Inhibitory effects of isoflavonoids on rat prostate testosterone 5α-reductase

Chickpea Sprouts as a Potential Dietary Support in Different Prostate Disorders-A Preliminary In Vitro Study

BACKGROUND

Prostate cancer (PC) and benign prostatic hyperplasia (BPH) are common health problems in the aging male population. Due to the unexplored and unconfirmed impact of food containing isoflavones, like sprouts, on the development of the management of BPH and prostate cancer, we decided to extend the knowledge in this area.

RESULTS

We have demonstrated for the first time that chickpea sprouts may play an important role in the chemoprevention of prostate disorders. However, attention should be paid to the isoflavone content in the sprouts, as in our study, chickpea sprouts with a moderate concentration of the compounds, harvested in natural light conditions (CA10L) and blue LED light (CA7B), showed the best scores in terms of their potential towards prostate disorders.

METHODS

Chickpea seeds were grown in LED chambers. The methanol extracts from sprouts were quantitatively defined using the HPLC system. Experiments such as the determination of PSA, 5-α-reductase, and dihydrotestosterone were performed on PNT2 and LNCaP cells. For anti-inflammatory assays (determination of NO, IL-6, and TNF-alpha release), murine RAW264.7 macrophages were used.

CONCLUSIONS

The role of legume products as a diet element should be deeply evaluated for the development of future dietary recommendations for prostate cancer and BPH prevention.

Searching for the primary metabolic alterations of polycystic ovary syndrome by application of the untargeted metabolomics approach

Despite a large number of studies, the pathogenesis of polycystic ovary syndrome (PCOS) still remains unexplained. In light of ambiguous observations reported in metabolomics, there is a need to carry out studies focusing on confirming the discriminating power of the proposed metabolomics biomarkers. Our research aimed to perform a validation study of metabolites detected in our previous study from serum samples, on the new set of samples obtained from PCOS women and healthy controls to confirm previously selected compounds. Additionally, the second biological matrix - urine - was used to get a more comprehensive insight into metabolic alterations. We applied two analytical techniques - gas chromatography and liquid chromatography coupled with mass spectrometry to analyze both serum and urine samples obtained from 35 PCOS patients and 35 healthy women. Thank to our approach, we identified and described a comprehensive set of metabolites altered in PCOS patients. Results of our study indicate increased steroid hormone synthesis, alteration in sphingo- and phospholipids metabolism, and disturbed fatty acids metabolism. Moreover, the citric acid cycle, γ-glutamyl cycle, vitamin B metabolism, and a few primary amino acids like tryptophan, phenylalanine, histidine, and alanine are altered.

SH-PRO extract alleviates benign prostatic hyperplasia via ROS-mediated activation of PARP/caspase 3 and inhibition of FOXO3a/AR/PSA signaling in vitro and in vivo

To target benign prostatic hyperplasia (BPH) as a common urinary disease in old men, in the current study, the antiproliferative and apoptotic mechanism of SH-PRO, a mixture of Angelica gigas and Astragalus membranaceus (2:1), was evaluated in BPH-1 cells and rats with testosterone-induced BPH. Herein, SH-PRO significantly reduced the viability of BPH-1 cells and dihydrotestosterone (DHT)-treated RWPE-1 cells. Also, SH-PRO increased the sub-G1 population in BPH-1 cells and consistently attenuated the expression of pro-PARP, pro-caspase 3, Bcl2, FOXO3a, androgen receptor (AR), and prostate-specific antigen (PSA) in BPH-1 cells and DHT-treated RWPE-1 cells. Of note, SH-PRO generated reactive oxygen species (ROS) in BPH-1 cells, while ROS inhibitor N-acetyl-l-cysteine (NAC) disturbed the ability of SH-PRO to reduce the expression of pro-PARP, FOXO3a, catalase, SOD, and increase sub-G1 population in BPH-1 cells. Furthermore, oral treatment of SH-PRO significantly abrogated the weight of the prostate in testosterone-treated rats compared to BPH control with the reduced expression of AR, PSA, and DHT and lower plasma levels of DTH, bFGF, and EGF with no toxicity. Overall, these findings highlight the antiproliferative and apoptotic potential of SH-PRO via ROS-mediated activation of PARP and caspase 3 and inhibition of FOXO3a/AR/PSA signaling as a potent anti-BPH candidate.

The Potential Therapeutic Properties of Prunetin against Human Health Complications: A Review of Medicinal Importance and Pharmacological Activities

BACKGROUND

Flavonoids are polyphenolic compounds found to be present in nature and abundant in flowers and fruits. Flavonoidal class phytochemicals have gained interest in the scientific field because of their important pharmacological activities. Several scientific studies have revealed anti-bacterial, anti-oxidant, anti-fungal, analgesic, anti-viral, anti-inflammatory, anti-tumor, anti-parasitic and anti-allergic activities of flavonoidal class phytochemicals. Prunetin is an O-methylated isoflavone that belongs to the phytochemical phytoestrogen class, found to be present in licorice, red cherry, soybean and legumes.

METHODS

Biological potential and pharmacological activities of prunetin have been investigated in the present work through scientific data analysis of numerous scientific research works. Numerous literature databases have been searched in order to collect the scientific information on prunetin in the present work. Pharmacological activities of prunetin have been investigated in the present work through literature data analysis of different scientific research works. Scientific data have been collected from Google Scholar, Google, PubMed, Science Direct and Scopus. Analytical data on prunetin has been collected from literature sources and analyzed in the present work.

RESULTS

Scientific data analysis revealed the biological importance of prunetin in medicine. Prunetin was found to be present in the pea, peach, Oregon cherry, skimmed cheese, cheese, cow kefir and goat kefir. Prunetin is also present in the Prunus avium, Andira surinamensis, Butea superba, Dalbergia sympathetica, Ficus nervosa, Pterospartum tridentatum and Pycnanthus angolensis. Pharmacological data analysis revealed the biological importance of prunetin on bone disorders, cancers, especially hepatocellular carcinoma, urinary bladder cancer, gastric cancer, ovarian cancer, human airway, gut health and enzymes. Scientific data analysis revealed biological effectiveness of prunetin for their angiogenic effects, anti-inflammatory, anti-oxidant, antimicrobial, estrogenic and vasorelaxant potential. Analytical data revealed the importance of modern analytical techniques for qualitative and quantitative analysis of prunetin in the scientific fields.

CONCLUSION

Scientific data analysis in the present investigation revealed the biological importance and pharmacological activities of prunetin in medicine.

Potential of natural phenolic antioxidant compounds from Bersama abyssinica (Meliathacea) for treatment of chronic diseases

Chronic diseases including cardiovascular, diabetes and cancer persist for a long time in the course of treatment affecting health and are currently the cause of many deaths. In most cases, the treatment of chronic infectious diseases especially Tuberculosis relies on conventional drugs which are currently becoming fruitless due to drug resistance and unpredicted complications in course of treatment. However, herbal medicines have for a long time been used in prevention and treatment of chronic diseases including asthma and heart diseases in Africa. In this study, we extracted metabolites and screened for active compounds with potential free radical scavenging and pharmacological activities from Bersama abyssinica, the plant commonly used in traditional medicine in Tanzania. B. abyssinica root, stembark and leaf were air dried, sequentially extracted in various solvents including petroleum ether, dichloromethane, ethylacetate and methanol to yield extracts and fractions. The extracts and fractions were tested for the presence of several metabolites and antioxidant activity. The analysis of chemical compounds from resultant extracts was done by GC–MS for non-polar factions and LC-MS/MC for moderate polar extracts.High amount of phenolic acid, flavonoids and tannin were identified in ethylacetate fraction compared to ethanol, dichloromethane and petroleum ether. The GC–MS analysis of petroleum ether extract of B. abyssinica stem back yielded twelve (12) compounds with varying composition. The most abundant compounds were 2-Butenoic acid, 3-methyl-, ethyl ester comprising 33.8%, n-Hexadecanoic acid comprising 16.7% and Ethanolpentamethyl- yielded in 16.7%.The LC-MS/MS analysis of Ethyl acetate fractions yielded 20 compounds including; Mangiferin and Isoquercitin were abundant in leaves, stembark and roots. Lastly, ethyl vanillate was identified in both roots and leaves whereas Quercitrin and 7,8-Dimethoxycoumarin were found in stembark and root.These findings indicated that B. abyssinica is rich in phenolic compounds ranging from phenolic acids, flavonoids and coumarin that possess high antioxidant and pharmacological properties potential for treatment of chronic diseases.

Astaxantin and Isoflavones Inhibit Benign Prostatic Hyperplasia in Rats by Reducing Oxidative Stress and Normalizing Ca/Mg Balance

Benign prostatic hyperplasia (BPH) is a common pathology among aging men. Despite the broad pharmacological interventions, the available remedies to treat BPH are yet not devoid of side effects. Herbal compounds are suggested to be an alternative option for the BPH treatment. In our study, we evaluated the effect of kudzu isoflavones and astaxanthin on the BPH animal model. The animals were randomly divided into five groups: control; testosterone-induced BPH group; and three BPH-induced groups, which received intragastrically for 28 days finasteride (5 mg/kg) as a positive control, isoflavones (200 mg/kg), and astaxanthin (25 mg/kg). BPH was induced by castration of animals and subsequent subcutaneous injections of prolonged testosterone (25 mg/kg). Prostate index and histology, biochemical parameters, and antioxidant activity were evaluated. A significant decrease in prostate weight, immunohistochemical markers, and normalization of prostate Ca/Mg ratio was found in all treatment groups. Astaxanthin treatment also resulted in decreased epithelial proliferation and normalized superoxide dismutase activity. In conclusion, both isoflavones and astaxanthin inhibited BPH development at a level comparable to finasteride in terms of prostate weight, prostatic epithelium proliferation, and prostate tissue cumulative histology score. These results suggest that isoflavones and especially astaxanthin could serve as a potential alternative therapy to treat BHP.

Estrogenic and antiandrogenic activities of methoxyflavans isolated from the fruit of Mauritia Flexuosa (Moriche Palm)

Moriche palm is consumed as both a fresh fruit and processed food in Peru and Brazil. Although its fruit contains phytoestrogens, the active compounds have not yet been identified. Therefore, we purified moriche palm extract (MPE) and identified compounds exhibiting estrogenic and antiandrogenic activities. Estrogenic activity was assessed by the estrogen-dependent growth of MCF-7 cells and increases in uterine weights in mice. Antiandrogenic activity was evaluated by 5α-reductase inhibitory activity and prostate-specific antigen (PSA) expression in LNCaP cells. In vivo antiestrogenic activity was also assessed based on testosterone-induced prostate growth in castrated mice. Four methoxyflavans were isolated from MPE and all, except for 7,4'-dihydroxy-5-methoxyflavan, promoted MCF-7 cell growth, indicating estrogenic activity. Uterine and ovary weights increased in mice orally administered MPE (400 mg/kg) for 2 weeks. Regarding antiandrogenic activity, among the four methoxyflavans isolated, 6,7,4'-trihydroxy-5-methoxyflavan (1 µg/ml) suppressed the mRNA and protein expression of PSA in LNCaP cells. Furthermore, prostate growth was suppressed in mice orally administered MPE (200 mg/kg) for 2 weeks. All methoxyflavans inhibited 5α-reductase activity with IC₅₀ less than 10 µg/ml. Collectively, the present results demonstrated that orally administered MPE exhibited estrogenic and antiandrogenic activities. Methoxyflavans, particularly 6,7,4'-trihydroxy-5-methoxyflavan, appear to be the active compounds for these activities. PRACTICAL APPLICATIONS: The fruit of Mauritia flexuosa (moriche palm) has been used for beverages and processed foods. Although it is said to contain phytoestrogens, the active compounds have not yet been identified. In this study, we isolated and identified methoxyflavans exhibiting estrogenic and antiandrogenic activities. Among them, 6,7,4'-trihydroxy-5-methoxyflavan appeared to be the most effective compounds for these activities.

An Uncontrolled Case Series Using a Botanically Derived, β-Cyclodextrin Inclusion Complex in Two Androgenetic Alopecia-Affected Male Subjects

Drug-based monotherapy provides limited clinical benefits in polygenic disorders, such as androgenetic alopecia. Possible benefits must be measured against non-trivial risks of negative side effects. Several well-controlled, peer-reviewed, basic science studies have demonstrated novel mechanisms of action and potential utility for natural-based phytochemicals in the treatment of androgen-mediated disorders, including androgenetic alopecia. Yet, due to phytochemical instability, volatility, and incompatibility, the bridge from in vitro potential to clinical efficacy remains largely unmet. Recent advances in nanomaterial manipulation provide enhanced platforms, such as cyclodextrins, in which these phytochemicals may be enveloped and delivered without triggering the loss of intended function. Unexpected, positive results of an uncontrolled case series for a cyclodextrin-enabled, natural-based formula containing γ linolenic acid, β-Sitosterol, epigallocatechin gallate, and genistein, administered concomitantly via oral and topical form in two androgenetic alopecia-affected, male subjects over the course of 270 days were found. At baseline, significant baldness in the vertex scalp of both subjects was observed. Subsequent 90-day time points demonstrated marked hair thickening. On treatment day 270 (conclusion), scalp hair loss was no longer evident in either patient. Particularly in the setting of a disorders, such as androgenetic alopecia, nano-complexed, botanically-based compositions may offer beneficial adjunctives or alternatives to traditional drug-based/surgical medical treatments.

The implications of vitamin content in the plasma in reference to the parameters of carbohydrate metabolism and hormone and lipid profiles in PCOS

So far, there have been no analyses of correlations between the level of water-soluble vitamins in women with polycystic ovary syndrome (PCOS) and hormone and lipid profiles as well as carbohydrate metabolism. The unpopular concept that PCOS may also be conditioned by a chronic infection leads to a suspicion that water-soluble vitamins may be involved in the struggle against PCOS. This is why the aim of this research was to determine whether there are any indications that could confirm this hypothesis. The study included 64 women of Caucasian race: 50 patients aged 29.52 ± 7.01 years with PCOS, diagnosed according to the Rotterdam criteria. The control group consisted of 14 women aged 30.23 ± 6.3 years with correct BMI. HPLC Infinity1260 Binary LC (Agilent Technologies, Waldbronn, Germany) was used to analyze nine vitamins. The vitamins were separated using the gradient method, a buffer of 25 mM HK2PO4 with pH equal to 7.0, and 100 % methanol buffer. The acquired results were compared using Statistica 12.0 (Statsoft, Tulsa, Oklahoma, USA). Non-parametric tests were used: Mann-Whitney tests for comparisons between groups (PCOS and control group, CG), in which p < 0.05 was considered statistically significant. Subsequently, we performed a correlation matrix of the biochemical parameters of blood with vitamins at p ≤ 0.05. Higher concentrations of ascorbic acid were observed in PCOS. The content of the remaining vitamins was higher in the control group, and the statistical differences were significant in reference to thiamine, riboflavin, pyridoxine and folic acid in comparison to the control group. A significant positive correlation was observed between vitamin C and testosterone/insulin, another between riboflavin and androstenedione/testosterone, next between biotin and thyrotropic hormone (TSH), between pantothenic acid and dehydroepiandrosteron (DHEA-SO4), and finally between pyridoxine and androstenedione. A negative correlation was observed in the case of niacin with sex hormone binding protein (SHBG) and high density lipoprotein (HDL). Water-soluble vitamins play an important role in the therapy of women with PCOS through the reduction of antioxidative stress and low-intensity inflammation caused by various factors, including chronic infection.

Urinary equol is associated with bioavailable testosterone but not total testosterone in women

Little is known about the association between equol and bioavailable testosterone (BT) in adults. In this study, we examined the associations of urinary equol concentrations with serum concentrations of total, bioavailable and free testosterone (FT), dehydroepiandrosterone sulfide (DHEAS), free androgen index (FAI) and sex hormone-binding globulin (SHBG). This cross-sectional study included 1,904 women with a mean age of 59.7 years. Urinary equol concentrations were measured using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The serum androgenic indices and SHBG were also determined. Overall, urinary equol tended to be inversely associated with bioactive forms of androgenic indices (BT, FT or FAI) but not with total testosterone (TT) or DHEAS. Urinary equol was also positively associated with SHBG. In multi-covariate-adjusted analyses stratified by menopausal status, graded and inverse associations between urinary equol and bioactive forms of androgenic indices (BT, FT and FAI) were observed in postmenopausal women (all p-trends < 0.05), but not in premenopausal women. A significant positive association between urinary equol and SHBG was observed only in postmenopausal women. No significant associations were observed between urinary equol and TT or DHEAS in either group. A path analysis indicated that these associations of equol with androgens in postmenopausal women might be mediated by SHBG. In conclusion, urinary equol exhibited graded and inverse associations with BT or FT, but not TT in women. However, further longitudinal studies of human patients are needed to confirm these results and overcome the limitations of cross-sectional studies.

The Polyphenols as Potential Agents in Prevention and Therapy of Prostate Diseases

In recent years, the progress of science and medicine greatly has influenced human life span and health. However, lifestyle habits, like physical activity, smoking cessation, moderate alcohol consumption, diet, and maintaining a normal body weight represent measures that greatly reduce the risk of various diseases. The type of diet is very important for disease development. Numerous epidemiological clinical data confirm that longevity is linked to predominantly plant-based diets and it is related to a long life; whereas the western diet, rich in red meat and fats, increases the risk of oxidative stress and thus the risk of developing various diseases and pre-aging. This review is focused on the bioavailability of polyphenols and the use of polyphenols for the prevention of prostate diseases. Special focus in this paper is placed on the isoflavonoids and flavan-3-ols, subgroups of polyphenols, and their protective effects against the development of prostate diseases.

Discovery of Natural Steroid 5 Alpha-Reductase Inhibitors

Human steroid 5 alpha-reductases (S5αRs) and NADPH irreversibly reduce testosterone to the more potent dihydrotestosterone (DHT). S5αR inhibitors are useful treatments for DHT-dependent diseases, including benign prostatic hyperplasia, androgenic alopecia and hair growth, and acne. There are three S5αR isozymes, and there is a need for safer and more isozyme selective inhibitors than finasteride and dutasteride currently licensed. In this study, we review the methods used to screen for S5αR inhibitory activity and describe studies that characterize the ability of herbal preparations and their constituents to inhibit S5αRs. We identified enormous variations between studies in IC₅₀s for finasteride and dutasteride used as standards. Accordingly, we make several recommendations: Stable isozyme specific transfection systems need creating a standardized enzyme/microsome preparation and all three isozymes, as well as androgen receptor binding, should be tested; agreed reaction conditions, especially the substrate concentrations, and separation/quantitation method optimized for high throughput screening; systematic screening of herbal compounds and most extensive use of leads to develop more potent and isozyme specific inhibitors.

Androgen receptor and soy isoflavones in prostate cancer

Androgens and androgen receptor (AR) play a critical role not only in normal prostate development, but also in prostate cancer. For that reason, androgen deprivation therapy (ADT) is the primary treatment for prostate cancer. However, the majority of patients develop castration-resistant prostate cancer, which eventually leads to mortality. Novel therapeutic approaches, including dietary changes, have been explored. Soy isoflavones have become a focus of interest because of their positive health benefits on numerous diseases, particularly hormone-related cancers, including prostate and breast cancers. An important strategy for the prevention and/or treatment of prostate cancer might thus be the action of soy isoflavones on the AR signaling pathway. The current review article provides a detailed overview of the anticancer potential of soy isoflavones (genistein, daidzein and glycitein), as mediated by their effect on AR.

Evaluation of bioactive compounds potential and antioxidant activity of brown, green and red propolis from Brazilian northeast region

The aim of the present study was to determine the contents of bioactive compounds present in brown, green and red species of propolis cultivated in the Brazilian northeast states of Alagoas and Sergipe. The contents of phenolic compounds, flavonoids and antioxidant activity (DPPH, ABTS⁺, FRAP, ORAC) were determined. Identification and quantification of phenolic and flavonoid compounds were performed by using UHPLC-QqQ-MS/MS system. The results revealed high contents of total phenolics and flavonoids. Among the three species, the antioxidant potential had higher capacity in the red propolis. The presence of some of bioactive compounds viz. acacetin, artepellin C, eriodictyol, gallic acid, isorhamnetin, protocatechuic acid, vanillin and vanillic acid in Brazilian red propolis is reported for the first time in this work. Positive correlation between total phenolics versus the FRAP and ORAC methods was established which led to conclusion that antioxidant activity of propolis is mainly due to its phenolic compounds.

Expected Next-Generation Drugs Under Development in Relation to Voiding Symptoms

New drug development is a high-risk venture, but if successful, will bring great revenues to those willing to accept the risk. In the field of urology, in particular for lower urinary tract symptoms (LUTS), the recent successful landing of drugs (e.g., mirabegron, botulinum toxin A, and tadalafil) has resulted in increased interest in new drug development. Benign prostatic hyperplasia and overactive bladder syndrome, representative LUTS diseases, are attractive targets because of their prevalence and market size in the field of urology. Additionally, the awareness about new stream of research is very important not only because of the market size and economic factors, but also because to keep steady attention to these research for the researcher’s. We have reviewed a selection of new drugs currently under development for the treatment of the two aforementioned diseases and hope to offer urologists an overview of the current situation and future directions in the field of urology.

Acute and sub-acute oral toxicity of Brazilian red propolis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Propolis is a bee product widely used in folk medicine due to its numerous pharmacological properties. However, samples from different regions can differ in chemical composition, effectiveness, and side effects. Despite the widespread use of Brazilian red propolis, which is an isoflavone-rich variety, its toxicity has not been carefully studied.

AIMS OF THE STUDY

To assess the acute and sub-acute toxicity of the hydroethanolic extract of red propolis (HERP) administered orally to rats.

MATERIALS AND METHODS

HERP for the acute (300mg/kg) and sub-acute (10, 100 and 200mg/kg) toxicity studies was administered orally to rats according to OECD Guidelines 420 and 407, respectively. Clinical signs were identified, and hematological and biochemical analyses were performed. Water and food uptake as well as body and organ weights of animals were recorded.

RESULTS AND CONCLUSIONS

The acute study revealed no lethal effects at 300mg/kg of HERP, but toxic signs were observed, as HERP had an LD50 of more than 300mg/kg, indicating a warning. The most toxic signals in sub-acute studies were observed in males at a dose of 200mg/kg HERP. These results suggest estrogen-like activity, possibly from the isoflavones in HERP.

Inhibition of Rat 5α-Reductase Activity and Testosterone-Induced Sebum Synthesis in Hamster Sebocytes by an Extract of Quercus acutissima Cortex

Objective. Bokusoku (BK) is an extract from the Quercus cortex used in folk medicine for treatment of skin disorders and convergence, and is present in jumihaidokuto, a traditional Japanese medicine that is prescribed for purulent skin diseases like acne vulgaris. The excess of sebum production induced by androgen is involved in the development of acne. Our aim is to examine whether BK and its constituents inhibit testosterone metabolism and testosterone-induced sebum synthesis. Methods. Measurements of 5α-reductase activity and lipogenesis were performed using rat liver microsomes and hamster sebocytes, respectively. Results. BK dose-dependently reduced the conversion of testosterone to a more active androgen, dihydrotestosterone in a 5α-reductase enzymatic reaction. Twenty polyphenols in BK categorized as gallotannin, ellagitannin, and flavonoid were identified by LC-MS/MS. Nine polyphenols with gallate group, tetragalloyl glucose, pentagalloyl glucose, eugeniin, 1-desgalloyl eugeniin, casuarinin, castalagin, stenophyllanin C, (−)-epicatechin gallate, and (−)-epigallocatechin gallate, inhibited testosterone metabolism. In particular, pentagalloyl glucose showed the strongest activity. BK and pentagalloyl glucose suppressed testosterone-induced lipogenesis, whereas they weakly inhibited the lipogenic action of insulin. Conclusions. BK inhibited androgen-related pathogenesis of acne, testosterone conversion, and sebum synthesis, partially through 5α-reductase inhibition, and has potential to be a useful agent in the therapeutic strategy of acne.

Tear film mucins: front line defenders of the ocular surface; comparison with airway and gastrointestinal tract mucins

The ocular surface including the cornea and conjunctiva and its overlying tear film are the first tissues of the eye to interact with the external environment. The tear film is complex containing multiple layers secreted by different glands and tissues. Each layer contains specific molecules and proteins that not only maintain the health of the cells on the ocular surface by providing nourishment and removal of waste products but also protect these cells from environment. A major protective mechanism that the corneal and conjunctival cells have developed is secretion of the innermost layer of the tear film, the mucous layer. Both the cornea and conjunctiva express membrane spanning mucins, whereas the conjunctiva also produces soluble mucins. The mucins present in the tear film serve to maintain the hydration of the ocular surface and to provide lubrication and anti-adhesive properties between the cells of the ocular surface and conjunctiva during the blink. A third function is to contribute to the epithelial barrier to prevent pathogens from binding to the ocular surface. This review will focus on the different types of mucins produced by the corneal and conjunctival epithelia. Also included in this review will be a presentation of the structure of mucins, regulation of mucin production, role of mucins in ocular surface diseases, and the differences in mucin production by the ocular surface, airways and gastrointestinal tract.