Botanical Therapeutics (Part II): Antimicrobial and In Vitro Anticancer Activity against MCF7 Human Breast Cancer Cells of Chamomile, Parsley and Celery Alcoholic Extracts

Petroselinum crispum L., essential oil as promising source of bioactive compounds, antioxidant, antimicrobial activities: In vitro and in silico predictions

This exploratory study aims to identify the volatile compounds in PC-Eo (Petroselinum crispum L. essential oil) and evaluate its antioxidant and antimicrobial properties in vitro. Molecular docking, drug-likeness prediction, and pharmacokinetics (absorption, distribution, metabolism, excretion, and toxicity-ADMET) were among the in silico simulations that were used to explain the biological properties observed in vitro. For PC-Eo's chemical screening, gas chromatography-mass spectrophotometry (GC-MS) was employed. The antioxidant activity of PC-Eo was evaluated using five in vitro complementary techniques, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging activity, β-Carotene bleaching test (BCBT), reducing power (RP), and phosphomolybdenum assay (TAC). GC-MS analysis revealed that the primary components of PC-Eo are apiol (49.05 %), Myristicin (21.01 %), and 1-allyl-2,3,4,5-tetramethoxybenzene (13.14 %). The results of the in vitro antioxidant assays indicate that PC-Eo exhibits a superior antioxidant profile. The in vitro antimicrobial activity of PC-Eo was assessed against five strains, including 2 g-positive bacteria, 2 g-negative bacteria, and one fungal strain (Candida albicans). The disc-diffusion assay revealed significant antibacterial and antifungal activities against all strains, with zones of inhibition exceeding 15 mm. The microdilution test highlighted the lowest MIC and MBC values with gram-positive bacteria, ranging from 0.25 to 0.5 % v/v for MIC and 0.5-1.0 % v/v for MBC. For the fungal strain, MIC was recorded at 1.25 % and MFC at 2.5 % v/v. PC-Eo demonstrates bactericidal and fungicidal activity based on the MBC/MIC and MFC/MIC ratios. According to the ADMET study, the primary PC-Eo compounds have advantageous pharmacokinetic characteristics. These findings provide empirical support for the traditional uses of this plant and indicate its possible use as a natural remedy.

Enhanced Cytotoxicity and Antimelanoma Activity of Novel Semisynthetic Derivatives of Betulinic Acid with Indole Conjugation

The prevalence and severity of skin cancer, specifically malignant melanoma, among Caucasians remains a significant concern. Natural compounds from plants have long been explored as potential anticancer agents. Betulinic acid (BI) has shown promise in its therapeutic properties, including its anticancer effects. However, its limited bioavailability has hindered its medicinal applications. To address this issue, two recently synthesized semisynthetic derivatives, N-(2,3-indolo-betulinoyl)diglycylglycine (BA1) and N-(2,3-indolo-betulinoyl)glycylglycine (BA2), were compared with previously reported compounds N-(2,3-indolo-betulinoyl)glycine (BA3), 2,3-indolo-betulinic acid (BA4), and BI. These compounds were evaluated for their effects on murine melanoma cells (B164A5) using various in vitro assays. The introduction of an indole framework at the C2 position of BI resulted in an increased cytotoxicity. Furthermore, the cytotoxicity of compound BA4 was enhanced by conjugating its carboxylic group with an amino acid residue. BA2 and BA3, with glycine and glycylglycine residues at C28, exhibited approximately 2.20-fold higher inhibitory activity compared to BA4. The safety assessment of the compounds on human keratinocytes (HaCaT) has revealed that concentrations up to 10 µM slightly reduced cell viability, while concentrations of 75 µM resulted in lower cell viability rates. LDH leakage assays confirmed cell membrane damage in B164A5 cells when exposed to the tested compounds. BA2 and BA3 exhibited the highest LDH release, indicating their strong cytotoxicity. The NR assay revealed dose-dependent lysosome disruption for BI and 2,3-indolo-betulinic acid derivatives, with BA1, BA2, and BA3 showing the most cytotoxic effects. Scratch assays demonstrated concentration-dependent inhibition of cell migration, with BA2 and BA3 being the most effective. Hoechst 3342 staining revealed that BA2 induced apoptosis, while BA3 induced necrosis at lower concentrations, confirming their anti-melanoma properties. In conclusion, the semisynthetic derivatives of BI, particularly BA2 and BA3, show promise as potential candidates for further research in developing effective anti-cancer therapies.

Inorganic Element Determination of Romanian Populus nigra L. Buds Extract and In Vitro Antiproliferative and Pro-Apoptotic Evaluation on A549 Human Lung Cancer Cell Line

Populus nigra L. is a plant from Salicaceae family, native in Europe. Many parts of this tree can be used as active ingredients, but the most valuable are the buds. In recent years, a growing number of studies reported their activity in the development of a wide range of pharmacological activities including diabetes, cardiovascular diseases, and cancer. The aim of this study was to determine the phytochemical composition and to evaluate the inorganic elements’ concentration as well as the in vitro antiproliferative and pro-apoptotic potential of a Populus nigra L. buds extract collected from Timișoara (Romania) against A549 human lung cancer cell line. Populus nigra L. bud extract was found to contain twelve different phenolic compounds. The inorganic elements concentrations were below the limit of detection for Co, Pb, and As, whereas Cu = 6.66 µg/g; Cr = 0.79 µg/g; Ni = 3.28 µg/g; Fe = 39.00 µg/g; Zn = 14.84 µg/g; Mn = 0.59 µg/g; Al = 2109.87 µg/g; and Cd = 0.019 µg/g. The extract was tested for the in vitro antiproliferative and pro-apoptotic potential on A549 human lung cancer cell line using different concentrations, namely 10, 25, 50, 75, 100, and 150 μg/mL. Results have shown that poplar bud extract induced a significant decrease of tumor cell viability in a dose-dependent manner with an IC₅₀ = 72.49 μg/mL and blocked the cells in the G0/G1 phase of the cell cycle. Phenomena of early apoptosis (from 1.34 ± 0.33% control cells to 2.68 ± 0.62% at 150 µg/mL) and late apoptosis (from 1.43 ± 0.14% control cells to 5.15 ± 1.02% at 150 µg/mL) were detected by Annexin V-PI double staining. Poplar bud extract can be regarded as a promising candidate for future studies involving lung cancer.