceptable validation parameters. The content of morin in M. cochinchinensis heartwood collected from eight different provinces in Thailand were in the ranges of 1.53%-2.73%. Conclusion: The simple and sensitive HPTLC method was successfully developed and validated for determination of morin in M. cochinchinensis heartwood. The proposed HPTLC method was found to be simple, fast and inexpensive, and can be used for the routine quality control of raw materials.

Yanangdaengin, a dihydrochalcone glucoside galloyl ester as active antioxidative agent from leaves of Lysiphyllum strychnifolium (syn. Bauhinia strychnifolia).

Objective: To isolate and identify the major bioactive components from the leaves of Lysiphyllum strychnifolium, an indigenous herb used in traditional Thai medicine for detoxification, longevity, and some other health related issues. Methods: Comparative HPLC analyses of the crude extracts from three provenances were carried out for an overview of characteristic compound profiles. Isolation of the major compounds was undertaken with chromatographic methods. Chemical structures were elucidated by NMR spectroscopic techniques and mass spectrometry. DPPH scavenging assay was carried out to determine the free radical scavenging activity of isolated compounds. Results: Yanangdaengin (3), a dihydrochalcone glucoside galloyl ester, has been isolated together with its corresponding dihydrochalcone glucoside trilobatin (2) as major compounds from the leaves of L. strychnifolium. Additionally, gallic acid (1) was co-chromatographically identified. Free radical scavenging activity of isolated compounds were determined. Compound 3 exhibited higher free radical scavenging activities in comparison to Trolox and quercetin. Conclusion: The isolated compounds could be used as chemical markers for quality assessment. The present work could promote the quality control and herbal medicinal product development of this plant.

Development and validation of a high-performance thin layer chromatography method for the simultaneous quantitation of α- and γ-mangostins in Thai stingless bee propolis

ABSTRACT 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.

Optimization of extraction method and HPLC analysis of six caffeoylquinic acids in Pluchea indica leaves from different provenances in Thailand

ABSTRACT Pluchea indica (L.) Less., Asteraceae, is a medicinal plant which contains a high amount of phenolic compounds such as caffeoylquinic acid derivatives. The leaves have been traditionally used as a nerve tonic and extensively as herbal tea. This study aimed to develop and validate an HPLC method to quantitatively analyze six caffeoylquinic acid derivatives, viz. 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 5-O caffeoylquinic acid, 3,4-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, and 4,5-O-dicaffeoylquinic acid in P. indica leaf extract. HPLC was carried out in a Hypersil BDS C18-column eluted with 0.5% acetic acid in water and methanol using gradient elution with a flow rate of 1 ml/min and detection at 326 nm. The method validation was performed to assure its linearity, precision, accuracy and limits of detection and quantitation. Several extraction techniques including maceration, decoction, digestion, Soxhlet extraction, and ultrasound extraction, were used to extract active constituents. The ultrasound extraction with 50% ethanol yielded the highest concentration of these caffeoylquinic acid derivatives in the P. indica leaf extract. Our developed HPLC method is simple and reliable for a routine analysis of the six caffeoylquinic acids in P. indica leaves and could potentially be applied to be used in commercial herbal products.

Simultaneous HPTLC Determination of Rhein and Aloe-emodin in Senna alata Leaves from Thailand and their Commercial Products.

A high performance thin layer chromatographic (HPTLC) method was developed and validated for simultaneous determination of rhein and aloe-emodin, major anthraquinone constituents, in S. alata leaves. The separation was performed on a silica gel 60 F254 HPTLC plate using ethyl acetate: methanol: water (100:17:10, v/v/v) as the development system. Validation of the analytical method for rhein and aloe-emodin promoted acceptable parameters. Good linearity in the range of 40-480 ng/band was obtained while intra-day and inter-day precisions were shown to be precise with relative standard deviations of less than 5%. The average percentage recoveries of rhein and aloe-emodin were 98.8% and 98.9%, suggesting acceptable accuracy. The content of rhein and aloe-emodin in S. alata leaves collected from 5 different provinces in Thailand analyzed by the validated HPTLC method were in the ranges of 0.098 ± 0.017 - 0.30±0.02%, w/w, and 0.081 ± 0.0006 - 0.34 ? 0.0009 %, w/w, respectively. Five commercial products of S. alata tea available in the market were purchased and analyzed for rhein and aloe-emodin contents. The contents of rhein and aloe-emodin in the tea samples were in the ranges of 0.085 ± 0.004 - 0:23 ± 0.04%, w/w, and 0.096 ±0.006 - 0.30 ± 0.01 %, w/w, respectively. The HPTLC method is rapid, reliable, sensitive and economical for routine analysis of rhein and aloe-emodin contents in-S. alata leaf raw materials and its commercial products.

HPLC quantitative analysis of rhein and antidermatophytic activity of Cassia fistula pod pulp extracts of various storage conditions.

Cassia fistula is well known for its laxative and antifungal properties due to anthraquinone compounds in the pods. This study quantitatively analyzed rhein in the C. fistula pod pulp decoction extracts kept under various storage conditions using HPLC. The antifungal activity of the extracts and their hydrolyzed mixture was also evaluated against dermatophytes. The contents of rhein in all stored decoction extracts remained more than 95% (95.69-100.66%) of the initial amount (0.0823 ± 0.001% w/w). There was no significant change of the extracts kept in glass vials and in aluminum foil bags. The decoction extract of C. fistula pod pulp and its hydrolyzed mixture containing anthraquinone aglycones were tested against clinical strains of dermatophytes by broth microdilution technique. The results revealed good chemical and antifungal stabilities against dermatophytes of C. fistula pod pulp decoction extracts stored under various accelerated and real time storage conditions.