PLGA Nanoparticles Containing Natural Flavanones for Ocular Inflammation.

Flavanones are natural compounds that display anti-inflammatory activity. The aim of this work was to prepare PLGA nanoparticles (NPs) containing natural flavanones I ((2S)-5,7-dihydroxy-6-methyl-8-(3-methyl-2-buten-1-il)-2-phenyl-2,3-dihydro-4H-1-Benzopyran-4-one) and II (2S)-5,7-dihydroxy-2-(4'-methoxyphenyl)-6-methyl-8-(3-methyl-2-buten-1-yl)-2,3-dihydro-4H-1-Benzopyran-4-one) (NP I and NP II, respectively) so as to evaluate their potential for topical anti-inflammatory ocular therapy. An in silico study was carried out using the Molinspiration® and PASS Online web platforms before evaluating the in vitro release study and the ex vivo porcine cornea and sclera permeation. The HPLC analytical method was also established and validated. Finally, the in vitro anti-inflammatory efficacy of NPs was studied in the HCE-2 model. The flavanones I and II could be released following a kinetic hyperbolic model. Neither of the two NPs was able to permeate through the tissues. NP I and NP II were found to be respectful of any changes in the tissues' morphology, as evidenced by histological studies. In HCE-2 cells, NP I and NP II were not cytotoxic at concentrations up to 25 µM. NP I showed higher anti-inflammatory activity than NP II, being able to significantly reduce IL-8 production in LPS-treated HCE-2 cells. In summary, ocular treatment with NP I and NP II could be used as a promising therapy for the inhibition of ocular inflammation.

Cytotoxic Activity of Wild Plant and Callus Extracts of Ageratina pichinchensis and 2,3-Dihydrobenzofuran Isolated from a Callus Culture.

Ageratina pichinchensis (Kunth) R.M. King & H. Rob. belongs to the Asteraceae family and is a plant native to Mexico to which several biological properties are attributed. In this study, the cytotoxic effect of four extracts from the wild plants and two extracts from A. pichinchensis callus culture were evaluated against carcinogenic cell lines including prostate carcinoma, cervical cancer, hepatocellular carcinoma, hepatoma human, lung cancer, and cellular keratinocytes. The extracts were obtained with ethyl acetate and methanol using both leaves and stems or the callus. Only the ethyl acetate extract of the callus culture influenced the cervical cancer cell line (HeLa) with an IC50 of 94.79 ± 2.0 µg/mL. From the ethyl acetate callus extract, 2,3-dihydrobenzofuran was isolated and purified and also evaluated against cancer cells. The cytotoxic evaluation of this compound showed a significant effect against the HeLa cell line with an IC50 of 23.86 ± 2.5 µg/mL. Our results contribute to the development of biotechnological alternatives and extraction processes to produce compounds with possible potential against certain types of human cancer.

In Vitro Approaches to Explore the Anticancer Potential of One Natural Flavanone and Four Derivatives Loaded in Biopolymeric Nanoparticles for Application in Topical Delivery Treatments.

The increasing number of skin cancer cases worldwide and the adverse side effects of current treatments have led to the search for new anticancer agents. In this present work, the anticancer potential of the natural flavanone 1, extracted from Eysenhardtia platycarpa, and four flavanone derivatives 1a-d obtained by different reactions from 1 was investigated by an in silico study and through cytotoxicity assays in melanoma (M21), cervical cancer (HeLa) cell lines and in a non-tumor cell line (HEK-293). The free compounds and compounds loaded in biopolymeric nanoparticles (PLGA NPs 1, 1a-d) were assayed. A structure-activity study (SAR) was performed to establish the main physicochemical characteristics that most contribute to cytotoxicity. Finally, ex vivo permeation studies were performed to assess the suitability of the flavanones for topical administration. Results revealed that most of the studied flavanones and their respective PLGA NPs inhibited cell growth depending on the concentration; 1b should be highlighted. The descriptors of the energetic factor were those that played a more important role in cellular activity. PLGA NPs demonstrated their ability to penetrate (Qp of 17.84-118.29 µg) and be retained (Qr of 0.01-1.44 g/gskin/cm2) in the skin and to exert their action for longer. The results of the study suggest that flavanones could offer many opportunities as a future anticancer topical adjuvant treatment.

Screening Anti-Inflammatory Effects of Flavanones Solutions.

There are a large number of remedies in traditional medicine focused on relieving pain and inflammation. Flavanones have been a potential source in the search for leading compounds and biologically active components, and they have been the focus of much research and development in recent years. Eysenhardtia platycarpa is used in traditional medicine for the treatment of kidney diseases, bladder infections, and diabetes mellitus. Many compounds have been isolated from this plant, such as flavones, flavanones, phenolic compounds, triterpenoid acids, chalcones, sugars, and fatty acids, among others. In this paper, natural flavanone 1 (extracted from Eysenhardtia platycarpa) as lead compound and flavanones 1a-1d as its structural analogues were screened for anti-inflammatory activity using Molinspiration® and PASS Online in a computational study. The hydro alcoholic solutions (FS) of flavanones 1, 1a-1d (FS1, FS1a-FS1d) were also assayed to investigate their in vivo anti-inflammatory cutaneous effect using two experimental models, a rat ear edema induced by arachidonic acid (AA) and a mouse ear edema induced by 12-O-tetradecanoylphorbol acetate (TPA). Histological studies and analysis of pro-inflammatory cytokines TNF-α, IL-1ß, and IL-6 were also assessed in AA-inflamed rat ear tissue. The results showed that the flavanone hydro alcoholic solutions (FS) caused edema inhibition in both evaluated models. This study suggests that the evaluated flavanones will be effective when used in the future in skin pathologies with inflammation, with the results showing 1b and 1d to be the best.

Biopharmaceutic study and in vivo efficacy of natural and derivatives flavanones formulations.

Aim: The development and characterization of nanostructured flavanone formulations (FF) of 1 extracted from Eysenhardtia platycarpa and 1a, 1b, 1c and 1d derivatives by structural modification of 1 as anti-inflammatory candidates for topical treatment of local inflammation. Materials & methods: The FF were physicochemical characterized and the behavior release, skin permeation and, in vivo anti-inflammatory efficacy in the rat model were studied. Results: The FF revealed sustained drug release and showed slow drug penetration in human skin. The FF reduced inflammation in comparison with the standard formulation. Conclusion: The FF could be effective systems for the delivery and controlled release of flavanones on the skin, and the chemical modification of lead molecule 1 improved the efficacy.

Development and characterization of two nano-structured systems for topical application of flavanones isolated from Eysenhardtia platycarpa.

Many of the inflammatory diseases are becoming common in ageing society throughout the world. The clinically used anti-inflammatory drugs suffer from the disadvantage of side effects. Alternative to these drugs are natural products, since ancient times traditional medicines are being used for the treatment of inflammation. In the present study, four flavanones isolated from Eysenhardtia platycarpa leaves with a potent pharmacological activity were formulated in effective drug delivery systems: nanoemulsion and polymeric nanoparticles for topical use as novel anti-inflammatory topical formulations. Nanoemulsion system exhibited droplet sizes less than 70 nm and polymeric nanoparticles with a size of 156-202 nm possessed zeta potential values less than -25 mV that provided good stability and obtained high entrapment efficiency (78-90%). In vitro release and ex vivo permeation studies were performed on Franz-type diffusion cells and quantified by high performance liquid chromatography (HPLC), all formulations showed steady state release profiles over time and steady increase of flavanones in the skin permeation test. The anti-inflammatory activity, tested by TPA (12-O-tetradecanoylphorbol-13-acetate), induced oedema in mice ear suggesting that prenylated flavanones improve significantly their anti-inflammatory activity when are vehiculized in nanosized systems. Our results suggested that 5-hydroxy-7-methoxy-6-prenyl flavanone loaded nanoemulsion and polymeric nanoparticle could be proposed as potential topical anti-inflammatory formulations with the best properties for the treatment of inflammatory disorders.

Anti-inflammatory, antioxidant and cytotoxicity activities of methanolic extract and prenylated flavanones isolated from leaves of Eysehardtia platycarpa.

From the methanolic extract of Eysenhardtia platycarpa (leaves), were isolated the prenylated flavanones: 5,7-dihydroxy-6-methyl-8-prenylflavanone (1), 5,7-dihydroxy-6-methyl-8-prenyl-4'-methoxy-flavanone (2), 5,7-dihydroxy-6-prenylflavanone (3), 5-dihydroxy-7-methoxy-6-prenylflavanone (4), 5,7-dihydroxy-8-prenyl-4'-methoxy-flavanone (5). Methanolic extract of E. platycarpa (leaves) and flavanones (5), (2) and (3) showed anti-inflammatory activity according to tested quantities. In addition, flavanone (5) revealed the best percentage reduction of free radical DPPH. Finally, after cytotoxic activity study, the methanolic extract from E. platycarpa leaves and flavanone (4) exhibited promising cytotoxic activity on brine shrimp.

Skin permeation of cacalol, cacalone and 6-epi-cacalone sesquiterpenes from a nanoemulsion.

The objective of the present study was to investigate the transdermal permeation of cacalol (1) and a mixture of cacalone (2) and 6-epi-cacalone (3) in comparison with diclofenac acid (4) delivered from the same characterized nanoemulsion using Franz diffusion cells (formulae I, II and III). Results show that de Kp, J, Q24, PI and P2 were higher for the acid diclofenac nanoemulsion than for the natural products nanoemulsions. As for the differences between the formulations I and II, with the natural products, Q24, the quantity extracted from skin and P2 were higher in the mixture of 2 and 3 nanoemulsion compared with the corresponding nanoemulsion of 1. In conclusion, the low permeability of the natural products nanoemulsions in comparison with that of diclofenac acid has the potential for development for drugs with local and systemic applications, respectively.