Utilizing Liposomal Quercetin and Gallic Acid in Localized Treatment of Vaginal Candida Infections

Abstract

Vulvovaginal candidiasis (VVC) is a widely spread fungal infection that causes itching, pain and inflammation at the vaginal site. Although common, currently available treatment suffers from limited efficacy and high recurrence. In addition, the growing problem of resistance to azole drugs used in current treatments emphasizes the need for superior treatment options. Antimicrobial polyphenols are an attractive approach offering multitargeting therapy. We aimed to develop novel liposomes for simultaneous delivery of two polyphenols (quercetin, Q, and gallic acid, GA) that, when released within the vaginal cavity, act in synergy to eradicate infection while alleviating the symptoms of VVC. Q was selected for its anti-itching and anti-inflammatory properties, while GA for its reported activity against Candida. Novel liposomes containing only Q (LP-Q), only GA (LP-GA) or both polyphenols (LP-Q+GA) were in the size range around 200 nm. Q was efficiently entrapped in both LP-Q and in LP-Q+GA (85%) while the entrapment of GA was higher in LP-Q+GA (30%) than in LP-GA (25%). Liposomes, especially LP-Q+GA, promoted sustained release of both polyphenols. Q and GA acted in synergy, increasing the antioxidant activities of a single polyphenol. Polyphenol-liposomes were not cytotoxic and displayed stronger anti-inflammatory effects than free polyphenols. Finally, LP-GA and LP-Q+GA considerably reduced C. albicans growth.

Keywords: Candida; gallic acid; liposomes; polyphenols; quercetin; vaginal infection.

Figure 1

Stability of liposomes: changes in (a) Q and GA EE %; (b) liposomes size (bars, left Y axis) and PDI (symbols, right Y axis) and (c) zeta potential over a storage period of 90 days at 4 °C (mean ± SD, n = 4). The statistical significance was calculated with respect to day 0; * p < 0.05.

Figure 2

In vitro polyphenol release expressed as cumulative percentages of (a) Q and (b) GA released over time from liposomes containing only Q (LP-Q), liposomes containing only GA (LP-GA) and liposomes containing both polyphenols (LP-Q+GA) compared to free Q and free GA (mean ± SD, n = 3).

Figure 3

Antioxidant activities of LP-Q, LP-GA and LP-Q+GA, vitamin E and vitamin C expressed as (a) ABTS and (b) DPPH free radicals scavenging activity (mean ± SD, n = 3). The statistical significance with respect to vitamin E and vitamin C (used as comparison) was reported; * p < 0.0001. Statistical differences between liposomes holding both polyphenols (LP-Q+GA) and liposomes holding only one polyphenol (LP-Q/LP-GA) were also calculated; a: p < 0.001.

Figure 4

Inhibitory effect of liposomal and free Q and/or GA on nitric oxide (NO) production in lipopolysaccharide (LPS)-induced macrophages (mean ± SD, n = 3). The statistical significance was calculated with respect to control (untreated cells); * p < 0.0001. Statistical differences between coupled polyphenols (LP-Q+GA or Q+GA) and single polyphenol (LP-Q/LP-GA or Q/GA) were also investigated; a: p < 0.001. Statistical differences between liposomes and corresponding free polyphenols were reported as follows: b′: p < 0.01; b″: p < 0.001; b‴: p < 0.0001.

Figure 5

Effect of liposomal and free polyphenols on RAW 264.7 cell viability compared to viability of untreated cells (100%) (mean ± SD, n = 3). The statistical significance was calculated with respect to control; * p < 0.01.