Phytochemistry and pharmacology of the genus Drypetes: A review

Valorization of the essential oil from Drypetes gossweileri S. Moore (Putranjivaceae): in vitro, in vivo, and in silico nematicidal activity

The chemical composition, insect antifeedant, in vtro/in vivo nematicidal activity, phytotoxicity, and in silico nematicidal activity of the essential oil (EO) of the African medicinal plant Drypetes gossweileri were studied. Chemical analysis using GC/MS indicated that benzyl isothiocyanate (96.23%) was the major compound, followed by benzyl cyanide (1.38%). The biocidal effects of this oil were tested against insect pests and root-knot nematodes. All the insect species tested were significantly affected by the oil according to their feeding adaptations (Spodoptera littoralis and Myzus persicae were less affected than Rhopalosiphum padi) with efficient doses (EC50) of 29.4 8.3 μg/cm2, 14.744 8.3 μg/cm2, and 8.3 μg/cm2, respectively. The oil was highly effective against juveniles J2 of the nematode Meloidogyne javanica, with LC50-LC90 values of 0.007 mg/mL-0.0113 mg/mL. D. gossweileri EO at minimum lethal concentrations (MLC) and below strongly inhibited egg hatching in vitro, whereas soil treatment caused a strong suppression of nematode population, infection frequency, and multiplication rate. The EO inhibited ryegrass (Lolium perenne) germination at 0.4 mg/mL, while at 0.1 mg/mL, its effects on germination, root and leaf growth were moderate (32.4%, 8.4%, and 18.3%, respectively). The tomato (Solanum lycopersicum) germination was not affected by the EO, but the root growth was reduced (56% at 0.1 mg/mL) at a dose 10 times higher than the LD50 calculated for M. javanica J2 mortality. Molecular docking of the nematicidal effects of the oil using PyRx revealed a strong interaction between potassium chloride transporting KCC3 (PDB ID: 7D90) and benzyl cyanide at a distance of 2.20 A° with GLN C:350, followed by benzyl isothiocyanate at a distance of 2.78 A° with ARG B:294. The in vivo nematicidal effects of D. gossweileri EO on M. javanica penetration and reproduction in tomato roots further support the potential of this EO as a nematicidal agent with insect antifeedant effects, which could be used by local farmers for crop protection.

Beyond the Bark: An Overview of the Chemistry and Biological Activities of Selected Bark Essential Oils

Essential oils have been used by indigenous peoples for medicinal purposes since ancient times. Their easy availability played an important role. Even today, essential oils are used in various fields—be it as aromatic substances in the food industry, as an aid in antibiotic therapy, in aromatherapy, in various household products or in cosmetics. The benefits they bring to the body and health are proven by many sources. Due to their complex composition, they offer properties that will be used more and more in the future. Synergistic effects of various components in an essential oil are also part of the reason for their effectiveness. Infectious diseases will always recur, so it is important to find active ingredients for different therapies or new research approaches. Essential oils extracted from the bark of trees have not been researched as extensively as from other plant components. Therefore, this review will focus on bringing together previous research on selected bark oils to provide an overview of barks that are economically, medicinally, and ethnopharmaceutically relevant. The bark oils described are Cinnamomum verum, Cedrelopsis grevei, Drypetes gossweileri, Cryptocarya massoy, Vanillosmopsis arborea and Cedrus deodara. Literature from various databases, such as Scifinder, Scopus, Google Scholar, and PubMed, among others, were used.

Drug Delivery of Natural Products Through Nanocarriers for Effective Breast Cancer Therapy: A Comprehensive Review of Literature

Despite recent advances in the diagnosis and treatment of breast cancer (BC), it remains a global health issue affecting millions of women annually. Poor prognosis in BC patients is often linked to drug resistance as well as the lack of effective therapeutic options for metastatic and triple-negative BC. In response to these unmet needs, extensive research efforts have been devoted to exploring the anti-BC potentials of natural products owing to their multi-target mechanisms of action and good safety profiles. Various medicinal plant extracts/essential oils and natural bioactive compounds have demonstrated anti-cancer activities in preclinical BC models. Despite the promising preclinical results, however, the clinical translation of natural products has often been hindered by their poor stability, aqueous solubility and bioavailability. There have been attempts to overcome these limitations, particularly via the use of nano-based drug delivery systems (NDDSs). This review highlights the tumour targeting mechanisms of NDDSs, the advantages and disadvantages of the major classes of NDDSs and their current clinical status in BC treatment. Besides, it also discusses the proposed anti-BC mechanisms and nanoformulations of nine medicinal plants' extracts/essential oils and nine natural bioactive compounds; selected via the screening of various scientific databases, including PubMed, Scopus and Google Scholar, based on the following keywords: "Natural Product AND Nanoparticle AND Breast Cancer". Overall, these nanoformulations exhibit improved anti-cancer efficacy against preclinical BC models, with some demonstrating biocompatibility with normal cell lines and mouse models. Further clinical studies are, however, warranted to ascertain their efficacy and biocompatibility in humans.

Bioassay-Guided Isolation of Nigracin, Responsible for the Tissue Repair Properties of Drypetes Klainei Stem Bark

Drypetes klainei Pierre ex Pax is used in Cameroon by Baka people in the wound healing process and for the treatment of burns. In a previous paper we demonstrated the ability of both water (WE) and defatted methanol (DME) extracts to accelerate scratch wound closure in fibroblast cultures, thus validating the traditional use of D. klainey stem bark in the treatment of skin lesions. In this work we carried out a bioassay-guided fractionation of the most active DME, which exhibited in vitro efficacy in accelerating wound healing process, in order to isolate and identify the compound/s responsible for the assessed biological activity. HPLC was used for the metabolite profiling of DME and fractions (analytical) and for the isolation of the bioactive compound (semi-preparative). MS analyses and NMR spectroscopy were used for identifying the isolated compound. The abilities of treatments in accelerating wound healing were studied on murine fibroblasts in terms of cell viability and cell migration (scratch wound-healing assay). The results obtained allowed to unambiguously identify the isolated bioactive compound as nigracin, a known phenolic glycoside firstly isolated and characterized from bark and leaves of Populus nigra in 1967. However, this is the first time that nigracin is identified in the Drypetes genus and that a wound healing activity is demonstrated for this molecule. Specifically, we demonstrated that nigracin significantly stimulates fibroblast growth and improves cell motility and wound closure of fibroblast monolayer in a dose-dependent manner, without any toxicity at the concentrations tested, and is still active at very low doses. This makes the molecule particularly attractive as a possible candidate for developing new therapeutic options for wound care.

Selaginella uncinata flavonoids ameliorated ovalbumin-induced airway inflammation in a rat model of asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Selaginella uncinata (Desv.) Spring, known as "Cuiyuncao", is a perennial herb widely distributed in the Southeast Asian countries. In the folk medicine, the local minority commonly use it to treat cough and asthma for centuries.

AIM OF THE STUDY

This study was carried out to investigate the protective mechanisms of total flavonoids from S. uncinata (SUF) on airway hyperresponsiveness, cytokine release and bitter taste receptors (T2Rs) signaling with emphasis on inflammatory responses in a rat model of ovalbumin (OVA)-induced asthma.

MATERIALS AND METHODS

Rats were sensitized and challenged with OVA to induce typical asthmatic reactions. Pathological changes of lung tissue were examined by HE staining. The serum levels of T cell-associated cytokines (IFN-γ, IL-4, IL-5 and IL-13), total IgE and OVA-specific IgE were determined by enzyme-linked immunosorbent assay (ELISA). Gene expressions of T2R10, IP3R1 and Orai1 in lung tissue were assayed by fluorescence quantitative real-time polymerase chain reaction (FQ-PCR) while protein expressions of NFAT1 and c-Myc were assayed by western blot analysis. The activation of SUF was investigated on tansgentic T2R10-GFP HEK293 cells.

RESULTS

SUF treatment attenuated airway hyperresponsiveness and goblet cell hyperplasia compared with OVA-challenged asthmatic rats. The serum levels of IL-4, IL-5 and IL-13 as well as total and OVA-specific IgE were decreased while serum IFN-γ was increased in SUF-treated rats. SUF treatment significantly up-regulated T2R10 gene expression, down-regulated IP3R1 and Orai1 gene expression. SUF further suppressed eotaxin, NFAT1 and c-Myc protein expression in lung tissues of OVA-challenged rats.

CONCLUSIONS

These results imply that SUF exerts anti-inflammatory function through the T2R10/IP3R1/NFAT1 dependent signaling pathway, and may warrant further evaluation as a possible agent for the treatment of asthma.