Bee Venom-Loaded Niosomes as Innovative Platforms for Cancer Treatment: Development and Therapeutical Efficacy and Safety Evaluation

Abstract

Despite past efforts towards therapeutical innovation, cancer remains a highly incident and lethal disease, with current treatments lacking efficiency and leading to severe side effects. Hence, it is imperative to develop new, more efficient, and safer therapies. Bee venom has proven to have multiple and synergistic bioactivities, including antitumor effects. Nevertheless, some toxic effects have been associated with its administration. To tackle these issues, in this work, bee venom-loaded niosomes were developed, for cancer treatment. The vesicles had a small (150 nm) and homogeneous (polydispersity index of 0.162) particle size, and revealed good therapeutic efficacy in in vitro gastric, colorectal, breast, lung, and cervical cancer models (inhibitory concentrations between 12.37 ng/mL and 14.72 ng/mL). Additionally, they also revealed substantial anti-inflammatory activity (inhibitory concentration of 28.98 ng/mL), effects complementary to direct antitumor activity. Niosome safety was also assessed, both in vitro (skin, liver, and kidney cells) and ex vivo (hen's egg chorioallantoic membrane), and results showed that compound encapsulation increased its safety. Hence, small, and homogeneous bee venom-loaded niosomes were successfully developed, with substantial anticancer and anti-inflammatory effects, making them potentially promising primary or adjuvant cancer therapies. Future research should focus on evaluating the potential of the developed platform in in vivo models.

Keywords: anti-inflammatory; anticancer; antitumor; bee venom; in vitro; nanosystems; natural compounds; niosomes.

Figure 1

Schematic representation of beehive derived compounds, including a photograph of the beehive at Polytechnic Institute of Bragança’s apiary, Bragança, Portugal (produced with Biorender, melittin, phospholipase and apamin molecular structures originated from PubChem).

Figure 2

Example chromatogram after UHPLC analysis of the bee venom sample, at 220 nm. IS—internal standard (cytochrome C, 25 µg/mL); UHPLC—ultra-high-performance liquid chromatography.

Figure 3

Particle size and PDI values of the developed niosomes (formulation vehicle), at all tested temperatures, and with a varying number of performed extrusion cycles; data is presented as mean ± standard deviation; **** p < 0.0001 and corresponds to the comparison of no extrusion with all extrusion cycles (R² 0.9991, one-way ANOVA with Tukey’s multiple comparisons test); PDI—polydispersity index.

Figure 4

Cytotoxic potential of the developed bee venom-loaded niosomes, compared to the empty niosomes (formulation vehicle) and bee venom solution, in several different cancer cell lines; GI₅₀ corresponds to the formulation concentration required to inhibit cell growth by 50%; data is represented as mean ± standard deviation; **** p < 0.0001 (R² 0.9991, one-way ANOVA with Tukey’s multiple comparisons test); AGS—gastric adenocarcinoma cell line; Caco-2—colorectal adenocarcinoma cell line; HeLa—cervical carcinoma cell line; MCF-7—breast adenocarcinoma cell line; NCI-H460—lung carcinoma cell line; PLP2—primary pig liver culture cell line; and Vero—African green monkey kidney cell line.

Figure 5

Anti-inflammatory potential of the developed bee venom-loaded niosomes (BVN), compared to the free compound (bee venom solution, BVS), and the formulation vehicle (empty niosomes, EN), evaluated in a mouse macrophage cell line (RAW 264.7); IC₅₀ values are depicted, and correspond to formulation concentrations providing 50% of inhibition of nitric oxide production; data is represented as mean ± standard deviation; **** p < 0.0001 (schematic representation produced with Biorender).

Figure 6

Cell viability percentage (%) variation with increasing applied formulation concentrations (µg/mL), on HFF-1 cell line (left bar graphs, in blue), and HaCaT cell line (right bar graphs, in pink), including the developed bee venom loaded niosomes (BVN), formulation vehicle (empty niosomes, EN), and compound solution (bee venom solution, BVS); data is represented as mean ± standard deviation; HaCaT—skin keratinocytes cell line; HFF-1—skin fibroblasts cell line.

Figure 7

HET-CAM assay schematic representation, and photographs of the hen’s egg chorioallantoic membranes after formulation application, either the developed bee venom-encapsulated niosomes (a), or the formulation vehicle (empty niosomes) (b); HET-CAM—hen’s egg chorioallantoic membrane.

Figure 8

Schematic illustration of niosome composition and production, using the thin-film hydration method, followed by extrusion through a nanometric pore membrane (produced with Biorender).