BASIC study: is intravaginal boric acid non-inferior to metronidazole in symptomatic bacterial vaginosis? Study protocol for a randomized controlled trial

Vaginal Sheets with Thymbra capitata Essential Oil for the Treatment of Bacterial Vaginosis: Design, Characterization and In Vitro Evaluation of Efficacy and Safety

We aimed to incorporate Thymbra capitata essential oil (TCEO), a potent antimicrobial natural product against bacterial vaginosis (BV)-related bacteria, in a suitable drug delivery system. We used vaginal sheets as dosage form to promote immediate relief of the typical abundant vaginal discharge with unpleasant odour. Excipients were selected to promote the healthy vaginal environment reestablishment and bioadhesion of formulations, while the TCEO acts directly on BV pathogens. We characterized vaginal sheets with TCEO in regard to technological characterization, predictable in vivo performance, in vitro efficacy and safety. Vaginal sheet D.O (acid lactic buffer, gelatine, glycerine, chitosan coated with TCEO 1% w/w) presented a higher buffer capacity and ability to absorb vaginal fluid simulant (VFS) among all vaginal sheets with EO, showing one of the most promising bioadhesive profiles, an excellent flexibility and structure that allow it to be easily rolled for application. Vaginal sheet D.O with 0.32 µL/mL TCEO was able to significantly reduce the bacterial load of all in vitro tested Gardnerella species. Although vaginal sheet D.O presented toxicity at some concentrations, this product was developed for a short time period of treatment, so this toxicity can probably be limited or even reversed when the treatment ends.

Data on Safety of Intravaginal Boric Acid Use in Pregnant and Nonpregnant Women: A Narrative Review

ABSTRACT

Intravaginal boric acid (IBA) represents one of the only options available to treat azole-resistant vulvovaginal candidiasis (VVC) and is included as part of multiple national guidelines (including the United Kingdom and the United States) for the treatment of VVC or recurrent bacterial vaginosis. Novel products using IBA are under development for treatment and suppression of VVC and bacterial vaginosis. Use of over-the-counter or clinician-prescribed IBA in reproductive-aged women is already widespread and may increase further if drug resistance in VVC rises. However, IBA is not a Food and Drug Administration-approved drug, and safety data are sparse. Given these factors, it is important to understand the currently available data on the safety of IBA use. Herein, we set out to synthesize human and animal data (converting, where appropriate, dose and serum values to standard units to facilitate comparison) to answer 2 key questions: (1) What are the data on the safety of IBA use for women? and (2) What are the data on the safety of IBA use in pregnancy? We find that, despite gaps, available data suggest IBA use is safe, at least when used in doses commonly described in the literature as being prescribed by clinicians. Information on harms in pregnancy is limited, and data remain insufficient to change current guidelines, which recommend IBA avoidance in pregnancy.

Effects of boron-containing compounds in the fungal kingdom

BACKGROUND

The number of known boron-containing compounds (BCCs) is increasing due to their identification in nature and innovative synthesis procedures. Their effects on the fungal kingdom are interesting, and some of their mechanisms of action have recently been elucidated.

METHODS

In this review, scientific reports from relevant chemistry and biomedical databases were collected and analyzed.

RESULTS

It is notable that several BCC actions in fungi induce social and economic benefits for humans. In fact, boric acid was traditionally used for multiple purposes, but some novel synthetic BCCs are effective antifungal agents, particularly in their action against pathogen species, and some were recently approved for use in humans. Moreover, most reports testing BCCs in fungal species suggest a limiting effect of these compounds on some vital reactions.

CONCLUSIONS

New BCCs have been synthesized and tested for innovative technological and biomedical emerging applications, and new interest is developing for discovering new strategic compounds that can act as environmental or wood protectors, as well as antimycotic agents that let us improve food acquisition and control some human infections.

Gardnerella and vaginal health: the truth is out there

The human vagina is a dynamic ecosystem in which homeostasis depends on mutually beneficial interactions between the host and their microorganisms. However, the vaginal ecosystem can be thrown off balance by a wide variety of factors. Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age but its etiology is not yet fully understood, with different controversial theories being raised over the years. What is generally accepted is that BV is often characterized by a shift in the composition of the normal vaginal microbiota, from a Lactobacillus species dominated microbiota to a mixture of anaerobic and facultative anaerobic bacteria. During BV, a polymicrobial biofilm develops in the vaginal microenvironment, being mainly composed of Gardnerella species. The interactions between vaginal microorganisms are thought to play a pivotal role in the shift from health to disease and might also increase the risk of sexually transmitted infections acquisition. Here, we review the current knowledge regarding the specific interactions that occur in the vaginal niche and discuss mechanisms by which these interactions might be mediated. Furthermore, we discuss the importance of novel strategies to fight chronic vaginal infections.

Clinicians' Use of Intravaginal Boric Acid Maintenance Therapy for Recurrent Vulvovaginal Candidiasis and Bacterial Vaginosis

A retrospective chart review characterized clinicians' use of maintenance intravaginal boric acid for women with recurrent vulvovaginal candidiasis or bacterial vaginosis. Average length of use was 13 months with high patient satisfaction and few adverse events. Prospective studies are needed to evaluate the efficacy of maintenance boric acid for these conditions.

Randomized Trial of Lactin-V to Prevent Recurrence of Bacterial Vaginosis

BACKGROUND

Bacterial vaginosis affects 15 to 50% of women of reproductive age, and recurrence is common after treatment with an antibiotic agent. The high incidence of recurrence suggests the need for new treatments to prevent recurrent bacterial vaginosis.

METHODS

We conducted a randomized, double-blind, placebo-controlled, phase 2b trial to evaluate the ability of Lactobacillus crispatus CTV-05 (Lactin-V) to prevent the recurrence of bacterial vaginosis. Women 18 to 45 years of age who had received a diagnosis of bacterial vaginosis and who had completed a course of vaginal metronidazole gel as part of the eligibility requirements were randomly assigned, in a 2:1 ratio, to receive vaginally administered Lactin-V or placebo for 11 weeks; follow-up occurred through week 24. The primary outcome was the percentage of women who had a recurrence of bacterial vaginosis by week 12.

RESULTS

A total of 228 women underwent randomization: 152 to the Lactin-V group and 76 to the placebo group; of these participants, 88% in the Lactin-V group and 84% in the placebo group could be evaluated for the primary outcome. In the intention-to-treat population, recurrence of bacterial vaginosis by week 12 occurred in 46 participants (30%) in the Lactin-V group and in 34 participants (45%) in the placebo group (risk ratio after multiple imputation for missing responses, 0.66; 95% confidence interval [CI], 0.44 to 0.87; P = 0.01). The risk ratio for recurrence by week 24 (also calculated with multiple imputation for missing responses) was 0.73 (95% CI, 0.54 to 0.92). At the 12-week visit, L. crispatus CTV-05 was detected in 79% of participants in the Lactin-V group. The percentage of participants who had at least one adverse event related to Lactin-V or placebo by week 24 did not differ significantly between the groups. The percentage of participants with local or systemic adverse events was similar in the two groups.

CONCLUSIONS

The use of Lactin-V after treatment with vaginal metronidazole resulted in a significantly lower incidence of recurrence of bacterial vaginosis than placebo at 12 weeks. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT02766023.).

Effects of boron-containing compounds on immune responses: review and patenting trends

INTRODUCTION

Boron-containing compounds induce effects on immune responses. Such effects are interesting to the biomedical field for the development of therapeutic tools to modulate the immune system.

AREAS COVERED

The scope of BCC use to modify immune responses is expanding, mainly with regard to inflammatory diseases. The information was organized to demonstrate the breadth of reported effects. BCCs act as modulators of innate and adaptive immunity, with the former including regulation of cluster differentiation and cytokine production. In addition, BCCs exert effects on inflammation induced by infectious and noninfectious agents, and there are also reports regarding their effects on mechanisms involving hypersensitivity and transplants. Finally, the authors discuss the beneficial effects of BCCs on pathologies involving various targets and mechanisms.

EXPERT OPINION

Some BCCs are currently used as drugs in humans. The mechanisms by which these BCCs modulate immune responses, as well as the required structure-activity relationship for each observed mechanism of action, should be clarified. The former will allow for the development of improved immunomodulatory drugs with extensive applications in medicine. Patenting trends involve claims concerning the synthesis and actions of identified molecules with a defined profile regarding cytokines, cell differentiation, proliferation, and antibody production.

Alternative and complementary therapies for vulvovaginal candidiasis

When it comes to women's health, treating vaginal infections makes up a high proportion of the gynecological services. Among the forms of vaginitis, vulvovaginal candidiasis (VVC) is considered the second most common. Demand for new treatment alternatives is increasingly relevant, especially for therapies with fewer side effects, better tolerability, and lower cost, while still offering improved quality of life in terms of disease prevention. This study intended to investigate the alternative therapies described for the adjuvant treatment of vulvovaginitis caused by Candida species, including alternative and complementary treatment methods used by women. This literature review is based on articles written in English and Portuguese in the PubMed, Google Scholar, and SciELO databases. This study was conducted for the most part using the Brazilian Government's Capes Periodicals Portal, which directs to Google Scholar and PubMed. Since the 1980s, there has been growing interest in alternative therapies in Brazil, a trend which also began in other Western countries in the second half of the twentieth century. Some alternative treatments include substances with antifungal activity, some substances help restore the balance of the vaginal microbiota, while others have an inhibitory activity on microbial virulence factors. The proper use of therapeutic alternatives can effectively contribute to the treatment of VVC, but it should be remembered that some chemical products, such as boric acid or vinegar, and even natural products such as propolis, garlic, and tea tree may have undesirable side effects, having not been tested by well-designed clinical studies. Even so, alternative therapies in the treatment of VVC do have support in the scientific literature.

Intravaginal boric acid: is it an alternative therapeutic option for vaginal trichomoniasis?

Objectives

Trichomoniasis, caused by Trichomonas vaginalis (TV), is the most common curable sexually transmitted infection worldwide. Current guidance in the UK is to treat TV with a nitroimidazole antibiotic. The high prevalence of TV, high rate of antibiotic resistance and limited tolerability to nitroimidazoles suggest that alternative treatment regimens are needed. Intravaginal boric acid (BA) has been used safely for the treatment of candida vulvovaginitis and bacterial vaginosis, and in vitro studies suggest BA is active against TV. We review the evidence for the efficacy of BA in patients with TV.

Methods

MEDLINE, EMBASE, CINAHL, AMED, HMIC and BNI and Grey literature databases, The Cochrane Library, Trial Registers, conference abstracts and proceedings were searched. Inclusion criteria were women aged 16 years or over with microbiological confirmation of TV infection and using BA as treatment. There were no restrictions on language, publication date or study design. The in vitro evidence for BA activity against TV was also reviewed.

Results

No randomised controlled trials or case series were found. Four case reports demonstrated TV clearance with BA using a variety of dose regimens (dose 600 mg alternate nights to 600 mg two times per day; duration 1–5 months). In vitro studies suggest that BA has activity against TV which is independent of its effect on pH.

Discussion

Further evaluation of BA for the treatment of uncomplicated TV is required, but it may be useful when therapeutic options are limited. If shown to be safe and effective, intravaginal BA might provide a well-tolerated alternative anti-infective treatment which reduces community exposure to systemic antibiotics.

The Efficacy of Boric Acid Used to Treat Experimental Osteomyelitis Caused by Methicillin-Resistant Staphylococcus aureus: an In Vivo Study

We explored the ability of local and systemic applications of boric acid (BA) to reduce the numbers of methicillin-resistant Staphylococcus aureus (MRSA) in a rat model of tibial osteomyelitis (OM), and compared boric acid with vancomycin (V). Implant-associated osteomyelitis was established in 35 rats. After 4 weeks, at which time OM was evident both radiologically and serologically in all animals, the rats were divided into five groups of equal number: group 1, control group (no local application of BA or other medication); group 2, V group; group 3, local BA + V group; group 4, local BA group; and group 5, local + systemic BA group. Serum total antioxidant status, and the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6, were measured. Pathological changes attributable to bone OM were evaluated using a grading system. Bacterial colony-forming units (CFUs) per gram of bone were counted. The lowest bacterial numbers were evident in group 3, and the bacterial numbers were significantly lower than that of the control group in all four test groups (p < 0.001). Group 3 also had the least severe bone infection (OM score 1.7 ± 1.1, p < 0.05). Upon histological and microbiological evaluation, no significant difference was evident between groups 2 and 3. Total antioxidant levels were significantly different in all treatment groups compared to the control group. Microbiological and histopathological evaluation showed that systemic or local application of BA was effective to treat OM, although supplementary V increased the effectiveness of BA.

Current data regarding the structure-toxicity relationship of boron-containing compounds

Boron is ubiquitous in nature, being an essential element of diverse cells. As a result, humans have had contact with boron containing compounds (BCCs) for a long time. During the 20th century, BCCs were developed as antiseptics, antibiotics, cosmetics and insecticides. Boric acid was freely used in the nosocomial environment as an antiseptic and sedative salt, leading to the death of patients and an important discovery about its critical toxicology for humans. Since then the many toxicological studies done in relation to BCCs have helped to establish the proper limits of their use. During the last 15 years, there has been a boom of research on the design and use of new, potent and efficient boron containing drugs, finding that the addition of boron to some known drugs increases their affinity and selectivity. This mini-review summarizes two aspects of BCCs: toxicological data found with experimental models, and the scarce but increasing data about the structure-activity relationship for toxicity and therapeutic use. As is the case with boron-free compounds, the biological activity of BCCs is related to their chemical structure. We discuss the use of new technology to discover potent and efficient BCCs for medicinal therapy by avoiding toxic effects.