Cytotoxic and apoptotic activities of Amorphophallus campanulatus (Roxb.) Bl. tuber extracts against human colon carcinoma cell line HCT-15.

Colorectal cancer is one of the leading causes of cancer death worldwide and is the third most common form of malignancy in both men and women. Several possible colon cancer chemopreventive agents are found in edible plants. Amorphophallus campanulatus (Roxb.) Blume (family: Araceae) is a tuber crop, largely cultivated throughout the plains of India for using its corm as food. This tuber has also been traditionally used for the treatment of abdominal tumors, liver diseases, piles etc. The aim of this study was to evaluate the dose-dependent cytotoxic and apoptosis inducing effects of the sub fractions of A. campanulatus tuber methanolic extract (ACME) viz. petroleum ether fraction (PEF), chloroform fraction (CHF), ethyl acetate fraction (EAF) and methanolic fraction (MEF) on the colon cancer cell line, HCT-15. Antiproliferative effects of the sub fractions of ACME were studied by MTT assay. Apoptotic activity was assessed by DAPI, Annexin V-FITC and JC-1 fluorescent staining. The chemotherapeutic drug, 5-flurouracil (5-FU) was used as positive drug control. The sub fractions of ACME significantly inhibited the proliferation of HCT-15 cells in a dose-dependent manner. In addition, the extracts were found to induce apoptosis and were confirmed by DAPI, Annexin V-FITC and JC-1 fluorescent staining. A pronounced results of cytotoxic and apoptotic activities were observed in the cells treated with 5-FU and CHF, whereas, EAF and MEF treated cells exhibited a moderate result and the least effect was observed in PEF treated cells. Our results suggested that, among the sub fractions of ACME, CHF had potent cytotoxic and apoptotic activity and thus it could be explored as a novel target for anticancer drug development. Furthermore, these findings confirm that the sub fractions of ACME dose-dependently suppress the proliferation of HCT-15 cells by inducing apoptosis.

Cytotoxic and apoptotic activities of Amorphophallus campanulatus tuber extracts against human hepatoma cell line.

Amorphophallus campanulatus (Roxb.) Blume belonging to the family of Araceae, is a perennial herb commonly known as elephant foot yam. Its tuber has been traditionally used for the treatment of liver diseases, abdominal tumors, piles. The aim of the present study was to evaluate the dose-dependent cytotoxic and apoptosis inducing effects of the sub fractions of Amorphophallus campanulatus tuber methanolic extract (ACME) namely petroleum ether fraction (PEF), chloroform fraction (CHF), ethyl acetate fraction (EAF) and methanolic fraction (MeF) on human liver cancer cell line, PLC/PRF/5. Antiproliferative effects of the sub fractions of ACME were studied by MTT assay. Apoptotic activity was assessed by 4',6-diamidino-2-phenylindole (DAPI), annexin V- fluorescein isothiocyanate (FITC) and 5,5',6,6' tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) fluorescent staining. The chemotherapeutic drug, 5-flurouracil (5-FU) was used as positive drug control. The sub fractions of ACME were found to produce considerable cytotoxicity in human liver cancer cell line, PLC/PRF/5. In addition, the extracts were found to induce apoptosis and were substantiated by DAPI, annexin V-FITC and JC-1 fluorescent staining. A pronounced results of cytotoxic and apoptotic activities were observed in the cells treated with 5-FU and CHF, whereas, EAF and MeF treated cells exhibited a moderate result and the least effect were observed in PEF treated cells. Furthermore, these findings confirm that the sub fractions of ACME dose-dependently suppress the proliferation of PLC/PRF/5 cells by inducing apoptosis.

Dose-response effects of Elephantopus scaber methanolic extract on N-nitrosodiethylamine-induced hepatotoxicity in rats.

AIM: A decoction of Elephantopus scaber (Asteraceae) root is used to treat liver disorders in Indian and Chinese traditional medicine. The study was designed to examine the dose response effects of E. scaber methanolic extract on rats exposed to N-nitrosodiethylamine (NDEA) induced hepatotoxicity (0.02% NDEA in water five days per week, per oral) in preventive and curative models. METHODS: In preventive groups, NDEA was administered for six weeks. Daily doses of E. scaber methanolic extract (200 and 100 mg·kg-1) started one week before the onset of NDEA intoxication and continued for six weeks. In curative animals, NDEA was administered for six weeks followed by treatment with the methanolic n-hexane extract of E. scaber (200 and 100 mg·kg-1) for ten days. RESULTS: E. scaber extract treatment significantly (P ≤ 0.05) reduced the levels of AST, ALT, and MDA in both experimental groups. The extract also enhanced the antioxidant enzyme and protein levels in rats intoxicated with NDEA. Treatment with the extract dose dependently protected the liver from NDEA-induced hepatotoxicity with normal hepatocytes and uniform sinusoids, but in some areas showed degenerating hepatic cells in both treatment groups. CONCLUSION: E. scaber methanolic extract dose dependently prevented and reversed the hepatotoxicity induced by NDEA in both experimental models.

The antibiofilm effects of Byotrol™ G32.

AIM: The purpose of this study was to evaluate a commercial antimicrobial formulation, Byotrol™ G32, as a potential coating for impeding biofilm formation on medical devices such as urinary catheters. METHODS AND RESULTS: The antimicrobial activity of Byotrol™ G32 and its individual constituents has been tested on planktonic and biofilm cultures of uropathogenic bacteria. The Byotrol™ G32 formulation was superior with MICs ranging from 3 µg ml(-1) to 15 µg ml(-1) for planktonic cultures and 3-20 µg ml(-1) for biofilms. Furthermore, Byotrol™ G32 was able to remove established biofilms and act as an antibiofilm surface coating. CONCLUSIONS: Byotrol™ G32 displays impressive antimicrobial activity both in suspension and as a coating. Pretreating medical devices with Byotrol™ G32 may significantly impede biofilm formation and prolong the lifetime of the device. SIGNIFICANCE AND IMPACT OF THE STUDY: Medical devices are indispensable in health care. They are, however, a predisposing factor in infection. This research has demonstrated that Byotrol™ G32 reduces bacterial growth and subsequent biofilm formation. Application of Byotrol™ G32 as a medical device coating could have a significant impact on the costs associated with device replacement and patient morbidity and mortality.

Chemopreventive action of Lygodium flexuosum extract in human hepatoma PLC/PRF/5 and Hep 3B cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Lygodium flexuosum (Lygodiaceae), a medicinal fern used in Indian traditional medicine against liver disorders. AIM OF THE STUDY: The rationale of the study was to examine whether the n-hexane extract from plant Lygodium flexuosum affects apoptosis on human hepatoma PLC/PRF/5 and Hep 3B cells. MATERIALS AND METHODS: Chemopreventive activity of the Lygodium flexuosum extract was determined by MTT assay, annexin-V FITC binding to phosphatidyl serine and cleavage of PARP. Subdiploid condition of cells treated with Lygodium flexuosum was analyzed by flow cytometry. Further, used transiently transfected NF-kappaB reporter in PLC/PRF/5 cells to evaluate the inhibitive effect of Lygodium flexuosum extract. RESULTS: Lygodium flexuosum extract inhibited the cell viability and induced apoptosis in hepatoma cells in a concentration dependent manner as evidenced by apoptotic changes such as flipping of phosphatidyl serine, cleavage of PARP. Cell cycle analysis showed the subG1 apoptotic population in cells treated with higher concentrations of the extract. When activated with exogenous TNF-alpha in transfected hepatoma cells it was observed that NF-kappaB dependent gene expression was inhibited by treatment with Lygodium flexuosum extract in PLC/PRF/5 cells dose-dependently. CONCLUSIONS: This investigation suggests that the Lygodium flexuosum extract has antiproliferative and apoptotic activity in both cancer cells and has inhibitive role in TNF-alpha induced NF-kappaB activation in PLC/PRF/5 cells confirms the potential of the extract as a chemopreventive agent.

Pigeon fanciers lung: a case report.

INTRODUCTION: Pigeon fanciers lung, a form of hypersensitivity pneumonitis, is an unusual but important occupational and recreational cause of severe and debilitating breathlessness. CASE PRESENTATION: We report the case of a 61-year-old Caucasian man suffering with severe breathlessness due to pigeon fanciers lung. He had previously raced and bred pigeons for 25 years but had discontinued the pursuit a decade ago. CONCLUSION: Pigeon fanciers lung can be associated with severe debilitating dyspnoea and patients may present many years after exposure to avian antigens. Physicians should be encouraged to take a detailed occupational and recreational history in any patient presenting with unexplained breathlessness.

Hepatoprotection of Phyllanthus maderaspatensis against experimentally induced liver injury in rats.

The hexane extract of Phyllanthus maderaspatensis (200 and 100 mg/kg) showed significant hepatoprotection on carbon tetrachloride and thioacetamide induced liver damage in rats. The protective effect was evident from serum biochemical parameters and histopathological analysis. Rats treated with P. maderaspatensis remarkably prevented the elevation of serum AST, ALT and LDH and liver lipid peroxides in CCl(4) and thioacetamide treated rats. Hepatic glutathione levels significantly increased by the treatment with the extracts. Histopathological changes induced by CCl(4) and thioacetamide were also significantly reduced by the extract treatment. The activity of hexane extracts of P. maderaspatensis was comparable to that of silymarin, the reference hepatoprotective drug.

Protective mechanism of Lygodium flexuosum extract in treating and preventing carbon tetrachloride induced hepatic fibrosis in rats.

The protective effect of Lygodium flexuosum extract in preventive and curative treatments of CCl(4) induced fibrosis was quantified. Hepatic fibrosis was induced in male Wistar rats by CCl(4) administration (150 microL/100 gm rat weight, oral) twice a week for 10 weeks. In preventive treatment daily doses of L. flexuosum n-hexane extract (200 mg/kg, p.o) were administered for 10 weeks. In curative treatment L. flexuosum extract (200 mg/kg, p.o) was given for 2 weeks after the establishment of fibrosis for 10 weeks. Treatment with the n-hexane extract (200 mg/kg) reduced the mRNA levels of proinflammatory cytokines, growth factors and other signaling molecules, which are involved in hepatic fibrosis. The expression levels of tumor necrosis factor-alpha, interleukin-1beta, transforming growth factor-beta1, procollagen-I, procollagen-III and tissue inhibitor of metalloproteinase-1 were elevated during carbon tetrachloride administration and reduced the levels to normal by the treatment with the extract treatment. The increased levels of matrix metalloproteinase-13 in extract treated rats were indicative of the protective action of L. flexuosum n-hexane extract. In conclusion, L. flexuosum n-hexane extract functions as a potent fibrosuppresant, effectively reverses carbon tetrachloride-induced hepatic fibrosis in curative treatment and reduces the effects of ongoing toxic liver injury in preventive treatment by promoting extracellular matrix degradation in the fibrotic liver.

Antiangiogenic effect of Lygodium flexuosum against N-nitrosodiethylamine-induced hepatotoxicity in rats.

The antiangiogenic effect of Lygodium flexuosum extract was evaluated in Wistar rats intoxicated with N-nitrosodiethylamine (NDEA) in preventive and curative models. In preventive groups, NDEA was administered for 20 weeks. Daily doses of L. flexuosumn-hexane extract (200mg/kg) started 1 week before the onset of NDEA intoxication and continued for 20 weeks. In curative animals, NDEA was administered for 20 weeks followed by treatment with the n-hexane extract of L. flexuosum for 28 days. Rats intoxicated with NDEA had elevated levels of serum gamma-GT, AST, ALT, LDH levels and hepatic MDA and decreased levels of hepatic GSH. When treated with L. flexuosum extract had normal levels of gamma-GT, AST, ALT, LDH levels, hepatic MDA and GSH. NDEA administered rat liver showed an overexpressed levels of angiopoietins 1 (Ang-1) and 2 (Ang-2) and its receptor Tie-2 mRNA. L. flexuosum extract treatment significantly (p

Protective effect of Lygodium flexuosum (L.) Sw. extract against carbon tetrachloride-induced acute liver injury in rats.

The hepatoprotective potential of Lygodium flexuosum (L.) Sw. was evaluated in male Wistar rats against carbon tetrachloride-induced liver damage in preventive and curative models. Toxic control and n-hexane extract-treated rats received a single dose of CCl4 (150 microL/100g, 1:1 in corn oil). Pre-treated rats were given n-hexane extracts at 200 and 100 mg/kg dose 48, 24 and 2 h prior to CCl4 administration. In post-treatment groups, rats were treated with n-hexane extract at a dose of 200 and 100 mg/kg, 2, 24 and 48 h after CCl4 intoxication. Rats pre-treated with Lygodium flexuosum remarkably prevented the elevation of serum AST, ALT, LDH and liver lipid peroxides in CCl4-treated rats. Rats treated with the extract after the establishment of CCl4 induced liver injury showed significant (p < or = 0.05) protection of liver as evidenced from normal AST, ALT, LDH and MDA levels. Hepatic glutathione levels were significantly (p < or = 0.05) increased by the treatment with the extracts in both the experimental groups. Histopathological changes induced by CCl4 were also significantly (p < or = 0.05) reduced by the extract treatment in preventive and curative groups. Phytochemical studies revealed the presence of saponins, triterpenes, sterols and bitter principles in Lygodium flexuosumn-hexane extract which could be responsible for the possible hepatoprotective action.

Protective effect of Lygodium flexuosum (L.) Sw. (Lygodiaceae) against D-galactosamine induced liver injury in rats.

The protective effect of Lygodium flexuosum n-hexane extract against D-galactosamine was evaluated in Wistar rats. In preventive groups extract was administered at 48, 24 and 2h before D-galactosamine intoxication whereas in post-treatment groups extract were administered 2, 24 and 48 h after D-galactosamine intoxication. Rats pre-treated with n-hexane extract at a dose of 200 and 100 mg/kg of Lygodium flexuosum showed a significant prevention of elevated AST, ALT, LDH levels and hepatic malondialdehyde in D-galactosamine treated rats. Hepatic glutathione levels significantly upregulated by the extract treatment in D-galactosamine treated rats. Quantification of histopathological sections supported the preventive action of n-hexane extract of Lygodium flexuosum. Rats treated with the extract at a dose of 200 and 100 mg/kg Lygodium flexuosum after the establishment of D-galactosamine induced liver injury showed complete protection of liver as evidenced from normal AST, ALT and LDH levels, hepatic GSH and MDA levels and also by normal histological index of liver in treated rats. Rats treated with n-hexane extract of Lygodium flexuosum were comparable to that of Silymarin, the standard hepatoprotective drug.

Preventive and curative effect of Lygodium flexuosum (L.) Sw. on carbon tetrachloride induced hepatic fibrosis in rats.

The preventive and curative effect of Lygodium flexuosum on experimentally induced hepatic fibrosis by carbon tetrachloride (CCl(4)) was evaluated in rats. Hepatic fibrosis was induced in male Wistar rats by CCl(4) administration (150 microL/100g rat weight, oral) twice a week for 10 weeks. In preventive treatment daily doses of Lygodium flexuosum n-hexane extract (200 mg/kg, p.o) was administered for 10 weeks. In curative treatment Lygodium flexuosum extract (200 mg/kg, p.o) was given for 2 weeks after the establishment of fibrosis for 10 weeks. Treatment with CCl(4) caused a significant decrease in body and liver weight. Lygodium flexuosum n-hexane extract prevented or reversed the decline in body and liver weight. Treatment with the extract prevented or restored the elevation of serum AST, ALT and LDH levels. Lygodium flexuosum treatment remarkably prevented or reversed an increase in liver hydroxyproline content in chronically treated rats. Histopathological changes of hepatic lesions induced by CCl(4) were significantly (p < or = 0.05) improved by treatment with Lygodium flexuosum. These results support that Lygodium flexuosum exerts effective protection in carbon tetrachloride induced hepatic fibrosis in rats.

Inhaled hyperosmolar agents for bronchiectasis.

BACKGROUND: Mucus retention in the lungs is a prominent feature of bronchiectasis. The stagnant mucus becomes chronically colonised with bacteria, which elicit a host neutrophilic response. This fails to eliminate the bacteria, and the large concentration of host-derived protease may contribute to the airway damage. The sensation of retained mucus is itself a cause of suffering, and the failure to maintain airway sterility probably contributes to the frequent respiratory infections experienced by many patients. Hypertonic saline inhalation is known to accelerate tracheobronchial clearance in many conditions, probably by inducing a liquid flux into the airway surface, which alters mucus rheology in a way favourable to mucociliary clearance. Inhaled dry powder mannitol has a similar effect. Such agents are an attractive approach to the problem of mucostasis, and deserve further clinical evaluation. OBJECTIVES: To determine whether inhaled hyperosmolar substances are efficacious in the treatment of bronchiectasis SEARCH STRATEGY: The Cochrane Airways Group Specialised Register was searched, and leaders in the field were contacted. Searches were current as of October 2005. Search updates will be run annually. SELECTION CRITERIA: Any trial using hyperosmolar inhalation in patients with bronchiectasis not caused by cystic fibrosis. DATA COLLECTION AND ANALYSIS: Two reviewers assessed studies for suitability. MAIN RESULTS: Two small studies met the inclusion criteria of the review (28 participants). One study reported tracheobronchial clearance of a particulate radio aerosol after inhalation of dry mannitol on a single occasion, with appropriate control. Airway clearance doubled in the central and intermediate regions of the lung, but not in the peripheral region, after mannitol administration. No side effects were observed, but two patients were premedicated with nedocromil to prevent bronchospasm. Findings from one further trial indicated that one domain of a sensitive health status instrument showed a favourable response to mannitol. AUTHORS' CONCLUSIONS: Dry powder mannitol has been shown to improve tracheobronchial clearance in bronchiectasis, as well as cystic fibrosis, asthmatics, and normal subjects. Hypertonic saline has not been specifically tested in bronchiectasis, but improves clearance in these other conditions and in chronic bronchitis. The measurement of health status in one of the studies should be repeated in future longer term randomised controlled studies of mannitol and hypertonic saline. Consideration should also be given to exacerbations and symptom scores, as well as drug-related adverse events.

Further studies on the antihepatotoxic activity of Phyllanthus maderaspatensis Linn.

Phyllanthus maderaspatensis (whole plant extracts) was evaluated for its antihepatotoxic and choleretic activities in rats. The plant extracts (200 mg/kg, n-hexane, ethyl alcohol or water) showed a remarkable hepatoprotective activity against acetaminophen-induced hepatotoxicity as judged from the serum marker enzymes. The water and ethyl alcohol extracts showed moderate activity compared to the n-hexane extract, which showed activity at a dose as low as 1.5 mg/kg. The antihepatotoxicity of the hexane extract was found to be better than silymarin, a standard hepatoprotective herbal drug. The effect of n-hexane extract was found to be concentration-dependent. This extract also exhibited choleretic activity in normal rats, and in vitro hydroxyl radical scavenging activity and inhibition of lipid peroxidation.

Inhaled hyperosmolar agents for bronchiectasis.

BACKGROUND: Mucus retention in the lungs is a prominent feature of bronchiectasis. The stagnant mucus becomes chronically colonised with bacteria, which elicit a host neutrophilic response. This fails to eliminate the bacteria, and the large concentration of host-derived protease may contribute to the airway damage. The sensation of retained mucus is itself a cause of suffering, and the failure to maintain airway sterility probably contributes to the frequent respiratory infections experienced by many patients. Hypertonic saline inhalation is known to accelerate tracheobronchial clearance in many conditions, probably by inducing a liquid flux into the airway surface, which alters mucus rheology in a way favourable to mucociliary clearance. Inhaled dry powder mannitol has a similar effect. Such agents are an attractive approach to the problem of mucostasis, and deserve further clinical evaluation. OBJECTIVES: To determine whether inhaled hyperosmolar substances are efficacious in the treatment of bronchiectasis SEARCH STRATEGY: MEDLINE and Cochrane databases were searched, and leaders in the field contacted. SELECTION CRITERIA: Any trial using hyperosmolar inhalation in patients with bronchiectasis not caused by cystic fibrosis. DATA COLLECTION AND ANALYSIS: One reference were identified by the searches conducted. MAIN RESULTS: Only one trial was identified, a crossover study of 11 patients with bronchiectasis. The outcome measure was tracheobronchial clearance of a particulate radioaerosol after inhalation of dry mannitol on a single occasion, with appropriate controls. Airway clearance doubled in the central and intermediate regions of the lung, but not in the peripheral region, after mannitol administration. No side effects were observed, but two patients were premedicated with nedocromil to prevent bronchospasm. A further search conducted in September 2001 did not identify any further studies. REVIEWER'S CONCLUSIONS: Dry powder mannitol has been shown to improve tracheobronchial clearance in bronchiectasis, as well as cystic fibrosis, asthmatics, and normal subjects. It is not yet available for clinical use. Hypertonic saline has not been specifically tested in bronchiectasis, but improve clearance in these other conditions and in chronic bronchitis. Longer term randomised controlled studies of mannitol and hypertonic saline with clinical endpoints are now needed.

Studies of solute self-association by sedimentation equilibrium: allowance for effects of thermodynamic non-ideality beyond the consequences of nearest-neighbor interactions.

A sedimentation equilibrium study of alpha-chymotrypsin self-association in acetate-chloride buffer, pH 4.1 I 0.05, has been used to illustrate determination of a dimerization constant under conditions where thermodynamic non-ideality is manifested beyond the consequences of nearest-neighbor interactions. Because the expressions for the experimentally determinable interaction parameters comprise a mixture of equilibrium constant and excluded volume terms, the assignment of reasonable magnitudes to the relevant virial coefficients describing non-associative cluster formation is essential for the evaluation of a reliable estimate of the dimerization constant. Determination of these excluded volume parameters by numerical integration over the potential-of-mean-force is shown to be preferable to their calculation by approximate analytical solutions of the integral for this relatively small enzyme monomer with high net charge (+10) under conditions of low ionic strength (0.05 M).

Inhaled hyperosmolar agents for bronchiectasis.

BACKGROUND: Mucus retention in the lungs is a prominent feature of bronchiectasis. The stagnant mucus becomes chronically colonised with bacteria, which elicit a host neutrophilic response. This fails to eliminate the bacteria, and the large concentration of host-derived protease may contribute to the airway damage. The sensation of retained mucus is itself a cause of suffering, and the failure to maintain airway sterility probably contributes to the frequent respiratory infections experienced by many patients. Hypertonic saline inhalation is known to accelerate tracheobronchial clearance in many conditions, probably by inducing a liquid flux into the airway surface, which alters mucus rheology in a way favourable to mucociliary clearance. Inhaled dry powder mannitol has a similar effect. Such agents are an attractive approach to the problem of mucostasis, and deserve further clinical evaluation. OBJECTIVES: To determine whether inhaled hyperosmolar substances are efficacious in the treatment of bronchiectasis SEARCH STRATEGY: MEDLINE and Cochrane databases were searched, and leaders in the field contacted. SELECTION CRITERIA: Any trial using hyperosmolar inhalation in patients with bronchiectasis not caused by cystic fibrosis. DATA COLLECTION AND ANALYSIS: One reference were identified by the searches conducted. MAIN RESULTS: Only one trial was identified, a crossover study of 11 patients with bronchiectasis. The outcome measure was tracheobronchial clearance of a particulate radioaerosol after inhalation of dry mannitol on a single occasion, with appropriate controls. Airway clearance doubled in the central and intermediate regions of the lung, but not in the peripheral region, after mannitol administration. No side effects were observed, but two patients were premedicated with nedocromil to prevent bronchospasm. REVIEWER'S CONCLUSIONS: Dry powder mannitol has been shown to improve tracheobronchial clearance in bronchiectasis, as well as cystic fibrosis, asthmatics, and normal subjects. It is not yet available for clinical use. Hypertonic saline has not been specifically tested in bronchiectasis, but improve clearance in these other conditions and in chronic bronchitis. Longer term randomised controlled studies of mannitol and hypertonic saline with clinical endpoints are now needed.

Autocatalysis, information and coding.

Autocatalytic self-construction in macromolecular systems requires the existence of a reflexive relationship between structural components and the functional operations they perform to synthesise themselves. The possibility of reflexivity depends on formal, semiotic features of the catalytic structure-function relationship, that is, the embedding of catalytic functions in the space of polymeric structures. Reflexivity is a semiotic property of some genetic sequences. Such sequences may serve as the basis for the evolution of coding as a result of autocatalytic self-organisation in a population of assignment catalysts. Autocatalytic selection is a mechanism whereby matter becomes differentiated in primitive biochemical systems. In the case of coding self-organisation, it corresponds to the creation of symbolic information. Prions are present-day entities whose replication through autocatalysis reflects aspects of biological semiotics less obvious than genetic coding.

The effect of erythromycin on mucociliary transportability and rheology of cystic fibrosis and bronchiectasis sputum.

BACKGROUND: Erythromycin has been shown to diminish sputum production in hypersecretory states by a mechanism that is still unclear. OBJECTIVES AND METHODS: We have investigated the effect of erythromycin on the ciliary transportability of cystic fibrosis and non-cystic fibrosis bronchiectasis sputum in vitro using the mucus-depleted bovine trachea. RESULTS: Additional erythromycin in concentrations up to 20 microg/g did not significantly alter the ciliary transportability of sputum from 6 cystic fibrosis and 6 bronchiectasis patients. Sputum viscoelasticity measured with parallel-plate rheology was also little changed. These erythromycin concentrations also had little effect on the beating frequency of bovine tracheal cilia. CONCLUSIONS: These results suggest that the presence of erythromycin in sputum neither alters the physical properties of the gel nor the activity of cilia. The clinical effects of erythromycin on pulmonary hypersecretory states therefore have another explanation.