Cytocidal Antitumor Effects against Human Ovarian Cancer Cells Induced by B-Lactam Steroid Alkylators with Targeted Activity against Poly (ADP-Ribose) Polymerase (PARP) Enzymes in a Cell-Free Assay

Investigation of the antibacterial activity, cytotoxicity, and effects on enamel and composite resin of mouthwash formulations prepared with three different Boron compounds

OBJECTIVE

This study investigated the use of oral rinse solutions formulated with boron-containing compounds, known for their antibacterial activity, as an alternative to chlorhexidine (CHX).

MATERIAL AND METHOD

Boron nitride (BN), boric acid (BA) and sodium borate (SB) were used in the study. BN was used in nanosuspension (BN-NS) due to its low solubility in water. BA and SB were also prepared and used in solution form (BA-S, SB-S). Antibacterial activity against cariogenic bacteria was evaluated using agar well diffusion and microdilution techniques, and antibiofilm activity was evaluated using the crystal violet method. Cytotoxicity in human gingival cell lines (HGF-1) was evaluated using MTT and LDH assays. Surface hardness was measured with Vicker's Microhardness tester and surface roughness was measured with a profilometer. CHX was used as the control group.

RESULTS

BN-NS, BA-S, and SB-S showed antibacterial and antibiofilm activity against all cariogenic bacteria. BN-NS and SB-S demonstrated much lower cytotoxicity compared to CHX, while BA-S exhibited similar cytotoxicity. SB-S caused an increase in enamel surface hardness (p = 0.017), whereas no significant changes were observed in surface roughness or hardness in the other groups (p > 0.05).

CONCLUSION

BN-NS and SB-S showed antibacterial effects and antibiofilm activity on all tested cariogenic bacteria. BN-NS and SB-S showed lower cytotoxicity than CHX, and their effects on enamel and composite resin surfaces were similar to the control group. Further studies are needed to support the use of BN-NS and SB-S as alternatives to CHX.

CLINICAL REVELANCE

BN-NS and SB-S are promising alternatives to the antibacterial agent CHX, which is known to be cytotoxic.

Secosteroid diacylhydrazines as novel effective agents against hormone-dependent breast cancer cells

This research aimed to develop novel selective secosteroids that are highly active against hormone-dependent breast cancer. A simple and convenient approach to N'-acylated 13,17-secoestra-1,3,5(10)-trien-17-oic acid hydrazides was disclosed and these novel types of secosteroids were screened for cytotoxicity against the hormone-dependent human breast cancer cell line MCF7. Most secosteroid N'-benzoyl hydrazides have demonstrated high cytotoxicity against MCF7 cells with IC50 values below 5 μM, which are superior to that of the reference drug cisplatin. Hit compounds 2c, 2e and 2i were characterized by high cytotoxicity (IC50 = 1.6-1.9 μM) and very good selectivity towards MCF7 breast cancer cells. The lead secosteroids 2c, 2e and 2i also exhibit antiestrogenic effects and alter the expression of cell cycle regulating proteins. The effect of selected compounds on PARP (poly(ADP-ribose) polymerase) and Bcl-2 (B-cell CLL/lymphoma 2) indicates their proapoptotic potential. The synthesized secosteroids may be considered as new promising anti-breast cancer agents targeting ERα and apoptosis pathways.

Synthesis and antiproliferative activities of steroidal lactam conjugates bearing a new nitrogen mustard

Alkylating agents are potent anticancer compounds that exert their anticancer properties through the inhibition of cell replication and transcription leading to cell death. Despite the numerous benefits, these agents also have serious drawbacks such as their high toxicity and low specificity towards cancer cells. As previously reported by our group, conjugation of alkylating agents with azasteroids can reduce their systemic toxicity and enhance their anticancer activity. In this work, novel steroidal alkylating agents bearing POPAM-OH were synthesized and their anticancer efficacy was evaluated in vitro and in vivo. All the novel hybrids demonstrated high antiproliferative effects against 5 different cancer cell lines in the low micromolar range. Treatment of SCID mice bearing SKOV-3 or PC-3 tumor xenografts with the most potent hybrid 19 led to significant reduction of tumor size (tumor inhibition TI = 95% in SKOV3 models and TI = 85.2% in PC3 models). Importantly, the acute toxicity of hybrid 19 (LD₁₀ = 36 μΜ, LD₅₀ = 62 μΜ) in CB17 SCID mice exhibited three-fold decrease compared to the acute toxicity of previously reported hybrids of POPAM-NH₂. This is an important finding since systemic cytotoxicity is a critical limitation of alkylating agents. Collectively, the steroidal conjugates of POPAM-OH displayed significant anticancer efficacy and reduced toxicity in vitro and in vivo rendering them as good candidates for cancer therapy.