Chemical Profiles and Cytotoxic Activities of Essential Oils from Six Species of Baccharis Subgenus Coridifoliae (Asteraceae).

Several Baccharis species are popularly known in traditional medicine as "carquejas", "vassouras", "ervas-santas" and "mio-mios", and are used as anti-inflammatories, digestives, and diuretics. This study aimed to investigate the chemical compositions and cytotoxic activities of essential oils (EOs) of six Baccharis species belonging to subgenus Coridifoliae, namely B. albilanosa, B. coridifolia, B. erigeroides, B. napaea, B. ochracea, and B. pluricapitulata. GC/MS analyses of the EOs showed that the oxygenated sesquiterpenes spathulenol (7.32-38.22 %) and caryophyllene oxide (10.83-16.75 %) were the major components for all the species. The EOs of almost all species were cytotoxic against cancer (BT-549, KB, SK-MEL and SK-OV-3) and normal kidney (VERO and LLC-PK1) cell lines, whereas B. erigeroides EO showed cytotoxicity only against LLC-PK1. This article augments the current knowledge about the chemical-biological properties of Baccharis subgenus Coridifoliae and discusses the therapeutic potentials of these economically unexploited plants.

Juniper Berries Regulate Diabetes and Obesity Markers Through Modulating PPARα, PPARγ, and LXR: In Vitro and In Vivo Effects.

The berries of Juniperus communis have been traditionally used for therapeutic purposes. They have been reported to possess various pharmacological effects such as anti-inflammatory, hypoglycemic and hypolipidemic activities. In this study, a methanolic extract of J. communis berries (JB) was evaluated for its effects on peroxisome proliferator-activated receptors alpha and gamma (PPARα and PPARγ), liver X receptor (LXR), glucose uptake and lipid accumulation using various cellular systems. At a concentration of 25 µg/mL, JB caused 3.77-fold activation of PPARα, 10.90-fold activation of PPARγ, and 4.43-fold activation of LXR in hepatic cells. JB inhibited (11%) the adipogenic effect induced by rosiglitazone in adipocytes and increased glucose uptake (90%) in muscle cells. In high-fat diet (HFD) fed mice, JB at a dose of 25 mg/kg body weight exhibited a 21% decrease in body weight. Fasting glucose levels in mice treated with 12.5 mg/kg of JB were significantly decreased (39%) indicating its efficacy in regulating hyperglycemia and obesity induced by HFD thus ameliorating the symptoms of type 2 diabetes. A series of energy metabolic genes, including Sirt1 (2.00-fold) and RAF1 (2.04-fold), were upregulated by JB, while rosiglitazone regulated the hepatic PPARγ only. Phytochemical analysis of JB indicated presence of a number of flavonoids and biflavonoids which seem to be responsible for the observed activity. It was concluded that JB acted as a multiple agonist of PPARα, PPARγ and LXR without the undesired effect of adipogenesis and exhibited the property of enhancing glucose uptake. The regulation of PPARα, PPARγ and LXR seems to be through Sirt1 and RAF1. In vivo results confirmed the antidiabetic and antiobesity potential of JB and indicated its utility in metabolic disorder and type 2 diabetes.

Evaluation of the Herb-Drug Interaction (HDI) Potential of Zingiber officinale and Its Major Phytoconstituents.

Ginger is currently one of the most popular herbs commonly added to diverse foods, beverages, and dietary supplements. We evaluated the ability of a well-characterized ginger extract, and several of its phytoconstituents, to activate select nuclear receptors as well as modulate the activity of various cytochrome P450s and ATP-binding cassette (ABC) transporters because phytochemical-mediated modulation of these proteins underlies many clinically relevant herb-drug interactions (HDI). Our results revealed ginger extract activated the aryl hydrocarbon receptor (AhR) in AhR-reporter cells and pregnane X receptor (PXR) in intestinal and hepatic cells. Among the phytochemicals investigated, (S)-6-gingerol, dehydro-6-gingerdione, and (6S,8S)-6-gingerdiol activated AhR, while 6-shogaol, 6-paradol, and dehydro-6-gingerdione activated PXR. Enzyme assays showed that ginger extract and its phytochemicals dramatically inhibited the catalytic activity of CYP3A4, 2C9, 1A2, and 2B6, and efflux transport capabilities of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP). Dissolution studies with ginger extract conducted in biorelevant simulated intestinal fluid yielded (S)-6-gingerol and 6-shogaol concentrations that could conceivably exceed cytochrome P450 (CYP) IC50 values when consumed in recommended doses. In summary, overconsumption of ginger may disturb the normal homeostasis of CYPs and ABC transporters, which in turn, may elevate the risk for HDIs when consumed concomitantly with conventional medications.

Is Baikiain in Tara Flour a Causative Agent for the Adverse Events Associated with the Recalled Frozen French Lentil & Leek Crumbles Food Product? - A Working Hypothesis.

The French Lentil & Leek Crumbles frozen food product was recently recalled due to reports of gastrointestinal issues. So far, 393 adverse illness complaints and 133 hospitalizations have been reported from consumption of this food, and the tara (Tara spinosa) protein flour ingredient is hypothesized to be responsible. A multipronged approach resulted in identification of (S)-(-)-baikiain in tara as a compound of interest due to its abundance, possible metabolic fate, and close resemblance to irreversible inhibitors of L-pipecolate oxidase. Oral administration of baikiain in ND4 mice showed a statistically significant increase in blood ALT levels and a reduction in liver GSH.

In Vitro Metabolism and CYP-Modulating Activity of Lavender Oil and Its Major Constituents.

The application of essential oils has historically been limited to topical (massage therapy) and inhalational (aromatherapy) routes of administration. More recently, however, evaluation of the therapeutic effects of essential oils has expanded to include the oral route of administration, which increases the herb-drug interaction potential. The purpose of this study was to evaluate the herb-drug interaction potential of lavender essential oil and two of its primary phytoactive constituents, namely linalool and linalyl acetate. The metabolic stability of linalool and linalyl acetate was determined in human liver microsomes (HLM) and S9 fractions by quantitative analysis using UPLC-MS/MS system. Linalool was metabolically unstable in HLM and S9 fractions with an intrinsic clearance of 31.28 mL·min-1·kg-1, and 7.64 mL·min-1·kg-1, respectively. Interestingly, it was observed that linalyl acetate converted to linalool both in HLM and S9 fractions. Lavender oil showed weak inhibitory effect on the catalytic activity of CYP3A4 and CYP1A2 enzymes (IC50 12.0 and 21.5 µg/mL). Linalyl acetate inhibited CYP3A4 (IC50 4.75 µg/mL) while linalool did not show any inhibitory effect on any of the enzymes. The lavender oil and its constituents did not activate PXR to a considerable extent, and no activation of AhR was observed, suggesting a lack of potential to modify the pharmacokinetic and pharmacodynamic properties of conventional medications if used concurrently.

Assessment of Herb-Drug Interaction Potential of Five Common Species of Licorice and Their Phytochemical Constituents.

The dried roots and rhizomes of Glycyrrhiza species (G. glabra, G. uralensis and G. inflata), commonly known as licorice, have long been used in traditional medicine. In addition, two other species, G. echinata and G. lepidota are also considered "licorice" in select markets. Currently, licorice is an integral part of several botanical drugs and dietary supplements. To probe the botanicals' safety, herb-drug interaction potential of the hydroethanolic extracts of five Glycyrrhiza species and their key constituents was investigated by determining their effects on pregnane X receptor, aryl hydrocarbon receptor, two major cytochrome P450 isoforms (CYP3A4 and CYP1A2), and the metabolic clearance of antiviral drugs. All extracts enhanced transcriptional activity of PXR and AhR (>2-fold) and increased the enzyme activity of CYP3A4 and CYP1A2. The highest increase in CYP3A4 was seen with G. echinata (4-fold), and the highest increase in CYP1A2 was seen with G. uralensis (18-fold) and G. inflata (16-fold). Among the constituents, glabridin, licoisoflavone A, glyasperin C, and glycycoumarin activated PXR and AhR, glabridin being the most effective (6- and 27-fold increase, respectively). Licoisoflavone A, glyasperin C, and glycycoumarin increased CYP3A4 activity while glabridin, glyasperin C, glycycoumarin, and formononetin increased CYP1A2 activity (>2-fold). The metabolism of antiretroviral drugs (rilpivirine and dolutegravir) was increased by G. uralensis (2.0 and 2.5-fold) and its marker compound glycycoumarin (2.3 and 1.6-fold). The metabolism of dolutegravir was also increased by G. glabra (2.8-fold) but not by its marker compound, glabridin. These results suggest that licorice and its phytochemicals could affect the metabolism and clearance of certain drugs that are substrates of CYP3A4 and CYP1A2.Supplemental data for this article is available online at https://doi.org/10.1080/19390211.2022.2050875 .

Screening of medicinal plants for possible herb-drug interactions through modulating nuclear receptors, drug-metabolizing enzymes and transporters.

ETHNOPHARMACOLOGICAL RELEVANCE: The last three decades have witnessed a surge in popularity and consumption of herbal products. An unintended consequence of such popularity is that chronic consumption of these products can often modulate the functions of various proteins involved in drug disposition and may, in turn, impose risks for herb-drug interactions (HDIs), leading to serious adverse health outcomes. Identifying plants that may give rise to clinically relevant HDIs is essential, and proactive dissemination of such research outcomes is necessary for researchers, clinicians, and average consumers. AIM OF THE STUDY: The main objective of this study was to evaluate the HDI potential of plants commonly used as ingredients in many herbal products, including BDS. MATERIALS AND METHODS: The dried material of 123 plants selected from the NCNPR repository was extracted with 95% ethanol. The extracts were screened for agonistic effects on nuclear receptors (PXR and AhR) by reporter gene assays in PXR-transfected HepG2 and AhR-reporter cells. For cytochrome P450 enzyme (CYP) inhibition studies, CYP450 baculosomes were incubated with enzyme-specific probe substrates by varying concentrations of extracts. The inhibitory effect on the efflux transporter P-glycoprotein (P-gp) was investigated via rhodamine (Rh-123) uptake assay in P-gp overexpressing MDR1-MDCK cells. RESULTS: Out of 123 plants, 16 increased transcriptional activity of human PXR up to 4 to 7-fold at 60 µg/mL, while 18 plants were able to increase AhR activity up to 10 to 40-fold at 30 µg/mL. Thirteen plants inhibited the activity of CYP3A4, while 10 plants inhibited CYP1A2 activity with IC50 values in the range of 1.3-10 µg/mL. Eighteen plants (at 50 µg/mL) increased intracellular accumulation of Rh-123 (>150%) in MDR1-MDCK cells. Additionally, other plants tested in this study were able to activate PXR, AhR, or both to lesser extents, and several inhibited the catalytic activity of CYPs at higher concentrations (IC50 >10 µg/mL). CONCLUSIONS: The results indicate that prolonged or excessive consumption of herbal preparations rich in such plants (presented in Figs. 1a, 2a, 3a, 4a, and 5a) may pose a risk for CYP- and P-gp-mediated HDIs, leading to unwanted side effects due to the altered pharmacokinetics of concomitantly ingested medications.

Evaluation of the Herb-Drug Interaction Potential of Commonly Used Botanicals on the US Market with Regard to PXR- and AhR-Mediated Influences on CYP3A4 and CYP1A2.

In this study, hydroethanolic extracts of 30 top-selling botanicals (herbs) commonly used as ingredients of herbal dietary supplements in the US were screened for their potential to activate the human pregnane X receptor (hPXR) and human aryl hydrocarbon receptor (hAhR) and to increase the activities of hPXR- and hAhR-regulated drug metabolizing cytochrome P450 enzymes (i.e., CYP3A4 and CYP1A2, respectively). Of the 30 botanicals tested, 21 induced PXR and 29 induced AhR transcriptional activities. Out of the 21 botanicals that induced hPXR transcriptional activity, 14 yielded >50% induction in CYP3A4 activity at concentrations ranging from 6 to 60 µg/mL and 16 out of the 29 botanicals that activated hAhR yielded >50% induction in CYP1A2 activity at concentrations ranging from 3 to 30 µg/mL. Moreover, eight botanicals (G. gummi-gutta [garcinia], Hemp [low and high CBD content], H. perforatum [St. John's wort], M. vulgare [horehound], M. oleifera [moringa], O. vulgare [oregano], P. johimbe [yohimbe] and W. somnifera [ashwagandha]) yielded >50% induction in both CYP3A4 and CYP1A2 activity. Herbal products are mixtures of phytoconstituents, any of which could modulate drug metabolism. Our data reveals that several top-selling botanicals may pose herb-drug interaction (HDI) risks via CYP450 induction. While in vitro experiments can provide useful guidance in assessing a botanical's HDI potential, their clinical relevance needs to be investigated in vivo. Botanicals whose effects on hPXR/CYP3A4, and hAhR/CYP1A2 activity were most pronounced will be slated for further clinical investigation.

Probing PXR activation and modulation of CYP3A4 by Tinospora crispa and Tinospora sinensis.

ETHNOPHARMACOLOGICAL RELEVANCE: The two Tinospora species, T. crispa and T. sinensis, native to Southeast Asia, are integral components of various traditional preparations with structure-function claims to treat various disorders, including diabetes and inflammation. AIM OF THE STUDY: To assure the safety of the botanicals finished products, herb-drug interaction potential of T. crispa and T. sinensis was investigated by testing their extracts and compounds for in vitro activation of the pregnane X-receptor (PXR) and the modulation of CYP3A4 isozyme, selectively. MATERIALS AND METHODS: A total of sixteen fully characterized phytochemicals from T. crispa and T. sinensis were evaluated for PXR activation by luciferase reporter gene assay. CYP3A4 inhibition studies were carried out for eleven compounds. In addition, docking studies were performed to elucidate the possible binding modes to the PXR by the compounds using computational methods. RESULTS: Significant activation of PXR (2-fold) was observed for both extracts and non-polar fractions of T. crispa. Among the pure compounds, columbin showed highest activation of PXR (3-fold), which was comparable with the positive control, rifampicin. Vital interactions were predicted with docking simulation of PXR-columbin complex with critical amino acid residues (Trp-299) that are known for the activation of PXR. The methanolic extracts of T. crispa and T. sinensis also showed considerable CYP3A4 inhibition. CONCLUSION: T. crispa and T. sinensis, both demonstrated the potential to mediate herb-drug interaction through PXR activation and inhibition of CYP3A4 isozyme. Moreover, the elucidation of the potential to induce herb-drug interaction, by the phytochemicals of these Tinospora plants, thereby supports the need for further investigation to establish the clinical relevancy of these constituents for possible adverse interactions with pharmaceutical drugs.

A Multitarget Approach to Evaluate the Efficacy of Aquilaria sinensis Flower Extract against Metabolic Syndrome.

Aquilaria sinensis (Lour.) Spreng is known for its resinous secretion (agarwood), often secreted in defense against injuries. We investigated the effects of A. sinensis flower extract (AF) on peroxisome proliferator-activated receptors alpha and gamma (PPARα and PPARγ), liver X receptor (LXR), glucose uptake, and lipid accumulation (adipogenesis). Activation of PPARα, PPARγ and LXR was determined in hepatic (HepG2) cells by reporter gene assays. Glucose uptake was determined in differentiated muscle (C2C12) cells using 2-NBDG (2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose). Adipogenesis was determined in adipocytes (3T3-L1 cells) by Oil red O staining. At a concentration of 50 µg/mL, AF caused 12.2-fold activation of PPARα and 5.7-fold activation of PPARγ, while the activation of LXR was only 1.7-fold. AF inhibited (28%) the adipogenic effect induced by rosiglitazone in adipocytes and increased glucose uptake (32.8%) in muscle cells at 50 µg/mL. It was concluded that AF acted as a PPARα/γ dual agonist without the undesired effect of adipogenesis and exhibited the property of enhancing glucose uptake. This is the first report to reveal the PPARα/γ dual agonistic action and glucose uptake enhancing property of AF along with its antiadipogenic effect, indicating its potential in ameliorating the symptoms of metabolic syndrome.

Rational Design of a Cu Chelator That Mitigates Cu-Induced ROS Production by Amyloid Beta.

Alzheimer's disease severely perturbs transition metal homeostasis in the brain leading to the accumulation of excess metals in extracellular and intraneuronal locations. The amyloid beta protein binds these transition metals, ultimately causing severe oxidative stress in the brain. Metal chelation therapy is an approach to sequester metals from amyloid beta and relieve the oxidative stress. Here we have designed a mixed N/O donor Cu chelator inspired by the proposed ligand set of Cu in amyloid beta. We demonstrate that the chelator effectively removes Cu from amyloid beta and suppresses reactive oxygen species (ROS) production by redox silencing and radical scavenging both in vitro and in cellulo. The impact of ROS on the extent of oxidation of the different aggregated forms of the peptide is studied by mass spectrometry, which, along with other ROS assays, shows that the oligomers are pro-oxidants in nature. The aliphatic Leu34, which was previously unobserved, has been identified as a new oxidation site.

Undescribed C-Glycosylflavones from Corn Silk and Potential Anti-inflammatory Activity Evaluation of Isolates.

Phytochemical investigation of corn silk resulted in isolation and characterization of four flavone C-glycosides, chrysoeriol 6-C-ß-oliopyranosyl-7-O-ß-D-glucopyranoside (1: ), 3'-methoxycassiaoccidentalin A (2: ), chrysoeriol 6-C-ß-boivinopyranosyl-7-O-ß-D-glucopyranoside (3: ), and ax-4″-OH-3'-methoxymaysin (4: ), a triterpenoid, friedelin (5: ), two sterols, (22E)-5α,8α-epidioxyergosta-6,22-dien-3ß-ol (6: ) and 6ß-hydroxystigmasta-4,22-diene-3-one (7: ), and a mixture of ß-sitosterol and stigmasterol. Compounds 1: and 2: were previously undescribed. Structure elucidation of the isolated compounds was attained using spectral data including 1D and 2D NMR and HRESIMS. Compounds1, 2, 5: , and 6: inhibited iNOS activity in LPS-induced macrophages and decreased nitrite levels by 68.64 ± 4.46, 65.67 ± 6.47, 88.50 ± 0.50, and 94.00 ± 4.00%, respectively, at 50 µM. Compound 5: also showed inhibition of NF-κB (51.00 ± 1.50%). Compounds 1: and 2: induced NAG-1 activity in chondrocytes by 1.80 ± 0.05 and 2.00 ± 0.13 fold, respectively. The extract of corn silk, however, did not exhibit inhibition of iNOS or NF-κB but induced NAG-1 by 1.80 ± 0.51 fold.

Bulbine natalensis (currently Bulbine latifolia) and select bulbine knipholones modulate the activity of AhR, CYP1A2, CYP2B6, and P-gp.

Bulbine natalensis, an emerging medicinal herb on the global market with androgenic properties, is often formulated in dietary supplements that promote perceived sexual enhancement. However, to date, comprehensive safety studies of B. natalensis are lacking, particularly those related to its herb-drug interaction potential. The purpose of this study was to assess the inductive and inhibitory effects of extracts and pure compounds of B. natalensis on human cytochrome P-450 isozymes in vitro. Our findings demonstrated that both water and methanolic extracts of B. natalensis as well as knipholone, bulbine-knipholone, and 6'-O-methylknipholone dose-dependently increased mRNA expression encoded by CYP2B6, CYP1A2, and ABCB1 genes. Functional analyses showed that water (60 to 2.20 µg/mL) and methanolic (30 to 3.75 µg/mL) extracts and knipholones (10 to 0.33 µM) increased CYP2B6 and CYP1A2 activity in a dose-dependent manner. Additionally, water extract (60 µg/mL), methanolic extract (30 µg/mL), and knipholone (10 µM) caused activation of the aryl hydrocarbon receptor up to 11.1 ± 0.7, 8.9 ± 0.6, and 7.1 ± 2.0-fold, respectively. Furthermore, inhibition studies revealed that methanolic extract attenuated the activity of metabolically active CYP1A2 (IC50, 22.6 ± 0.4 µg/mL) and CYP2B6 (IC50, 34.2 ± 6.6 µg/mL) proteins, whereas water extracts had no inhibitory effect on either isoform. These findings suggest that chronic consumption of B. natalensis may affect normal homeostasis of select CYPs with subsequent risks for HDIs when concomitantly ingested with conventional medications that are substrates of CYP2B6 and CYP1A2. However, more in-depth translational studies are required to validate our current findings and their clinical relevance.

Ethnopharmacological investigation of the cardiovascular effects of the ethanol-soluble fraction of Aloysia polystachya (Griseb.) Moldenke leaves in spontaneously hypertensive rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Aloysia polystachya (Griseb) Moldenke (Verbenaceae), popularly known as "burrito", is a South American species widely prescribed by local Brazilian healers for the treatment of cardiovascular diseases. However, its antihypertensive and cardioprotective effects are still unknown. AIM: To evaluate the role of the ethanol-soluble fraction of A. polystachya leaves (ESAP) against hypertension in spontaneously hypertensive rats (SHRs), as well as its safety, morphoanatomical and phytochemical aspects. MATERIALS AND METHODS: First, the leaves and stems of A. polystachya were analyzed by optical and scanning electron microscopy in order to provide anatomical data for quality control. Then, ESAP was obtained and its chemical profile was analyzed by LC-DAD-MS. In addition, the cytotoxic and acute toxicity potential of ESAP were evaluated in six cell lines and in female Wistar rats, respectively. Next, female spontaneously hypertensive rats (SHRs) received ESAP (30, 100, 300 mg/kg), hydrochlorothiazide (25 mg/kg), or vehicle once daily for 28 days. Weekly kidney function was monitored by analyzing urinary parameters. At the end of the 28-day treatment, the electrocardiographic profile, blood pressure, and renal and mesenteric vascular reactivity were evaluated. Relative organ (heart, kidney, and liver) weights and biochemical parameters were also evaluated. Finally, the heart, kidneys, and aorta were collected for determination of the tissue redox state, cardiac morphometry, and histopathological analysis. RESULTS: The chemical profile of ESAP was composed by organic acids, a nucleoside, methoxylated flavones and glycosylated compounds including phenolic acids, phenylpropanoids, iridoids and monoterpenes. No signs of toxicity were observed in all cell's lines nor in female Wistar rats submitted to this trial. All SHRs from the negative control group presented a reduction in renal function, alterations in the renal and mesenteric vascular reactivity, and electrocardiographic and morphometric changes typical of ventricular hypertrophy. Oral prolonged ESAP-administration in SHRs was able to reverse renal, electrocardiographic and hemodynamic changes induced by hypertension. Moreover, ESAP-treatment was able to modulate the vascular and renal arterial reactivity and tissue redox state. The aforementioned data were accompanied by reduction of cardiac hypertrophy. CONCLUSION: In this study, we present important anatomical and phytochemical data that contributed to the correct identification and quality control of A. polystachya. In addition, we have shown that ESAP is safe after acute administration and present significant cardioprotective effects (at 30, 100, and 300 mg/kg doses) in SHRs after prolonged treatment.

Modulation of CYP3A4 and CYP2C9 activity by Bulbine natalensis and its constituents: An assessment of HDI risk of B. natalensis containing supplements.

BACKGROUND: Bulbine natalensis is an African-folk medicinal plant used as a dietary supplement for enhancing sexual function and muscle strength in males by presumably boosting testosterone levels, but no scientific information is available about the possible herb-drug interaction (HDI) risk when bulbine-containing supplements are concomitantly taken with prescription drugs. PURPOSE: This study was aimed to investigate the HDI potential of B. natalensis in terms of the pregnane X receptor (PXR)-mediated induction of major drug-metabolizing cytochrome P450 enzyme isoforms (i.e., CYP3A4 and CYP2C9) as well as inhibition of their catalytic activity. RESULTS: We found that a methanolic extract of B. natalensis activated PXR (EC50 6.2 ± 0.6 µg/ml) in HepG2 cells resulting in increased mRNA expression of CYP3A4 (2.40 ± 0.01 fold) and CYP2C9 (3.37 ± 0.3 fold) at 30 µg/ml which was reflected in increased activites of the two enzymes. Among the constituents of B. natalensis, knipholone was the most potent PXR activator (EC50 0.3 ± 0.1 µM) followed by bulbine-knipholone (EC50 2.0 ± 0.5 µM), and 6'-methylknipholone (EC50 4.0 ± 0.5 µM). Knipholone was also the most effective in increasing the expression of CYP3A4 (8.47 ± 2.5 fold) and CYP2C9 (2.64 ± 0.3 fold) at 10 µM. Docking studies further confirmed the unique structural features associated with knipholones for their superior inductive potentials in the activation of PXR compared to other anthraquinones. In a CYP inhibition assay, the methanolic extract as well as the anthraquinones strongly inhibited the catalytic activity of CYP2C9 while, inhibition of CYP3A4 was weak. CONCLUSIONS: These results suggest that consumption of B. natalensis may pose a potential risk for HDI if taken with conventional medications that are substrates of CYP3A4 and CYP2C9 and may contribute to unanticipated adverse reactions or therapeutic failures. Further studies are warranted to validate these findings and establish their clinical relevancy.

Antimalarials and Phytotoxins from Botryosphaeria dothidea Identified from a Seed of Diseased Torreya taxifolia.

The metabolic pathways in the apicoplast organelle of Plasmodium parasites are similar to those in plastids in plant cells and are suitable targets for malaria drug discovery. Some phytotoxins released by plant pathogenic fungi have been known to target metabolic pathways of the plastid; thus, they may also serve as potential antimalarial drug leads. An EtOAc extract of the broth of the endophyte Botryosphaeria dothidea isolated from a seed collected from a Torreya taxifolia plant with disease symptoms, showed in vitro antimalarial and phytotoxic activities. Bioactivity-guided fractionation of the extract afforded a mixture of two known isomeric phytotoxins, FRT-A and flavipucine (or their enantiomers, sapinopyridione and (-)-flavipucine), and two new unstable γ-lactam alkaloids dothilactaenes A and B. The isomeric mixture of phytotoxins displayed strong phytotoxicity against both a dicot and a monocot and moderate cytotoxicity against a panel of cell lines. Dothilactaene A showed no activity. Dothilactaene B was isolated from the active fraction, which showed moderate in vitro antiplasmodial activity with high selectivity index. In spite of this activity, its instability and various other biological activities shown by related compounds would preclude it from being a viable antimalarial lead.

Norlignan glucosides from Hypoxis hemerocallidea and their potential in vitro anti-inflammatory activity via inhibition of iNOS and NF-κB.

Eleven diarylpentanoid/norlignan glucosides, along with five other specialized metabolites, were isolated and characterized from the hydro-alcoholic extract of Hypoxis hemerocallidea corms. Hypoxhemerolosides A-F were found to be undescribed compounds. Curcapicycloside was isolated and identified for the first time in its original form, previously it was reported as a methylated derivative. In addition, (1S,2R)-1-(3,4-dihydroxyphenyl)-5-(4-ß-D-glucopyranoxy-3-hydroxyphenyl)-1-methoxypent-4-yn-2-ol and (1S,2R)-1-(3,4-dihydroxyphenyl)-1-ethoxy-5-(4-ß-D-glucopyranoxy-3-hydroxyphenyl)pent-4-yn-2-ol were isolated and characterized as artifacts, generated during extraction/isolation procedures from possible 1-(3,4-dihydroxyphenyl)-5-(4-ß-D-glucopyranoxy-3-hydroxyphenyl)pent-4-yne-1,2-diol. Structure elucidation was mainly achieved by the interpretation of 1D and 2D NMR and HRESIMS data. The isolated compounds were screened for anti-inflammatory activity in terms of iNOS and NF-κB inhibition as well as for cytotoxicity. Hypoxhemerolosides C-E and obtuside A moderately inhibited nitric oxide production in LPS-stimulated mouse macrophages (RAW 264.7).

In search for potential antidiabetic compounds from natural sources: docking, synthesis and biological screening of small molecules from Lycium spp. (Goji).

Current clinical antidiabetic drugs, like rosiglitazone 1, have been implicated in some serious side effects like edema, weight gain, and heart failure, making it necessary to find alternative agents. Partial agonists of peroxisome-proliferator activated receptor-gamma (PPARγ) were determined to possess improved insulin sensitivity without undeseirable side-effects when compared to full agonists of PPARγ, like rosiglitazone 1. The traditional Chinese medicine (TCM) plants, Goji (Lycium barbarum and Lycium chinense) are widely used for treating symptoms related to various diseases including diabetes and hypertension. Twenty-seven reported compounds from Goji were docked into both partial- and full-agonist binding sites of PPARγ. Amongst the docked compounds, phenylethylamide-based phytochemicals (5-9) (termed as tyramine-derivatives, TDs) were found to possess good docking scores and binding poses with favorable interactions. Synthesis of 24 TDs, including three naturally occuring amides (6, 8, 9) were synthesized and tested for PPARγ gene induction with cell-based assay. Three compounds showed similar or higher fold induction than the positive control, rosiglitazone. Among these three active TDs, trans-N-feruloyloctopamine (9) and tyramine derivatives-enriched extract (TEE) (21%) of the root bark of L. chinense were further studied in vivo using db/db mice. However, both TEE as well as 9 did not show significant antidiabetic properties in db/db mice. In vivo results suggest that the proposed antidiabetic property of Lycium species may not be due to tyramine derivatives alone. Further studies of tyramine derivatives or enriched extract(s) for other bioactivities like hypocholesterolemic activities, and studies of novel isolated compounds from Goji will enable a more complete understanding of their bioactivities.

Isolation, synthesis, and drug interaction potential of secondary metabolites derived from the leaves of miracle tree (Moringa oleifera) against CYP3A4 and CYP2D6 isozymes.

BACKGROUND: Moringa oleifera Lam. is known as a drumstick tree that is widely cultivated in various subtropical and tropical provinces. Previous studies indicated that both aqueous and methanolic extracts of M. oleifera leaves have potent inhibitory effects on two major drug metabolizing Cytochrome P450 enzymes, namely, CYP3A4 and CYP2D6. PURPOSE: The current study was aimed to isolate the secondary metabolites from M. oleifera and investigate their cytotoxicity and inhibitory effects on CYP3A4 and CYP2D6 to assess their herb-drug interaction (HDI) potential. METHODS: Chemical structure elucidation was achieved by interpreting the spectroscopic data (UV, IR, 1D, and 2D NMR experiments), confirming by HR-ESI-MS, and comparing with the previously reported data in the literature. All the isolates were evaluated for their cytotoxicity against a panel of cell lines (SK-MEL, KB, BT-549, SK-OV-3, VERO, LLC-PK1, and HepG2) and inhibition of two principal CYP isozymes (CYP3A4 and CYP2D6). RESULTS: Phytochemical investigation of M. oleifera leaves resulted in the isolation and characterization of one new compound, namely omoringone (1), along with twelve known secondary metabolites (2-13) belonging to several chemical classes including flavonoids, terpenoids, lignans, and phenylalkanoids. A plausible biosynthetic pathway for compound 1 was provided. Because of the low isolation yield and limited supply, omoringone (1) and niazirin (12) were successively synthesized. No cytotoxicity was observed on any of the tested cell lines up to 50 µM. The extract exhibited an inhibitory effect on CYP3A4 isoform (IC50 = 52.5 ±â€¯2.5 µg/ml). Among the isolates, 1-4 and 7-9 inhibited CYP3A4 with the IC50 values ranging from 41.5 to 100 µM with no remarkable effect on CYP2D6 isozyme. CONCLUSION: This work aided in ascertaining components of M. oleifera contributing to CYP3A4 inhibition exhibited by the extract using an in vitro assay. Nonetheless, further studies are warranted to determine the bioavailability of the phytochemicals and extrapolate these findings in more physiologically relevant conditions to further establish the clinical relevance of in vitro observations.

Safety Assessment of Phytochemicals Derived from the Globalized South African Rooibos Tea ( Aspalathus linearis) through Interaction with CYP, PXR, and P-gp.

Rooibos tea ( Aspalathus linearis) is a well-known South African herbal tea enjoyed worldwide. Limited reports indicate the potential of rooibos tea to alter the activity of certain cytochrome P450 (CYP450) isozymes. In this study, the phytochemical investigation of MeOH extract of A. linearis (leaves and stems) resulted in the isolation and characterization of 11 phenolic compounds. The MeOH extract exhibited significant inhibition of the major human CYP450 isozymes (CYP3A4, CYP1A2, CYP2D6, CYP2C9, and CYP2C19). The strongest inhibition was observed by the extract for CYP3A4 (IC50 1.7 ± 0.1 µg/mL) followed by CYP2C19 (IC50 4.0 ± 0.3 µg/mL). Among the tested phytochemicals, the most potent inhibitors were isovitexin on CYP3A4 (IC50 3.4 ± 0.2 µM), vitexin on CYP2C9 (IC50 8.0 ± 0.2 µM), and thermopsoside on CYP2C19 (IC50 9.5 ± 0.2 µM). The two major, structurally related compounds aspalathin and nothofagin exhibited a moderate pregnane-X receptor (PXR) activation, which was associated with increased mRNA expression of CYP3A4 and CYP1A2, respectively. These results indicate that a high intake of nutraceuticals containing rooibos extracts may pose a risk of herb-drug interactions when consumed concomitantly with clinical drugs that are substrates of CYP enzymes.