Exploring in vitro anti-proliferative and anti-inflammatory activities of Prasachandaeng remedy, and its bioactive compounds.

BACKGROUND: Prasachandaeng (PSD) remedy has been empirically used in Thai traditional medicine to treat fever in bile duct and liver and cancer patients through Thai folk doctors. However, there have been no scientific reports on the bioactive compounds and bioactivities related to inflammation-associated carcinogenesis or cytotoxicity against cancer cell lines. In this study, we investigated the chemical content of the remedy, and evaluated its cytotoxic activity against two cancer cell lines in comparison with a non-cancerous cell line and determined tumor necrosis factor-alpha (TNF-α) production in a murine macrophage cell line (RAW 264.7) to evaluate anti-inflammatory activity. A novel HPLC method was used for quality control of its chemical content. METHODS: Pure compounds from the EtOH extract of D. cochinchinensis were isolated using bioassay-guided fractionation and chemical content of the PSD remedy was determined using HPLC. The cytotoxic activity against the hepatocarcinoma cell line (HepG2) and cholangiocarcinoma cell line (KKU-M156), in comparison with non-cancerous cell line (HaCaT), were investigated using antiproliferative assay (SRB). The anti-inflammatory activity measured by TNF-α production in RAW 264.7 was determined using ELISA. RESULTS: All crude extracts and isolated compounds exhibited significant differences from vincristine sulfate (****p < 0.0001) in their cytotoxic activity against HepG2, KKU-M156, and HaCaT. The PSD remedy exhibited cytotoxic activity against HepG2 and KKU-M156 with IC50 values of 10.45 ± 1.98 (SI = 5.3) and 4.53 ± 0.74 (SI = 12.2) µg/mL, respectively. Some constituents from C. sappan, D. cochinchinensis, M. siamensis, and M. fragrans also exhibited cytotoxic activity against HepG2 and KKU-M156, with IC50 values less than 10 µg/mL. The isolated compounds, i.e., Loureirin B (1), 4-Hydroxy-2,4'-dimethoxydihydrochalcone (2), and Eucomol (3) exhibited moderate cytotoxicity against two cancer cell lines. None of the crude extracts and isolated compounds showed cytotoxicity against HaCaT. D. cochinchinensis and PSD remedy exhibited higher anti-inflammatory activity measured as TNF-α production than acetaminophen. CONCLUSION: The findings provide evidence of bioactivity for EtOH extracts of PSD remedy and the isolated compounds of D. Cochinchinensis. The results consistent the use clinical activity and use of PSD remedy as a antipyretic treatment for liver and bile duct cancer patients by Thai traditional practitioners.

Development and optimization of Benjakul microemulsion formulations for enhancing topical anti-inflammatory effect and delivery.

Background and purpose: Benjakul (BJK) is a combination of five botanical herbal constituents widely used in Thai traditional medicine as an anti-inflammatory remedy. This study aimed to develop a novel topical microemulsion containing BJK for clinical use. Experimental approach: The microemulsions were produced by a phase inversion temperature (PIT) methodology. Physicochemical properties and stability were evaluated to determine an optimal formula. The stable BJK-loaded microemulsion formulas were then subjected to in vitro studies for their anti-inflammatory activity, skin cell toxicity, drug permeation, and stability. Finding/Results: Two novel formulations containing isopropyl myristate (ME1-BJK and ME2-BJK) passed the compendial stability test. BJK constituents were completely dissolved in the oil phase and incorporated into the microemulsion base Transcutol® and Labrasol® avoiding the use of alcohol, both microemulsion formulations demonstrated high anti-inflammatory activity with IC50 values of 3.41 ± 0.36 and 3.95 ± 1.73 µg/mL, respectively. However, dissolution of ME1-BJK showed a superior release profile through both lipophilic and hydrophilic membranes with the highest accumulated amount at 4 h of 25.13% and 38.06%, respectively. All tested formulations of BJK extract demonstrated no apparent skin cell toxicity at concentrations up to 50 µg/mL. After six-month storage under accelerated conditions, there were no significant changes in anti-inflammatory activity. Conclusions and implications: A novel and stable BJK-loaded microemulsion formulation was successfully developed with excellent release and stability properties. Further clinical research to evaluate pain reduction, edema, and skin irritation using this formulation in animal models is ongoing.

Investigations of the antipyretic effect and safety of Prasachandaeng, a traditional remedy from Thailand national list of essential medicines.

Prasachandaeng (PSD) remedy from the Thailand National List of Essential Medicines (NLEM) has been used as an antipyretic for chronic fever in both adults and children for centuries. Its therapeutic effect in treating fever and its safety have not been studied in animal models. We evaluated its antipyretic activity on lipopolysaccharide (LPS)-induced fever and safety in the liver in comparison with acetaminophen (ACP). Correlation between biochemistry of liver function and the level of cytochrome P450 (CYP2E1) was also evaluated using an ELISA kit. All doses of PSD powder (PSDP) and a 95% ethanol extract of PSD (PSDE) (50, 200, and 400 mg/kg) showed a significant antipyretic effect (* p < 0.05) as compared to ACP. We investigated clinical biochemistry of liver and kidney functions, histopathology, and concentrations of CYP2E1. All treatment groups demonstrated a normal range of clinical biochemistry of liver and kidney functions in comparison with ACP on days 1, 3, 7, and 10. Serum AST, ALP, and LDH levels of PSDE and PSDP showed mean values less than that of ACP on the corresponding days (* p < 0.05). None of the treatment groups showed evidence of hepatocellular damage, nor did they affect CYPE21. The results of histopathology on liver tissue correlated with the biochemistry of liver functions which indicated no hepatotoxicity effect in liver tissue during the seven day treatment. These findings suggest that both forms of PSD remedy possessed marked antipyretic activity and were not hepatotoxic during the seven days of administration in rats.

The effects of Benjakul extract and its isolated compounds on cell cycle arrest and apoptosis in human non-small cell lung cancer cell line NCI-H226.

BACKGROUND AND PURPOSE: Benjakul, a traditional Thai formulation for cancer treatment, is composed of five plants. This study aimed to assess the cytotoxicity of Benjakul, its five plants, and its isolated compounds against non-small cell lung cancer (NSCLC) by the sulforhodamine B (SRB) assay. EXPERIMENTAL APPROACH: Analyses of cell cycle and membrane asymmetry changes were performed with different fluorescent dyes and analyzed by flow cytometry in NCI-H226 cells. Activation of caspase-3 was measured using a caspase-3 colorimetric assay kit. The pan-caspase inhibitor Z-VAD-FMK was used in analyses of cell cycle and caspase-3 activity. FINDINGS/RESULTS: Benjakul exhibited cytotoxicity against NSCLC with IC50 between 5.56-5.64 µg/mL. Among its five ingredients, Benjakul displayed the highest selectivity with selectivity index values ranging from 2.93 to 6.88, with the exception of Plumbago indica, indicating its protective effects. Plumbagin and 6- shogaol displayed the highest cytotoxicity and underwent molecular studies in NCI-H226 cells. Flow cytometry analysis revealed that Benjakul and 6-shogaol dose-dependently induced G2/M phase arrest, and plumbagin dose-dependently induced S-G2/M phase arrest with the highest percentage in early incubation time (12-24 h). At the highest doses, Benjakul extract, 6-shogaol, and plumbagin time-dependently increased the population of sub-G1 apoptotic cells with the highest percentage in longer incubation time (60-72 h). Similarly, membrane asymmetry changes showed time-dependent increases in the percentage of early and late apoptotic cells. Moreover, the apoptosis-inducing effect of Benjakul, 6-shogaol, and plumbagin at the highest dose, via the caspase cascade was confirmed by time-dependent induction of caspase-3 activity, followed by its complete reduction and abolished sub-G1 peaks upon addition of Z-VAD-FMK. CONCLUSION AND IMPLICATION: Our findings demonstrated for the first time the effects of Benjakul and its compounds on S-G2/M or G2/M phase arrest and caspase-dependent apoptosis in lung cancer cells.

Development of an Assessment Tool of Menstrual-Cycle-Related Signs and Symptoms Based on Thai Traditional Medicine Principles for Evaluation of Women's Health.

BACKGROUND: Utilization of Thai traditional medicine (TTM) was considered in menstrual-cycle-related signs and symptoms (MCSs) to evaluate women's health. TTM clinicians diagnosed the MCSs by signs, symptoms, and associated factors of patients including a physical examination to find patterns of imbalance elements and the origin of the disorder to optimize treatment. Thus, the purpose of this study was to develop a new assessment tool, the menstrual-cycle-related signs and symptoms questionnaire (MCSQ) based on TTM principles for evaluation of women's menstrual health. METHODS: The items and components of the MCSQ were adjusted by TTM expert consensus using the Delphi technique. The content validity of the MCSQ was quantified by the content validity index (CVI). MCSQ were examined by construct validity and internal consistency reliability using exploratory factor analysis (EFA) and Cronbach's α coefficient, respectively. RESULTS: : All 19 experts (100%) responded to the questionnaires in the three rounds of the Delphi technique. The MCSQ showed high content validity of individual items (I-CVI = 0.83-1.00) and high overall content validity of the questionnaire (S-CVI/AVE = 0.98). Overall, 429 of 432 participants completed the questionnaire (99.31%). After factor analysis, the final MCSQ was divided into two sections, which consisted of 49 items. The first had 23 items focusing on the MCSs. And, the second had 14 items of personal and medical data including 12 items of associated factors. Cronbach's α coefficient of the final MCSQ was 0.87, and that of each component was between 0.32 and 0.82. CONCLUSIONS: This study reports a new MCS questionnaire tool, which was developed from TTM knowledge to evaluate women's health. This questionnaire showed an acceptable level of validity and reliability. Thus, it is also expected to be useful in clinical practice and ongoing research on evaluation of women's health.

Anti-Inflammatory Investigations of Extracts of Zanthoxylum rhetsa.

Zanthoxylum rhetsa has been consumed in the diet in northern Thailand and also used as a medicament in ancient scripture for arthropathies. Thus, this study aimed to evaluate the activity of various extracts from differential parts of Z. rhetsa via inhibition of inflammatory mediators (NO, TNF-α, and PGE2) in RAW264.7 macrophages. The chemical composition in active extracts was also analyzed by GC/MS. The parts of this plant studied were whole fruits (F), pericarp (P), and seed (O). The methods of extraction included maceration in hexane, 95% ethanol and 50% ethanol, boiling in water, and water distillation. The results demonstrated that the hexane and 95% ethanolic extract from pericarp (PH and P95) and seed essential oil (SO) were the most active extracts. PH and P95 gave the highest inhibition of NO production with IC50 as 11.99 ± 1.66 µg/ml and 15.33 ± 1.05 µg/ml, respectively, and they also showed the highest anti-inflammatory effect on TNF-α with IC50 as 36.08 ± 0.55 µg/ml and 34.90 ± 2.58 µg/ml, respectively. PH and P95 also showed the highest inhibitory effect on PGE2 but less than SO with IC50 as 13.72 ± 0.81 µg/ml, 12.26 ± 0.71 µg/ml, and 8.61 ± 2.23 µg/ml, respectively. 2,3-Pinanediol was the major anti-inflammatory compound analyzed in PH (11.28%) and P95 (19.82%) while terpinen-4-ol constituted a major anti-inflammatory compound in SO at 35.13%. These findings are the first supportive data for ethnomedical use for analgesic and anti-inflammatory activity in acute (SO) and chronic (PH and P95) inflammation.

Efficacy and Safety of Sahastara Remedy Extract Capsule in Primary Knee Osteoarthritis: A Randomized Double-Blinded Active-Controlled Trial.

Sahastara (SHT) remedy is a Thai traditional medicine described in the Thai National List of Essential Medicine (NLEM) for the relief of muscle pain. The purpose of this study was to investigate the efficacy and safety of SHT remedy extract capsule for treating primary OA. A phase 2, double-blind, randomized, and controlled trial study was used to determine the clinical efficacy and safety of SHT in comparison with diclofenac for the treatment of knee OA. The outcome of reduce pain was measured from VAS, 100 meter time walk, and the WOMAC score of day 14 and day 28 which should reduce significantly when compared with day 0 and should be equal with or better than diclofenac. Blood pressure and blood chemistry values at day 14 and day 28 did not change when compared with day 0. The results found that SHT remedy ethanolic extract capsule can reduce all OA knee scores at day 14 and day 28 significantly when compared with day 0 and also no significant difference with diclofenac (P > 0.05). The SHT also showed safety values on blood pressure and blood chemistry. The SHT was observed that it had no serious side effect. The results of this study are the first report of using the SHT ethanolic extract capsule in the treatment of primary osteoarthritis of the knee. It can be recommended as an anti-inflammatory herbal drug for reducing pain in knee osteoarthritis patients.

Effects of Various Preextraction Treatments of Crinum asiaticum Leaf on Its Anti-Inflammatory Activity and Chemical Properties.

Crinum asiaticum Linn. has been used in Thai traditional medicine to relieve inflammatory symptoms and treat osteoarthritis. There have been reports on its potent anti-inflammatory property but nothing on the effects of different pretreatments on its chemical properties and anti-inflammatory activity. Pretreatment of herbal raw materials is an important step which affects the overall quality of Thai traditional medicine. The objectives of this study were to investigate different treatments of C. asiaticum leaves prior to ethanolic extraction and to compare the extracts for their anti-inflammatory activity and chemical properties. The treatments included hot air drying in an oven, microwave drying, traditional grilling on a charcoal stove before drying in an oven, and temperature shock in hot and cold water before hot air drying. The anti-inflammatory activity and chemical properties of the extracts were analyzed using the established methods. Results showed that 95% ethanolic extract of hot air oven-dried leaves had the highest anti-inflammatory activity and total phenolic and lycorine contents. We recommend hot air drying as a preextraction treatment for C. asiaticum leaves for its simplicity, best retention of the herbal quality, and suitability for scaling up to an industrial process.

Ethnopharmacological analysis from Thai traditional medicine called prasachandaeng remedy as a potential antipyretic drug.

ETHNOPHARMACOLOGICAL RELEVANCE: Prasachandaeng (PSD) remedy is a famous antipyretic drug for adults and children in Thai traditional medicine used and is described in Thailand's National List of Essential Medicine. Relationship between the taste of this herbal medicine, ethnopharmacological used and its pharmacological properties was reviewed. AIMS OF STUDY: Since there has been no scientific report on the antipyretic activity of PSD, aim of this study was to investigate the efficacy related antipyretic drug of the remedy and its 12 herbal ingredients. It involved quality evaluation of raw materials, extraction of PSD and its ingredients, in vitro evaluation of their inhibitory activities on fever mediators, i.e. NO and PGE2 production in murine macrophage (RAW 264.7) cell line stimulated by lipopolysaccharide, and its stability study of the 95% ethanolic extract of PSD remedy. MATERIALS AND METHODS: PSD remedy was extracted by maceration with 50% and 95% ethanol (PSD50 and PSD95), by decoction with distilled water (PSDW), and hydrolysis of PSDW with 0.1 N HCl (PSDH). The 12 plant ingredients were extracted with 95% ethanol. Quality evaluation of PSD ingredients was performed according to the standard procedures for the quality control of herbal materials. The inhibitory activity on nitric oxide production was determined by the Griess reaction and the inhibition of prostaglandin E2 production was determined using the ELISA test kit. RESULTS: PSD ingredients passed the quality standard stipulated for herbal materials. PSD95 exhibited the highest inhibitory activities on the production of NO and PGE2 with the IC50 values of 42.40 ± 0.72 and 4.65 ± 0.76 µg/mL, respectively. A standard drug acetaminophen (ACP) exhibited inhibition of NO and PGE2 production with the IC50 values of 99.50 ± 0.43 and 6.110 ± 0.661 µg/mL, respectively. The stability study was suggested two years shelf-life of PSD95. This is the first report on the activity related antipyretic activity of PSD remedy and its ingredients against two fever mediators, NO and PGE2. CONCLUSION: The results suggested that the 95% ethanolic extracts of PSD remedy and some of its ingredients, were better than ACP in reducing fever. PSD should be further studied using in vivo models and clinical trials to support its use as an antipyretic drug in Thai traditional medicine.

In Vitro Cytotoxic Activity against Breast, Cervical, and Ovarian Cancer Cells and Flavonoid Content of Plant Ingredients Used in a Selected Thai Traditional Cancer Remedy: Correlation and Hierarchical Cluster Analysis.

This study aimed to investigate in vitro cytotoxic activity of selected plant ingredients from a traditional Thai remedy for the treatment of cancer patients against cancer cells occurring in women such as MCF-7 (breast cancer), SKOV3 (ovarian cancer), and HeLa (cervical cancer) cell lines. The plants and the remedy were macerated with 95% ethanol and boiled in water. Cytotoxic activity of the extracts was analyzed by SRB assay. Total flavonoid contents of the extracts were determined and their correlation with cytotoxic activity was evaluated. The hierarchical cluster analysis (HCA) was used to classify the extracts by their cytotoxic characteristics. A total of 66.7% of the plants was active against the tested cancer cell lines. Among the 44 plants in the remedy used for cancer treatment, nine plants that are also used in Thai cuisine exerted significant cytotoxicity against tested cancer cell lines. Eleven plants in the remedy were active against at least one of the tested cancer cell lines. All extracts were grouped into three groups and illustrated as heat map and hierarchical dendrogram. Total flavonoid content showed weak or no correlation with cytotoxic activity. A. dahurica, F. albopurpurea, and T. indica selectively exerted potent cytotoxic activity against MCF-7 with SI value more than 6. A. galanga, P. amarus, L. striatum, H. indicum, and F. vulgare exerted moderate cytotoxicity to all tested cell with low toxicity to normal cells. The correlation and HCA performed in this study provided an alternative way to investigate biological activities of plant ingredients in polyherbal traditional remedies.

Bactericidal Effect and Anti-Inflammatory Activity of Cassia garettiana Heartwood Extract.

Natural products are used as alternative drugs in traditional medicine to treat infection and inflammation and relieve pain. Heartwood of Cassia garettiana Craib has been investigated as an ingredient in Thai traditional medicine for anti-HIV protease, but there is no report on its antibacterial and anti-inflammatory activities. The objectives of this study were to investigate the anti-inflammatory and antibacterial activities, time-kill profile, and main active constituents of an ethanolic extract of C. garettiana heartwood. The study followed the generally accepted experimental design. All tests were investigated in triplicate. The heartwood of C. garettiana was extracted by maceration with 95% EtOH. The antibacterial activity of the extract and its chemical constituents were determined by their MIC values using resazurin as an indicator. Time-kill profile was determined at 0, 2, 4, 6, 8, 10, 12, and 24 hrs and expressed as log CFU/mL. The anti-inflammatory activity of the extract and its chemical components was investigated by their inhibiting effect on IL-6 and TNF-α production by ELISA. The ethanolic extract was analyzed for its chemical constituents by HPLC technique. The ethanolic extract showed both dose- and time-dependent bactericidal effects against Staphylococcus aureus, methicillin-resistance Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhi, Salmonella Typhimurium, Klebsiella pneumoniae, and Shigella dysenteriae with MIC values of 312.5, 312.5, 312.5, 1,250, 2,500, 625, 625, 2,500, and 625 µg/mL, respectively. It showed an inhibiting effect on IL-6 production at concentrations of 12.5 to 100 µg/mL. The main active chemical constituent of C. garettiana was piceatannol that showed antibacterial activity against all test bacteria except P. aeruginosa. C. garettiana showed a broad spectrum of antibacterial activity against both Gram-negative and Gram-positive bacteria. Piceatannol and resveratrol from the plant strongly inhibited IL-6 production. Based on these results, we concluded that the ethanolic extract of C. garettiana showed both an antibacterial activity and inhibition of IL-6. Piceatannol is the active constituent of the extract and showed anti-inflammatory and antibacterial activities against Gram-negative and Gram-positive bacteria.

In Vitro and In Vivo Anti-Inflammatory Activities of Benjakul: A Potential Medicinal Product from Thai Traditional Medicine.

Benjakul (BJK) is a Thai traditional remedy consisting of five plants: Piper chaba Hunt., Piper sarmentosum Roxb., Piper interruptum Opiz., Plumbago indica Linn., and Zingiber officinale Roscoe. It is used as a first-line drug to balance patient's symptoms before other treatments. BJK ethanolic extract has been reported to show anti-inflammatory activity through various mediators, e.g., nitric oxide, TNF-α, IL-1ß, and IL-6. Therefore, BJK could serve as a potential novel anti-inflammatory herbal medicine. However, studies on prostaglandin E2 (PGE2), one of the key mediators in acute inflammation, and anti-inflammation in animal models (in vivo) have not been done. This study investigated the anti-inflammatory activity of BJK extract and some of its chemical compounds against PGE2 production in murine macrophage (RAW 264.7) cell line and two in vivo models of anti-inflammatory studies. Ethanolic extract of BJK (BJK[E]) showed high inhibitory activity against PGE2 production with an IC50 value of 5.82 ± 0.10 µg/mL but its water extract (BJK[W]) was inactive. Two chemicals from BJK[E], i.e., plumbagin and myristicin, which served as biological markers, showed strong activity with IC50 values of 0.08 ± 0.01 and 1.80 ± 0.06 µg/mL, respectively. BJK[E] was administered both topically and orally to rats inhibited with inflammation induced by ethyl phenylpropiolate (rat ear edema model) and carrageenan (hind paw edema model). Moreover, the biological activity of BJK extract did not reduce after six-month storage under accelerated condition (40°C, 75% RH). This indicated its stability and a 24-month shelf-life under normal condition. These results supported not only the use of BJK in Thai traditional medicine but also the possibility of further development of phytopharmaceutical products from BJK.

In Vitro Wound Healing Activities of Three Most Commonly Used Thai Medicinal Plants and Their Three Markers.

Skin ensures that a constant internal environment can be maintained in an ever-changing external environment. When a wound occurs on the skin, the inflammatory and proliferative phases are initiated in response to injury. Thai traditional medicine (TTM), using medicinal plants and ancient knowledge, has been used to treat wounds. Eight Thai medicinal plants, most commonly used to treat wounds, were evaluated for their in vitro biological activities such as antioxidation by NBT assay, anti-inflammation by production inhibition of NO, promoting fibroblast cell proliferation, and wound closure activities. Plant materials were extracted with 95% ethanol or distilled water and then concentrated and dried. Statistical analysis of data was done using one-way ANOVA at p value of 0.05. The ethanolic extracts of Garcinia mangostana L., Glycyrrhiza glabra L., and Nigella sativa L. could inhibit the production of superoxide anion with the IC50 values of 13.97 ± 0.38, 28.62 ± 1.91, and 71.54 ± 3.22 µg/ml and nitric oxide with the IC50 values of 23.97 ± 0.91, 46.35 ± 0.43, and 78.48 ± 4.46 µg/ml, respectively. These extracts could promote cell proliferation and accelerate wound recovery at the rate of 2.02 ± 0.03, 2.12 ± 0.03, and 2.65 ± 0.05% per hour, respectively. Three established markers from these three plants were selected according to the selection criteria. Alpha-mangostin, glycyrrhizin, and thymoquinone were found to be the active markers for wound closure activities. The ethanolic extracts of G. mangostana, G. glabra, and N. sativa could scavenge superoxide anion and inhibit the production of nitric oxide; therefore these extracts could assist in surpassing the inflammatory phase and protected the cells surrounding the wound area. Most importantly, these extracts also increased the proliferation and accelerated wound closure, indicating that these plant extracts could be promoting wound healing processes and support the use of TTM.

Antimicrobial activity of vanillin against spoilage microorganisms in stored fresh-cut mangoes.

The antimicrobial activity of vanillin against four bacteria (Pantoea agglomerans, Aeromonas enteropelogenes, Micrococcus lylae, and Sphingobacterium spiritovorun), four fungi (Alternaria sp., Aspergillus sp., Penicillium sp., and Fusarium sp.), and three unidentified yeasts isolated from spoiling fresh-cut mango slices was verified in laboratory media adjusted to pH 5.0. MICs of vanillin against the fungi (12.5 to 13.3 mM), bacteria (10 to 13.3 mM), and yeasts (5.0 to 6.7 mM) indicated that all the test species were sensitive to the antimicrobial effects of vanillin. Fresh-cut mango slices were dipped for 1 min in solutions containing 40 and 80 mM vanillin before being packaged in rigid trays and stored at 5 and 10 degrees C to verify the effects of vanillin on the development of the spoilage microflora. Microbiological analysis for up to 14 days of storage revealed that treatment with 80 mM vanillin significantly delayed (P < 0.05) the development of total aerobic bacteria and yeast and mold populations. Vanillin may be a practical preservative for processing fresh-cut mango.

Supercritical fluid extraction of alkylamides from Echinacea angustifolia.

Echinacea has been known for its immunostimulatory activity, and its alkylamide components have been linked to such biological activity. Consequently, alkylamides in Echinacea angustifolia were extracted using supercritical carbon dioxide from fresh and dried roots at 45-60 degrees C and 34-55 MPa, and the alkylamide yield in the extracts was determined. The yield of alkylamides from fresh roots increased with temperature yet decreased with pressure, whereas the yield from air-dried roots (moisture content 8.4%) increased with both temperature and pressure. Freeze-drying of the roots to a moisture content of 4.9% did not result in any further increase in the yield compared to that of air-dried roots. Alkylamide yield of the ground dried roots extract was the highest (p < or = 0.05) among those from fresh, ground and unground E. angustifolia roots. Supercritical fluid extraction therefore shows potential for the recovery of alkylamides from dried Echinacea roots.