In Vitro Evaluation of Photodynamic Activity of Plant Extracts from Senna Species against Microorganisms of Medical and Dental Interest

Anti-proliferative and photodynamic activities of Senna didymobotrya (Fresen.) leaf alkaloid-rich extracts against breast cancer cells

BACKGROUND

Amongst all neoplastic diseases, breast cancer represents a major cause of death among the female population in developed and developing countries. Since alkaloid drugs are commonly used in chemotherapy to manage this disease, this study investigated the anti-proliferative effectiveness of alkaloid-rich fractions of Senna didymobotrya leaves only and with laser irradiation against MCF-7 breast cancer cells.

METHOD AND MATERIALS

A powdered sample of the plant leaves was extracted with 50% ethanol, filtered and their pH was adjusted with acid and base solution followed by partitioning with chloroform and ethyl acetate solvents. Cells were treated with 240 μg/mL of the respective extracts, while those in the photodynamic therapy groups, cells were exposed to laser (405 nm wavelength and 10 Jcm-2) irradiation 6 h post extracts' administration.

RESULTS

Treatment with the S. didymobotrya leaves alkaloid extracts significantly decreased the ATP concentration and overall viability of the MCF-7 cells. Reactive oxygen species (ROS) levels in cell groups treated with the extracts and laser light were considerably higher than in experimental groups treated with only the extracts. Moreover, the molecular docking analysis revealed the involvement of only hydrophobic bonds in the interactions of the plant's alkaloid-derived phytoconstituents' with selected cancer protein biomarkers.

CONCLUSION

Although the in silico analysis suggests that the plant-identified alkaloid phytoconstituents inhibition of estrogen receptor-alpha, human epidermal growth factor receptor-2 and progesterone receptor proteins involved in breast cancer pathogenesis could explain a possible mechanism for the observed anticancer effect, more detailed in vitro molecular experiments are necessary to confirm these findings.

Potential of using medicinal plant extracts as photosensitizers for antimicrobial photodynamic therapy

Antimicrobial photodynamic therapy (APDT) is a promising approach to overcome antimicrobial resistance. However, for widespread implementation of this approach, approved photosensitizers are needed. In this study, we used commercially available preparations (Calendulae officinalis floridis extract, Chamomillae recutitae floridis extract, Achillea millefolii herbae extract; Hypericum perforatum extract; Eucalyptus viminalis folia extract) as photosensitizers for inactivation of gram-negative (Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria. Spectral-luminescent analysis has shown that the major chromophores are of chlorophyll (mainly chlorophyll a and b) and hypericin nature. The extracts are efficient generators of singlet oxygen with quantum yield (γΔ) from 0.40 to 0.64 (reference compound, methylene blue with γΔ = 0.52). In APDT assays, bacteria before irradiation were incubated with extracts for 30 min. After irradiation and 24 h of incubation, colony-forming units (CFU) were counted. Upon exposure of P. aeruginosa to radiation of 405 nm, 590 nm, and 660 nm at equal energy dose of 30 J/cm2 (irradiance - 100 mW/cm2, exposure time - 5 min), the most pronounced effect is observed with blue light (>3 log10 reduction); in case of S. aureus, the effect is approximately equivalent for light of indicated wavelengths and dose (>4 log10 reduction).

A preliminary study of cutaneous wound healing on the upper eyelid in a small Brazilian population using Rhizophora mangle-based cream

Plants used in traditional medicine offer an affordable new alternative in tissue repair therapy. This study aimed to evaluate the effectiveness of the 5% Rhizophora mangle cream compared to the 5% dexpanthenol cream in healing open surgical wounds on the upper eyelid. A total of 18 patients were submitted to the experiment and divided into 2 groups with 9 patients each who used topically and daily 5% dexpanthenol cream (control group) or 5% R.mangle cream (intervention group) for 7 days. Clinical, morphometric and histomorphometric analyses of wounds and surgical procedures for skin removal were performed. In the morphometric analysis, all wounds treated with R.mangle and dexpanthenol creams showed complete macroscopic scars, without inflammatory signs and infection free. The skin hydration values in pre and post application periods of the cream were 43.82 ± 43.93 and 62.12 ± 67.40 respectively. The histomorphometric study showed lower values of epithelium distance in R. mangle group and higher in dexpanthenol group with significant difference between groups (p < 0.05). The R.mangle 5% cream proved to be effective in healing wounds of human upper eyelid skin with a significant improvement in epithelization compared to dexpanthenol 5% cream.