Is wetter better? An evaluation of over-the-counter personal lubricants for safety and anti-HIV-1 activity

Abstract

Because lubricants may decrease trauma during coitus, it is hypothesized that they could aid in the prevention of HIV acquisition. Therefore, safety and anti-HIV-1 activity of over-the-counter (OTC) aqueous- (n = 10), lipid- (n = 2), and silicone-based (n = 2) products were tested. The rheological properties of the lipid-based lubricants precluded testing with the exception of explant safety testing. Six aqueous-based gels were hyperosmolar, two were nearly iso-osmolar, and two were hypo-osmolar. Evaluation of the panel of products showed Gynol II (a spermicidal gel containing 2% nonoxynol-9), KY Jelly, and Replens were toxic to Lactobacillus. Two nearly iso-osmolar aqueous- and both silicone-based gels were not toxic toward epithelial cell lines or ectocervical or colorectal explant tissues. Hyperosmolar lubricants demonstrated reduction of tissue viability and epithelial fracture/sloughing while the nearly iso-osmolar and silicon-based lubricants showed no significant changes in tissue viability or epithelial modifications. While most of the lubricants had no measurable anti-HIV-1 activity, three lubricants which retained cell viability did demonstrate modest anti-HIV-1 activity in vitro. To determine if this would result in protection of mucosal tissue or conversely determine if the epithelial damage associated with the hyperosmolar lubricants increased HIV-1 infection ex vivo, ectocervical tissue was exposed to selected lubricants and then challenged with HIV-1. None of the lubricants that had a moderate to high therapeutic index protected the mucosal tissue. These results show hyperosmolar lubricant gels were associated with cellular toxicity and epithelial damage while showing no anti-viral activity. The two iso-osmolar lubricants, Good Clean Love and PRÉ, and both silicone-based lubricants, Female Condom 2 lubricant and Wet Platinum, were the safest in our testing algorithm.

Figure 1. Impact of the over-the-counter lubricants on Lactobacillus species viability.

Lactobacillus species (L. crispatus (open bar); L. jensenii 25258 (diagonal line bar); L. jensenii 28Ab (diamond hatch bar)) were cultured in the presence of lubricants for 30 min then plated. The reduction of colony forming units was compared to control cultures. The data are presented as the Log₁₀ growth compared to the control cultures.

Figure 2. Impact of the over-the-counter aqueous-based lubricants on epithelial cell line viability.

Caco-2 (upper panel) and HEC-1-A (lower panel) epithelial cells were treated with serial dilutions of the indicated lubricants for 24 h and their viability was measured and presented as the %Viability of the control (untreated) cells. The data presented are the mean ± standard deviation of 5 independent experiments.

Figure 3. Impact of the over-the-counter silicone-based lubricants on epithelial cell lines.

(A) Caco-2 and HEC-1-A epithelial cell lines were treated with Female Condom 2 (FC 2) lubricant or Wet Platinum for 15, 30 or 60 min and %Viability of the control (untreated) cells was measured. (B) TZM-bl cells were treated with FC2 lubricant or Wet Platinum for 15, 30, or 60 min and %Viability or %Anti-HIV-1 activity of the control (untreated) cells was measured. The data presented are the mean ± standard deviation of 5 independent experiments.

Figure 4. Effect of the over-the-counter aqueous-based lubricants on epithelial cell line monolayer integrity.

(A) Caco-2 or (B) HEC-1-A epithelial cell lines were grown on transwell supports until a polarized monolayer was established. A 1∶10 dilution of each of the lubricants was applied to the apical surface to allow for even spread over the cell surface, and the monolayers were followed over a 24 h period. The data presented are the mean ± standard deviation of 5 independent experiments.

Figure 5. Effect of the over-the-counter silicone-based lubricants on epithelial cell line monolayer integrity.

(A) Female Condom 2 lubricant (FC2) or (B) Wet Platinum were evaluated for their impact on Caco-2 and HEC-1-A epithelial cell line monolayers. Lubricant was directly applied to the apical surface of the monolayers for 60 min and then medium containing fluorescent microbeads was applied. Baselateral supernatant was collected over a 24 h period and the fluorescence was measured. The data presented are the %Transmission and represents the mean ± standard deviation of 5 independent experiments.

Figure 6. Impact of the over-the-counter lubricants on colorectal (CR) and ectocervical (CVX) tissue viability and architecture.

Ex vivo tissue was placed in transwell supports with the luminal surface exposed to the air. The edges were sealed to ensure the lubricant was exposed to the luminal epithelium in duplicate cultures. After an overnight exposure, tissue was washed with one piece further cultured in medium containing 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan for the MTT assay (A) or the other piece fixed in paraformaldehyde for hematoxylin and eosin staining of CR tissue (B) and CVX tissue (C). The MTT assay represents the mean ± standard deviation of a minimum of 5 independent tissues. The histology is representative of one of those tissues.

Figure 7. Effect lubricants have on HIV-1 infection of ectocervical tissue.

Ectocervical tissue was placed in transwell supports with the luminal surface exposed to the air. The edges were sealed to ensure the lubricant was exposed to the luminal epithelium in duplicate cultures. Tissues were cultured with the indicated lubricant overnight. Controls consisted of no treatment or additional well reserved for 0.1% EDTA. After washing, the control tissues and those exposed to lubricants were rested for 2 h while the reserved tissue was treated with 0.1% EDTA during the 2 h. The EDTA-treated tissues were then washed and all tissues were exposed to HIV-1 overnight. The tissues were washed and cultured for 21 days; the medium in the basolateral chamber was replenished every 3 to 4 days. HIV-1 replication was monitored in saved supernatant by p24 ELISA. At study end, tissue was fixed and stained for HIV-1 infected cells by immunohistochemistry. The data shown represent the median ± the 95% confidence interval of 4 to 5 independent tissues. The immunohistochemistry is representative of one of those tissues.