Anti-inflammatory and modulatory effects of steroidal saponins and sapogenins on cytokines: A review of pre-clinical research.

BACKGROUND: Saponins are glycosides which, after acid hydrolysis, liberate sugar(s) and an aglycone (sapogenin) which can be triterpenoid or steroidal in nature. Steroidal saponins and sapogenins have attracted significant attention as important natural anti-inflammatory compounds capable of acting on the activity of several inflammatory cytokines in various inflammatory models. PURPOSE: The aim of this review is to collect preclinical in vivo studies on the anti-inflammatory activity of steroidal saponins through the modulation of inflammatory cytokines. STUDY DESIGN AND METHODS: This review was carried out through a specialized search in three databases, that were accessed between September and October, 2021, and the publication period of the articles was not limited. Information about the name of the steroidal saponins, the animals used, the dose and route of administration, the model of pain or inflammation used, the tissue and experimental method used in the measurement of the cytokines, and the results observed on the levels of cytokines was retrieved. RESULTS: Forty-five (45) articles met the inclusion criteria, involving the saponins cantalasaponin-1, α-chaconine, dioscin, DT-13, lycoperoside H, protodioscin, α-solanine, timosaponin AIII and BII, trillin, and the sapogenins diosgenin, hecogenin, and ruscogenin. The surveys were carried out in seven different countries and only articles between 2007 and 2021 were found. The studies included in the review showed that the saponins and sapogenins were anti-inflammatory, antinociceptive and antioxidant and they modulate inflammatory cytokines mainly through the Nf-κB, TLR4 and MAPKs pathways. CONCLUSION: Steroidal saponins and sapogenins are promising compounds in handling of pain and inflammation for the development of natural product-derived drugs. However, it is necessary to increase the methodological quality of preclinical studies, mainly blinding and sample size calculation.

Anticancer activity of limonene: A systematic review of target signaling pathways.

Limonene (LIM) is a monoterpene, which is abundant in essential oils of Citrus fruits peels (Rutaceae). More recently, LIM, as a potential natural anticancer compound, has attracted major attention and exerted a chemopreventive activity, stimulating the detoxification of carcinogenic compounds and limiting tumor growth and angiogenesis in various cancer models. Twenty-six (26) articles were selected based on previously established criteria. Anticancer activity of LIM was related to the inhibition of tumor initiation, growth, and angiogenesis and the induction of cancer cells apoptosis. LIM was able to increase Bax expression, release cytochrome c, and activate the caspase pathway. In addition, LIM increased the expression of p53 and decreased the activity of Ras/Raf/MEK/ERK and PI3K/Akt pathways. LIM also decreased the expression of VEGF and increased the activities of the Man-6-P / IGF2R and TGF-ßIIR receptors. These results highlight LIM as an abundant natural molecule with low toxicity and pleiotropic pharmacological activity in cancer cells, targeting various cell-signaling pathways critically involved in the initiation, growth, and chemoresistance of cancer cells.

Physicochemical Characterization and Antinociceptive Effect of ß-cyclodextrin/Lippia pedunculosa Essential Oil in Mice.

BACKGROUND: Some research studies have shown that Lippia pedunculosa essential oil (EOLP) has interesting biological activities. However, its low water solubility is the main challenge to achieve its therapeutic potential. In this context, Cyclodextrins (CDs) have been widely used in order to overcome this problem due to your capability to improve the physicochemical properties of drugs. OBJECTIVE: In this perspective, the main goal of this study was to investigate how the improvement of the physicochemical properties of inclusion complexes (EOLP and ß-CD) enhance the antinociceptive effect in mice. METHODS: To achieve that, we prepared samples by Physical Mixture (PM), Paste Complexation (PC) and Slurry Complexation (SC) methods, followed by their physicochemical characterization. In addition, it was evaluated if the use of ß-CD enhances the antinociceptive effect of EOLP in mice. RESULTS: The analysis showed that rotundifolone (72.02%) was the major compound of EOLP and we found out based on DSC results that ß-CD protected it from oxidation. In addition, TG techniques demonstrated that the best inclusion methods were PC and SC, due to their greater weight loss (10.8 and 11.6%, respectively) in the second stage (171-312°C), indicating that more complexed oil was released at the higher temperature than oil free. Other characteristics, such as changes in the typical crystalline form, and reduced particle size were observed by SEM and laser diffraction, respectively. The SC was the most effective complexation method, once the presence of rotundifolone was detected by FTIR. Based on that, SC method was used in all mice tests. In this regard, the number of paw licks was reduced for both compounds (all doses), but EOLP was more effective in reducing the nociceptive behavior. CONCLUSION: Therefore, CDs seem not to be a good tool to enhance the pharmacological properties of EOs rich in peroxide compounds such as rotundifolone.

Palladium-benzodiazepine derivatives as promising metallodrugs for the development of antiepileptic therapies.

We synthesized two organometallic diazepam-palladium(II) derivatives by C-H activation of diazepam (DZP) with palladium salts, i.e., PdCl2 and Pd(OAc)2 (OAc=acetate). Both compounds obtained are air stable and were isolated in good yields. The anticonvulsant potential of the complexes, labeled [(DZP)PdCl]2 and [(DZP)PdOAc]2, was evaluated through two animal models: pentylenetetrazole (PTZ)- and picrotoxin (PTX)-induced convulsions. The organometallic DZP-palladium(II) acetate complex, [(DZP)PdOAc]2, significantly increased (p<0.01 or p<0.001) latencies and protected the animals against convulsions induced by PTZ and PTX, while the analogous chloro derivative, [(DZP)PdCl]2, was effective (p<0.01) only in the PTZ model. These effects appear to be mediated through the GABAergic system. The possible mechanism of action of the DZP-palladium(II) complexes was also confirmed with the use of flumazenil (FLU), a GABAA-benzodiazepine receptor complex site antagonist. Herein, we present the first report of the anticonvulsant properties of organometallic DZP-palladium(II) complexes as well as evidence that these compounds may play an important role in the study of new drugs to treat patients with epilepsy.