Clinical characteristics of Demodex-associated recurrent hordeola: an observational, comparative study.

Our study evaluated the association between Demodex infestation and recurrent hordeola and examined the clinical features associated with these eyelid lesions. This was an observational, comparative study. We reviewed 250 patients and divided them into the recurrent hordeolum (n = 153) and control (n = 97) groups. Demodex infestation was detected by epilating eyelashes around the lesion/s and viewing them under a light microscope. Patient medical records and photographs were retrospectively analyzed to identify the clinical characteristics of Demodex-associated recurrent hordeola. Demodex was detected in 91 (59.5%) and 17 (17.5%) patients in the recurrent hordeolum and control groups (p < 0.001), respectively. In the recurrent hordeolum group, Demodex mites were found in 74 (68.5%) and 17 (37.8%) of the adult and pediatric patients (p < 0.001), respectively. Among patients with recurrent hordeola, patients in their 20s were most likely to have concomitant Demodex infestation. Patients with Demodex infestations were also more likely to develop recurrent lesions within a shorter period of time from the primary incision and curettage. The most common presentation of Demodex-associated recurrent lesions was external hordeola (67%) (p = 0.002). Demodex infestation may cause recurrent hordeola in adults and children. These mites may play a greater role in the development of lesions in adult patients. The strongest association between Demodex infestation and recurrent lesions was seen in patients in their 20s. Our results suggest that if the hordeola recur within a short period of time with the clinical characteristics of external location of eyelid, multiple numbers of lesions, or anterior blepharitis, eyelash epilation should be performed to identify the presence of Demodex mites.

Oleanane triterpenoids from Rubia philippinensis and their inhibitory effect on 20-HETE synthesis.

A new oleanane triterpenoid (2) was isolated from the roots of Rubia philippinensis. The structure of 2 was determined by analysis of HRMS and NMR data and identified as a rubiprasin analogue, 16ß-hydroxyrubiprasin B. Four related known compounds were also encountered which include rubiprasin B (1), maslinic acid (3), 4-epi-hederagenin (4) and oleanolic acid (5). The compounds 3-5 displayed moderate inhibitory activity against the synthesis of the eicosanoid 20-HETE.

Quasi-Irreversible Inhibition of CYP2D6 by Berberine.

In our previous study, Hwang-Ryun-Hae-Dok-Tang, which contains berberine (BBR) as a main active ingredient, inhibited cytochrome P450 (CYP) 2D6 in a quasi-irreversible manner. However, no information is available on the detailed mechanism of BBR-induced CYP2D6 inhibition. Thus, the present study aimed to characterize the inhibition mode and kinetics of BBR and its analogues against CYP2D6 using pooled human liver microsomes (HLM). BBR exhibited selective quasi-irreversible inhibition of CYP2D6 with inactivation rate constant (kinact) of 0.025 min-1, inhibition constant (KI) of 4.29 µM, and kinact/KI of 5.83 mL/min/µmol. In pooled HLM, BBR was metabolized to thalifendine (TFD), demethyleneberberine (DMB), M1 (proposed as demethylene-TFD), and to a lesser extent berberrubine (BRB), showing moderate metabolic stability with a half-life of 35.4 min and a microsomal intrinsic clearance of 7.82 µL/min/mg protein. However, unlike BBR, those metabolites (i.e., TFD, DMB, and BRB) were neither selective nor potent inhibitors of CYP2D6, based on comparison of half-maximal inhibitory concentration (IC50). Notably, TFD, but not DMB, exhibited metabolism-dependent CYP2D6 inhibition as in the case of BBR, which suggests that methylenedioxybenzene moiety of BBR may play a critical role in the quasi-irreversible inhibition. Moreover, the metabolic clearance of nebivolol (ß-blocker; CYP2D6 substrate) was reduced in the presence of BBR. The present results warrant further evaluation of BBR-drug interactions in clinical situations.

Erratum: Validation of Dietary Reference Intakes for predicting energy requirements in elementary school-age children.

[This corrects the article on p. 336 in vol. 12, PMID: 30090171.].

Discovery of rubiarbonone C as a selective inhibitor of cytochrome P450 4F enzymes.

Cytochrome P450 (CYP) enzymes, particularly CYP4A/4F, are the major ω-hydroxylases of arachidonic acid (AA) that can produce 20-hydroxyeicosatetraenoic acid (20-HETE). Although there are dissimilarities in substrate specificity, tissue distribution, and gene regulation between CYP4A and CYP4F, selective CYP4A or 4F inhibitors are currently unavailable. Therefore, this study was designed to develop CYP4F selective inhibitors using a novel inhibitory assay of 20-HETE formation. The assay was established using pooled human kidney microsomes (HKMs) and human recombinant CYP4 enzymes incubated with 1,2,3,4,5-13C AA (13C5 AA) as a substrate to minimize interference by endogenous AA. The intrinsic clearance (Vmax/Km) values were 9.5 µL/min/mg for HKMs and 0.02, 0.9, and 10.1 µL/min/pmol for CYP4A11, CYP4F2, and CYP4F3B, respectively, which suggests a major role for CYP4F in ω-hydroxylation of AA. To validate the assay, we tested well-known pan-CYP4 inhibitor HET0016 along with 50 compounds derived from natural products. Of the screened compounds, rubiarbonone C showed the most potent inhibitory activity. The 50% inhibitory concentrations of rubiarbonone C against CYP4A11, CYP4F2, and 4F3B were > 50, 4.2, and 4.2 µM, respectively. Moreover, epoxyeicosatrienoic acid formation from 13C5 AA was not inhibited by up to 30 µM rubiarbonone C. Meanwhile, in pooled human liver microsomes, CYP1, 2, and 3 family enzymes involved in drug metabolism were not substantially inhibited by rubiarbonone C. Thus, rubiarbonone C is a selective inhibitor of CYP4F and can be used to discriminate among CYP4 family enzymes and evaluate their roles in physiological and pathophysiological conditions.

Validity of predictive equations for resting energy expenditure in Korean non-obese adults.

BACKGROUND/OBJECTIVES: Indirect calorimetry is the gold-standard method for the measurement of resting energy expenditure. However, this method is time consuming, expensive, and requires highly trained personnel. To overcome these limitations, various predictive equations have been developed. The objective of this study was to assess the validity of predictive equations for resting energy expenditure (REE) in Korean non-obese adults. SUBJECTS/METHODS: The present study involved 109 participants (54 men and 55 women) aged between 20 and 64 years. The REE was measured by indirect calorimetry. Nineteen REE equations were evaluated for validity, by comparing predicted and measured REE results. Predictive equation accuracy was assessed by determining percent bias, root mean squared prediction error (RMSE), and percentage of accurate predictions. RESULTS: The measured REE was significantly higher in men than in women (P < 0.001), but the difference was not significant after adjusting for body weight (P > 0.05). The equation developed in this study had an accuracy rate of 71%, a bias of 0%, and an RMSE of 155 kcal/day. Among published equations, the FAOweight equation gave the highest accuracy rate (70%), along with a bias of -4.4% and an RMSE of 184 kcal/day. CONCLUSIONS: The newly developed equation provided the best accuracy in predicting REE for Korean non-obese adults. Among the previously published equations, the FAOweight equation showed the highest overall accuracy. Regardless, at an individual level, the equations could lead to inaccuracies in a considerable number of subjects.

Validation of Dietary Reference Intakes for predicting energy requirements in elementary school-age children.

BACKGROUND/OBJECTIVES: Dietary Reference Intakes (DRI) for energy are derived from total energy expenditure (TEE) measured using the doubly labelled water (DLW) method. The objective of this study was to assess the validity of DRI for predicting the energy requirements of elementary school-age children. SUBJECTS/METHODS: The present study involved 25 elementary school-age children aged between 9 and 11 years. TEE was assessed by the DLW method, and the results were compared with the TEE predicted by the DRI equations in order to evaluate accuracy. RESULTS: The subjects' TEE measured by the DLW method was 1,925.2 ± 380.9 kcal/day in boys and 1,930.0 ± 279.4 kcal/day in girls, whereas resting energy expenditure was 1,220.2 ± 176.9 kcal/day in boys and 1,245.9 ± 171.3 kcal/day for girls. The physical activity level was 1.58 ± 0.20 in boys and 1.55 ± 0.13 in girls. The mean bias between the predicted and measured TEE was 12.6% in boys and -1.6% in girls, and the percentage of accurate predictions was 28.6% and 63.6%, respectively. In boys, the equation resulted in underprediction of TEE among the subjects having low TEE values, whereas there was overprediction among subjects having high TEE values as shown by the Bland-Altman plot. On the contrary, this proportional bias was not observed in girls. CONCLUSIONS: The findings of this study suggest that the DRI equation for energy could result in the overestimation of energy requirements in elementary school-age boys. In the case of girls, the equations could be accurate at the group level. However, the DRI appears to be invalid for individual girls, as more than one third of girls had their TEE inaccurately predicted. We recommend more studies for confirmation of these results.

Herbal Medicines Showing Synergistic Effects with Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) against A549 TRAIL-resistant Lung Cancer Cells: A Screening Study.

BACKGROUND: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine that activates apoptosis through death receptors on the cell surface and is regarded as a potential anticancer agent. However, many cancer cells are resistant to TRAIL-induced apoptosis. OBJECTIVE: The aim is to identify the herbal medicines that could help overcome resistance in TRAIL-resistant lung cancer cells. MATERIALS AND METHODS: TRAIL-resistant A549 cells and 13 herbal medicines with known apoptosis-related anticancer effects were used in this study: Clematidis Radix, Corydalis Tuber Rhizoma, Paeoniae Radix Rubra, Corni Fructus, Curcumae longae Rhizoma (CLR), Moutan Cortex, Salviae miltiorrhizae Radix, Phellodendri Cortex, Farfarae Flos, Paeoniae Radix Alba, Angelicae gigantis Radix, Coptidis Rhizoma (CR), and Taraxaci Herba. Cytotoxic effects were investigated after a 48-h incubation, using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, to identify the herbal medicines with the most potent synergistic effects with TRAIL. RESULTS: The majority of the 13 medicines exhibited concentration-dependent cytotoxicity against A549 cells. Among them, CR and CLR showed the most potent cytotoxic effects, based on the IC50. We then investigated the use of these two medicines in combination with TRAIL and identified synergistic cytotoxic effects against TRAIL-resistant A549 cells. CONCLUSION: Synergistic cytotoxic effects of the combination of TRAIL and herbal medicines, in particular, CR and CLR, were confirmed in A549 cells. Therefore, CR and CLR showed potential to be used as candidates to overcome TRAIL resistance. Future studies to identify their underlying mechanism of action are required. SUMMARY: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an attractive anticancer agent which can induce apoptosis in tumor cells without causing cytotoxicity to normal cellsHowever, resistance to TRAIL is often observed in some tumor cells, including nonsmall cell lung cancers, which may limit its cytotoxic efficacy in cancer treatmentThe combination treatment of TRAIL and herbal medicines, particularly Coptidis Rhizoma (CR) and Curcumae longae Rhizoma (CLR), can induce the synergistic cytotoxic effects against TRAIL-resistant A549 cells, indicating that TRAIL resistance was reduced by combination therapy. Abbreviations used: TRAIL: Tumor necrosis factor-related apoptosis-inducing ligand; CLR: Curcumae longae Rhizoma; CR: Coptidis Rhizoma; NSCLC: non-small cell lung cancer.

Pharmacokinetics and Metabolism of Streptochlorin and Its Synthetic Derivative, 5-Hydroxy-2'-isobutyl Streptochlorin, in Mice.

The purpose of this study was to investigate the pharmacokinetics and metabolism of streptochlorin and its derivative 5-hydroxy-2'-isobutyl streptochlorin (HIS) in mice. Plasma concentration of streptochlorin declined rapidly resulting in a high sustemic plasma clearance (CLp) (5.8±1.7 L/h/kg), a large volume of distribution (Vss) (1.4±0.9 L/kg) and a short half-life (t1/2) (0.4±0.1 h) after a single intravenous administration (5 mg/kg). Oral bioavailability (F) was 10.3±3.4% after a single oral administration (10 mg/kg). HIS also showed a rapid plasma decline with a high CLp (11.3±8.8 L/h/kg), a high Vss (0.8±1.0 L/kg) and a short t1/2 (0.070±0.004 h) following intravenous administration. It was not detected in plasma after oral administration. Metabolic stability studies using mouse liver microsomes and S9 fractions predicted a high hepatic clearance for both compounds, consistent with the in vivo data. Metabolite identification studies revealed three metabolic pathways for streptochlorin: monooxygenation, glucuronidation of the indole moiety and oxidative opening of the 4-chlorooxazole ring. HIS was metabolized via monooxygenation of the isobutyl chain and glucuronidation of the indole ring. These results may aid in structural optimization to mitigate the metabolic liability of streptochlorin.

Cytochrome P450 4A11 inhibition assays based on characterization of lauric acid metabolites.

This study was designed to characterize lauric acid metabolism to facilitate the establishment of cytochrome P450 4A11 (CYP4A11) inhibition assay. Three metabolites (2-, 11-, and 12-hydroxylauric acids) were identified in pooled human liver microsomes based on comparisons with authentic standards. Reaction phenotyping using 14 recombinant CYPs showed that ω-hydroxylation was mediated dominantly by CYP4A11 and marginally by CYP4F3B. CYP2B6 played an exclusive role in the formation of 2-hydroxylauric acid. The production of 11-hydroxylauric acid was mediated by CYP2E1, CYP2C9, CYP2B6, CYP1A2, CYP3A4, and CYP4A11. The IC50 values of HET0016, a well-known pan-CYP4 inhibitor, against the formation of 12-, 11-, and 2-hydroxylauric acid were 1.0, 1.0, and 0.009 µM, respectively. Among the 50 natural compounds examined, plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone) inhibited the formation of 12-, 11-, and 2-hydroxylauric acid with IC50 values of 1.7, 2.3, and 2.7 µM, respectively. In the selectivity study, HET0016 inhibited CYP2B6 with an IC50 of 9.2 nM, as well as CYP1A2, CYP2C19, and CYP2E1 with IC50 values of 1-2 µM. Plumbagin inhibited all CYP enzymes tested with IC50 values of 1.7-3.0 µM. These methods can be used as tools to develop CYP4A11 inhibitors; simultaneous determination of the hydroxylauric acid metabolites provides further information on selectivity.

A novel model for metabolic syndrome risk quantification based on areal similarity degree.

Metabolic syndrome (MS) refers to a clustering of specific cardiovascular disease (CVD) risk factors whose underlying pathology is thought to be related to insulin resistance. The risk factors include insulin resistance, obesity, dyslipidemia, and hypertension and it is known to increase the risk for CVD and type II diabetes. Since MS helps to identify individuals at high risk for both CVD and type II diabetes, it has become a major public healthcare issue in many countries. There has been much effort to establish diagnostic criteria for MS, but the current diagnostic criteria of MS have weaknesses, such as binary decision based on diagnostic criteria, equal weight among risk factors, and difficulty in estimating the temporal progress of the risk factors. To resolve these problems, this paper proposes a risk quantification model for MS, which is based on areal similarity degree analysis between weighted radar charts comprising MS diagnostic criteria and examination results of risk factors. The clinical effectiveness of the proposed model is extensively evaluated by using data of a large number of subjects obtained from the third Korea National Health and Nutrition Examination Survey. The evaluation results show that the proposed model can quantify the risk of MS and effectively identify a group of subjects who might be classified into a potential risk group for having MS in the future.