Antioxidant, Anticancer Activity and Phytochemical Analysis of Green Algae, Chaetomorpha Collected from the Arabian Gulf.

Seaweeds are a group of marine multicellular algae; the presence of antioxidant phytochemical constituents in Seaweed Chaetomorpha sp. extracts has received attention for their role in the prevention of human diseases. This study explores the phytochemical constituents, antioxidant, and anticancer properties of the Cladophoraceae, Chaetomorpha sp. Energy dispersive x-ray spectroscopy (EDX), and Gas chromatography-mass spectrometry (GC/MS) were performed to study the chemical structure and chemical formula. Different concentrations of ethanol and aqueous extracts of Chaetomorpha were used to estimate antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and total flavonoid, phenolic, and tannins content assays. Anti-tumor activity against breast cancer cell lines (MCF-7 and MDA-MB-231) was assessed by 3-(4,5-Dimethylthiazol-2-cyl)-2,5-Diphenyltetrazolium Bromide (MTT) assay. The EDX analysis indicated the presence of oxygen, silicon, and calcium as dominant elements. Antioxidant assays indicated that the ethanol extracts of Chaetomorpha consisted of a total of 189.14 ± 0.99 mg QE/g flavonoid content, 21.92 ± 0.43 mg GAE/g phenolic content and 21.81 ± 0.04 mg GAE/g tannins content. The DPPH radical scavenging assay exhibited higher antioxidant activity IC50 (9.41 ± 0.54 mg/mL) in the ethanol extract. Moreover, it showed high anticancer activity by growth inhibition in the MDA-MB-231 breast cancer cell line and low IC50 (225.18 ± 0.61 µg/mL). GC/MS analysis revealed the presence of Dichloracetic acid (DCA) as the active antitumor constituent of Chaetomorpha sp.; other anticancer compounds identified were Oximes and L-α-Terpinol. The results revealed that the type of Chaetomorpha sp. studied here possesses very unique and novel constituents and active potent antitumor chemical constituents and it can act as a promising antioxidant and anticancer agent for future applications in pharmaceutical industries.

The systemic effect of PEG-nGO-induced oxidative stress in vivo in a rodent model.

Oxidative stress (OS) plays an important role in the pathology of certain human diseases. Scientists have developed great interest regarding the determination of oxidative stress caused after the administration of nano-graphene composites (PEG-nGO). Graphene oxide sheets (GOS) were synthesized via a modified Hummer's method and were characterized by X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV), and transmission electron microscopy (TEM). The method of Zhang was adopted for cracking of GOS. Then nano-graphene oxide was PEGylated with polyethylene glycol (PEG). PEGylation of nGO was confirmed by Fourier-transform infrared spectroscopy (FTIR), UV spectroscopy and TEM. The average size distribution of nGO and PEG-nGO was determined by using dynamic light scattering (DLS). Subsequently, an in vivo study measuring a marker for oxidative stress, namely lipid peroxides, as well as antioxidant agents, including catalase, superoxide dismutase, glutathione, and glutathione S-transferase was conducted. A comparison at different intervals of time after the administration of a dose (5 mg/kg) of PEG-nGO was carried out. An increase in free radicals and a decrease in free radical scavenging enzymes in organs were observed. Our results indicated that the treatment with PEG-nGO caused an increased OS to the organs in the first few hours of treatment. However, the liver completely recovered from the OS after 4 h. Brain, heart and kidneys showed an increased OS even after 4 h. In conclusion increased OS induced by PEG-nGO could be detrimental to brain, heart and kidneys.