Oral administration of bovine lactoferrin for treatment of tinea pedis. A placebo-controlled, double-blind study

Potential Application of Camel Milk as a Therapeutic Ingredient in Bath Soaps and Shampoos

The increasing worldwide market for natural-ingredient-based cosmetic toiletries is fuelled by the awareness of the dangers of synthetic cosmetics and benefits of natural-based cosmetics on the skincare and management of skin disorders. Besides naturally formulated cosmetics being biodegradable, they also contain ingredients which are chemically beneficial to human skin. Milk-based cosmetics are very promising since milk is rich in essential components such as lactoferrins, vitamins, and lactic acids, which have shown therapeutic properties against disorders such as skin cancer, acne scars, and dandruff. One of the milk that is very promising in the cosmetics industry is the camel milk. Currently, there is limited information in literature regarding the use of camel milk in cosmetics and their benefits. Camel milk stands out from bovine milk following its unique therapeutic properties and chemical composition, making it a potential ingredient for skincare and haircare products such as bath soaps and shampoos. The aim of this paper is to review the available literature on camel milk composition and evaluate the contribution of camel milk constituents to cosmetics.

Effects of Lactoferrin on Subjective Skin Conditions in Winter: A Preliminary, Randomized, Double-Blinded, Placebo-Controlled Trial

Objective

To investigate the effects of lactoferrin (LF) on subjective skin conditions in winter.

Design

A preliminary, randomized, double-blinded, placebo-controlled trial.

Setting and subjects

Healthy adults in Japan.

Interventions

Intake of placebo, 200 mg, or 600 mg of LF for 12 weeks in winter.

Endpoints

Changes in the scores of subjective skin conditions.

Results

Three hundred and forty-six subjects were randomized. Nine subjects (placebo, n=0; 200 mg, n=5; 600 mg, n=4) withdrew consent, and 7 subjects (placebo, n=4; 200 mg, n=2; 600 mg, n=1) were lost to follow-up, resulting in 330 for a full analysis set.

Outcomes

Changes in the scores of moisture were greater in the 600 mg group than in the placebo group. Changes in the scores of moisture were greater in the 200 mg and 600 mg groups, and of texture were greater in the 600 mg group than in the placebo group in female subjects.

Conclusion

Intake of LF may improve moisture or texture of skin in winter.

A systematic review of lactoferrin use in dermatology

Lactoferrin is a glycoprotein widely present in mammalian secretions and possesses documented protective effects, including antimicrobial and anti-inflammatory properties. While its therapeutic use is being investigated for a myriad of diseases, there is increasing interest in its application for skin disease. Our objective was to systematically review the clinical evidence for the use and efficacy of lactoferrin for the treatment of dermatological conditions. Pubmed and Embase databases were searched for clinical studies evaluating lactoferrin for dermatological conditions. A total of six studies were reviewed. Of the current clinical trials, there is encouraging evidence to suggest that lactoferrin may be beneficial in acne, psoriasis, and diabetic ulcerations. Although the current evidence is promising, further research is necessary to establish lactoferrin as complementary therapy in the clinical setting.

Bovine lactoferrin ingestion protects against inflammation via IL-11 induction in the small intestine of mice with hepatitis

Accumulating evidence suggests that orally ingested lactoferrin protects against inflammation. To assess the efficacy of orally administered bovine lactoferrin (bLF) against hepatitis and to identify the underlying mechanism, in the present study, we used four mouse models of hepatitis induced by d-galactosamine (GalN), carbon tetrachloride (CCl4), GalN plus lipopolysaccharide (LPS) and zymosan plus LPS. Intraperitoneal (i.p.) injection of GalN (500 mg/kg body weight) in mice treated with bovine serum albumin (BSA) for 14 d significantly increased serum aspartate aminotransferase (AST) concentrations compared with the untreated mice. However, orally administered bLF reduced AST concentrations compared with BSA treatment. In mice that received a single injection (0·4 ml/kg) and twice-weekly injections (0·08 ml/kg) of CCl4 for 24 weeks and pretreated with bLF for 14 d and 24 weeks, respectively, significantly suppressed alanine aminotransferase and AST concentrations were observed compared with the BSA-treated control. Oral administration of bLF for 14 d before i.p. injection of LPS (5 mg/kg) plus GalN (1 g/kg) significantly improved the survival rate. In mice that received intravenous injection of zymosan (25 mg/kg) and LPS (15 μg/kg) at 7 d intervals, bLF reduced the elevation of AST concentrations and enhanced the production of IL-11 and bone morphogenetic protein 2 in the small intestine compared with the BSA-treated control. To evaluate the effects of IL-11, we used IL-11 receptor α-null mice treated with GalN, CCl4 and zymosan plus LPS. In this group, the activity of bLF was not significantly different from that of BSA. These data indicate that orally ingested bLF enhances the expression of IL-11 in the small intestine and up-regulates protective activity in mice with hepatitis.

Lactoferrin

Lactoferrin is found in milk - human and animal. It has therapeutic potential as an iron supplement, against infection, inflammation and cancer.

The evidence is so far mainly laboratory and animal data, with a small number of human trials beginning to be published, to this point with mixed results. An example is its use as treatment for Helicobacter pylori infection.

Oral treatments for fungal infections of the skin of the foot

BACKGROUND

About 15% of the world population have fungal infections of the feet (tinea pedis or athlete's foot). There are many clinical presentations of tinea pedis, and most commonly, tinea pedis is seen between the toes (interdigital) and on the soles, heels, and sides of the foot (plantar). Plantar tinea pedis is known as moccasin foot. Once acquired, the infection can spread to other sites including the nails, which can be a source of re-infection. Oral therapy is usually used for chronic conditions or when topical treatment has failed.

OBJECTIVES

To assess the effects of oral treatments for fungal infections of the skin of the foot (tinea pedis).

SEARCH METHODS

For this update we searched the following databases to July 2012: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 1946), EMBASE (from 1974), and CINAHL (from 1981). We checked the bibliographies of retrieved trials for further references to relevant trials, and we searched online trials registers.

SELECTION CRITERIA

Randomised controlled trials of oral treatments in participants who have a clinically diagnosed tinea pedis, confirmed by microscopy and growth of dermatophytes (fungi) in culture.

DATA COLLECTION AND ANALYSIS

Two review authors independently undertook study selection, 'Risk of bias' assessment, and data extraction.

MAIN RESULTS

We included 15 trials, involving 1438 participants. The 2 trials (71 participants) comparing terbinafine and griseofulvin produced a pooled risk ratio (RR) of 2.26 (95% confidence interval (CI) 1.49 to 3.44) in favour of terbinafine's ability to cure infection. No significant difference was detected between terbinafine and itraconazole, fluconazole and itraconazole, fluconazole and ketoconazole, or between griseofulvin and ketoconazole, although the trials were generally small. Two trials showed that terbinafine and itraconazole were effective compared with placebo: terbinafine (31 participants, RR 24.54, 95% CI 1.57 to 384.32) and itraconazole (72 participants, RR 6.67, 95% CI 2.17 to 20.48). All drugs reported adverse effects, with gastrointestinal effects most commonly reported. Ten of the trials were published over 15 years ago, and this is reflected by the poor reporting of information from which to make a clear 'Risk of bias' assessment. Only one trial was at low risk of bias overall. The majority of the remaining trials were judged as 'unclear' risk of bias because of the lack of clear statements with respect to methods of generating the randomisation sequence and allocation concealment. More trials achieved blinding of participants and personnel than blinding of the outcome assessors, which was again poorly reported.

AUTHORS' CONCLUSIONS

The evidence suggests that terbinafine is more effective than griseofulvin, and terbinafine and itraconazole are more effective than no treatment. In order to produce more reliable data, a rigorous evaluation of different drug therapies needs to be undertaken with larger sample sizes to ensure they are large enough to show any real difference when two treatments are being compared. It is also important to continue to follow up and collect data, preferably for six months after the end of the intervention period, to establish whether or not the infection recurred.

Bovine lactoferrin induces interleukin-11 production in a hepatitis mouse model and human intestinal myofibroblasts

PURPOSE

Orally administered bovine lactoferrin (bLF) exerts an anti-inflammatory effect on hepatitis and colitis animal models. To investigate the mechanism underlying the action of bLF, we explored the expression of inflammation-related factors in the intestine of a hepatitis mouse model after the oral administration of bLF and in several human intestinal cell lines treated with bLF.

METHODS

The effects of bLF on the expression of interleukin-11 (IL-11) and bone morphogenetic protein 2 (BMP2) in the intestinal mucosa of a hepatitis mouse model as well as in cell cultures of human intestinal epithelial cells, myofibroblasts, and monocytes were examined using the real-time reverse transcription polymerase chain reaction. Epithelial cells and myofibroblasts were also cocultured using transwells. bLF transport, and IL-11 and BMP2 induction, as well as the interactions between the two cell types, were then analyzed after bLF treatment.

RESULTS

In vivo, oral bLF administration increased the production of IL-11 and BMP2 in intestinal specimens. In vitro, bLF only stimulated the production of IL-11 in human intestinal myofibroblasts; i.e., it had no effect on BMP2 production in any cell type. In the transwell cocultures, bLF passed through the epithelium and directly stimulated IL-11 production in the myofibroblasts on the basolateral side. The IL-11 produced in the myofibroblasts subsequently acted protectively on the epithelial cells of the coculture.

CONCLUSIONS

bLF upregulated the activity of anti-inflammatory factors, such as IL-11, in the intestine of a hepatitis mouse model and human intestinal myofibroblasts.

Lactoferrin and cancer disease prevention

Lactoferrin (LF) is an iron-binding glycoprotein that is composed of the transferrin family and is predominantly found in the products of the exocrine glands located in the gateways of the digestive, respiratory, and reproductive systems, suggesting a role in the non-specific defence against invading pathogens. Additionally, several physiological roles have been attributed to LF, namely regulation of iron homeostasis, host defence against infection and inflammation, regulation of cellular growth, and differentiation and protection against cancer development and metastasis. These findings have suggested LF's great potential therapeutic use in cancer disease prevention and/or treatment, namely as a chemopreventive agent. This review looks at the recent advances in understanding the mechanisms underlying the multifunctional roles of LF and future perspectives on its potential therapeutic applications.

Bovine lactoferrin supplementation supports immune and antioxidant status in healthy human males

Dietary supplements of bovine lactoferrin are purported in consumer literature to enhance and support the immune system response through their antioxidant, antibacterial, and antiviral properties. Our aim was to investigate more fully the potential immune modulating properties and antioxidant activity of an oral supplementation of bovine lactoferrin in humans. Using an intraindividual repeated measure design, 8 healthy males aged 30 to 55 years, self-administered daily for 21 days, one capsule of placebo for 7 days, followed by 100 mg of lactoferrin for 7 days, followed by 200 mg of lactoferrin for 7 days. Peripheral blood lymphocyte subset counts, T-cell activation, natural killer (NK) cell cytotoxicity, serum cytokine levels (tumor necrosis factor [TNF]-alpha, interferon [IFN]-gamma, interleukin [IL]-2, IL-4, IL-6, and IL-10), and serum hydrophilic, lipophilic, and total antioxidant capacity were repeatedly measured before and after each progressive supplementation. Statistically significant increases were found between presupplementation levels and levels after 200 mg of supplementation in total T-cell activation (as measure by CD3(+)) (P < .001), helper T-cell activation (as measure by CD4(+)) (P < .001), cytotoxic T-cell activation (as measured by CD8(+)) (P < .001), and hydrophilic antioxidant capacity (P < .05). No significant changes were seen in the other parameters measured. These results support the proposal that oral supplements of bovine lactoferrin may be a useful adjunct toward modulation of immune activity, in particular T-cell activation and antioxidant status.

Recombinant human intelectin binds bovine lactoferrin and its peptides

Intelectin (IntL), a lectin that exists on the brush border membrane of the small intestine, plays a role in the innate immune response and also acts as a receptor for lactoferrin (LF), an iron-binding glycoprotein found in milk and other secretions. Similar to human LF (hLF), bovine LF (bLF) has been shown to induce proliferation and differentiation of human enterocytes and to modulate their cytokine productions. To evaluate the interaction between human IntL (hIntL) and bLF, recombinant hIntL (rhIntL) conjugated with a tag sequence was examined for its ligand-binding capacity by using microtiter plates coated with LF or other proteins. Interestingly, rhIntL showed higher binding for bLF than hLF. It also bound pepsin hydrolysate of bLF, but to a lower degree than native bLF. A very low binding of rhIntL was observed for bovine serum albumin or transferrin. These findings suggest that hIntL acts as a receptor for bLF and its digested fragments.

Regulation of physiological and pathological Th1 and Th2 responses by lactoferrin

In recent years, Lf has gained increasing interest as a result of its protective effects against a variety of diseases. While iron binding and interactions with mammalian receptors and microbial components are the best described mechanisms of action, recent studies have provided evidence that Lf properties may be related to immunoregulatory effects on Th1/Th2 cell activities. In vitro and in vivo experiments show that Lf is able to stimulate the differentiation of T cells from their immature precursors through the induction of the CD4 antigen. Studies performed under nonpathogenic conditions have shown distinct results with regard to the ability of Lf to support the proliferation and differentiation of Th cells into the Th1 or the Th2 phenotype. In addition, Lf plays different roles in diseases by affecting the Th1/Th2 cytokine balance in a manner dependent on the host's immune status. Thus, Lf could cause a Th1 polarization in diseases in which the ability to control infection or tumor relies on a strong Th1 response. Lf may also reduce the Th1 component to limit excessive inflammatory responses. Finally, Lf may provide protection against Th1- or Th2-induced diseases, such as autoimmune or allergic diseases, through correction of the Th1/Th2 imbalance.

Bovine lactoferrin: benefits and mechanism of action against infections

Ingestion of bovine lactoferrin (bLF) has been reported to show anti-infective, anti-cancer, and anti-inflammatory effects. In particular, it has become evident that oral bLF had a beneficial effect on infections of both digestive and nondigestive tract tissue in various animal models. Furthermore, the effects of bLF have been indicated in clinical studies on patients with Helicobacter pylori infection, chronic hepatitis C, tinea pedis, and other diseases. Immunomodulation in the intestine and systemic sites has been suggested to mediate the protective effects of oral bLF against infection. Recently, we demonstrated the beneficial effects of oral bLF in influenza virus infected mice. BLF administration reduced the lung consolidation score and the number of infiltrating leukocytes in bronchoalveolar lavage fluid. We also investigated the effect of oral bLF on the transcription of genes related to immunity in the small intestine of mice using the quantitative RT-PCR method. We found that intake of bLF increased the expression of IL-12p40, IFN-beta, and NOD2. Thus, oral bLF activates the transcription of important immune-related genes in the small intestine, and such transcriptional activation may promote systemic host immunity.

Oral administration of lactoferrin increases NK cell activity in mice via increased production of IL-18 and type I IFN in the small intestine

Evidence that lactoferrin (LF) influences various immune functions is now accumulating. Recent reports have shown that bovine LF (BoLF) enhances antimicrobial, antiviral, and antitumor immune activities when orally administered. Here, we report that orally administered BoLF increases natural killer (NK) cell populations in peripheral blood and spleen in a dose-dependent manner and enhances interferon-gamma (IFN-gamma) production by NK cells. Using intraperitoneal (i.p.) injection of poly(I:C) to induce NK cell trafficking into the peritoneum, oral BoLF increased NK cell migration. Oral BoLF also produced an immediate increase in the levels of interleukin-18 (IL-18) in the portal circulation. In IL-18 knockout (KO) mice, BoLF did not increase the numbers of NK cells, although NK cell cytotoxic activity and poly(I:C)-induced trafficking activity were both enhanced by oral BoLF, even in IL-18 KO mice. Furthermore, oral BoLF increased the expression of IFN-alpha and IFN-beta in Peyer's patches (PP) and mesenteric lymph nodes (MLN). Oral administration of 2- chloroadenosine selectively depleted the PP cells and blocked the ability of oral BoLF to increase NK cell accumulation in the peritoneum following poly(I:C) i.p. injection. Collectively, these results demonstrate that orally administered BoLF stimulates intestine-associated immune functions, including the production of IL- 18 and type I IFNs and increased NK cell activity.

Modulation of immunity-related gene expression in small intestines of mice by oral administration of lactoferrin

Oral administration of lactoferrin (LF), an antimicrobial and immunomodulatory protein, shows a protective effect against infectious diseases, possibly via immunomodulation of the host. Initially, we confirmed an immunomodulatory effect of LF by observing changes in the number of cells in the leukocyte subsets in the peripheral blood and spleens of mice 1 day after oral administration of LF. Then we developed a quantitative reverse transcription-PCR method for 20 immunity-related genes of antimicrobial proteins, pattern recognition receptors, cytokines, and lymphocyte mobilization-related proteins, and we assessed the expression of these genes in the small intestines of mice 2 h after administration of water, bovine serum albumin (BSA), or LF. Expression of the LF gene was lower in mice administered LF than in mice administered water or BSA, implying a negative-feedback control. Expression of gamma interferon (IFN-gamma) and interleukin-10 (IL-10) was lower in both BSA- and LF-administered mice than in water administered mice, suggesting a nonspecific effect of protein ingestion. Expression of NOD2, IFN-beta, and IL-12p40 was higher with LF administration than with water or BSA administration. The expression levels of these three genes were correlated. This study indicated that oral administration of LF modulates the small intestinal expression of genes closely related to the host defense in a specific or a nonspecific manner.

Effects of orally administered bovine lactoferrin and lactoperoxidase on influenza virus infection in mice

Milk contains a wide variety of host protective factors against infectious microbes. Among these protective factors, lactoferrin (LF) and lactoperoxidase (LPO) have been reported to exhibit antiviral activities as well as immuno-modulatory effects. In the present study, the effects of orally administered LF and LPO were assessed in a mouse influenza virus infection model. BALB/c mice were intranasally infected with 6.6x10(2) p.f.u. of influenza virus A/PR/8/34(H1N1). Bovine LF or LPO was administered once daily at a dose of 62.5 mg per mouse by gavage, starting 1 day before infection. Mice given LF or LPO showed a significantly lower lung consolidation score on day 6 after infection compared with the control mice that were given water instead. Concurrently, the number of infiltrated leukocytes recovered from bronchoalveolar lavage fluid (BALF) on day 6 was significantly lower in mice given LF or LPO. However, the virus yield in the BALF was not affected by these treatments. The serum level of IL-6, a pro-inflammatory cytokine, positively correlated with the lung consolidation score in each group and was significantly lower on day 6 in the mice given LPO. These results suggest the potential of oral administration of LF or LPO to attenuate pneumonia in influenza-virus-infected mice through the suppression of infiltration of inflammatory cells in the lung.

Effect of orally administered bovine lactoferrin on the immune response in the oral candidiasis murine model

Therapeutic activity against oral candidiasis of orally administered bovine lactoferrin (LF), a multifunctional milk protein, was shown in a previous report using an immunosuppressed murine model. In the present study, the influence of orally administered LF on immune responses relevant to this therapeutic effect was examined. Because mice were immunosuppressed with prednisolone 1 day before and 3 days after the infection with Candida, the numbers of peripheral blood leukocytes (PBL) and cervical lymph node (CLN) cells were reduced. LF feeding prevented the reduction in the numbers of PBL on day 1 and CLN cells on days 1, 5 and 6 in the Candida-infected mice. The number of CLN cells of individual mice on days 5 and 6 was inversely correlated with the Candida c.f.u. in the oral cavity. Increased production of IFN-gamma and TNF-alpha by CLN cells stimulated with heat-killed Candida albicans on day 6 was observed in LF-treated mice compared with non-treated mice. Concanavalin A (ConA)-stimulated CLN cells from LF-treated mice also showed a significant increase in the production of IFN-gamma and IL12 on day 5 and a tendency for increased production of IFN-gamma and TNF-alpha on day 6. The levels of cytokine production by ConA-stimulated CLN cells on day 6 were inversely correlated with the Candida c.f.u. in the oral cavity. In conclusion, the alleviation of oral candidiasis by LF feeding in this model may correlate with the enhancement of the number of leukocytes and their cytokine responses in regional lymph nodes against Candida infection.

Lactoferrin functions: current status and perspectives

Lactoferrin, an iron-binding glycoprotein synthesized by neutrophils and exocrine glands, plays an important role in human innate defense mechanisms against bacteria, fungi, and viruses. First, a bacteriostatic activity of lactoferrin, depending on iron withholding to bacteria, and successively a bactericidal iron-independent effect, related to its binding on bacterial surfaces, was recognized. Many other functions have been ascribed to this cationic protein, including the inhibiting action toward bacterial adhesion and invasion of target host cells. Recent research also reported the lactoferrin influence on bacterial aggregation and biofilm development of Pseudomonas aeruginosa and Streptococcus mutans. The different lactoferrin functions can be justified by different physicochemical properties of the molecule, which include the iron-binding capability, the binding to anionic cell surfaces and molecules, and serine protease activity.

An epidemiological and clinical study of untreated patients with tinea pedis within a company in Japan

In this study, we investigated epidemiological and clinical aspects of dermatophyte foot infections among employees of one dairy product company located in Kanagawa prefecture in central Japan. Sixty-nine of 377 subjects were reported having "athlete's foot" in response to a simple questionnaire. A subsequent mycological examination revealed 41 untreated patients with tinea pedis and/or tinea unguium (89% of subjects examined) and the overall prevalence was estimated at 18%. Comparing severity scores of five clinical symptoms (itching, erythema, vesicles/pustules, erosion/maceration, and scales) between those untreated patients within the subjects and another group of patients who spontaneously attended dermatological clinics to treat tinea pedis, itching, erythema, and total score were significantly higher in the latter group.

Lactoferrin feeding augments peritoneal macrophage activities in mice intraperitoneally injected with inactivated Candida albicans

Oral administration of lactoferrin (LF), an innate-defense protein present in exocrine secretions such as milk and in neutrophils, is reported to improve host-protection against infections with microorganisms including pathogenic fungi, possibly due to an immunomodulatory effect. This study aimed to evaluate the effect of bovine LF feeding on peritoneal macrophage activities in mice intraperitoneally injected with inactivated Candida albicans. Time course analysis during the 14 days following Candida-priming revealed that LF administration slightly increased the number of peritoneal exudate cells, and significantly enhanced the production of superoxide anion (O2(-)) and nitric oxide (NO) by peritoneal macrophages at day 7. LF administration facilitated NO production and Candida hyphal-growth inhibition by macrophages derived from Candida-primed mice but not non-primed mice, suggesting that the action of LF is dependent on the immune status of the host. LF administration altered the kinetics of cytokines in the peritoneal lavage fluid of Candida-primed mice. Enhancement of cytokine levels by LF was observed for IL-12 at day 5 and IFN-gamma at day 9, but not for TNF-alpha or IL-10. In conclusion, LF feeding augmented the activities of macrophages in a manner dependent on Candida-priming and these effects may be related to enhanced cytokine levels.

Bovine lactoferrin and lactoferricin derived from milk: production and applications

Bovine lactoferrin is produced on an industrial scale from cheese whey or skim milk. The safety of purified lactoferrin has been confirmed from the results of a reverse mutation test using bacteria, a 13-week oral repeated-dose toxicity study in rats, and clinical studies. In order to apply active lactoferrin to various products, a process for its pasteurization was developed. Subsequently, lactoferrin has been used in a wide variety of products since it was first added to infant formula in 1986. A pepsin hydrolysate of lactoferrin is also used in infant formula. This hydrolysate contains a potent antimicrobial peptide named lactoferricin that is derived from the lactoferrin molecule by pepsin digestion. Semilarge-scale purification of lactoferricin can be performed by hydrophobic interaction chromatography. Lactoferricin also exhibits several biological actions and appears to be the functional domain of lactoferrin. Recent studies have demonstrated that oral administration of lactoferrin or lactoferricin exerts a host-protective effect in various animals and in humans. The results of these studies strongly suggest that the effects of oral lactoferrin are mediated by modulation of the immune system. Further elucidation of the clinical efficacy and mechanism of action of lactoferrin will increase the value of lactoferrin-containing products.

Effect of lactoferrin feeding on the host antifungal response in guinea-pigs infected or immunised with Trichophyton mentagrophytes

Earlier studies revealed that oral administration of lactoferrin (LF), a multi-functional milk protein, facilitated curing of dermatophytosis in guinea-pigs and man by an unknown mechanism. The present study aimed to assess the effect of feeding bovine LF on the host antifungal defence systems in guinea-pigs infected or immunised with Trichophyton mentagrophytes, a dermatophytosis-causing fungus. The unbound iron-binding capacity (UIBC) of the plasma of individual animals varied, and plasma with higher UIBC inhibited growth of T. mentagrophytes in vitro. However, LF administration did not enhance plasma UIBC or the anti-T. mentagrophytes activity of plasma in infected or uninfected animals. Phagocytic activity and reactive oxygen (RO) production of blood neutrophil polymorphonuclear leucocytes (PMNLs) were estimated by flow cytometry. LF administration caused no significant effects on phagocytic activity or RO production of neutrophil PMNLs in infected or uninfected animals. The functions of mononuclear cells (MNC) from the spleen were investigated in guinea-pigs immunised with heat-killed T. mentagrophytes conidia. The MNC were cultured with concanavalin A or inactivated T. mentagrophytes. In the bromo-deoxyuridine incorporation assay, the stimulation index was higher for MNC derived from LF-treated animals than for those from control animals. The culture supernates of MNC enhanced the ability of macrophages to kill T. mentagrophytes conidia. Furthermore, stronger augmentation was observed with the culture supernate from LF-treated animals than with that from control animals. In conclusion, LF feeding may potentiate the host antifungal defence systems by modulating MNC function rather than plasma antifungal activity or peripheral blood neutrophil PMNL activity.