Due to their physical-chemical characteristics, NPs have incredible pharmacokinetic properties and can be used as carriers of drugs or molecules for a specific purpose (antibiotics, antibodies, or organic molecules) [3; 4]. However, nanoparticle stability remains challenging, due to the electrostatic attraction in naked NPs, which tend to agglomerate. PdNPs superficial modification to avoid agglomeration has been reported [5; 6]. Molecules as glucosamine [7], sodium dodecyl sulfate (SDS) [8; 9], tween [10], and PEG [5; 6; 11] have been used to superficially modified the NPs. The mechanisms reported to avoid agglomeration were the addition of negative charges to NP surfaces, which increases the repulsion forces inhibiting the union of several NPs [12], and molecule additions to surface NPs generate a steric stabilization [13]. Palladium nanoparticles (PdNPs) have been added to carbon nanofibers using SDS as a surfactant. The ends of SDS bind to palladium ions and the fast ion reduction suppresses the agglomeration of PdNPs [14]. Palladium is a platinum group element (PEG). In this group, it is possible to find the platinum derivate cisplatin, a metal-based drug used in cancer therapy. Nevertheless, cancer therapy with platinum showed high secondary effects, and many cancer types have developed resistance to it. In this respect, the palladium complex derivate and PdNPs show promising antitumor activity. A few PdNP antitumor effects have been reported. PdNPs were used in a transferrin platform, loaded with paclitaxel, and used to study inhibitory effects in an MCF-7 cellular line. The results showed that a combination of PdNP and paclitaxel in polymeric nanoparticles increased cytotoxicity more than PdNPs or paclitaxel alone. The use of lasers increased cytotoxicity activity [15]. [PERSON] et al. [16] synthesized PdNP coatings with chitosan, which showed a 20% inhibition in MDA-MB-231 cells when irradiated with infrared light. Moreover, PdNPs have been used for bacterial [17] or fungal inhibition [18], showing effective inhibition. Different PdNP synthesis methods have been validated. The use of such plant extracts as _Ananus comosus_[19], _Spiurulina platensis_[20], and _Sapium sebjferum_[21], among other reducing agents, have shown that metabolites from natural sources can be used as reducing and stabilizing agents. The presence of proteins and phytochemicals such as steroids, flavonoids, alkaloids, and other molecules in these extracts favors metal reduction and nanoparticle stability [22; 23]. The activity shown in these nanoparticles can be mediated by the functional groups adhering to the PdNP surface. Among the molecules adhering to the NP superfices are flavonoids. Flavonoids are molecules that show important antioxidant (activating enzymes involved in oxidative stress response), antitumor, and anti-inflammatory activity. Anti-inflammatory activity inhibits cytokine production, among other activities [24]. It has been reported that this flavonoid affects cell proliferation in different cancer cell line types [25; 26]. One of the most studied flavonoids is quercetin due to its antioxidant, anti-inflammatory, and antiproliferative effects [27]. Quercetin is the most abundant flavonoid and is ubiquitously distributed in plants. Dietary sources of quercetin include apples, strawberries, onion, tea, and wine [28]. Moreover, the role of quercetin in iron regulation through inhibiting lipid oxidation and reducing iron valence is well described [29]. It has been stated that quercetin inhibits cell proliferation and triggers apoptosis by deregulating the genes Bax and Bcl-2, and this generates an arrested cell cycle at G2/M phases in glioblastoma U251 cells [30]. It was reported that in metastatic ovarian cancer cells, quercetin increases the level of proapoptotic molecules such as cytochrome c, Bid, Bad, Bax, caspase-3, and caspase-9, indicating the mitochondrial-mediated apoptotic pathway [31].