‘Secondary prevention’ against female HPV infection: literature review of the role of carrageenan

ABSTRACT

Introduction: Human papillomaviruses (HPVs) are common sexually transmitted pathogens, causally associated with cervical cancer and other anogenital cancers, as well as approximately 20% of head and neck cancers. The HPV vaccine is an exceptional primary prevention tool, but the question of adequate secondary-prevention strategies remains open. The aim of this review is to better clarify the role of carrageenan in HPV prevention-strategies.

Areas covered: A comprehensive literature search was performed (PubMed/MEDLINE, Embase, Google Scholar, Cochrane Databases) to identify articles on the use of carrageenan against HPV infection. The studies were identified using combinations of the search terms ‘carrageenan,’ ‘papillomavirus,’ ‘HPV,’ including only English language papers.

Expert opinion: Our review data confirmed the ‘inhibitory role’ of carrageenan against HPV- pseudoviruses infection on different cell types. The most accredited mechanism to explain this effect involves the direct binding of CG to the viral capsid creating a ‘physical’ obstacle. However, a different susceptibility to carrageenan for different HPV types has been highlighted, suggesting the possibility of other strategies to infect the host. There are also relevant emerging data regarding the possible role of carrageenan as an adjuvant for antigen-specific immune responses and antitumor effects.

KEYWORDS:

• Carrageenan
• papillomavirus
• prevention
• HPV
• microbicide

Article highlights

• Human papillomaviruses (HPVs) are the most common sexually transmitted viral pathogens known today, causally associated with cervical cancer as well as other anogenital cancers. The prevention of HPV infection has become one of the main ‘health’ goals in the last few years.

• Topical microbicides have been proposed and pursued as a means to address an adequate secondary-prevention strategy and the application of carrageenan (CG), a class of sulfated polysaccharides extracted from marine red algae, is hypothesized as a possible solution.

• Results of this review are encouraging about the use of CG-based gels against HPV infections. CG is safe and acceptable for topical use in humans, it is potentially useful as a vehicle for future microbicides and has an intrinsic antiviral activity.

• The most accredited mechanism to explain this effect involves the direct binding of CG to the capsid. However, a different susceptibility to CG for different HPV genotypes has been highlighted, with the possibility of different strategies of infection.

• Considering the different molecular variety of CG, data of our review suggested that iota-carrageenan was highly effective, both in vivo and in vitro. If this element is confirmed, it could be very useful in the development of new CG-based microbicides.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants, or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.