Multilingual Speech Acquisition by Vietnamese-English-Speaking Children and Adult Family Members.

PURPOSE: This article presents a large-scale example of culturally responsive assessment and analysis of multilingual Vietnamese-English-speaking children and their family members using the VietSpeech Protocol involving (a) examining all spoken languages, (b) comparing ambient phonology produced by family members, (c) including dialectal variants in the definition of accuracy, and (d) clustering participants with similar language experience. METHOD: The VietSpeech participants (N = 154) comprised 69 children (2;0-8;10 [years;months]) and 85 adult family members with Vietnamese heritage living in Australia. Speech was sampled using the Vietnamese Speech Assessment (Vietnamese) and the Diagnostic Evaluation of Articulation and Phonology (English). RESULTS: Children's Vietnamese consonant accuracy was significantly higher when dialectal variants were accepted (percentage of consonants correct-dialect [PCC-D]: M = 87.76, SD = 8.18), compared to when only Standard Vietnamese was accepted as the correct production (percentage of consonants correct-standard [PCC-S]: M = 70.34, SD = 8.78), Cohen's d = 3.55 (large effect). Vietnamese voiced plosives, nasals, semivowels, vowels, and tones were more often correct than voiceless plosives and fricatives. Children's Standard Australian English consonant accuracy (PCC-S) was 82.51 (SD = 15.57). English plosives, nasals, glides, and vowels were more often correct than fricatives and affricates. Vietnamese word-initial consonants had lower accuracy than word-final consonants, whereas English consonant accuracy was rarely influenced by word position. Consonant accuracy and intelligibility were highest for children with high proficiency in both Vietnamese and English. Children's consonant productions were most similar to their mothers' than other adults or siblings' productions. Adults' Vietnamese consonants, vowels, and tones were more likely to match Vietnamese targets than their children's productions. CONCLUSIONS: Children's speech acquisition was influenced by cross-linguistic, dialectal, maturational, language experience, and environmental (ambient phonology) factors. Adults' pronunciation was influenced by dialectal and cross-linguistic factors. This study highlights the importance of including all spoken languages, adult family members, dialectal variants, and language proficiency to inform differential diagnosis of speech sound disorders and identify clinical markers in multilingual populations. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23290055.

Transcribing multilingual children's and adults' speech.

Speech-language pathologists (SLPs) face challenges in transcription and diagnosis of speech sound disorders (SSD) in multilingual children due to ambient language influences and cross-linguistic transfer. The VietSpeech Multilingual Transcription Protocol, a 4-step process to undertake impressionistic transcription of multilingual speech was tested using data from Vietnamese-Australian children (n = 69) and adult family members (n = 85). The transcription team included an English-speaking SLP, a Vietnamese-English-speaking linguist and accredited interpreter, and two Vietnamese-English-speaking SLPs. (1) Training: The team completed training together in Vietnamese and English phonology. (2) Speech assessment: The participants were assessed using the Diagnostic Evaluation of Articulation and Phonology (DEAP) in English and the Vietnamese Speech Assessment (VSA). (3) Transcription comparison: Inter-rater reliability for 10 children and 12 adults was calculated using consonant-by-consonant agreement. For English the 3-way inter-rater agreement was 92.62% for children and 88.69% for adults. For Vietnamese the 4-way inter-rater agreement was 86.57% for children and 96.05% for adults. There was a significant correlation between speech accuracy and inter-rater reliability for children's consonants in English (r = 0.95) and Vietnamese (r = 0.91), and adults' consonants in English (r = 0.90), but not for Vietnamese (r = 0.49). Reliability was influenced by phoneme class and whether the target consonant was shared between languages. (4) Rule generation and consensus: Rules based on near functional equivalence were implemented to maintain consistency and reach consensus. SLPs who do not speak clients' home languages can be supported to transcribe multilingual speech by working with multilingual teams, and understanding personal limitations during multilingual speech assessments.

Three Australian Lepidosperma Labill. Species as sources of prenylated and oxyprenylated derivatives of piceatannol, resveratrol and pinosylvin: Melatoninergic binding and inhibition of quinone reductase 2.

Prenylated and hydroxyprenylated piceatannol, resveratrol and pinosylvin derivatives were isolated from resin produced by three Australian Lepidosperma Labill. Species (Cyperaceae). From L. congestum R.Br. one known compound, 3',5'-bis-prenyl-E-resveratrol, and five undescribed compounds were isolated, 3'-O-prenyl-5'-prenyl-E-piceatannol, 5',6'-bis-prenyl-E-piceatannol, 5'-prenyl-E-piceatannol, 3',5'-bis(3-hydroxy-3-methylbutyl)-E-resveratrol and 3',5'-bis-E-hydroxyprenyl-E-resveratrol. From L. gunnii Boeckeler one undescribed compound was isolated, 3'-E-hydroxyprenyl-5'-Z-hydroxyprenyl-E-resveratrol. From L. laterale R.Br. six undescribed compounds were isolated, 3-O-prenyl-E-pinosylvin, 3-O-Z-hydroxyprenyl-E-pinosylvin, 3'-Z-hydroxyprenyl-E-resveratrol, 3-O-Z-hydroxyprenyl-E-resveratrol, 3-O-Z-hydroxyprenyl-4'-O-methyl-E-resveratrol, and 3-O-prenyl-3'-δ,δ'-dihydroxyprenyl-E-resveratrol. Compounds, including a reference compound 3-O-prenyl-3'-O-methyl-E-piceatannol, were screened in an assay for melatoninergic binding to MT1 and MT2 receptors and binding to QR2/MT3 enzyme, and for inhibition of QR2/MT3 in a functional assay. Strong binding was observed for 3-O-Z-hydroxyprenyl-E-resveratrol with a Ki of 0.022 nM and the strongest inhibition of QR2/MT3 observed was for the reference compound, 3-O-prenyl-3'-O-methyl-E-piceatannol, with an inhibition of 61% at 1 µM and 95% at 10 µM. The three most active binders and inhibitors of QR2/MT3 were found to have a common substructure corresponding to 3-O-prenylresveratrol.

SuperSpeech: Multilingual Speech and Language Maintenance Intervention for Vietnamese-Australian Children and Families via Telepractice.

PURPOSE: The aim of this pilot feasibility study was to evaluate the effectiveness of the group VietSpeech SuperSpeech program targeting speech skills and home language maintenance via telepractice. METHOD: In Stage 1, using a case-control design, 30 Vietnamese-English-speaking children were assessed in English and Vietnamese, and parents completed questionnaires about speech and language competency and practices. During Stage 2, children were allocated to intervention (n = 14) or control (n = 16) conditions. COVID-19 restrictions resulted in changes including nonrandom allocation. Online group intervention targeting speech, home language maintenance, and multilingualism as a superpower was delivered 1 hr/week for 8 weeks. For Stage 3, assessments were undertaken approximately 10 weeks after the pre-intervention assessment. RESULTS: Parents in the intervention group significantly increased encouragement of their children to speak Vietnamese. The intervention group significantly increased intelligibility in English. Growth of Vietnamese vocabulary was faster for the control group. There was a moderate effect of intervention for children's perception of being happy talking in Vietnamese and English. There was no significant mean change from pre- to post-intervention compared with the control group for measures of speech sound accuracy in Vietnamese or English, Vietnamese intelligibility, English vocabulary, or hours of Vietnamese spoken each week. CONCLUSIONS: This study presents preliminary evidence that this 8-hr online group program targeting speech skills and home language maintenance had some impact on Vietnamese-Australian children's speech and home language maintenance. Further research involving a randomized trial is warranted.

Speech acquisition within a 3-generation Vietnamese-English family: the influence of maturation and ambient phonology.

The emergence approach to speech acquisition theorises the influence of intrinsic capabilities (e.g., maturation), interactional capabilities, and extrinsic contexts (e.g., ambient phonology). Intrinsic and extrinsic influences were examined via a case study of a 3-generation Vietnamese-English family with two brothers (C1 aged 5;6 and C2 aged 3;10), their mother (M), grandfather (GF) and grandmother (GM). Their speech was assessed using the Diagnostic Evaluation of Articulation and Phonology (DEAP) and the Vietnamese Speech Assessment (VSA). Standard Australian English/Standard Vietnamese productions were defined as 'correct', even though the adults spoke different Vietnamese dialects. Their percentage of standard consonants correct (PSCC) was: C1 (English:92.27%, Vietnamese:89.05%), C2 (E:86.47%, VN:86.13%), M (E:90.34%, VN:96.35%), GF (E:82.61%, VN:97.81%), GM (VN:99.27%). Percentages were higher when dialectal variants were included. C1 and C2 had more pronunciation matches with English (86.96%) than Vietnamese (79.56%). C1's pronunciation matched: M (E:85.02%, VN:83.94%), GF (E:79.23%, VN:77.37%), GM (VN:73.72%) and C2's pronunciation matched: M (E:79.23%, VN:73.72%), GF (E:73.91%, VN:75.18%), GM (VN:72.26%). There was evidence of ambient phonology influences and cross-linguistic transfer. For example, in Vietnamese 'r' is produced as /ʐ/ or /r/ , but was produced by C1 as [ɹ] (English approximant) and by C2 [w] (age-appropriate/ɹ/substitution). The children demonstrated maturation influences for late-occurring English consonants (e.g., English /θ/ →[f]). This study found evidence for the emergence approach and recommends knowledge of the ambient phonology augments traditional child-focused understandings of children's speech acquisition.

Profiles of Linguistic Multicompetence in Vietnamese-English Speakers.

Purpose Speech-language pathologists work with increasing numbers of multilingual speakers; however, even when the same languages are spoken, multilingual speakers are not homogeneous. Linguistic multicompetence (aka multi-competence) considers competency across all languages and is associated with multiple demographic, migration, linguistic, and cultural factors. Method This article examines the linguistic multicompetence of adults with Vietnamese heritage living in Australia (n = 271) and factors associated with varying profiles of multilingualism. Participants completed a self-report questionnaire (available in English and Vietnamese) regarding their language proficiency and associated factors. Results Participants were largely (76.6%) first-generation migrants to Australia. Three distinct profiles of linguistic multicompetence were statistically identified using a cluster analysis: (a) Vietnamese proficient (n = 81, 31%), (b) similar proficiency (n = 135, 52%), and (c) English proficient (n = 43, 17%); that is, half were proficient in both languages. Multinomial logistic regression analyses compared participants profiled as having similar proficiency with those who were more dominant in one language. Factors associated with the Vietnamese proficient group (compared with the similar proficiency group) were that the participants used Vietnamese much more than English with different people across different situations, were more likely to believe that maintaining Vietnamese helped them communicate in English, and earned less. Participants in the English proficient group used English more than Vietnamese with different people across different situations, were more likely to have lived in English-speaking countries longer, were younger in age, and were less likely to believe that maintaining Vietnamese helped improve academic study than those with similar proficiency. Conclusion Undertaking a comprehensive language profile is an important component of any multilingual assessment to enable speech-language pathologists to develop an understanding of different presentations of linguistic multicompetence, engage in culturally responsive practice, and acknowledge that high levels of competence can be achieved across multiple languages. Supplemental Material https://doi.org/10.23641/asha.14781984.

Kangaroo Island propolis types originating from two Lepidosperma species and Dodonaea humilis.

The endemic Australian plants Lepidosperma sp. Flinders Chase (Cyperaceae), Lepidosperma viscidum (Cyperaceae) and Dodonaea humilis (Sapindaceae) were found to be the botanical origin of three propolis types found on Kangaroo Island identified by TLC and 1H NMR matching of propolis and plant resin analytical profiles. Resin samples extracted from the plant, Lepidosperma sp. Flinders Chase, were chromatographically fractionated to give: methyl 3-phenyl-2-(E-cinnamoyloxy)propanoate (1), 3-(E-8-methoxy-8-oxo-3,7-dimethyloct-2-enyl)-4-hydroxy-E-cinnamic acid (2), 3-(E-6,7-dihydroxy-3,7-dimethyloct-2-enyl)-4-hydroxy-E-cinnamic acid (3), previously undescribed; and the known stilbenes, 2-prenyl-3,5-dihydroxy-E-stilbene (6) and 2-prenyl-3-methoxy-5-hydroxy-E-stilbene (7). The resin from L. viscidum gave: 5'-(E-4-hydroxy-3-methylbut-2-enyl)-4,2',4'-trihydroxydihydrochalcone (4); 5'-(E-4-hydroxy-3-methylbut-2-enyl)-4'-methoxy-4,2'-dihydroxydihydrochalcone (5), previously undescribed; and three known flavanones, farrerol (8), 5,7,3',5'-tetrahydroxy-6,8-dimethylflavanone (9) and 5,7,3',5'-tetrahydroxy-6-methylflavanone (10). The major constituent in the propolis identified as being sourced from D. humilis was identified as 6,8-diprenyl-5,7,3',4'-tetrahydroxyflavanone (11), a known compound identified in several unrelated plant species.

Study of the beneficial role of exhaled nitric oxide in combination with GINA guidelines for titration of inhaled corticosteroids in children with asthma.

BACKGROUND: The use of FENO in association with current guidelines in the treatment of asthma has not been studied thoroughly. This study aimed to evaluate the beneficial role of FENO in combination with GINA (Global Initiative for Asthma) guidelines for titration of inhaled corticosteroids (ICS) in asthmatic children. METHODS: It was a prospective and descriptive study. Uncontrolled asthmatic children were randomized to two groups: group 1 (followed GINA guidelines) or group 2 (followed GINA guidelines + FENO modification for ICS titration). The two groups were followed-up for 12 months. RESULTS: The mean age of the patients in the study was 10 ± 4 years for group 1 (n = 116) and 11 ± 5 years for group 2 (n = 108). There were 87.9% patients in group 1 and 82.4% in group 2 that had a familial allergic history. There were 58.6% of moderate asthma and 41.4% of severe asthma in group 1, versus 56.4% and 43.6% in group 2, respectively. The percentage of moderate and severe asthma was also significantly modified after 6th and 12th month versus at inclusion (43.1% and 35.3% versus 58.6%, P < 0.01 and P < 0.005; 23.2% and 12.9% versus 41.4%, P < 0.005 and P < 0.001, respectively). The total daily dose of ICS in group 2 at 12th months was significantly lower than that in group 1 (3515 ± 1175 versus 4785 ± 1235 mcg; P < 0.005). The daily cost of ICS treatment in group 2 was also lower than that of group 1 (18 ± 4 versus 27 ± 3 USD; P < 0.05). CONCLUSION: The use of FENO in combination with GINA guidelines for ICS titration is useful in reducing the daily ICS dose and treatment cost.

A sedge plant as the source of Kangaroo Island propolis rich in prenylated p-coumarate ester and stilbenes.

Propolis samples from Kangaroo Island, South Australia, were investigated for chemical constituents using high-field nuclear magnetic resonance spectral profiling. A type of propolis was found containing a high proportion of prenylated hydroxystilbenes. Subsequently, the botanical origin of this type of propolis was identified using a beehive propolis depletion method and analysis of flora. Ligurian honey bees, Apis mellifera ligustica Spinola, were found to produce propolis from resin exuded by the Australian native sedge plant Lepidosperma sp. Montebello (Cyperaceae). The plants, commonly known as sword sedge, were found to have resin that matched with the propolis samples identified as the most abundant propolis type on the island containing C- and O-prenylated tetrahydroxystilbenes (pTHOS) in addition to a small amount of prenylated p-coumarate. The isolation of five pTHOS not previously characterized are reported: (E)-4-(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene, (E)-2,4-bis(3-methyl-2-buten-1-yl)-3,3',4',5-tetrahydroxystilbene, (E)-2-(3-methyl-2-buten-1-yl)-3-(3-methyl-2-butenyloxy)-3',4',5-trihydroxystilbene, (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,3',5,5'-tetrahydroxystilbene and (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene. A National Cancer Institute 60 human cell line anticancer screen of three of these compounds showed growth inhibitory activity. The large Australasian genus Lepidosperma is identified as a valuable resource for the isolation of substances with medicinal potential.

Preventative effect of Zingiber officinale on insulin resistance in a high-fat high-carbohydrate diet-fed rat model and its mechanism of action.

Insulin resistance is a core component of metabolic syndrome and usually precedes the development of type 2 diabetes mellitus. We have examined the preventative effect of an ethanol extract of ginger (Zingiber officinale, Zingiberaceae) on insulin resistance in a high-fat high-carbohydrate (HFHC) diet-fed rat model of metabolic syndrome. The HFHC control rats displayed severe insulin resistance, whilst rats treated with ginger extract (200 mg/kg) during HFHC diet feeding showed a significant improvement of insulin sensitivity using the homeostatic model assessment of insulin resistance (HOMA-IR) after 10 weeks (p < 0.01). An in vitro mechanistic study showed that (S)-[6]-gingerol, the major pungent phenolic principle in ginger, dose-dependently (from 50 to 150 µM) increased AMPK α-subunit phosphorylation in L6 skeletal muscle cells. This was accompanied by a time-dependent marked increment of PGC-1α mRNA expression and mitochondrial content in L6 skeletal muscle cells. These results suggest that the protection from HFHC diet-induced insulin resistance by ginger is likely associated with the increased capacity of energy metabolism by its major active component (S)-[6]-gingerol.

Identification of a Calcium Signalling Pathway of S-[6]-Gingerol in HuH-7 Cells.

Calcium signals in hepatocytes control cell growth, proliferation, and death. Members of the transient receptor potential (TRP) cation channel superfamily are candidate calcium influx channels. NF κ B activation strictly depends on calcium influx and often induces antiapoptotic genes favouring cell survival. Previously, we reported that S-[6]-gingerol is an efficacious agonist of the transient receptor potential cation channel subfamily V member 1 (TRPV1) in neurones. In this study, we tested the effect of S-[6]-gingerol on HuH-7 cells using the Fluo-4 calcium assay, RT-qPCR, transient cell transfection, and luciferase measurements. We found that S-[6]-gingerol induced a transient rise in [Ca(2+)] i in HuH-7 cells. The increase in [Ca(2+)] i induced by S-[6]-gingerol was abolished by preincubation with EGTA and was also inhibited by the TRPV1 channel antagonist capsazepine. Expression of TRPV1 in HuH-7 cells was confirmed by mRNA analysis as well as a test for increase of [Ca(2+)] i by TRPV1 agonist capsaicin and its inhibition by capsazepine. We found that S-[6]-gingerol induced rapid NF κ B activation through TRPV1 in HuH-7 cells. Furthermore, S-[6]-gingerol-induced NF κ B activation was dependent on the calcium gradient and TRPV1. The rapid NF κ B activation by S-[6]-gingerol was associated with an increase in mRNA levels of NF κ B-target genes: cIAP-2, XIAP, and Bcl-2 that encode antiapoptotic proteins.

(S)-[6]-Gingerol enhances glucose uptake in L6 myotubes by activation of AMPK in response to [Ca2+]i.

PURPOSE: The aim of this study was to investigate the mechanism of (S)-[6]-gingerol in promoting glucose uptake in L6 skeletal muscle cells. METHODS: The effect of (S)-[6]-gingerol on glucose uptake in L6 myotubes was examined using 2-[1,2-3H]-deoxy-D-glucose. Intracellular Ca2+ concentration was measured using Fluo-4. Phosphorylation of AMPKα was determined by Western blotting analysis. RESULTS: (S)-[6]-Gingerol time-dependently enhanced glucose uptake in L6 myotubes. (S)-[6]-Gingerol elevated intracellular Ca2+ concentration and subsequently induced a dose- and time-dependent enhancement of threonine172 phosphorylated AMPKα in L6 myotubes via modulation by Ca2+/calmodulin-dependent protein kinase kinase. CONCLUSION: The results indicated that (S)-[6]-gingerol increased glucose uptake in L6 skeletal muscle cells by activating AMPK. (S)-[6]-gingerol, a major component of Zingiber officinale, may have potential for development as an antidiabetic agent.

Attenuation of Proinflammatory Responses by S-[6]-Gingerol via Inhibition of ROS/NF-Kappa B/COX2 Activation in HuH7 Cells.

Introduction. Hepatic inflammation underlies the pathogenesis of chronic diseases such as insulin resistance and type 2 diabetes mellitus. S-[6]-Gingerol has been shown to have anti-inflammatory properties. Important inflammatory mediators of interleukins include nuclear factor κ B (NF κ B) and cyclooxygenase 2 (COX2). We now explore the mechanism of anti-inflammatory effects of S-[6]-gingerol in liver cells. Methods. HuH7 cells were stimulated with IL1ß to establish an in vitro hepatic inflammatory model. Results. S-[6]-Gingerol attenuated IL1ß-induced inflammation and oxidative stress in HuH7 cells, as evidenced by decreasing mRNA levels of inflammatory factor IL6, IL8, and SAA1, suppression of ROS generation, and increasing mRNA levels of DHCR24. In addition, S-[6]-gingerol reduced IL1ß-induced COX2 upregulation as well as NF κ B activity. Similar to the protective effects of S-[6]-gingerol, both NS-398 (a selective COX2 inhibitor) and PDTC (a selective NF κ B inhibitor) suppressed mRNA levels of IL6, IL8, and SAA1. Importantly, PDTC attenuated IL1ß-induced overexpression of COX2. Of particular note, the protective effect of S-[6]-gingerol against the IL1ß-induced inflammatory response was similar to that of BHT, an ROS scavenger. Conclusions. The findings of this study demonstrate that S-[6]-gingerol protects HuH7 cells against IL1ß-induced inflammatory insults through inhibition of the ROS/NF κ B/COX2 pathway.

Synthesis of C- and O-prenylated tetrahydroxystilbenes and O-prenylated cinnamates and their action towards cancer cells.

Synthesis of the naturally occurred C- and O-prenylated tetrahydroxystilbenes and O-prenylated cinnamates was carried out by decarbonylative Heck reaction and selenium dioxide catalysed oxidation, respectively. In the decarbonylative Heck synthetic route, fusion of benzoyl chloride and styrene derivatives was catalysed by an N-heterocyclic carbene system generated in situ by palladium acetate and 1,3-bis(2,6-diisopropylphenyl)imidazolinium chloride to form a E-tetrahydroxystilbene derivative. Formation of allyl ether was subsequently carried out by reaction of the deprotected OH in the A phenyl ring of the stilbene with 3,3-dimethylallyl bromide and a base (sodium hydride) to form O-prenylated tetrahydroxystilbene derivatives. [1,5]-Rearrangement of the isoprenyl unit from O- to C-position in the A ring was carried out at elevated temperature in the presence of magnesium silicate (Florisil) to form the corresponding C-prenylated tetrahydroxystilbene. Formation of O-prenylated cinnamate was first carried out by base catalysed allyl ether formation between 3,3-dimethylallyl bromide and hydroxycinnamic acid methyl ester. The methyl group of the isoprenyl unit was subsequently oxidized using selenium dioxide to form a terminal hydroxyl group. The prenylated tetrahydroxystilbenes and cinnamate synthesized in this study were novel derivatives of piceatannol and methyl 4-(3'-methylbut-2'-enyloxy)cinnamate isolated from propolis in Kangaroo Island, South Australia. The synthetic compounds were tested against K562 cancer cells and potent growth inhibitory activity was observed for E-1-[5-hydroxy-3-methoxy-2-(3-methyl-2-butenyl)phenyl]-2-[4-hydroxy-3-methoxyphenyl]ethene, IC50 = 0.10 µM.

Preventive and Protective Properties of Zingiber officinale (Ginger) in Diabetes Mellitus, Diabetic Complications, and Associated Lipid and Other Metabolic Disorders: A Brief Review.

Zingiber officinale (ginger) has been used as herbal medicine to treat various ailments worldwide since antiquity. Recent evidence revealed the potential of ginger for treatment of diabetes mellitus. Data from in vitro, in vivo, and clinical trials has demonstrated the antihyperglycaemic effect of ginger. The mechanisms underlying these actions are associated with insulin release and action, and improved carbohydrate and lipid metabolism. The most active ingredients in ginger are the pungent principles, gingerols, and shogaol. Ginger has shown prominent protective effects on diabetic liver, kidney, eye, and neural system complications. The pharmacokinetics, bioavailability, and the safety issues of ginger are also discussed in this update.

Propolis with high flavonoid content collected by honey bees from Acacia paradoxa.

Honey bees, Apis mellifera var ligustica, on Kangaroo Island, Australia, were found to collect propolis from the sticky exudate on the stem shoots and seed pods of an Australian endemic plant, Acacia paradoxa. Extracts of the plant stem shoots and seed pods, the propolis carried on the legs of bees and freshly collected propolis in hives contained major flavonoid components consisting of 2',3',4'-trimethoxychalcone, 2'-hydroxy-3',4'-dimethoxychalcone, 2',4'-dihydroxy-3'-methoxychalcone, 5,7-dihydroxy-2,3-dihydroflavonol 3-acetate (pinobanksin 3-acetate) and 5,7-dihydroxy-6-methoxy-2,3-dihydroflavonol 3-acetate, a substance not previously characterized. HPLC and (1)H NMR analyses of the propolis and plant extracts indicated smaller amounts of other flavonoids. A survey of propolis samples from 47 apiary sites widely distributed on Kangaroo Island showed that 15 samples from 6 sites were largely sourced from A. paradoxa.

Gingerols of Zingiber officinale enhance glucose uptake by increasing cell surface GLUT4 in cultured L6 myotubes.

In this study we investigate the active constituents of the rhizome of Zingiber officinale, Roscoe (ginger) and determine their activity on glucose uptake in cultured L6 myotubes and the molecular mechanism underlying this action. Freeze-dried ginger powder was extracted with ethyl acetate (1 kg/3 L) to give the total ginger extract, which was then separated into seven fractions, consisting of nonpolar to moderately polar compounds, using a short-column vacuum chromatographic method. The most active fraction (F7) was further purified for identification of its active components. The effect of the extract, fractions, and purified compounds on glucose uptake was evaluated using radioactive labelled 2-[1,2-³H]-deoxy-D-glucose in L6 myotubes. The pungent phenolic gingerol constituents were identified as the major active compounds in the ginger extract enhancing glucose uptake. (S)-[6]-Gingerol was the most abundant component among the gingerols, however, (S)-[8]-gingerol was the most potent on glucose uptake. The activity of (S)-[8]-gingerol was found to be associated primarily with an increase in surface distribution of GLUT4 protein on the L6 myotube plasma membrane, as detected by expression of hemagglutinin epitope-tagged GLUT4 in L6 muscle cells. The enhancement of glucose uptake in L6 rat skeletal muscle cells by the gingerol pungent principles of the ginger extract supports the potential of ginger and its pungent components for the prevention and management of hyperglycemia and type 2 diabetes.

Prenylated cinnamate and stilbenes from Kangaroo Island propolis and their antioxidant activity.

A prenylated cinnamic acid derivative as well as six prenylated tetrahydroxystilbenes were isolated from the ethyl acetate extract of propolis that originated from Kangaroo Island, Australia. Furthermore, six known stilbenes and two known flavanones were also identified from the same sample. Stilbenes are not common in propolis; therefore, Kangaroo Island propolis is considered a unique type of propolis that is rich in prenylated stilbenes. Stilbene propolis from Kangaroo Island showed a stronger scavenging activity towards DPPH free radical than Brazilian green propolis. This strong activity can be explained by the presence of large number of stilbenes, most of them showed strong free radical scavenging activity.

Modulation of P-glycoprotein-mediated anticancer drug accumulation, cytotoxicity, and ATPase activity by flavonoid interactions.

Flavonoids are components of plant foods and of many herbal medicines taken in combination with anticancer drugs. We have examined the potential of flavonoids to affect the accumulation and cytotoxicity of 3 cytotoxic drugs [vinblastine (VLB), daunorubicin (DNR), and colchicine (COL)] that are substrates for the ABC transporter, P-glycoprotein in a vinblastine-resistant T-cell leukemia, CEM/VBL(100), that overexpresses P-glycoprotein. The effects of the flavonoids on accumulation and cytotoxicity of these drugs were different depending on the P-gp substrate used. Most of the 30 flavonoids tested decreased DNR accumulation in the VBL-resistant, but not sensitive, leukemia cells. By contrast, flavonoids that inhibited DNR accumulation enhanced the accumulation of fluorescently labeled vinblastine. None of these flavonoids affected COL accumulation. The effects of the flavonoids on the cytotoxicities of these drugs paralleled their effects on accumulation; the same flavonoids decreased DNR cytotoxicity but increased VLB cytotoxicity and had no effect on COL. Verapamil reversed the accumulation deficit and cytotoxicity of all three P-gp substrates. These effects correlated with the effects of flavonoids on P-gp-ATPase activity. Flavonoids that decreased DNR accumulation stimulated DNR-activated P-gp ATPase, whereas flavonoids that increased fluorescently labeled VLB accumulation inhibited VBL-stimulated P-gp ATPase activity, thereby accounting for the decrease or increase in cancer drug accumulation in resistant cells. We conclude that flavonoids often ingested by cancer patients may have different effects on anticancer drugs and that these findings should be considered in designing future combination treatments for cancer patients.

Characterization of PXR mediated P-glycoprotein regulation in intestinal LS174T cells.

Intestinal P-glycoprotein (P-gp) is an important target in drug-drug interactions. Pregnane X receptor (PXR) mediates the induction of intestinal P-gp. The LS174T intestinal cell line has been used in several studies as an in vitro tool to identify the effect of PXR inducers on intestinal P-gp expression. In this study we aimed to further characterize this cell line by focusing on the time dependence of P-gp expression, localization and function in the presence of rifampicin, a P-gp inducer. P-gp protein expression was increased in a time and dose dependent manner following exposure of cells to rifampicin (5-50 µM). The induction of P-gp by rifampicin and its inhibition by ketoconazole (an inhibitor of PXR mediated P-gp induction) confirms the suitability of these cells for PXR induction studies. Confocal microscopy showed that P-gp translocated from intracellular compartments to plasma membrane over 7 days in LS174T cells. P-gp function, as established by rhodamine 123 (Rh123) intracellular accumulation, correlated with increasing P-gp expression and plasma membrane localization over this period. Our data demonstrates that LS174T cells provide a suitable in vitro model to test for the effect of PXR inducers/inhibitors on P-gp induction, localization and function over this culture period. This model also has application for the screening of drug candidates for effects on oral bioavailability via effects on the subcellular distribution and trafficking of P-gp.