The aim of this study was to evaluate the potential anticancer properties and modulatory effect of selected Aloe vera (A. vera) active principles on antioxidant enzyme activities. Thus, three anthraquinones (Namely: aloesin, aloeemodin and barbaloin) were extracted from A. vera leaves by supercritical fluid extraction and subsequently purified by high performance liquid chromatography. Additionally, the N-terminal octapeptide derived from verectin, a biologically active 14 kDa glycoprotein present in A. vera, was also tested. In vivo, active principles exhibited significant prolongation of the life span of tumor-transplanted animals in the following order: barbaloin > octapeptide > aloesin > aloe-emodin. A. vera active principles exhibited significant inhibition on Ehrlich ascite carcinoma cell (EACC) number, when compared to positive control group, in the following order: barbaloin > aloe-emodin > octapeptide > aloesin. Moreover, in trypan blue cell viability assay, active principles showed a significant concentration-dependent cytotoxicity against acute myeloid leukemia (AML) and acute lymphocytes leukemia (ALL) cancerous cells. Furthermore, in MTT cell viability test, aloeemodin was found to be active against two human colon cancer cell lines (i.e. DLD-1 and HT2), with IC50 values of 8.94 and 10.78 μM, respectively. Treatments of human AML leukemic cells with active principles (100 μg ml-1) resulted in varying intensities of internucleosomal DNA fragmentation, hallmark of cells undergoing apoptosis, in the following order: aloe-emodin > aloesin > barbaloin > octapeptide. Intererstingly, treatment of EACC tumors with active principles resulted in a significant elevation activity of key antioxidant enzymes (SOD, GST, tGPx, and LDH). Our data suggest that the tested A. vera compounds may exert their chemo-preventive effect through modulating antioxidant and detoxification enzyme activity levels, as they are one of the indicators of tumorigenesis. These findings are discussed in the light of the potential of A. vera plant extracts for developing efficient, specific and non-toxic anticancer drugs that are affordable for developing countries.

DE-ETIOLATED 1 (DET1) is an evolutionarily conserved component of the ubiquitination machinery that mediates the destabilization of key regulators of cell differentiation and proliferation in multicellular organisms. In this study, we provide evidence from Arabidopsis that DET1 is essential for the regulation of histone H2B monoubiquitination (H2Bub) over most genes by controlling the stability of a deubiquitination module (DUBm). In contrast with yeast and metazoan DUB modules that are associated with the large SAGA complex, the Arabidopsis DUBm only comprises three proteins (hereafter named SGF11, ENY2 and UBP22) and appears to act independently as a major H2Bub deubiquitinase activity. Our study further unveils that DET1-DDB1-Associated-1 (DDA1) protein interacts with SGF11 in vivo, linking the DET1 complex to light-dependent ubiquitin-mediated proteolytic degradation of the DUBm. Collectively, these findings uncover a signaling path controlling DUBm availability, potentially adjusting H2Bub turnover capacity to the cell transcriptional status.

The present work aims to design and synthesize novel series of spiro pyrazole-3,3’-oxindoles analogues and investigate their bioactivity as antioxidant and antimicrobial agents, as well as antiproliferative potency against selected human cancerous cell lines (i.e., breast, MCF-7; colon, HCT-116 and liver, HepG-2) relative to healthy noncancerous control skin fibroblast cells (BJ-1). The mechanism of their cytotoxic activity has been also examined by immunoassaying the levels of key anti- and proapoptotic protein markers. The analytical and spectral data of the all synthesized target congeners were compatible with their structures. Synthesized compounds showed diverse moderate to powerful antimicrobial and antioxidant activities. Results of MTT assay revealed that seven synthesized compounds (i.e., 11a, 11b, 12a, 12b, 13b, 13c and 13h) particularly exhibited significant cytotoxicity against the three cancerous cell lines under investigation. Ranges of IC₅₀ values obtained were 5.7–21.3 and 5.8–37.4 µg/mL against HCT-116 and MCF-7, respectively; which is 3.8 and 6.5-fold (based on the least IC₅₀ values) more significant relative to the reference chemotherapeutic drug doxorubicin. In HepG-2 cells, the analogue 13h exhibited the highest cytotoxicity with IC₅₀ value of 19.2µg/mL relative to doxorubicin (IC₅₀ = 21.6µg/mL). The observed cytotoxicity was specific to cancerous cells, as evidenced by the minimal toxicity in the noncancerous control skin-fibroblast cells. ELISA results indicated that the observed antiproliferative effect against examined cancer cell lines is mediated via engaging the activation of apoptosis as illustrated by the significant increase in proapoptotic protein markers (p53, bax and caspase-3) and reduction in the antiapoptotic marker bcl-2. Taken together, results of the present study emphasize the potential of spiro pyrazole-oxindole analogues as valuable candidate anticancer agents against human cancer cells.

Due to excessive use of synthetic pesticides the pest resistance developed along with pesticide residues accumulation in crops. Therefore, many nations are switching from chemical-based agriculture to “green” agriculture for pest control. The destructive pest black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), is a polyphagous species that economically lead to extensive loss of a broad range of crops including corn, cotton, wheat, and many vegetables through the damage of foliar and roots. In this study, lemon peel essential oil (LPEO) was subjected to nano-formulation using polyethylene glycol as nanocarrier. The lethal activity of LPEO and its nano-form (LPEO-NPs) were tested against A. ipsilon second larval instar using feeding bioassay at different concentrations. Growth and developmental parameters, including larval and pupal duration, larval and pupal mortality, malformations % and adult emergence were evaluated. Results showed that LPEO exhibited insecticidal activity and causes different levels of effects on the development of A. ipsilon according to its concentration and formulation. In addition, at 75 mg/ml LPEO and LPEO-NPs significantly increased the larval mortality to 80.00% and 90.00%, respectively. The overall data revealed that insecticidal toxicity of LPEO was increased by nano-formulation.