The Anti-Melanoma Effect of Betulinic Acid Functionalized Gold Nanoparticles: A Mechanistic In Vitro Approach

Implementing metallic nanoparticles as research instruments for the transport of therapeutically active compounds remains a fundamentally vital work direction that can still potentially generate novelties in the field of drug formulation development. Gold nanoparticles (GNP) are easily tunable carriers for active phytocompounds like pentacyclic triterpenes. These formulations can boost the bioavailability of a lipophilic structure and, in some instances, can also enhance its therapeutic efficacy. In our work, we proposed a biological in vitro assessment of betulinic acid (BA)-functionalized GNP. BA-GNP were obtained by grafting BA onto previously synthesized citrate-capped GNP through the use of cysteamine as a linker. The nanoformulation was tested in HaCaT human keratinocytes and RPMI-7951 human melanoma cells, revealing selective cytotoxic properties and stronger antiproliferative effects compared to free BA. Further examinations revealed a pro-apoptotic effect, as evidenced by morphological changes in melanoma cells and supported by western blot data showing the downregulation of anti-apoptotic Bcl-2 expression coupled with the upregulation of pro-apoptotic Bax. GNP also significantly inhibited mitochondrial respiration, confirming its mitochondrial-targeted activity.

Semisynthetic Derivatives of Pentacyclic Triterpenes Bearing Heterocyclic Moieties with Therapeutic Potential

Medicinal plants have been used by humans since ancient times for the treatment of various diseases and currently represent the main source of a variety of phytocompounds, such as triterpenes. Pentacyclic triterpenes have been subjected to numerous studies that have revealed various biological activities, such as anticancer, antidiabetic, anti-inflammatory, antimicrobial, and hepatoprotective effects, which can be employed in therapy. However, due to their high lipophilicity, which is considered to exert a significant influence on their bioavailability, their current use is limited. A frequent approach employed to overcome this obstacle is the chemical derivatization of the core structure with different types of moieties including heterocycles, which are considered key elements in medicinal chemistry. The present review aims to summarize the literature published in the last 10 years regarding the derivatives of pentacyclic triterpenes bearing heterocyclic moieties and focuses on the biologically active derivatives as well as their structure-activity relationships. Predominantly, the targeted positions for the derivatization of the triterpene skeleton are C-3 (hydroxyl/oxo group), C-28 (hydroxyl/carboxyl group), and C-30 (allylic group) or the extension of the main scaffold by fusing various heterocycles with the A-ring of the phytocompound. In addition, numerous derivatives also contain linker moieties that connect the triterpenic scaffold with heterocycles; one such linker, the triazole moiety, stands out as a key pharmacophore for its biological effect. All these studies support the hypothesis that triterpenoid conjugates with heterocyclic moieties may represent promising candidates for future clinical trials.

The Role of Cyclodextrins in the Design and Development of Triterpene-Based Therapeutic Agents

Triterpenic compounds stand as a widely investigated class of natural compounds due to their remarkable therapeutic potential. However, their use is currently being hampered by their low solubility and, subsequently, bioavailability. In order to overcome this drawback and increase the therapeutic use of triterpenes, cyclodextrins have been introduced as water solubility enhancers; cyclodextrins are starch derivatives that possess hydrophobic internal cavities that can incorporate lipophilic molecules and exterior surfaces that can be subjected to various derivatizations in order to improve their biological behavior. This review aims to summarize the most recent achievements in terms of triterpene:cyclodextrin inclusion complexes and bioconjugates, emphasizing their practical applications including the development of new isolation and bioproduction protocols, the elucidation of their underlying mechanism of action, the optimization of triterpenes’ therapeutic effects and the development of new topical formulations.

Natural Compounds in Sex Hormone-Dependent Cancers: The Role of Triterpenes as Therapeutic Agents

Sex hormone-dependent cancers currently contribute to the high number of cancer-related deaths worldwide. The study and elucidation of the molecular mechanisms underlying the progression of these tumors was a double-edged sword, leading to the expansion and development of new treatment options, with the cost of triggering more aggressive, therapy resistant relapses. The interaction of androgen, estrogen and progesterone hormones with specific receptors (AR, ER, PR) has emerged as a key player in the development and progression of breast, ovarian, prostate and endometrium cancers. Sex hormone-dependent cancers share a common and rather unique carcinogenesis mechanism involving the active role of endogenous and exogenous sex hormones to maintain high mitotic rates and increased cell proliferation thus increasing the probability of aberrant gene occurrence and accumulation highly correlated with abnormal cell division and the occurrence of malignant phenotypes. Cancer related hormone therapy has evolved, currently being associated with the blockade of other signaling pathways often associated with carcinogenesis and tumor progression in cancers, with promising results. However, despite the established developments, there are still several shortcomings to be addressed. Triterpenes are natural occurring secondary metabolites biosynthesized by various pathways starting from squalene cyclization. Due to their versatile therapeutic potential, including the extensively researched antiproliferative effect, these compounds are most definitely a cornerstone in the research and development of new natural/semisynthetic anticancer therapies. The present work thoroughly describes the ongoing research related to the antitumor activity of triterpenes in sex hormone-dependent cancers. Also, the current review highlights both the biological activity of various triterpenoid compounds and their featured mechanisms of action correlated with important chemical structural features.

Solid Polymeric Nanoparticles of Albendazole: Synthesis, Physico-Chemical Characterization and Biological Activity

Albendazole is a benzimidazole derivative with documented antitumor activity and low toxicity to healthy cells. The major disadvantage in terms of clinical use is its low aqueous solubility which limits its bioavailability. Albendazole was incorporated into stable and homogeneous polyurethane structures with the aim of obtaining an improved drug delivery system model. Spectral and thermal analysis was used to investigate the encapsulation process and confirmed the presence of albendazole inside the nanoparticles. The in vitro anticancer properties of albendazole encapsulated in polyurethane structures versus the un-encapsulated compound were tested on two breast cancer cell lines, MCF-7 and MDA-MB-231, in terms of cellular viability and apoptosis induction. The study showed that the encapsulation process enhanced the antitumor activity of albendazole on the MCF-7 and MDA-MB-23 breast cancer lines. The cytotoxic activity manifested in a concentration-dependent manner and was accompanied by changes in cell morphology and nuclear fragmentation.

Hydro-alcoholic Extracts of Roots and Sprouts of Armoracia rusticana: Assessment of Antioxidant and Cytotoxic Activity

Armoracia rusticana � horseradish is a well-known vegetable used from ancient times and consumed nowadays more for its taste than its pharmacological properties, even though it proved to be a good agent in fighting several health problems. This study focuses on a comparative assessment of several horseradish hydro-alcoholic extracts, obtained from roots and sprouts, respectively, mainly evaluating the antioxidant activity but also a potential cytotoxic effect. The DPPH evaluation revealed that horseradish extracts made from roots or sprouts exhibit a strong antioxidant activity compared to the ascorbic acid used as etalon. The in vitro evaluation established that a significant inhibitory effect on cell viability and morphology of MDA-MB-231 � breast adenocarcinoma cell line was displayed by the hydroalcoholic extracts in a dose-dependent manner.

Gold Nanoparticles as Targeted Delivery Systems and Theranostic Agents in Cancer Therapy

Cancer is still a leading cause of death worldwide, while most chemotherapies induce nonselective toxicity and severe systemic side effects. To address these problems, targeted nanoscience is an emerging field that promises to benefit cancer patients. Gold nanoparticles are nowadays in the spotlight due to their many well-established advantages. Gold nanoparticles are easily synthesizable in various shapes and sizes by a continuously developing set of means, including chemical, physical or eco-friendly biological methods. This review presents gold nanoparticles as versatile therapeutic agents playing many roles, such as targeted delivery systems (anticancer agents, nucleic acids, biological proteins, vaccines), theranostics and agents in photothermal therapy. They have also been outlined to bring great contributions in the bioimaging field such as radiotherapy, magnetic resonance angiography and photoacoustic imaging. Nevertheless, gold nanoparticles are therapeutic agents demonstrating its in vitro anti-angiogenic, anti-proliferative and pro-apoptotic effects on various cell lines, such as human cervix, human breast, human lung, human prostate and murine melanoma cancer cells. In vivo studies have pointed out data regarding the bioaccumulation and cytotoxicity of gold nanoparticles, but it has been emphasized that size, dose, surface charge, sex and especially administration routes are very important variables.

Thyme Leaves Aqueous Extract and its Formulations. A comparative study based on chemical structures and biological activity

The present study was conducted in order to evaluate the biological activity of thyme aqueous extract as compared to the silver nanoparticles obtained on it on four different cancer lines: non-melanoma skin cancer (A431 cell line), melanoma skin cancer (A375cell line), hormone dependent breast cancer (MCF-7 cell line), and non-hormone dependent breast cancer (MDA-MB-231 cell line). Of particular importance in the study of biological activity is the chemical composition. Formulas rich in compounds of classes like those of flavonoids are recognized for their efficacy and important antioxidant effect. The extract tested at various concentrations ranging from 10-1000 �g/mL exhibited a pronounced effect only on MCF-7 cells at the highest concentration tested and regarding the biosynthesized silver nanoparticles, the effect can be noted even at 1 � M also only in the case of MCF-7 cells.

Melanoma Cell Lines Role in Obtaining New Drug Candidates for Combating the Malignant Pathology of the Cutaneous Organ

As prophylactic and therapeutic approaches for melanoma, of great interest and importance are the in vitro studies using cell lines to elucidate several tumoral phenomena. Therefore, the similarities and differences between the different tumor cells must be known and understood in order to obtain a more accurate correlation with processes that occur in vivo. In this study, six cell lines of melanoma, both of mouse and human origin were analyzed from the point of view of cell culture growth, morphology and use in the research of new therapies. In brief, the current paper exhibits a comparison of melanoma cells which can be utilized as a starting point for further in vitro studies and in vivo animal models.

Biostatistical Analysis and Possible Forecasting of Relationship Between Uric Acid and Specific Laboratory Tests in Cases of Gouty Arthritis

Acute gouty arthritis represents an inflammatory response to microcrystals of monosodium urate that precipitate in joint tissues from supersaturated body fluids or are shed from preexisting articular deposits [1]. Gout is a metabolic disease characterized by recurrent episodes of arthritis associated with the presence of monosodium urate crystals in the tissue or synovial fluid during the attack.These forms of crystal-induced arthritis usually affect peripheral joints, including knee, ankle, wrist, and metacarpophalangeal and metatarsophalangeal joints. All of them may be associated with other inflammatory, endocrine diseases [2]. The present study was done to highlight the relationship between increased levels of uric acid and specific laboratory tests in order to possible forecast development of further disease in patients with gouty arthrithis.The present study was done on 34 patients hospitalized in Felix Hospital of Rehabilitation in 2015-2016, with age between 44 and 74, having the main diagnosis of gouty arthritis.We studied the following laboratory tests:urea and other related analysis, like uric acid, creatinine, cholesterol, glutamate pyruvate transaminase and glutamate oxalate transaminase.

Dietary Supplements with Resveratrol, Flavonoids and Phenolic Acids: in-depth HPLC Profiling and Antioxidant Capacity as Quality Markers

Dietary supplements containing natural compounds, including resveratrol, are increasingly used as health improving products. The present study had three objectives, namely: the quantification of resveratrol by HPLC-MS in nine dietary supplements, the qualitative and quantitative assessment of 18 phenolic acids and flavonoids in the same supplements, and finally the measurement of the antioxidant capacity of these products. The content of resveratrol in commercial samples ranged between 22.8 and 104.7 % of the declared amount. The highest number of polyphenols that could be quantified in a dietary supplement was nine. The values obtained for antioxidant capacity suggest that resveratrol supplements containing below 10 mg of the stilbene have, even in the presence of other components, a very low antioxidant capacity which may be insufficient for an attainment of the desired antioxidant status. To our knowledge, this is the first HPLC-analysis cumulating the quantification of resveratrol with that of eighteen other polyphenols in dietary supplements, giving an in-depth overview of their composition and health benefits from the viewpoint of antioxidant capacity.

Evaluation of phenolic profile, antioxidant and anticancer potential of two main representants of Zingiberaceae family against B164A5 murine melanoma cells

BACKGROUND

Curcuma longa Linnaeus and Zingiber officinale Roscoe are two main representatives of Zingiberaceae family studied for a wide range of therapeutic properties, including: antioxidant, anti-inflammatory, anti-angiogenic, antibacterial, analgesic, immunomodulatory, proapoptotic, anti-human immunodeficiency virus properties and anticancer effects. This study was aimed to analyse the ethanolic extracts of Curcuma rhizome (Curcuma longa Linnaeus) and Zingiber rhizome (Zingiber officinale Roscoe) in terms of polyphenols, antioxidant activity and anti-melanoma potential employing the B164A5 murine melanoma cell line.

RESULTS

In order to evaluate the total content of polyphenols we used Folin-Ciocâlteu method. The antioxidant activity of the two ethanolic extracts was determined by DPPH assay, and for the control of antiproliferative effect it was used MTT proliferation assay, DAPI staining and Annexin-FITC-7AAD double staining test. Results showed increased polyphenols amount and antioxidant activity for Curcuma rhizome ethanolic extract. Moreover, 100 μg/ml of ethanolic plant extract from both vegetal products presented in a different manner an antiproliferative, respectively a proapoptotic effect on the selected cell line.

CONCLUSIONS

The study concludes that Curcuma rhizome may be a promising natural source for active compounds against malignant melanoma.

The Hydractinia echinata test-system. III: Structure-toxicity relationship study of some azo-, azo-anilide, and diazonium salt derivatives

Structure-toxicity relationships for a series of 75 azo and azo-anilide dyes and five diazonium salts were developed using Hydractinia echinata (H. echinata) as model species. In addition, based on these relationships, predictions for 58 other azo-dyes were made. The experimental results showed that the measured effectiveness Mlog(1/MRC₅₀) does not depend on the number of azo groups or the ones corresponding to metobolites, but it is influenced by the number of anilide groups, as well as by the substituents’ positions within molecules. The conformational analysis pointed out the intramolecular hydrogen bonds, especially the simple tautomerization of quinoidic (ST_OH) or aminoidic (ST_NH2) type. The effectiveness is strongly influenced by the “push-pull” electronic effect, specific to two hydroxy or amino groups separated by an azo moiety (double alternate tautomery, (DAT), to the –COOH or –SO₃H groups which are located in ortho or para position with respect to the azo group. The levels of the lipophylic/hydrophilic, electronic and steric equilibriums, pointed out by the Mlog(1/MRC₅₀) values, enabled the calculation of their average values Clog(1/MRC₅₀) (“Köln model”), characteristic to one derivative class (class isotoxicity). The azo group reduction and the hydrolysis of the amido/peptidic group are two concurrent enzymatic reactions, which occur with different reaction rates and mechanisms. The products of the partial biodegradation are aromatic amines. No additive or synergic effects are noticed among them.

The synergistic biologic activity of oleanolic and ursolic acids in complex with hydroxypropyl-γ-cyclodextrin

Oleanolic and ursolic acids are natural triterpenic compounds with pentacyclic cholesterol-like structures which gives them very low water solubility, a significant disadvantage in terms of bioavailability. We previously reported the synthesis of inclusion complexes between these acids and cyclodextrins, as well as their in vivo evaluation on chemically induced skin cancer experimental models. In this study the synergistic activity of the acid mixture included inside hydroxypropyl-gamma-cyclodextrin (HPGCD) was monitored using in vitro tests and in vivo skin cancer models. The coefficient of drug interaction (CDI) was used to characterize the interactions as synergism, additivity or antagonism. Our results revealed an increased antitumor activity for the mixture of the two triterpenic acids, both single and in complex with cyclodextrin, thus proving their complementary biologic activities.

Fosinopril-cyclodextrin inclusion complexes: phase solubility and physicochemical analysis

Fosinopril is one of the most hydrophobic substances among the angiotensin-converting enzyme inhibitors, exhibiting low water solubility and poor bioavailability following oral administration. Inclusion complexes between the drug substance and cyclodextrins (CDs) were obtained in order to improve its solubility. The purpose of this study was to investigate the guest-host interaction of fosinopril sodium (FOS) with beta-cyclodextrin (beta-CD) and its derivative, randomly methylated beta-cyclodextrin (RAMEB) in solution by phase solubility diagrams (PSD) and in solid state by using thermal analysis, powder X-ray diffractometry (PXRD) and Fourier transform infrared spectroscopy (FTIR). The phase solubility analysis indicated that the solubility of FOS in simulated gastric fluid was increased in the presence of CDs and revealed for RAMEB an A(L)-type diagram, suggesting the formation of a 1:1 inclusion complex, and for beta-CD a B(s)-type phase diagram. The estimated apparent stability constant (K1:1), according to the Higuchi and Connors method, is 3209.99 M(-1) and 1770.34 M(-1) for RAMEB and beta-CD complexes respectively. The binary systems FOS/CDs were prepared using the kneading method in the molar ratio 1:1. The PXRD patterns and the thermograms indicated a drug amorphization process, higher for FOS/RAMEB binary system and the FTIR analysis suggested that the ester group of FOS is probably enclosed in the CD's cavity. The results of this study confirm the formation of inclusion complexes both in solution and in solid state and suggest that the complexes formation between FOS and CDs could improve the bioavailability of the drug due to the enhancing absorption expected from increased drug solubility.

Fluconazole-Beta-Cyclodextrin Inclusion Complexes. Preparation and Characterization in Solid State

Fluconazole is a bistriazole derivative with antifungal activity. The major weak points of fluconazole are the development of antifungal resistance and low water solubility, which impairs its administration. Binary systems between fluconazole and beta-cyclodextrin were prepared with the aim of obtaining a new delivery system that will overcome the limitations of fluconazole administration. Using two feasible laboratory methods, inclusion complexes between fluconazole and beta-cyclodextrin were obtained. Thermal and spectroscopic analyses were used to characterize the inclusion complexes.