Pancreatic cancer is the eighth leading cause of cancer death worldwide. For this reason, the development of more effective therapies is a major concern for the scientific community. Accordingly, plants belonging to Plectranthus genus and their isolated compounds, such as Parvifloron D, were found to have cytotoxic and antiproliferative activities. However, Parvifloron D is a very low water-soluble compound. Thus, nanotechnology can be a promising delivery system to enhance drug solubility and targeted delivery. The extraction of Parvifloron D from P. ecklonii was optimized through an acetone ultrasound-assisted method and isolated by Flash-Dry Column Chromatography. Then, its antiproliferative effect was selectivity evaluated against different cell lines (IC₅₀ of 0.15 ± 0.05 μM, 11.9 ± 0.7 μM, 21.6 ± 0.5, 34.3 ± 4.1 μM, 35.1 ± 2.2 μM and 32.1 ± 4.3 μM for BxPC3, PANC-1, Ins1-E, MCF-7, HaCat and Caco-2, respectively). To obtain an optimized stable Parvifloron D pharmaceutical dosage form, albumin nanoparticles were produced through a desolvation method (yield of encapsulation of 91.2%) and characterized in terms of size (165 nm; PI 0.11), zeta potential (−7.88 mV) and morphology. In conclusion, Parvifloron D can be efficiently obtained from P. ecklonii and it has shown selective cytotoxicity to pancreatic cell lines. Parvifloron D nanoencapsulation can be considered as a possible efficient alternative approach in the treatment of pancreatic cancer.

Pancreatic cancer is one of the most lethal cancers, with an extremely poor prognosis. The development of more effective therapies is thus imperative. Natural origin compounds isolated from Plectranthus genus, such as parvifloron D (PvD), have cytotoxic and antiproliferative activity against human tumour cells. However, PvD is a very low water-soluble compound, being nanotechnology a promising alternative strategy to solve this problem. Therefore, the aim of this study was to optimize a nanosystem for preferential delivery of PvD to pancreatic tumour cells. Albumin nanoparticles (BSA NPs) were produced through a desolvation method. Glucose cross-linking and bioactive functionalization profiles of BSA platform were elucidated and analysed using static lattice atomistic simulations in vacuum. Using the optimized methodology, PvD was encapsulated (yield higher than 80%) while NPs were characterized in terms of size (100–400 nm) and morphology. Importantly, to achieve a preferential targeting to pancreatic cancer cells, erlotinib and cetuximab were attached to the PvD-loaded nanoparticle surface, and their antiproliferative effects were evaluated in BxPC3 and Panc-1 cell lines. Erlotinib conjugated NPs presented the highest antiproliferative effect toward pancreatic tumour cells. Accordingly, cell cycle analysis of the BxPC3 cell line showed marked accumulation of tumour cells in G1-phase and cell cycle arrest promoted by NPs. As a result, erlotinib conjugated PvD-loaded BSA NPs must be considered a suitable and promising carrier to deliver PvD at the tumour site, improving the treatment of pancreatic cancer.

The Plectranthus genus is commonly used in traditional medicine due to its potential to treat several illnesses, including bacterial infections and cancer. As such, aiming to screen the antibacterial and cytotoxic activities of extracts, sixteen selected Plectranthus species with medicinal potential were studied. In total, 31 extracts obtained from 16 Plectranthus spp. were tested for their antibacterial and anticancer properties. Well diffusion method was used for preliminary antibacterial screening. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the five most active acetonic extracts (P. aliciae, P. japonicus, P. madagascariensis var. “Lynne”, P. stylesii, and P. strigosus) were determined. After preliminary toxicity evaluation on Artemia salina L., their cytotoxic properties were assessed on three human cancer cell lines (HCT116, MCF-7, and H460). These were also selected for mechanism of resistance studies (on NCI-H460/R and DLD1-TxR cells). An identified compound—parvifloron D—was tested in a pair of sensitive and MDR-Multidrug resistance cancer cells (NCI-H460 and NCI-H460/R) and in normal bronchial fibroblasts MRC-5. The chemical composition of the most active extract was studied through high performance liquid chromatography with a diode array detector (HPLC-DAD/UV) and liquid chromatography–mass spectrometry (LC–MS). Overall, P. strigosus acetonic extract showed the strongest antimicrobial and cytotoxic potential that could be explained by the presence of parvifloron D, a highly cytotoxic diterpene. This study provides valuable information on the use of the Plectranthus genus as a source of bioactive compounds, namely P. strigosus with the potential active ingredient the parvifloron D.