Chemical Constituents of the Essential Oil from Ecuadorian Endemic Species Croton ferrugineus and Its Antimicrobial, Antioxidant and α-Glucosidase Inhibitory Activity

Croton ferrugineus Kunth is an endemic species of Ecuador used in traditional medicine both for wound healing and as an antiseptic. In this study, fresh Croton ferrugineus leaves were collected and subjected to hydrodistillation for extraction of the essential oil. The chemical composition of the essential oil was determined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against three Gram-positive bacteria, one Gram-negative bacterium and one dermatophyte fungus. The radical scavenging properties of the essential oil was evaluated by means of DPPH and ABTS assays. The chemical analysis allowed us to identify thirty-five compounds representing more than 99.95% of the total composition. Aliphatic sesquiterpene hydrocarbon trans-caryophyllene was the main constituent with 20.47 ± 1.25%. Other main compounds were myrcene (11.47 ± 1.56%), β-phellandrene (10.55 ± 0.02%), germacrene D (7.60 ± 0.60%), and α-humulene (5.49 ± 0.38%). The essential oil from Croton ferrugineus presented moderate activity against Candida albicans (ATCC 10231) with an MIC of 1000 μg/mL, a scavenging capacity SC₅₀ of 901 ± 20 µg/mL with the ABTS method, and very strong antiglucosidase activity with an IC₅₀ of 146 ± 20 µg/mL.

Serum and colon metabolomics study reveals the anti-ulcerative colitis effect of Croton crassifolius Geisel

BACKGROUND

Croton crassifolius Geisel (CCG, also known as Ji-Gu-Xiang in Traditional Chinese Medicine), is traditionally prescribed for the therapy of rheumatic arthritis and gastrointestinal ulcer. However, the effect of CCG on ulcerative colitis (UC) has not been investigated.

PURPOSE

To explore the therapeutic potential and underlying mechanism of CCG extract against UC by colonic and serum metabolomics.

METHODS

In order to standardize the CCG extract, UPLC-QTOF-MS was used for quantitative and qualitative analysis of the representative terpenoids. C57BL/6J mice were divided into control, Dextran Sulfate Sodium (DSS), mesalazine (100 mg•kg^-1), CCG extract (150 and 600 mg•kg^-1) groups. The mice were provided 3% DSS dissolved in distilled water ad libitum for 7 days except control group. Weight change, disease activity index (DAI), colon lengths and expression of inflammatory mediators iNOS and COX-2 in colonic tissue were determined. Serum and colon metabolomics using UPLC-QTOF-MS technology coupled with multivariate data analysis were performed to reveal the underlying mechanism.

RESULTS

Thirty-five terpenoids in CCG were identified by fingerprint, in which ten representative terpenes were quantified. CCG could relieve the weight loss, the degree of bloody stool and ulcer of colon, as well as significantly lowering the expression level of iNOS and COX-2. Metabolomics analysis showed that 25 biomarkers were obviously interfered by CCG treatment and 16 of them were highly correlated with the efficacy of CCG. The analysis of metabolic pathway showed that the anti-UC effect of CCG was associated with the regulation on linoleic acid metabolism, sphingolipid metabolism, α-linolenic acid metabolism, and glycerophospholipids metabolism.

CONCLUSIONS

The oral administration of CCG significantly alleviated DSS-induced UC symptoms by reducing inflammation and rectifying the metabolic disorder. CCG may provide a new strategy for the management of UC.

Modulation of Cardiopulmonary Toxicity and Oxidative Stress by Phenolic-Rich Fraction of Croton zambiscus Leaves in Rat Exposed to Chronic Mixture of Environmental Toxicants

Chronic mixed toxicant exposure has been implicated in the aetiology of lung and heart failure through prolonged free radical generations. This study was carried out to assess the protective effect of naturally occurring phenolic components from Croton zambesicus (400 mg/kg C-ZAMB) leaves against cardiopulmonary toxicity induced by chronic mixed toxicant (0.5 mL EOMABRSL) in rats. Chronic cardiopulmonary injury via oral administration of 0.5 ml EOMABRSL for 98 days (non-withdrawal) and 70 days (withdrawal) caused unhealthy alteration in the levels of oxidative stress biomarkers [malondialdehyde (MDA), reduced glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase]. Similarly, both withdrawal and non-withdrawal approaches of EOMABRSL-exposed animals exhibited increase in the activity of eco-51-nucleotidase (51ENT) with corresponding diminution in the activity of lactate dehydrogenase (LDH), i.e. the metabolic fuel for cardiopulmonary wellness. Ultimately, histology examination confirmed hyperplastic, bronchopneumonia and cloudy swelling of cardiovascular cells followed by the accumulation of cellular exudates and haemorrhage in the alveoli and bronchioles. The active antioxidants of 400 mg/kg C-ZAMB leaves were responsible for the biological protection of cardiopulmonary toxicity by modulating the activities of 51ENT and LDH. The oxidative stress was also reversed by 400 mg/kg phenolic C-ZAMB leaves in the heart and lungs. Hence, 400 mg/kg phenolic C-ZAMB leaves may be a natural therapy for the treatment of cardiovascular disorder associated with pulmonary dysfunction in rats.

Evaluation of Antioxidant and Enzyme Inhibition Properties of Croton hirtus L'Hér. Extracts Obtained with Different Solvents

Croton hirtus L'Hér methanol extract was studied by NMR and two different LC-DAD-MSn using electrospray (ESI) and atmospheric pressure chemical ionization (APCI) sources to obtain a quali-quantitative fingerprint. Forty different phytochemicals were identified, and twenty of them were quantified, whereas the main constituents were dihydro α ionol-O-[arabinosil(1-6) glucoside] (133 mg/g), dihydro β ionol-O-[arabinosil(1-6) glucoside] (80 mg/g), β-sitosterol (49 mg/g), and isorhamnetin-3-O-rutinoside (26 mg/g). C. hirtus was extracted with different solvents-namely, water, methanol, dichloromethane, and ethyl acetate-and the extracts were assayed using different in vitro tests. The methanolic extracts presented the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), and ferric reducing antioxidant power (FRAP) values. All the tested extracts exhibited inhibitory effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), with a higher activity observed for dichloromethane (AChE: 5.03 and BChE: 16.41 mgGALAE/g), while the methanolic extract showed highest impact against tyrosinase (49.83 mgKAE/g). Taken together, these findings suggest C. hirtus as a novel source of bioactive phytochemicals with potential for commercial development.

Anti-inflammatory and histopathological studies of leaves extracts of Croton bonplandianus in Albino rats

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used for the treatment and prevention of inflammation with the increase in number of side effects. Traditional plants have been used to treat inflammation owing to lesser adverse responses. Croton bonplandianus being an anti-inflammatory plant is extensively utilized all over the world. The methanolic and aqueous leaves extracts of Croton bonplandianus were exposed to anti-inflammatory activity in the carrageenan induced paw edema against standard diclofenac sodium, followed by the histopathlogical examination. The highest dose of methanolic extract were shown significant anti-inflammatory action having a significant P-value (P<0.05-0.001) compared with the diclofenac sodium (P<0.01-0.001) and aqueous extracts (P<0.5-0.01). The histopathological examination illustrated the vasodialation with reduction in the intensity of edema, neutrophils infiltration and other inflammatory cells. C. bonplandianus being a reactive oxygen species scavenger, responsible to exert an excellent anti-inflammatory activity. The present study confirmed the anti-inflammatory potential of drug extracts and authors recommended its utilization in the treatment of pain, inflammation and relevant diseases in future. However, phytochemical screening is to be required for the complete evaluation of active chemical constituent (s).

Croton urucurana Baillon stem bark ointment accelerates the closure of cutaneous wounds in knockout IL-10 mice

ETHNOPHARMACOLOGICAL RELEVANCE

Croton urucurana Baill. (Euphorbiaceae) is a plant used in Brazilian popular medicine for the treatment of wound healing, inflammatory diseases, gastritis, infections, and hemorrhoids.

AIM

The present study aimed to evaluate the in vivo wound healing activity of an ointment based on ethanolic extract of C. urucurana stem bark, at concentrations of 5% and 10%, and to relate it with compounds that could be associated with this activity.

MATERIALS AND METHODS

Analyses by FIA-ESI-IT-MSⁿ were carried out to investigate the chemical composition of C. urucurana. Knockout IL-10 (n = 60) mice and wild type C57 (n = 12) mice were separated into 6 groups to evaluate the wound healing activity. Knockout IL-10 mice: SAL (0.9% saline); BAS (ointment base); SS (1% silver sulfadiazine); CR1 (ointment with extract of C. urucurana 5%); CR2 (ointment with extract of C. urucurana 10%); and wild mice C57: SALC57 (Saline 0.9%). A circular wound with 10 mm in diameter was generated on the dorsal of the animals. Tissue specimen of the wounds were removed on days 7 and 14 of the treatment for histopathological, oxidative status and analyses of pro-and anti-inflammatory cytokines in scar tissue.

RESULTS

In the phytochemical profile, twelve proanthocyanidins were identified (in the form of monomers, dimers, trimers, and tetramers), based on (epi)catechin and (epi)gallocatechin. Furthermore, two quercetin derivatives and two alkaloids were detected. The groups treated with CR1 and CR2 ointments presented higher rate of wound closure, increased total number of cells, mast cells, blood vessels and higher deposition of type III and I collagen. In addition, they showed increased amount of pro-inflammatory cytokines (IL- 2 and IFN-γ), and anti-inflmatory cytokines (IL-4), on the 7th day of treatment.

CONCLUSION

The results presented support the popular use of preparations based on the bark of C. urucurana as a healing compound.

Croton tiglium essential oil compounds have anti-proliferative and pro-apoptotic effects in A549 lung cancer cell lines

As a traditional Chinese medicine, Croton tiglium has the characteristics of laxative, analgesic, antibacterial and swelling. This study aimed to analyze the chemical composition of C. tiglium essential oil (CTEO) extracted from the seeds of C. tiglium and its cytotoxicity and antitumor effect in vitro. Supercritical CO2 fluid extraction technology was used to extract CTEO and the chemical constituents of the essential oil were identified by comparing the retention indices and mass spectra data taken from the NIST library with those calculated based on the C7-C40 n-alkanes standard. In vitro cytotoxicity of the CTEO was assessed against cancer cell lines (A549) and the human normal bronchial epithelial cells (HBE) using the CCK-8 assay. Proliferation was detected by colony formation experiments. Wound scratch and cell invasion assays were used to detect cell migration and invasion. Levels of apoptotic markers, signaling molecules, and cell cycle regulators expression were characterized by Western blot analysis. As the results, twenty-eight compounds representing 92.39% of the total oil were identified in CTEO. The CTEO has significant antitumor activity on A549 cancer cells (IC50 48.38 μg/mL). In vitro antitumor experiments showed that CTEO treatment significantly inhibited the proliferation and migration of A549 cells, disrupted the cell cycle process, and reduced the expression levels of cyclin A, cyclin B and CDK1. CTEO can also reduce mitochondrial membrane potential, activate caspase-dependent apoptosis pathway, and finally induce apoptosis. CTEO may become an effective anti-cancer drug and will be further developed for cancer treatment.

Evaluation of the Biological Efficiency of Silver Nanoparticles Biosynthesized Using Croton tiglium L. Seeds Extract against Azoxymethane Induced Colon Cancer in Rats

BACKGROUND

Colorectal cancer (CRC) is considered as the most common type of gastrointestinal cancers. Chemotherapy became limited due to the adverse side effects. Therefore, the most effective Croton tiglium extract was selected to be incorporated by silver nanoparticles (Ag-NPs) then evaluated against colon cancer induced by azoxymethane (AOM) in rats.

METHODS

Different hematological and biochemical measurements were quantified in addition to markers of oxidative stress. Specific tumor and inflammatory markers were assayed. Colonic tissues were examined histopathologically in addition to immunohistochemistry (IHC). Native proteins and isoenzymes patterns were electrophoretically assayed beside expression of Tumor Protein P53 (TP53) and Adenomatous Polyposis Coli (APC) genes in colonic tissues.

RESULTS

It was found that AOM caused significant (P≤0.05) elevation in the hematological and biochemical measurements. C. tiglium nano-extract restored these measurements to normalcy. Tumor and inflammatory markers elevated significantly (P≤0.05) in sera of AOM induced colon cancer group in addition to increasing peroxidation products with decline in antioxidant enzymes activities in colon tissues. Nano-extract restored these measurements to normalcy in post-treated group. Histopathological study revealed that nano-extract minimized severity of inflammatory reactions in all nano-extract treated groups and prevented  anti-Keratin 20 antibody expression in post-treated group. The lowest similarity index (SI%) values were noticed with electrophoretic protein (SI=71.43%), lipid (SI=0.00%) and calcium (SI=75.00%) moieties of protein patterns, catalase (SI=85.71%), peroxidase (SI=85.71%), α-esterase (SI=50.00%) and β-esterase (SI=50.00%) isoenzymes in colon cancer group. Furthermore, AOM altered the relative quantities of total native bands. The nano-extract prevented the alterations that occurred qualitatively in nano-extract post-treated group and quantitatively in all nano-extract treated groups. Levels of TP53 and APC gene expression increased in AOM injected group and nano-extract restored their levels to normalcy in the post-treated group.

CONCLUSION

C. tiglium nano-extract exhibited ameliorative effect against the biochemical and molecular alterations induced by AOM in nano-extract post-treated group.

Phenolic Profile of Croton urucurana Baill. Leaves, Stems and Bark: Pairwise Influence of Drying Temperature and Extraction Solvent

Cerrado biome represents an area with great biodiversity. Some of its plants have significant ethnopharmacological uses, with specific purposes. Croton urucurana Baill., for instance, was previously acknowledged for its anti-hemorrhagic, anti-inflammatory, antiseptic, healing, and potentially antifungal and entomopathogenic actions. Nevertheless, the compounds supporting these empirical applications are still unknown. Accordingly, this work was designed to achieve a complete characterization of the phenolic profile of different botanical tissues obtained from C. urucurana, and also to verify how different operational conditions (different drying temperatures and extraction conditions) affect that profile. All samples were further characterized by HPLC-DAD-ESI/MSn, and results were compared by advanced chemometric tools. In general, the drying temperatures that maximize the extraction yield of specific individual phenolic compounds were established. Likewise, it was possible to verify that samples extracted with the hydroethanolic solution allowed higher phenolic yields, either in individual compounds (except (epi)catechin-di-O-gallate) or total phenolics. The identification of the best operational conditions and phenolic profiles associated with each C. urucurana botanical part contributes to enabling their use in food or pharmaceutical-related applications.

Diterpenoids with inhibitory activity of nitrite production from Croton floribundus

ETHNOPHARMACOLOGICAL RELEVANCE

Croton floribundus Spreng. (Euphorbiaceae), popularly known as Capixinguí, stands out due to its widespread use in traditional medicine to treat wounds, syphilis, hemorrhoids, eye diseases and as a purgative.

AIM OF THE STUDY

To characterize clerodanes diterpenes from C. floribundus and to evaluate the effects of the fraction and diterpenes (1-5) on inhibition of nitrite production.

MATERIALS AND METHODS

The hydroethanolic root extract of C. floribundus was fractionated on a solid phase extraction column to obtain the fraction named Fr80%. From this, five compounds were obtained and characterized. The absolute configuration of compound 1 was determined by a combination of electronic and vibrational circular dichroism spectroscopies. Additionally, compounds 1-5 were evaluated for their inhibitory effects on nitrite production induced by lipopolysaccharide (LPS) in RAW 264 macrophage cell.

RESULTS

Five clerodane diterpenoids were characterized, and the absolute stereochemistry of 1 was established as 3R,4R,5R,8R,9R,10S,12S. The IC₅₀ values obtained through inhibition of nitrite production were 28.52 ± 2.21 μM (1), 40.26 ± 2.79 μM (2), 25.47 ± 2.16 μM (3), 35.78 ± 2.93 μM (4) and 40.58 ± 4.78 μM (5). In the tested concentrations, the samples presented low toxicity in macrophages.

CONCLUSIONS

Four new diterpenes were characterized from C. floribundus, these being croflorins A-D (1-4) and a known halimane (5). These compounds exhibited inhibitory effect on nitrite production.

19-nor-, 20-nor-, and tetranor-Halimane-Type Furanoditerpenoids from Croton crassifolius

The phytochemical investigation of the roots of Croton crassifolius led to the isolation of 16 new halimane furanoditerpenoids, crohalifuranes A-P (1-16), along with 15 known analogues, 17-31. The new structures including their absolute configurations were elucidated by NMR and MS data analysis, comparison of experimental and calculated electronic circular dichroism data, single-crystal X-ray diffraction data, and chemical methods. Crohalifuranes A (1) and B (2) are tetranor- and 19-nor-halimane diterpenoids featuring a rare decahydroacenaphthene core, respectively, which might be derived from the accompanying crassifoliusin A by loss of the furan ring or the C-19 substituent. Crohalifurane C (3) represents the first example of a 20-nor-halimane diterpenoid, and crohalifurane D (4) is characterized by an unusual 6,20-δ-lactone moiety. All compounds were examined for their inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide in RAW264.7 cells, and 2 and 23 exhibited moderate inhibition on NO production with IC₅₀ values of 17.2 ± 1.3 and 23.7 ± 1.4 μM, respectively.

Discovery of a novel protein kinase C activator from Croton tiglium for inhibition of non-small cell lung cancer

BACKGROUND

The incidence of non-small cell lung cancer (NSCLC) accounts for approximately 85-90% of lung cancer, which has been shown to be challenging for treatment owing to poorly understanding of pathological mechanisms. Natural products serve as a source of almost all pharmaceutical preparations or offer guidance for those chemicals that have entered clinical trials, especially in NSCLC.

PURPOSE

We investigated the effect of B10G5, a natural products isolated from the Croton tiglium, in human non-small cell lung canceras as a protein kinase C (PKC) activator.

METHODS

The cell viability assay was evaluated by the MTT assay. The apoptosis and cell cycle distribution were assessed by flow cytometry. Reactive oxygen species (ROS) production was determined by using the fluorescent probe DCFDA. Cell migration ability of H1975 cells was analyzed by using the wound healing assay. The inhibiting effect of B10G5 against the phosphorylation level of the substrate by PKCs was assessed by using homogeneous time-resolved fluorescence (HTRF) technology. The correlation between PKCs and overall survival (OS) of Lung Adenocarcinoma (LUAD) patients was analysis by TCGA portal. The binding mode between B10G5 and the PKC isoforms was explored by molecular docking. Protein expression was detected by western blotting analysis.

RESULTS

B10G5 suppressed cell proliferation and colony formation, as well as migration ability of NSCLC cells, without significant toxic effect on normal lung cells. B10G5 induced the cell apoptosis through the development of PARP cleavage, which is evidenced by means of the production of mitochondrial ROS. In addition, the B10G5 inhibitory effect was also related to the cell cycle arrest at G2/M phase. Mechanistically, molecular modelling technology suggested that the potential target of B10G5 was associated with PKC family. In vitro PKC kinase assay indicated that B10G5 effectively activated the PKC activity. Western blotting data revealed that B10G5 upregulated PKC to activate PKC-mediated RAF/MEK/ERK pathway.

CONCLUSION

Our results showed that B10G5, a naturally occurring phorbol ester, considered to be a potential and a valuable therapeutic chemical in the treatment of NSCLC.

Does Croton Argyrophyllus Extract Has an Effect on Muscle Damage and Lipid Peroxidation in Rats Submitted to High Intensity Strength Exercise?

Many species of the genus Croton have been used for anti-inflammatory, antiproliferative, antidiabetic, and antitumor purposes. The objective was to evaluate the effect of a hydroethanolic extract (HEE) from the inner bark of Croton argyrophyllus (Euphorbiaceae) on muscle damage and oxidative stress in rats after high intensity exercise. The animals were divided into four groups: (i) the sedentary group (SV; n = 7), (ii) the exercise vehicle group (EV, n = 7), (iii) the sedentary group HEE (SHG; n = 7) composed of sedentary animals and treated with the hydroethanolic extract of C. argyrophyllus (200 mg/kg, v.o.), and (iv) the HEE exercise group (HEE; n = 7) composed of animals submitted to resistance exercise (RE) and treated with the hydroethanolic extract of C. argyrophyllus (200 mg/kg, v.o.). In the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) test, the HEE showed lower values of inhibition potential (IP%) at 39.79% compared to gallic acid, 87.61%, and lipoperoxidation inhibition at 27.4% (100 µg/mL) or 28.6% (200 µg/mL) (p < 0.001). There was inhibition in free radicals in vivo. The HEE of C. argyrophyllus partially reduced the biomarkers of oxidative stress in muscle tissue and muscular damage (creatine kinase (CK) and Lactate Dehydrogenase (LDH)) (p < 0.05) in rats, and in this sense it can be an aid to the recovery process after exhaustive efforts.

Phytotoxic and nematicide evaluation of Croton ehrenbergii (Euphorbiaceae)

BACKGROUND

Within its natural habitat, Croton ehrenbergii exhibits an innate defense mechanism that is not seen in other plants; it grows unharmed amidst predators and nature, while other species perish. In light of its capacity for defense, C. ehrenbergii was evaluated to better understand the scope of its phytotoxic and nematicide properties. To assess this, fractions obtained by bipartition of a hydro-alcoholic extract, and l-quebrachitol, the main constituent of C. ehrenbergii, were evaluated on Lactuca sativa (dicotyledon) and Lolium perenne (monocotyledon) seeds. Additionally, bipartition fractions and l-quebrachitol were evaluated on a population of Meloidogyne incognita for their nematicide activity.

RESULTS

From this phytochemical research, l-quebrachitol (1), phenylalanine (2), trans-4-hydroxy-N-methylproline (3) and the flavonoids: kaempferol (4), tiliroside (5), nicotiflorine (6) and rutin (7) were identified by spectroscopic analysis. Both methanol and hexane fractions from aerial parts of the plant inhibited the germination and elongation of roots and stems in L. sativa, but not in Lolium perenne, showing that these fractions mostly inhibit the dicotyledon species used in this research. l-Quebrachitol showed slightly higher seed germination inhibition for Lolium perenne in comparison with L. sativa. Three of the fractions evaluated showed nematicide activity against Meloidogyne incognita larvae (J2) at the 48 h benchmark, compared with carbofuran. l-Quebrachitol shows higher mortality after 48 h exposure at a lower concentration than carbofuran.

CONCLUSION

A variety of compounds were isolated from this research, some were common within the Croton genus (4-7), whereas others were not (1-3). This is the first phytochemical, phytotoxic and nematicide report on C. ehrenbergii. Methanol and hexane fractions from the aerial parts of C. ehrenbergii and l-quebrachitol could be used as alternative natural herbicides, predominantly against dicotyledon weed seeds. All fractions had a good mortality percentage against J2 Meloidogyne incognita larvae. © 2019 Society of Chemical Industry.

Supercritical CO2 fluid extraction of croton crassifolius Geisel root: Chemical composition and anti-proliferative, autophagic, apoptosis-inducing, and related molecular effects on A549 tumour cells

BACKGROUND

The use of plant essential oils as pharmaceuticals is a fast-growing market especially in China. Throughout the 20th century, a rapid increase took place in the use of many essential oil-derived products in the medicinal industry as nutraceuticals, medicinal supplements, and pharmaceuticals.

PURPOSE

The objective of this study was to explore the chemical composition of Croton crassifolius essential oil as well as its potential anti-tumour properties and related anti-proliferative, autophagic, and apoptosis-inducing effects.

METHODS

Supercritical CO₂ fluid extraction technology was used to extract CCEO and the chemical constituents of the essential oil were identified by comparing the retention indices and mass spectra data taken from the NIST library with those calculated based on the C7-C40 n-alkanes standard. The cytotoxic activity and anti-proliferative effects of CCEO were evaluated against five cancer cell lines and one normal human cell line via CCK-8 assays. In addition, flow cytometry was used to detect cell cycle arrest. The efficacy of CCEO treatments in controlling cancer cell proliferation was assessed by cell cycle analysis, clonal formation assays, RT-qPCR, and western blot analysis. Autophagic and apoptosis-inducing effects of oils and the associated molecular mechanisms were assessed by flow cytometry, cell staining, reactive oxygen species assays, RT-qPCR, and western blot analysis.

CONCLUSION

Forty compounds representing 92.90% of the total oil were identified in CCEO. The results showed that CCEO exerted a measurable selectivity for cancer cell lines, especially for A549 with the lowest IC₅₀ value of 25.00 ± 1.62 μg/mL. Assessment of the anti-proliferative effects of CCEO on A549 cells showed that the oil inhibited cell proliferation and colony formation in a dose- and time-dependent manner. Investigation of the molecular mechanisms of cell cycle regulation confirmed that the oil arrested A549 cells in G2/M phase by decreasing the expression of cyclin B1-CDK1 and cyclin A-CDK1 and increasing the expression of cyclin-dependent kinase inhibitor (CKI) P21 at both the transcriptional and translational levels. Autophagy staining assays and western blot analysis revealed that CCEO promoted the formation of autophagic vacuoles in A549 cells and increased the expression of autophagy-related proteins beclin-1 and LC3-II in a dose-dependent manner. A series of apoptosis analyses indicated that CCEO induces apoptosis through a mitochondria-mediated intrinsic pathway. This study revealed that CCEO is a promising candidate for development into an anti-tumour drug of the future.

Antioxidant and Hepatoprotective Effects of Croton hypoleucus Extract in an Induced-Necrosis Model in Rats

The aim of this study was to evaluate the antioxidant and hepatoprotective activity of Croton hypoleucus (EC). The present work reports the first pharmacological, toxicological, and antioxidant studies of EC extract on liver injury. Liver necrosis was induced by thioacetamide (TAA). Five groups were established: Croton Extract (EC), thioacetamide (TAA), Croton extract with thioacetamide (EC + TAA), vitamin E with thioacetamide (VE + TAA) and the positive control and vehicle (CT). For EC and EC + TAA, Wistar rats (n = 8) were intragastrically pre-administered for 4 days with EC (300 mg/kg.day) and on the last day, EC + TAA received a single dose of TAA (400 mg/kg). At 24 h after damage induction, animals were sacrificed. In vitro activity and gene expression of superoxide dismutase (SOD), catalase (Cat), and Nrf2 nuclear factor were measured. The results show that EC has medium antioxidant properties, with an IC₅₀ of 0.63 mg/mL and a ferric-reducing power of 279.8 µM/mg. Additionally, EC reduced hepatic damage markers at 24 h after TAA intoxication; also, it increased SOD and Cat gene expression against TAA by controlling antioxidant defense levels. Our findings demonstrated the hepatoprotective effect of EC by reducing hepatic damage markers and controlling antioxidant defense levels. Further studies are necessary to identify the mechanism of this protection.

Sesquiterpenoids from the roots of Croton crassifolius

Phytochemical investigation of Croton crassifolius roots afforded five sesquiterpenes (1-5), including two new sesquiterpenes 6S-hydroxy-cyperenoic acid (1) and crassifterpenoid A (5), together with three known compounds (2-4). The structures of the new compounds were determined by comprehensive spectroscopic methods, and their absolute configurations were determined by quantum chemical ECD calculation. Crassifterpenoid A (5) is the first germacrane-type sesquiterpene isolated from C. crassifolius, which enriched the diversity of chemical constituents in Croton crassifolius. In addition, the cytotoxicities of all compounds against human liver cancer lines HepG2 and Hep3B were determined, but none showed significant activity.

Cytotoxic Tigliane Diterpenoids from Croton damayeshu

Chemical investigation of an EtOH extract of the twigs and leaves of Croton damayeshu afforded 10 new tigliane diterpenoids, crodamoids A-J (1-10), along with five known compounds. Their structures were elucidated by physical data analysis. Compounds 8, 9, and 15 displayed cytotoxic effects against two human tumor cell lines, A549 and HL-60 (IC₅₀: 0.9-2.4 μM).

Antimicrobial activity of leaf extracts and isolated constituents of Croton linearis

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves of Croton linearis, known as "rosemary", are widely used in folk medicine in Caribbean countries to treat fever and colds (associated to infections).

AIM OF THE STUDY

To evaluate the in vitro antimicrobial activity of extracts and fractions derived from C. linearis leaves.

MATERIALS AND METHODS

Bioassay-guided fractionation and isolation of compounds from an ethanolic extract of C. linearis, using flash chromatography and semi-preparative HPLC-DAD-MS (High Performance Liquid Chromatography - Diode Array Detection - Mass Spectrometry). Isolated compounds were characterized by MS, 1D- and 2D-NMR (Nuclear Magnetic Resonance) spectroscopy. The microdilution method with resazurin, as well as direct counting with an optical microscope, were used to determine the in vitro antimicrobial activity against bacteria, fungi and parasites. Moreover, the cytotoxicity on human fetal lung fibroblasts (MRC-5) was evaluated.

RESULTS

The total extract and chloroform fraction (ClF) showed high activity against protozoa with IC₅₀ values ranging from 1 to 26 μg/mL, but also cytotoxicity on MRC-5 and PMM (Peritoneal Murine Macrophages). Seven compounds were isolated and characterized for first time in this species: the alkaloids laudanidine, laudanosine, reticuline, corydine, glaucine and cularine and the flavonoid glycoside isorhamnetin-3-O-(6″O-p-trans-coumaroyl)-β-glucopyranoside. Reticuline showed a weak activity against L. infantum (IC₅₀ 148.0 ± 1.2 μM), while the flavonoid was active against T. cruzi (IC₅₀ 35.6 ± 2.3 μM).

CONCLUSIONS

The results show the antiprotozoal potential of the extract and some isolated constituents, which supports the use of this species in Caribbean folk medicine.

Laevifins A-G, clerodane diterpenoids from the Bark of Croton oblongus Burm.f

A phytochemical investigation of the stem barks of the Malaysian Croton oblongus Burm.f. (Syn. Croton laevifolius Blume) (Euphorbiaceae) yielded seven previously undescribed ent-neo-clerodane diterpenoids, laevifins A - G and the known crovatin (3). Structures were established by a combination of spectroscopic methods including HRESIMS, NMR spectroscopy and X-ray crystallography. The absolute configuration of crovatin and laevifins A-G was established by comparison of experimental ECD and theoretical TDDFT ECD calculated spectra. This is the first report on the occurrence of the sesquiterpenoid cryptomeridiol in a Croton species. In vitro cytotoxicity assays on laevifins A, B and G showed moderate activities against the MCF-7 cancer cell line (IC₅₀ 102, 115 and 106 μM, respectively) while β-amyrin and acetyl aleuritolic acid showed good anti-inflammatory activity on the LPS-induced NF-κB translocation inhibition in RAW 264.7 cells assay with IC₅₀ values of 23.5 and 35.4 μg/mL, respectively.

Antitumor Effect of the Essential Oil from the Leaves of Croton matourensis Aubl. (Euphorbiaceae)

Croton matourensis Aubl. (synonym Croton lanjouwensis Jabl.), popularly known as “orelha de burro”, “maravuvuia”, and/or “sangrad’água”, is a medicinal plant used in Brazilian folk medicine as a depurative and in the treatment of infections, fractures, and colds. In this work, we investigated the chemical composition and in vitro cytotoxic and in vivo antitumor effects of the essential oil (EO) from the leaves of C. matourensis collected from the Amazon rainforest. The EO was obtained by hydrodistillation using a Clevenger-type apparatus and characterized qualitatively and quantitatively by gas chromatography coupled to mass spectrometry (GC–MS) and gas chromatography with flame ionization detection (GC–FID), respectively. In vitro cytotoxicity of the EO was assessed in cancer cell lines (MCF-7, HCT116, HepG2, and HL-60) and the non-cancer cell line (MRC-5) using the Alamar blue assay. Furthermore, annexin V-FITC/PI staining and the cell cycle distribution were evaluated with EO-treated HepG2 cells by flow cytometry. In vivo efficacy of the EO (40 and 80 mg/kg/day) was demonstrated in C.B-17 severe combined immunodeficient (SCID) mice with HepG2 cell xenografts. The EO included β-caryophyllene, thunbergol, cembrene, p-cymene, and β-elemene as major constituents. The EO exhibited promising cytotoxicity and was able to cause phosphatidylserine externalization and DNA fragmentation without loss of the cell membrane integrity in HepG2 cells. In vivo tumor mass inhibition rates of the EO were 34.6% to 55.9%. Altogether, these data indicate the anticancer potential effect of C. matourensis.

Cytotoxic 8,9-seco-ent-kaurane diterpenoids from Croton kongensis

Chemical study on the ethanolic extract generated from the aerial parts of Croton kongensis led to the isolation of three new 8,9-seco-ent-kaurane diterpenoids, kongeniods A‒C (1‒3), together with seven known analogs (4-10). The structures of these compounds were assigned by spectroscopic data analysis. The vitro cytotoxic tests showed that compounds 1-3 exhibited strong activities against HL-60 cell lines with IC₅₀ values of 0.47, 0.58, and 1.27 μM, respectively.

Six new diterpenoids from Croton laevigatus

Six new ent-labdane-type diterpeniods (1‒6), along with one known compound, were identified from the twigs and leaves of Croton laevigatus. Their structures were elucidated on the basis of extensive spectroscopic interpretation. Compounds 2 and 7 showed inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) with IC₅₀ values of 4.11 and 8.33 μg/ml, respectively.

Phorbol Rearrangements

An alternative procedure for isolation of 4β-phorbol from seeds of Croton tiglium has been developed, and an artifact containing a furan ring formed by rearrangement of 12,13,20- O-triacylated phorbol derivatives into (6b S,7 R,8 R,8a S)-2-(hydroxymethyl)-5,7,9,9-tetramethyl-3,7,8,9,9a,9b-hexahydrocyclopropa[3',4']benzo[1',2':3,4]cyclohepta[1,2- b]furan-6b,8,8a-triol (8a) has been characterized. A mechanism involving an oxidative rearrangement and a decarboxylation for formation of the artifact is proposed.

Assessment of acute, 14-day, and 13-week repeated oral dose toxicity of Tiglium seed extract in rats

BACKGROUND

Seed of mature Croton tiglium Linne, also known as Tiglium seed (TS), has been widely used as a natural product due to its several health beneficial properties including anti-tumor and antifungal activities. Despite its ethnomedicinal beneficial properties, toxicological information regarding TS extract, especially its long-term toxicity, is currently limited. Therefore, the objective of the present study was to evaluate acute and subchronic toxicity of TS extract in rats after oral administration following test guidelines of the Organization for Economic Cooperation and Development (OECD).

METHODS

Toxicological properties of TS extract were evaluated by toxicity assays to determine its single-dose acute toxicity (125, 250, 500, 1000, or 2000 mg/kg), 14-day repeated-dose toxicity (125, 250, 500, 1000, or 2000 mg/kg) and 13-week repeated-dose toxicity (31.25, 62.5, 125, 250, and 500 mg/kg) in Sprague-Dawley rats and F344 rats. Hematological, serum biochemical, and histopathological parameters were analyzed to determine its median lethal dose (LD50) and no-observed-adverse-effect-level (NOAEL).

RESULTS

Oral single dose up to 2000 mg/kg of TS extract resulted in no mortalities or abnormal clinical signs. In 13-week toxicity study, TS extract exhibited no dose-related changes (mortality, body weight, food/water consumption, hematology, clinical biochemistry, organ weight, or histopathology) at dose up to 500 mg/kg, the highest dosage level suggested based on 14-day repeat-dose oral toxicity study.

CONCLUSION

Acute oral LD50 of TS extract in rats was estimated to be greater than 2000 mg/kg. NOAEL of TS extract administered orally was determined to be 500 mg/kg/day in both male and female rats. Results from these acute and subchronic toxicity assessments of TS extract under Good Laboratory Practice regulations indicate that TS extract appears to be safe for human consumption.