No abstract

The current study investigated the inhibiting effect on reactive oxygen species (ROS), reactive nitrogen species (RNS), and matrix metalloproteinase-1 (MMP-1) production in a cell-based study of standardized rosmarinic acid enriched extract (SRAEE) prepared from Thunbergia laurifolia leaves. HPLC chromatogram revealed that rosmarinic acid is a major component in prepared SRAEE, followed by caffeic acid. SRAEE exhibited antioxidant activity both in vitro and cell-based studies. SRAEE showed scavenging effects on nitric oxide and superoxide anion and inhibition effects on lipid peroxidation in vitro. SRAEE also inhibited ROS and MMP-1 production in normal human dermal fibroblast cells induced by H2O2 and UVA, respectively, without exerted cytotoxicity. Additionally, collagen degradation was protected by SRAEE induced by UVA. Nitric oxide and inducible nitric oxide synthase (iNOS) productions were also inhibited by SRAEE in RAW264.7 mouse macrophage cells induced by combined lipopolysaccharide (LPS)-interferon-γ (IFN-γ). The results indicated that SRAEE is a potential candidate as a natural pharmaceutical active ingredient for cosmeceutical product application.

This study was carried out to investigate the protective effect of standardized γ-oryzanol-rich extracts on oxidative DNA damage induced by Fenton reaction and antiproliferative activity against human cancer cells. Six cultivars of Thai purple rice were collected in northern Thailand. Rice bran was extracted with hexane/ethyl acetate mixture and the extract was evaporated to obtain crude rice bran oil. Each rice bran oil was further purified by column chromatography to obtain the γ-oryzanol-rich extract. The extracts contained γ-oryzanol in the range of 1.17 -7.54 % w/w, in which GAM THOR exhibited the highest γ-oryzanol content. The extr \acts containing more than 5.0 % w/w γ-oryzanol (GAM THOR, GAM DOI MUSUR and GAM SUKHOTHAI-2) were selected to be standardized with γ-oryzanol and then the protective effect on oxidative DNA damage and antiproliferative activity against four human cancer cell lines (HT-29, HCT 116, MDA-MB-468 and PC3) were investigated. The extracts (10 µg/ml) exhibited a protective effect on oxidative DNA damage induced by Fenton reaction as compared with standard quercetin (lower than 5 µg/ml). Furthermore, all of the extracts exerted antiproliferative activity against human cancer cell lines in a dose-dependent manner. GAM THOR exhibited the highest antiproliferative activity against HT-29, HCT 116, MDA-MB-468 and PC3 with an 50% inhibition concentration value of 52.18 ± 1.21, 40.58 ± 5.69, 48.59 ± 2.40 and 51.61 ± 1.30 µg/ml, respectively. From these findings, γ-oryzanolrich extracts from Thai purple rice bran show potential as chemopreventive supplements or in nutraceuticals.

Five glutinous purple rice cultivars and non-glutinous purple rice cultivated in different altitudes in the north of Thailand were collected. The samples were extracted using ethanol and determined for anthocyanins using HPLC. The total phenolic content (TPC), total flavonoid content (TFC), and the antioxidant, anti-inflammatory, and antimicrobial activities against foodborne pathogens were investigated. The highland glutinous cultivar named Khao’ Gam Luem-Phua (KGLP) extract had significantly high levels of cyanidin 3-O-glucoside, peonidin 3-O-glucoside, delphinidin 3-O-glucoside, TPC, and TFC, as well as exerting a potent antioxidant activity through ABTS assay (524.26 ± 4.63 VCEAC, mg l-ascorbic-ascorbic/g extract), lipid peroxidation (IC50 = 19.70 ± 0.31 µg/mL), superoxide anions (IC50 = 11.20 ± 0.25 µg/mL), nitric oxide (IC50 = 17.12 ± 0.56 µg/mL), a suppression effect on nitric oxide (IC50 = 18.32 ± 0.82 µg/mL), and an inducible nitric oxide synthase production (IC50 = 23.43 ± 1.21 µg/mL) in combined lipopolysaccharide-interferon-γ-activated RAW 264.7 murine macrophage cells. Additionally, KGLP also exhibited antimicrobial activity against foodborne pathogens, Staphylococcus aureus, Escherichia coli, Salmonella Enteritidis, and Vibrio parahaemolyticus. These results indicate that Thai glutinous purple rice cultivated on the highland could be a potent natural source of antioxidants, anti-inflammatories, and antimicrobial agents for use as a natural active pharmaceutical ingredient in functional food and nutraceutical products.

Recipes for Thai traditional herbal teas have been formulated based on Thai traditional medicine, which tries to achieve a balance of the body’s elements (fire, water, wind and earth) in each season. This study aims to assess the benefits of Thai traditional herbal teas through evaluating their antioxidant properties and measuring the satisfaction levels of healthy volunteers. Antioxidant activity tests performed on 11 tea recipes and on green tea (positive control) included 2,2-diphenyl-1-picrylhydrazyl (DPPH), a radical scavenging assay and a 2,2’-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) assay. In addition, total phenolic contents were determined using a Folin-Ciocalteu assay. Tests of satisfaction were performed on volunteer subjects aged between 18 and 30 years old, using the criteria of color, flavor, taste and overall satisfaction. Among the 11 tea recipes tested, the summer recipe 1 containing Aegle marmelos (L.) Correa, Stevia rebaudiana (Bert.) Bertoni, Pandanus amaryllifolius Roxb. and Morus alba L. demonstrated the most promising antioxidant properties (p > 0.05) and a phenolic content (p > 0.05), which was comparable to green tea. Furthermore, it got the highest satisfaction scores in every assessed category. Therefore, this study shows that Thai traditional herbal teas, developed based on the concepts of Thai traditional medicine, could be a good choice for people looking for health-promoting beverages.

Caesalpinia sappan L. heartwood was collected from Mae Chaem District, Chiang Mai Province, Thailand. Crude extracts were prepared by Soxhlet’s extraction using 50, 60, and 70% of ethanol (EtOH) at 50, 60, and 70 °C, and the brazilin content was measured using reversed-phase high performance liquid chromatography (RP-HPLC). The antibacterial activity against foodborne pathogens and anti-inflammatory aspects were investigated. C. sappan, prepared from 70% EtOH at 70 °C (E70T70), significantly (p < 0.05) exhibited the highest amount of brazilin (7.90 ± 0.50% w/w). All extracts were investigated for anti-inflammatory activity through an inhibition effect on nitric oxide (NO) and inducible nitric oxide synthase (iNOS) production in RAW264.7 mouse macrophage cells. The inhibitory effect on cyclooxygenase-2 (COX-2) production in HT-29 and HCT116 was also studied. All the extracts inhibited NO, iNOS, and COX-2 production induced by combined lipopolysaccharide and interferon-γ, especially E70T70, indicating the highest inhibition effect among other extracts. Additionally, E70T70 was selected to determine the antibacterial activity against foodborne pathogens, including Staphylococcus aureus, Escherichia coli, Salmonella enteritidis, and Vibrio parahaemolyticus. The result showed that 200 µg/mL extract reduced all test pathogens 100% at 24 h. These results suggested the potential of using C. sappan L. extract as a natural preservative in food and a natural active pharmaceutical ingredient.

Dracaena fragrans (L.) Ker Gawl., with its green leaves and attractive shape, is a popular ornamental plant in Thailand, used for both interior decorating and outdoor landscaping. Its fragrant flowers only bloom at night. This study investigated the volatile chemicals from the flowers of D. fragrans during the day and night. Volatile compounds were extracted by Head Space Solid Phase Micro-extraction (HS-SPME) technique and determined by Gas Chromatography-Mass Spectrometry (GC-MS). Thirty compounds were identified; sesquiterpenes were the most prevalent (α-farnesene, 23.1-50.8%). The composition of the volatile compounds from the flowers differed between day and night.

Traditional medicine uses a multitude of plants to create medicinal formulations, some of which show antiviral properties that may be of benefit in treating emerging viral diseases, including Covid-19. Lanna, an ancient Kingdom in northern Thailand, with a thriving culture that continues to this day and has a rich history of traditional medicine using local plants that is still practiced today. To find potential antiviral medicinal candidates, we examined ancient manuscripts, interviewed traditional healers practicing today, and inventoried current traditional medicines to catalogue 1400 medicinal formulations used in Lanna traditional medicine. We then narrowed this list to find those traditionally used to treat diseases that in their original use and descriptions most likely map to those we know today to be viral diseases. We identified the plants used in these formulations to create a list of 64 potential antiviral herbal candidates drawn from this ancient Lanna wisdom and matched these to the scientific literature to see which of these plants had already been shown to possess antiviral properties, generating a list of 64 potential antiviral medicinal candidates from Lanna traditional medicine worth further investigation for treating emerging viral diseases.