Backonja, M. M., T. P. Malan, G. F. Vanhove and J. K. Tobias. 2010. NGX-4010, a High-Concentration Capsaicin Patch, for the Treatment of Postherpetic Neuralgia: A Randomized, Double-Blind, Controlled Study with an Open-Label Extension. Pain Med.
Objectives. To assess the efficacy, tolerability, and safety of NGX-4010, a high-concentration capsaicin dermal patch (capsaicin 640 mug/cm(2), 8%) in patients with postherpetic neuralgia (PHN). Methods. Patients were randomized to receive NGX-4010 or control patch in a 4-week, double-blind study. This was followed by an open-label extension phase (up to 48 weeks total) where patients could receive up to three additional treatments no sooner than 12 weeks after initial treatment. The primary efficacy variable was mean change from baseline in mean morning and evening numerical pain rating scale (NPRS) scores. Results. During days 8-28 after the double-blind treatment, NGX-4010 patients had a mean change in NPRS scores from baseline of -32.7% compared with -4.4% for control patients (P = 0.003). Mean NPRS scores decreased from baseline during week 1 in both treatment groups, remained relatively stable through week 12 in NXG-4010 patients, but returned to near baseline during weeks 2-4 in controls. Mean change in NPRS scores from baseline during weeks 2-12 was -33.8% for NGX-4010 and +4.9% for control recipients. A similar decrease in NPRS scores from baseline was maintained with subsequent NGX-4010 treatments, regardless of the number of treatments received. Transient increases in application site pain were adequately managed with analgesics. No increases in application site reactions or adverse events were observed with repeated treatments. No patients discontinued the study due to an adverse event. Conclusion. NGX-4010 is a promising topical treatment for PHN patients, which appears to be tolerable, generally safe, and effective.
Jankovic, B., D. A. Loblaw and R. Nam. 2010. Capsaicin may slow PSA doubling time: case report and literature review. Can Urol Assoc 4, 1: E9-E11.
Capsaicin is the main pungent component of chili peppers. This is the first case, to our knowledge, that describes prostate-specific antigen (PSA) stabilization in a patient with prostate cancer, who had biochemical failure after radiation therapy. A 66-year-old male underwent radiotherapy treatment for a T2b, Gleason 7 (3+4) adenocarcinoma of the prostate, with a PSA level of 13.3 ng/mL in April 2001. He had 3-dimensional conformal radiotherapy of 46 Gy in 23 fractions to the prostate and pelvis, and a prostate boost of 30 Gy in 15 fractions. Radiotherapy was completed in May 2001 and PSA nadired in January 2002 (0.57). Due to the continued PSA rise, the patient was started on bicalutamide (50 mg orally, daily) and leuprolide acetate (1 dose of 22.5 mg intramuscularly) in July 2005 when PSA was 38.5 ng/mL. Due to poor tolerance of androgen ablation therapy, the patient discontinued treatment and started taking 2.5 mL of habaneros chili sauce, containing capsaicin, 1 to 2 times a week in April 2006. Prostate-specific antigen doubling time (PSAdt) increased from 4 weeks before capsaicin to 7.3 months by October 2006. From October 2006 until November 2007, the patient remained on capsaicin (2.5 to 15 mL daily) and his PSA was stable (between 11 to 14 ng/mL). By January 2008, his PSA rose to 22.3 and he has maintained a PSAdt between 4 and 5 months, where it presently remains. Due to the patient's continued PSA rise, he was restarted on bicalutamide (12.5 mg daily). Apart from PSA relapse, the patient remains free of signs or symptoms of recurrence.
Hursel, R., M. S. Westerterp-Plantenga. 2010. Thermogenic ingredients and body weight regulation. Int J Obes (Lond).
The global prevalence of obesity has increased considerably in the last decade. Tools for obesity management, including consumption of caffeine, capsaicin and different teas such as green, white and oolong tea, have been proposed as strategies for weight loss and weight maintenance, as they may increase energy expenditure (4-5%), fat oxidation (10-16%) and have been proposed to counteract the decrease in metabolic rate that is present during weight loss. Daily increases in thermogenesis of approximately 300-400 kJ can eventually lead to substantial weight loss. However, it becomes clearer that certain conditions have to be met before thermogenic ingredients yield an effect, as intra-variability with respect to body weight regulation has been shown between subjects. Furthermore, the sympathetic nervous system is involved in the regulation of lipolysis, and the sympathetic innervation of white adipose tissue may have an important role in the regulation of total body fat in general. Taken together, these functional ingredients have the potential to produce significant effects on metabolic targets such as satiety, thermogenesis and fat oxidation. A significant clinical outcome may sometimes appear straightforward and may also depend very strongly on full compliance of subjects. Nevertheless, thermogenic ingredients may be considered as functional agents that could help in preventing a positive energy balance and obesity.
Oyagbemi, A. A, A. B. Saba and O. I. Azeez. 2010. Capsaicin: a novel chemopreventive molecule and its underlying molecular mechanisms of action. Indian J Cancer 47, 1: 53-8.
Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is the a principal pungent ingredient of hot red and chili peppers that belong to the plant genus Capsicum (Solanaceae). Capsaicin is a cancer-suppressing agent. It blocks the translocation of nuclear factor kappa B (NF-kB), activator protein 1 (AP-1), and signal transducer and activator of transcription (STAT3) signaling pathway that are required for carcinogenesis. The anti-inflammatory potential of capsaicin is attributed to its inhibitory effect on inducible COX-2 mRNA expression. Cytochrome P4502E1 mediates the activation of xenobiotics such as vinyl carbamate and dimethyl nitrosamine to their toxic metabolites. This metabolic activation of xenobiotics by Cytochrome P4502E1 has been shown to be inhibited by capsaicin. Capsaicin also generates reactive oxygen species in cells with resultant induction of apoptosis and cell cycle arrest, which is beneficial for cancer chemoprevention. Therefore, the use of capsaicin as a chemopreventive agent is of immense benefit for cancer chemoprevention. The search strategy included printed journals, pubmed, and medline, using the terms 'capsaicin' and 'anticancer' citations, relevant to anticancer properties of capsaicin.
Frericka, H. A., W. Keitelb, U. Kuhna, S. Schmidta, A. Bredehorstc and M. Kuhlmannc. (2003). Topical treatment of chronic low back pain with a capsicum plaster. Pain, 106, 59-64
Abstract; The efficacy and tolerance of a capsicum plaster in non-specific low back pain was investigated in a double-blind, randomised, placebocontrolled multicentre parallel group study. A total of 320 patients were randomly assigned to two groups of n = 160 subjects treated by the active or the placebo plaster. The main outcome measures used were a compound pain subscore of the Arhus low back rating scale (continuous variable), and a response criterion of a reduction in pain subscore ¼ 30% from baseline to final assessment (secondary, non-continuous variable). In addition, the partial pain scores, disability and mobility restriction subscores, the total score of the Arhus low back rating scale, the global evaluation of efficacy by investigator and patient, adverse events, a patient questionnaire on use of the plaster, and an evaluation of tolerance by investigator and patient were obtained. After 3 weeks treatment with capsicum and placebo plaster respectively, the compound pain subscore was reduced by 42% (capsicum) and 31% (placebo) from values on entry. Responder rate was 67% versus 49% (p = 0.002). The investigators rated efficacy as “excellent” or “good” by 74% and 36%; the patient’s efficacy rating “symptomfree” or “improved” reached 82% and 50%. Adverse local drug reactions were found in 12 patients (7.5%) on capsicum and 5 (3.1%) on placebo. No systemic side-effects were observed. The superiority of the treatment of chronic non-specific low back pain with capsicum plaster compared to placebo was clinically relevant and highly statistically significant. The capsicum plaster offers a genuine alternative in the treatment of non-specific low back pain.
Walter, A. A., T. J. Herda, E. D. Ryan, P. B. Costa, K. M. Hoge, T. W. Beck, J. R. Stout and J. T. Cramer. 2009 . Acute effects of a thermogenic nutritional supplement on cycling time to exhaustion and muscular strength in college-aged men. Journal of the International Society of Sports Nutrition 6, 15.
Background: The purpose of the present study was to examine the acute effects of a thermogenic nutritional supplement containing caffeine, capsaicin, bioperine, and niacin on muscular strength and endurance performance.
Methods: Twenty recreationally-active men (mean SD age = 21.5 ± 1.4 years; stature = 178.2 ± 6.3 cm; mass = 76.5 ± 9.9 kg; VO2 PEAK = 3.05 ± 0.59 L/min-1) volunteered to participate in this randomized, double-blinded, placebo-controlled, cross-over study. All testing took place over a three-week period, with each of the 3 laboratory visits separated by 7 days (± 2 hours). During the initial visit, a graded exercise test was performed on a Lode Corival cycle ergometer (Lode, Groningen, Netherlands) until exhaustion (increase of 25 W every 2 min) to determine the maximum power output (W) at the VO2 PEAK (Parvo Medics TrueOne® 2400 Metabolic Measurement System, Sandy, Utah). In addition, one-repetition maximum (1-RM) strength wasassessed using the bench press (BP) and leg press (LP) exercises. During visits 2 and 3, the subjects were asked to consume a capsule containing either the active supplement (200 mg caffeine, 33.34 mg capsaicin, 5 mg bioperine, and 20 mg niacin) or the placebo (175 mg of calcium carbonate, 160 mg of microcrystalline cellulose, 5 mg of stearic acid, and 5 mg of magnesium stearate in an identical capsule) 30 min prior to the testing. Testing included a time-to-exhaustion (TTE) ride on a cycle ergometer at 80% of the previously-determined power output at VO2 PEAK followed by 1-RM LP and BP tests.
Results: There were no differences (p > 0.05) between the active and placebo trials for BP, LP, or TTE. However, for the BP and LP scores, the baseline values (visit 1) were less than the values recorded during visits 2 and 3 (p ≤ 0.05).
Conclusion: Our findings indicated that the active supplement containing caffeine, capsaicin, bioperine, and niacin did not alter muscular strength or cycling endurance when compared to a placebo trial. The lack of increases in BP and LP strength and cycle ergometry endurance elicited by this supplement may have been related to the relatively small dose of caffeine, the high intensity of exercise, the untrained status of the participants, and/or the potential for caffeine and capsaicin to increase carbohydrate oxidation.
Lorenz, J., S. Minoshima and K. L. Casey. 2003. Keeping pain out of mind: the role of the dorsolateral prefrontal cortex in pain modulation. Brain 126: 1079-1091.
Summary; Frontal lobe activity during pain is generally linked to attentional processing. We addressed the question of whether `bottom-up' processing and `top-down' modulation of nociceptive information dissociate anatomically within the frontal lobe by using PET scanning during painful thermal stimulation of normal and capsaicin treated skin. We showed recently that pain following normally non-painful heat stimuli on chemically irritated skin (heat allodynia) uniquely engages extensive areas of the bilateral dorsolateral prefrontal (DLPFC), ventral/orbitofrontal (VOFC) and perigenual anterior cingulate (ACC) cortices. Here, we applied principal component analysis (PCA) and multiple regression analysis to study the covariance structure of the volumes of interest (VOI) activated specifically during heat allodynia in 14 male healthy subjects and evaluated the relationship of these VOI to ratings of pain intensity and affect. Results yielded a primary principal component (PC) that correlated positively with intensity and unpleasantness and accounted for activity in the medial thalamus, bilateral anterior insula, ventral striatum, perigenual ACC and bilateral VOFC. Activities in the right and left DLPFC loaded on separate PC and correlated negatively with perceived intensity and unpleasantness. The inter-regional correlation of midbrain and medial thalamic activity was significantly reduced during high left DLPFC activity, suggesting that its negative correlation with pain affect may result from dampening of the effective connectivity of the midbrain-medial thalamic pathway. In contrast, right DLPFC activity was associated with a weakened relationship of the anterior insula with both pain intensity and affect. We propose that the DLPFC exerts active control on pain perception by modulating corticosubcortical and corticocortical pathways.
Galluzzi, K. E. 2007. Management Strategies for Herpes Zoster and Postherpetic Neuralgia, J Am Osteopath Assoc. 107, 3: S8-S13.
Abstract; Evidence-based strategies for the management of herpes zoster and postherpetic neuralgia (PHN) include the use of antiviral agents in acute zoster and specific analgesics in PHN. Antiviral agents are effective in reducing the severity and duration of acute herpes zoster when given within 72 hours of rash onset, but they do not prevent PHN. Anticonvulsants, tricyclic antidepressants, opioids, and topical treatment modalities such as lidocaine-containing patches and capsaicin cream offer moderate pain relief to some patients with PHN, but they may be associated with adverse events that limit their use. Therefore, prevention of herpes zoster and PHN with prophylactic vaccination using the zoster virus vaccine is an effective strategy to reduce the morbidity of these conditions. Treatment modalities are available, however, that may shorten the duration of acute herpes zoster and alleviate the pain of PHN.
Paul F. White. 2008. Red-Hot Chili Peppers: A Spicy New Approach to Preventing Postoperative Pain. International Anesthesia Research Society 107, 1: 6-8.
Robbins, W. R., P. S. Staats, J. Levine, H. L. Fields, R. W. Allen, J. N. Campbell and M. Pappagallo. 1998. Treatment of Intractable Pain with Topical Large-Dose Capsaicin: Preliminary Report. Anesth Analg. 86: 579-583.
Abstract; Complex regional pain syndromes (CRPS) and neuropathic pain are often poorly controlled by conventional pharmacologic interventions. We administered g-methyl-N-vanillyl-6-noneamide (capsaicin) at doses of 5%-10% to individuals with such disorders in this trial. Previous limitations to trials with larger-dose, topical concentrations of capsaicin included intense burning sensations experienced after application. To enable patients to tolerate the high concentrations, we first performed regional anesthesia. All patients reported at least some relief. Of 10 patients, 9 obtained substantial analgesia that lasted 1-18 wk. At Week 1 after therapy, the mean verbal analog scale (VAS) scores decreased from 8.0 to 3.0. At Week 4 after therapy, mean VAS score was 4.5. Analgesia lasted from <1 wk (1 patient) to more than 50 wk (1 patient). Patients received one to eight treatments. With one exception, patients receiving more than one treatment obtained additional relief with subsequent treatment. Pain responsive to opioids was the only side effect of treatment. Large dose capsaicin administered with regional anesthesia may effectively minimiz refractory CRPS and neuropathic pain. A double-blind, placebo-controlled study in patients with bilateral peripheral neuropathy using epidural anesthesia with and without large-dose topical capsaicin is in progress.
Implications: Sensory neuropathies are associated with many diseases. Pain from these disorders can produce greater disability than the primary disease processes themselves. Currently available therapies are limited. However, the intermittent application of large-dose topical capsaicin may provide significant pain relief, decrease chronic analgesic dependence, and decrease aggregate health care expenditures.
Gary McCleane. 2000. Topical application of doxepin hydrochloride, capsaicin and a combination of both produces analgesia in chronic human neuropathic pain: a randomized, double-blind, placebo-controlled study. Br J Clin Pharmacol. 49: 574-579.
Aims; To assess the analgesic efficacy of topical administration of 3.3% doxepin hydrochloride, 0.025% capsaicin and a combination of 3.3% doxepin and 0.025% capsaicin in human chronic neuropathic pain.
Methods; A randomized, double-blind, placebo-controlled study of 200 consenting adult patients. Patients applied placebo, doxepin, capsaicin or doxepin/capsaicin cream daily for 4 weeks. Patients recorded on a daily basis overall pain, shooting, burning, paraesthesia and numbness using a 0±10 visual analogue scale during the week prior to cream application (baseline levels) and for the 4 week study period. Side-effects and desire to continue treatment were also recorded.
Results; Overall pain was significantly reduced by doxepin, capsaicin and doxepin/capsaicin to a similar extent. The analgesia with doxepin/capsaicin was of more rapid onset. Capsaicin significantly reduced sensitivity and shooting pain. Burning pain was increased by doxepin and by capsaicin and to a lesser extent by doxepin/capsaicin. Side-effects were minor. One patient requested to continue placebo cream, 17 doxepin cream, 13 capsaicin and 9 the combination of doxepin and capsaicin.
Conclusions; Topical application of 3.3% doxepin, 0.025% capsaicin and 3.3% doxepin/0.025% capsaicin produces analgesia of similar magnitude. The combination produces more rapid analgesia.
Ki Ok shin and Toshio Moritani. 2007. Alterations of Autonomic Nervous Activity and Energy Metabolism by Capsaicin Ingestion During Aerobic Exercise in Healthy Men. J Nutr Sci Vitaminol. 53: 124-132.
Summary; We investigatec whether capsaicin ingestion (150 mg) enhances substrate oxidation associated with thermogenic sympathetic activity as an energy metabolic modulator without causing prolongation of the cardiac QT interval during aerobic exercise in humans. Ten healthy males [24.4 (4.3) y] volunteered for this study. The cardiac autonomic nervous activities evaluated by means of heart rate variability of power spectral analysis, energy metabolism and ECG QT interval were continuously measured during 5-min rest and 30 min exercise at 50% of maximal ventilatory threshold (50% VTmax) on a stationary ergometer with placebo or capsaicin oral administration chosen at random.The results indicated that there were no significant differences in heart rate during rest or exercise between the two trials. Autonomic nervous activity increased in the capsaicin tablet trial during exercise, but the difference did not reach statistical significance. Capsaicin, however, significantly induced a lower respiratory gas exchange ratio [0.92 (0.02) vs. 0.94 (0.02), means (SE), p < 0.05] and higher fat oxidation [0.17 (0.04) vs. 0.12 (0.04) g/min, means (SE), p < 0.05] during exercise. On the other hand, the data on the cardiac OT interval showed no significant difference, indicating that oral administration of capsaicin did not cause any adverse effect on cardiac depolarization-repolarization. In conclusion, it may be considered that capsaicin consumption 1 h before low intensity exercise (50% VT(max)) is a valuable supplement for the treatment of individuals with hyperlipidemia and/or obesity because it improves lipolysis without any adverse effects on the cardiac depolarization and repolarization process.
Hachiya, S., F. Kawabata, K. Ohnuki, N. Inoue, H. Yoneda, S. Yazawa and T. Fushiki 2007. Effects of CH-19 Sweet, a non-pungent cultivar of red pepper, on sympathetic nervous activity, body temperature, heart rate, and blood pressure in humans. Biosci Biotechnol Biochem. 71, 3: 671-676.
We investigated the changes in autonomic nervous activity, body temperature, blood pressure (BP), and heart rate (HR) after intake of the non-pungent pepper CH-19 Sweet and of hot red pepper in humans to elucidate the mechanisms of diet-induced thermogenesis (DIT) due to CH-19 Sweet. We found that CH-19 Sweet activates the sympathetic nervous system (SNS) and enhances thermogenesis as effectively as hot red pepper, ant that the heat loss effect due to CH-19 Sweet is weaker than that due to hot red pepper. Furthermore, we found that intake of CH-19 Sweet does not affect systolic BP or HR, while hot red pepper transiently elevates them. These results indicate that DIT due to CH-19 Sweet can be induced via the activation of SNS as well as hot red pepper, but that the changes in BP, HR, and heat loss effect are different between these peppers.
Ma, W., L. Yu, Y. Wang, X. Li, H. LÜ and Z. Qiu. 2009. Changes in health-related quality of life and clinical implications in Chinese patients with chronic cough. Cough 5, 7.
Background: Chronic cough has negative effects on quality of life. However, the changes in health-related quality of life and clinical implications remain unclear in Chinese patients with chronic cough.
Methods: A standard Chinese version of Leicester cough questionnaire (LCQ) was developed by an established translation procedure and its repeatability was assessed in a preliminary study involving 20 untreated patients with stable chronic cough. The quality of life was measured with the Short form-36 health survey and compared between 110 patients with chronic cough and 90 healthy volunteers. The changes in health-related quality of life were evaluated in the patients with chronic cough with the LCQ just before the specific treatment was initiated and a week after the cough had resolved completely. Cough threshold with inhaled capsaicin, expressed as the lowest concentration of capsaicin required for the induction of ≥5 coughs, was also measured.
Results: The repeatability of the Chinese version of the LCQ was validated at a four day interval with the intraclass correlation coefficients of 0.89-0.94 for total and domain score (n = 20). The scores of the Short form-36 health survey were significantly lower in patients with chronic cough than those in healthy volunteers. In general, there was no significant difference in overall quality of life between different causes of chronic cough or genders although embarrassment, frustration and sleep disturbance were more common in female patients, as indicated by the LCQ. However, the successful treatment of cough obviously increased the total scores of the LCQ from 14.2 ± 2.7 to 19.5 ± 1.9 (t = 13.7, P < 0.0001). There was a significant correlation between the total score of the LCQ and physical (r = 0.39, P < 0.0001) or mental (r = 0.30, P < 0.001) component summary of the Short form-36 health survey but not between the LCQ and capsaicin cough threshold.
Conclusion: The quality of life is significantly impaired in Chinese patients with chronic cough. The Chinese version of the LCQ is a valid measure of cough related quality of life and is repeatable and responsive.
Ryan, N. M., A. E. Vertigan and P. G. Gibson. 2009. Chronic cough and laryngeal dysfunction improve with specific treatment of cough and paradoxical vocal fold movement. Cough 5, 4.
Rationale: Chronic persistent cough can be associated with laryngeal dysfunction that leads to symptoms such as dysphonia, sensory hyperresponsiveness to capsaicin, and motor dysfunction with paradoxical vocal fold movement and variable extrathoracic airflow obstruction (reduced inspiratory airflow). Successful therapy of chronic persistent cough improves symptoms and sensory hyperresponsiveness. The effects of treatment for chronic cough on laryngeal dysfunction are not known.
Objective: The aim of this study was to investigate effects of therapy for chronic cough and paradoxical vocal fold movement.
Methods: Adults with chronic cough (n = 24) were assessed before and after treatment for chronic persistent cough by measuring quality of life, extrathoracic airway hyperresponsiveness to hypertonic saline provocation, capsaicin cough reflex hypersensitivity and fibreoptic laryngoscopy to observe paradoxical vocal fold movement. Subjects with chronic cough were classified into those with (n = 14) or without (n = 10) paradoxical vocal fold movement based on direct observation at laryngoscopy.
Results: Following treatment there was a significant improvement in cough related quality of life and cough reflex sensitivity in both groups. Subjects with chronic cough and paradoxical vocal fold movement also had additional improvements in extrathoracic airway hyperresponsiveness and paradoxical vocal fold movement. The degree of improvement in cough reflex sensitivity correlated with the improvement in extrathoracic airway hyperresponsiveness.
Conclusion: Laryngeal dysfunction is common in chronic persistent cough, where it is manifest as paradoxical vocal fold movement and extrathoracic airway hyperresponsiveness. Successful treatment for chronic persistent cough leads to improvements in these features of laryngeal dysfunction.
PECOVA, R., J. ZUCHA, M. PEC, M. NEUSCHLOVA, P. HANZEL and M. TATAR. 2008. COUGH REFLEX SENSITIVITY TESTING IN SEASONAL ALLERGIC RHINITIS PATIENTS AND HEALTHY VOLUNTEERS. JOURNAL OF PHYSIOLOGY AND PHARMACOLOG. 59: 557-564.
Dysfunction of upper and lower airways frequently coexists, and they appear to share key elements of pathogenesis. The interrelationship between upper and lower airway manifestations of allergy remains still incompletely investigated. Little is known about the critical factors that determine airway afferent nerve endings reactivity (cough sensitivity) in patients with allergic rhinitis. Subclinical inflammatory changes within the lower airways and/or chronic upper airway cough syndrome (previously referred to as postnasal drip syndrome) are probably responsible for this effect. The aim of this study was to evaluate capsaicin cough sensitivity in pollen sensitive patients with seasonal allergic rhinitis without treatment out of a grass pollen season time using the European Respiratory Society (ERS) guidelines on the assessment of cough. Cough sensitivity was defined as the lowest capsaicin concentration which evoked two (C2) or five (C5) coughs. Capsaicin aerosol in doubling concentrations (from 0.49 to 1000 μmol/l) was inhaled by a single breath method (KoKo DigiDoser; nSpire heath Inc, Louisville, CO), modified by the addition of an inspiratory flow regulator valve (RIFR; nSpire heath Inc, Louisville, CO). The seasonal rhinitis subjects (5M, 7F; mean age 23 yr) had not been complaining primarily about coughing. Their pulmonary function was within normal range. Concentrations of capsaicin causing two (C2) and five coughs (C5) were reported. Volunteers’ (5M, 7F, mean age 23 yr) cough sensitivity (geometric mean and 95 % CI) for C2 was 16.5 (4.1-67.0) μmol/l vs. allergic rhinitis patients‘ C2 3.5 (1.9 - 6.4) (P= 0.018). Volunteers’ C5 was 132.4 (41.3 – 424.5) μmol/l vs. allergic rhinitis patients‘ C5 13.1 (6.0 – 28.6) μmol/l (P= 0.013). We conclude that airway afferent nerve endings reactivity in pollen sensitive subjects suffering from seasonal allergic rhinitis was significantly increased out of pollen season compared with healthy volunteers.
Ishiura,Y., M. Fujimura, H. Yamamoto, T. Ishiguro, N. Ohkura, and S. Myou. 2009. COX-2 Inhibition Attenuates Cough Reflex Sensitivity to Inhaled Capsaicin in Patients With Asthma. J Investig Allergol Clin Immunol. 19, 5, 370-374.
Background and objective: Cyclooxygenase (COX) is an enzyme that converts arachidonic acid to prostanoids. There are two isoforms of COX, namely COX-1 and COX-2. COX-2 is highly inducible by several stimuli and is associated with infl ammation. Recent studies have shown that COX-2 is upregulated in the airway epithelium of patients with asthma but little is known about the role it plays in cough, a common symptom of bronchial asthma. This study was designed to investigate the role of COX-2 in cough refl ex sensitivity in patients with asthma.
Patients and methods: The effect of etodolac, a potent COX-2 inhibitor, on cough response to inhaled capsaicin was examined in 17 patients with stable asthma in a randomized, placebo-controlled crossover study. Capsaicin cough threshold, defi ned as the lowest concentration of capsaicin eliciting 5 or more coughs, was measured as an index of airway cough refl ex sensitivity.
Results: The geometric mean (geometric SEM) cough threshold was signifi cantly increased after a 2-week treatment program with oral etodolac (200 mg twice a day) compared with placebo (36.7 [1.2] vs 21.6 [1.2] μM, P<.02).
Conclusions: These findings indicate that COX-2 may be a possible modulator augmenting airway cough reflex sensitivity in asthmatic airways.
Harada, N. and K. Okajima. 2009. Effects of capsaicin and isoflavone on blood pressure and serum levels of insulin-like growth factor-I in normotensive and hypertensive volunteers with alopecia. Biosci Biotechnol Biochem. 73, 6: 1456-1459.
Abstract; Insulin-like growth factor-I (IGF-I) reduces arterial blood pressure. Since administration of capsaicin and isoflavone increases serum levels of IGF-I by sensory neuron stimulation in subjects with alopecia, it is possible that administration of capsaicin and isoflavone reduces arterial blood pressure in patients with hypertension. Systolic and diastolic blood pressure (BP) and serum levels of IGF-I were determined before and at 1, 3, and 5 months after administration of capsaicin and isoflavone in 42 volunteers with alopecia, 29 normotensive and 13 hypertensive volunteers. Neither systolic nor diastolic BP changed in the normotensive volunteers after combined administration of capsaicin and isoflavone. In contrast, systolic and diastolic BP was significantly reduced in hypertensive volunteers after administration of capsaicin and isoflavone. Serum levels of IGF-I significantly increased in both normotensive and hypertensive volunteers after administration of capsaicin and isoflavone. These observations suggest that administration of capsaicin and isoflavone might reduce BP in hypertensive, but not in normotensive subjects, probably by increasing serum levels of IGF-I.