Carbon Sources Attribute to Pathogenicity in Candida albicans

This topic was to examine the impact of galactose or fructose upon the assimilation of secondary carbon sources by Candida albicans. C. albicans ICL1 gene is repressed upon addition of 2% galactose or fructose to lactate- and oleic acid-grown cells. Further studies on CaFOX2, CaFBP1 and CaMLS1 transcripts in response to galactose or fructose on assimilation of lactate and oleic acid resulted in repression of these genes. The CaICL1 gene, which encode the glyoxylate cycles enzymes isocitrate lyase are required for growth on non-fermentable carbon sources. However, the enzyme CaIcl1 was not destabilized by galactose, but was degraded in response to fructose. In contrast, S. cerevisiae Icl1 has retained the molecular apparatus of protein degradation in response to either galactose or fructose. Screening of ubiquitination site by http://www.ubpred.org/ showed that C. albicans lacks ubiquitination site in gluconeogenic and glyoxylate cycles enzymes as compare to S. cerevisiae. Addition of a putative S. cerevisiae ubiquitination site carboxy terminus of CaIcl1 led to galactose- accelerated degradation of this protein in C. albicans cell via a ubiquitin-dependent process. In the other hand, CaIcl prior to addition of ubiquitination site was degraded upon exposure to fructose; addition of S. cerevisiae ubiquitination site to CaIcl1 further increased the speed of protein degradation

Anti-Tumor Study Of Scopoletin And Rubbing-Mercapto-Nitrile From Nicotiana Glauca

Nicotiana glauca (Solanaceae) telah digunakan secara tradisional untuk merawat jangkitan dan kanser. Tumbuhan ini dilaporkan kaya dengan komponen–komponen yang baik untuk kesihatan. Dalam kajian ini, dua komponen anti-tumor daripada ekstrak n-heksana N. glauca telah berjaya diasingkan, iaitu scopoletin dan satu komponen baru, Rubbing-Mercapto-Nitrile (RMN). Pengasingan scopoletin berpandukan aktiviti anti-angiogenesis telah dijalankan menggunakan ekstrak daripada batang N. glauca. Aktiviti anti-angiogenesis scopoletin dikaji menggunakan model–model angiogenesis secara ex vivo dan in vivo. Keberkesanan anti-tumorigenik scopoletin dikaji menggunakan xenograf tumor kolorektal manusia pada mencit nude atimik. Scopoletin menyebabkan perencatan signifikan dalam percambahan salur mikro pada eksplan aortik tikus dengan nilai kepekatan perencatan 50% adalah 34 μg/ml. Scopoletin (100 dan 200 mg/kg) merencat dengan berkesan vaskularisasi plak matrigel yang diimplan pada mencit nude, masing–masing sebanyak 59.72% dan 89.4%. Nicotiana glauca (Solanaceae) has been traditionally used as a folk remedy to treat infections and cancer. It has been reported as a rich source of beneficial phytochemicals. In the present study, two anti-tumor compounds derived from n-hexane extract of N. glauca namely scopoletin and, a novel compound, Rubbing-Mercapto-Nitrile (RMN) have been isolated. Antiangiogenesis-guided isolation of scopoletin was conducted using an extract from the stem of N. glauca. The anti-angiogenic activity of scopoletin was investigated using ex vivo and in vivo angiogenesis models. The antitumorigenic efficacy of scopoletin was studied in human colorectal tumor xenografts using athymic nude mice. Scopoletin caused significant suppression of microvessel sprouting in rat aortic explants with IC50 of 34 μg/ml. Scopoletin (100 and 200 mg/kg) strongly inhibited (59.72% and 89.4%, respectively) vascularization in matrigel plugs implanted in nude mice

Effects of different mycotoxins on humans, cell genome and their involvement in cancer (Review)

The chemical nature of most of the mycotoxins makes them highly liposoluble compounds that can be absorbed from the site of exposure such as from the gastrointestinal and respiratory tract to the blood stream where it can be dissimilated throughout the body and reach different organs such as the liver and kidneys. Mycotoxins have a strong tendency and ability to penetrate the human and animal cells and reach the cellular genome where it causes a major mutagenic change in the nucleotide sequence which leads to strong and permanent defects in the genome. This defect will eventually be transcribed, translated and lead to the development of cancer. In this review, the chemical and physical nature of mycotoxins, the action of mycotoxins on the cellular genome and its effect on humans, mycotoxins and their carcinogenicity and mycotoxins research gaps are discussed, and new research areas are suggested. The research review posed various questions. What are the different mycotoxins that can cause cancer, what is the role of mycotoxins in causing cancer and what types of cancers can be caused by mycotoxins? These questions have been selected due to the significant increase in the mycotoxin contamination and the cancer incidence rate in the contemporary world. By revealing and understanding the role of mycotoxins in developing cancer, measures to reduce the risks and incidents of cancer could be taken

Metabolic adaptation via regulated enzyme degradation in the pathogenic yeast Candida albicans

The virulence of Candida albicans is dependent upon fitness attributes as well as virulence factors. These attributes include robust stress responses and metabolic flexibility. The assimilation of carbon sources is important for growth and essential for the establishment of infections by C. albicans. Previous studies showed that the C. albicans ICL1 genes, which encode the glyoxylate cycle enzymes isocitratelyase are required for growth on non-fermentable carbon sources such as lactate and oleic acid and were repressed by 2% glucose. In contrast to S. cerevsiae, the enzyme CaIcl1 was not destabilised by glucose, resulting with its metabolite remaining at high levels. Further glucose addition has caused CaIcl1 to lose its signal and mechanisms that trigger destabilization in response to glucose. Another purpose of this study was to test the stability of the Icl1 enzyme in response to the dietary sugars, fructose, and galactose. In the present study, the ICL1 mRNAs expression was quantified using Quantitative Real Time PCR, whereby the stability of protein was measured and quantified using Western blot and phosphoimager, and the replacing and cloning of ICL1 ORF by gene recombination and ubiquitin binding was conducted via co-immuno-precipitation. Following an analogous experimental approach, the analysis was repeated using S. cerevisiaeas a control. Both galactose and fructose were found to trigger the degradation of the ICL1 transcript in C. albicans. The Icl1 enzyme was stable following galactose addition but was degraded in response to fructose. C. albicans Icl1 (CaIcl1) was also subjected to fructose-accelerated degradation when expressed in S. cerevisiae, indicating that, although it lacks a ubiquitination site, CaIcl1 is sensitive to fructose-accelerated protein degradation. The addition of an ubiquitination site to CaIcl1 resulted in this enzyme becoming sensitive to galactose-accelerated degradation and increases its rate of degradation in the presence of fructose. It can be concluded that ubiquitin-independent pathways of fructose-accelerated enzyme degradation exist in C. albicans

Inhibitory effect of Labisia pumila leaf extract on angiogenesis via down-regulation of vascular endothelial growth factor

Purpose: To investigate the anti-angiogenic activity of a methanol leaf extract of Labisia pumila (ME), and its bioactive water fraction (WF), using in vitro models.Methods: The antioxidant activity and total phenolic contents of ME and WF were assessed using DPPH and Folin–Ciocalteu reagents. Antiproliferative effects of extracts towards human umbilical vein endothelial cells (HUVECs) were evaluated using MTT assay. Isolated rat aortic ring and matrigel tube formation assays were performed to assess the antiangiogenic potential of Me and its WF. Levels of VEGF protein in the cell lysates were measured using ELISA kit.Results: Among all the extracts prepared, ME and its WF showed higher total phenolic contents and exhibited moderate antioxidant effects. Significant (p < 0.001) suppression of microvessels outgrowth with half-maximal concentration (IC50) values of 20 and 26 μg/mL for ME and WF, was observed in rat aortic ring assay. ME and its WF halted proliferation and tube formation capacity of HUVECs in in vitro assays. Marked reduction in VEGF levels was observed in lysates of HUVECs treated with ME and its WF.Conclusion: Labisia pumila leaf extract and its water fraction halted angiogenesis by blocking VEGF secretion leading to inhibition of endothelial cells proliferation and differentiation which is suggested to be due to its phenolic antioxidant contents.Keywords: Labisia pumila, Anti-angiogenesis, Antioxidant, Tube formation, Rat aort

Pharmacokinetics and antiangiogenic studies of potassium koetjapate in rats

© 2020 Purpose: Koetjapic acid is an active compound of a traditional medicinal plant, Sandoricum koetjape. Although koetjapic acid has a promising anticancer potential, yet it is highly insoluble in aqueous solutions. To increase aqueous solubility of koetjapic acid, we have previously reported a chemical modification of koetjapic acid to potassium koetjapate (KKA). However, pharmacokinetics of KKA has not been studied. In this study, pharmacokinetics and antiangiogenic efficacy of KKA are investigated. Methods: Pharmacokinetics of KKA was studied after intravenous and oral administration in SD rats using HPLC. Anti-angiogenic efficacy of KKA was investigated in rat aorta, human endothelial cells (EA.hy926) and nude mice implanted with matrigel. Results: Pharmacokinetic study revealed that KKA was readily absorbed into blood and stayed for a long time in the body with Tmax 2.89 ± 0.12 h, Cmax 7.24 ± 0.36 μg/mL and T1/2 1.46 ± 0.03 h. The pharmacological results showed that KKA significantly suppressed sprouting of microvessels in rat aorta with IC50 18.4 ± 4.2 μM and demonstrated remarkable inhibition of major endothelial functions such as migration, differentiation and VEGF expression in endothelial cells. Further, KKA significantly inhibited vascularization in matrigel plugs implanted in nude mice. Conclusions: The results indicate that bioabsorption of KKA from oral route was considerably efficient with longer retention in body than compared to that of the intravenous route. Further, improved antiangiogenic activity of KKA was recorded which could probably be due to its increased solubility and bioavailability. The results revealed that KKA inhibits angiogenesis by suppressing endothelial functions and expression of VEGF

Neuroprotective and Anti-Inflammatory Effects of \u3ci\u3eRhus coriaria\u3c/i\u3e Extract in a Mouse Model of Ischemic Optic Neuropathy

Modulating oxidative stresses and inflammation can potentially prevent or alleviate the pathological conditions of diseases associated with the nervous system, including ischemic optic neuropathy. In this study we evaluated the anti-neuroinflammatory and neuroprotective activities of Rhus coriaria (R. coriaria) extract in vivo. The half maximal inhibitory concentration (IC50) for DPPH, ABTS and B-carotene were 6.79 ± 0.009 µg/mL, 10.94 ± 0.09 µg/mL, and 6.25 ± 0.06 µg/mL, respectively. Retinal ischemia was induced by optic nerve crush injury in albino Balb/c mice. The anti-inflammatory activity of ethanolic extract of R. coriaria (ERC) and linoleic acid (LA) on ocular ischemia was monitored using Fluorescence Molecular Tomography (FMT). Following optic nerve crush injury, the mice treated with 400 mg/kg of ERC and LA exhibited an 84.87% and 86.71% reduction of fluorescent signal (cathepsin activity) respectively. The results of this study provide strong scientific evidence for the neuroprotective activity of the ERC, identifying LA as one of the main components responsible for the effect. ERC may be useful and worthy of further development for its adjunctive utilization in the treatment of optic neuropathy

Target identification of small molecules: an overview of the current applications in drug discovery

Abstract Target identification is an essential part of the drug discovery and development process, and its efficacy plays a crucial role in the success of any given therapy. Although protein target identification research can be challenging, two main approaches can help researchers make significant discoveries: affinity-based pull-down and label-free methods. Affinity-based pull-down methods use small molecules conjugated with tags to selectively isolate target proteins, while label-free methods utilize small molecules in their natural state to identify targets. Target identification strategy selection is essential to the success of any drug discovery process and must be carefully considered when determining how to best pursue a specific project. This paper provides an overview of the current target identification approaches in drug discovery related to experimental biological assays, focusing primarily on affinity-based pull-down and label-free approaches, and discusses their main limitations and advantages

The Anticancer, Antioxidant and Antimicrobial Properties of the Sesquiterpene β-Caryophyllene from the Essential Oil of Aquilaria crassna

The present study reports a bioassay-guided isolation of β-caryophyllene from the essential oil of Aquilaria crassna. The structure of β-caryophyllene was confirmed using FT-IR, NMR and MS. The antimicrobial effect of β-caryophyllene was examined using human pathogenic bacterial and fungal strains. Its anti-oxidant properties were evaluated by DPPH and FRAP scavenging assays. The cytotoxicity of β-caryophyllene was tested against seven human cancer cell lines. The corresponding selectivity index was determined by testing its cytotoxicity on normal cells. The effects of β-caryophyllene were studied on a series of in vitro antitumor-promoting assays using colon cancer cells. Results showed that β-caryophyllene demonstrated selective antibacterial activity against S. aureus (MIC 3 ± 1.0 µM) and more pronounced anti-fungal activity than kanamycin. β-Caryophyllene also displayed strong antioxidant effects. Additionally, β-caryophyllene exhibited selective anti-proliferative effects against colorectal cancer cells (IC50 19 µM). The results also showed that β-caryophyllene induces apoptosis via nuclear condensation and fragmentation pathways including disruption of mitochondrial membrane potential. Further, β-caryophyllene demonstrated potent inhibition against clonogenicity, migration, invasion and spheroid formation in colon cancer cells. These results prompt us to state that β-caryophyllene is the active principle responsible for the selective anticancer and antimicrobial activities of A. crassnia. β-Caryophyllene has great potential to be further developed as a promising chemotherapeutic agent against colorectal malignancies

The Anticancer Potential of <i>Psidium guajava</i> (Guava) Extracts

The fruits, leaves, and bark of the guava (Psidium guajava) tree have traditionally been used to treat a myriad of ailments, especially in the tropical and subtropical regions. The various parts of the plant have been shown to exhibit medicinal properties, such as antimicrobial, antioxidant, anti-inflammatory, and antidiabetic activities. Recent studies have shown that the bioactive phytochemicals of several parts of the P. guajava plant exhibit anticancer activity. This review aims to present a concise summary of the in vitro and in vivo studies investigating the anticancer activity of the plant against various human cancer cell lines and animal models, including the identified phytochemicals that contributes to their activity via the different mechanisms. In vitro growth and cell viability studies, such as the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the sulforhodamine B (SRB) assay, and the trypan blue exclusion test, were conducted using P. guajava extracts and their biomolecules to assess their effects on human cancer cell lines. Numerous studies have showcased that the P. guajava plant and its bioactive molecules, especially those extracted from its leaves, selectively suppress the growth of human cancer cells without cytotoxicity against the normal cells. This review presents the potential of the extracts of P. guajava and the bioactive molecules derived from it, to be utilized as a feasible alternative or adjuvant treatment for human cancers. The availability of the plant also contributes towards its viability as a cancer treatment in developing countries