Bioelectrogenesis with microbial fuel cells (MFCs) using the microalga Chlorella vulgaris and bacterial communities

Background: Microbial Fuel Cell (MFC) technology is used in various applications such as wastewater treatment with the production of electrical energy. The objective of this study was to estimate the biodepuration of oils and fats, the elimination of blue dye brl and bioelectro-characterization in MFCs with Chlorella vulgaris and bacterial community. Results: The operation of MFCs at 32 d showed an increase in bioelectrogenic activity (from 23.17 to 327.67 mW/m2 ) and in the potential (from 200 to 954 mV), with biodepuration of fats and oils (95%) in the microalgal cathode, and a removal of the chemical oxygen demand COD (anode, 71%, cathode, 78.6%) and the blue dye brl (73%) at the anode, here biofilms were formed by the bacterial community consisting of Actinobacteria and Deltaproteobacteria. Conclusions: These findings suggest that MFCs with C. vulgaris and bacterial community have a simultaneous efficiency in the production of bioelectricity and bioremediation processes, becoming an important source of bioenergy in the future.

Potential role of marine algae extract on 3T3-L1 cell proliferation and differentiation: an in vitro approach

BACKGROUND: From ancient times, marine algae have emerged as alternative medicine and foods, contains the rich source of natural products like proteins, vitamins, and secondary metabolites, especially Chlorella vulgaris (C. vulgaris) contains numerous anti-inflammatory, antioxidants and wound healing substances. Type 2 diabetes mellitus is closely associated with adipogenesis and their factors. Hence, we aimed to investigate the chemical constituents and adipo-genic modulatory properties of C. vulgaris in 3T3-L1 pre-adipocytes. RESULTS: We analysed chemical constituents in ethanolic extract of C. vulgaris (EECV) by LC-MS. Results revealed that the EECV contains few triterpenoids and saponin compounds. Further, the effect of EECV on lipid accumulation along with genes and proteins expressions which are associated with adipogenesis and lipogenesis were evaluated using oil red O staining, qPCR and western blot techniques. The data indicated that that EECV treatment increased differentiation and lipid accumulation in 3T3-L1 cells, which indicates positive regulation of adipogenic and lipogenic activity. These increases were associated with up-regulation of PPAR-γ2, C/EBP-α, adiponectin, FAS, and leptin mRNA and protein expressions. Also, EECV treatments increased the concentration of glycerol releases as compared with control cells. Troglitazone is a PPAR-γ agonist that stimulates the PPAR-y2, adiponectin, and GLUT-4 expressions. Similarly, EECV treatments significantly upregulated PPAR-γ, adiponectin, GLUT-4 expressions and glucose utilization. Further, EECV treatment decreased AMPK-α expression as compared with control and metformin treated cells. CONCLUSION: The present research findings confirmed that the EECV effectively modulates the lipid accumulation and differentiation in 3T3-L1 cells through AMPK-α mediated signalling pathway.

Toxicological, phytochemical, and antibacterial assessment of Chlorella vulgaris and Spirulina platensis powder in albino rats. A preliminary study

Objectives: To describe acute toxicity, antibacterial activity and phytochemical assessment of Chlorella vulgaris and Spirulina platensis powders. Material and Methods: FeCl3 test, Wagner test, Keller Killiani test, frothing test, alkaline solution and dilute acid; concentrated sulphuric acid were used for phytochemical analysis. Antibacterial screening of the extracts was conducted using the disc gel diffusion method in E. coli, S. aureus and B. cereus clinical strains. In order to evaluate acute toxicity and its effects on haematological and biochemical parameters; 15 albino rats were grouped into five groups: I (powder of aqueous extract of Chlorella vulgaris), II (powder of methanol extract of Chlorella vulgaris), III (powder of aqueous extract of Spirulina platensis), IV (powder of methanol extract of Spirulina platensis) and V (control). The dosage was 25g/day/rat. After six days, haematological and biochemical parameters and gross pathologic changes were evaluated. Results: Alkaloids and flavonoids were detected from the methanol extracts of both Chlorella vulgaris and Spirulina platensis (Arthrospira). Only cardiac glycosides and steroids were detected from Spirulina's extracts. Chlorella vulgaris extracts significantly inhibited B. cereus. Rats fed with Chlorella vulgaris and Spirulina platensis powder showed an increase in white blood cell counts and haemoglobin level compared to negative control rats (p<0.001). Serum glumatic oxalate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) had normal values but significative differences between groups (p<0.001). Conclusion: This powder is rich in bioactive phytochemicals but only Chlorella's extracts have shown antibacterial effect. Signs of toxicity weren't found in any parameter.

Objetivos: Describir la toxicidad aguda, efecto antibacteriano y análisis fitoquímico de los polvos de Chlorella vulgaris y Spirulina platensis. Materiales y métodos: Se realizaron las pruebas de FeCl3, Keller Killiani, de saponinas, solución alcalina y de concentración de ácido sulfúrico para el análisis fitoquímico. El efecto antibacteriano de los extractos fue evaluado mediante el método de difusión con discos en cepas de E. coli, S. aureus y B. cereus. Para evaluar la toxicidad aguda y los efectos del polvo en parámetros hematológicos y bioquímicos, se agruparon 15 ratas albinas en cinco grupos: I (polvo de extracto acuoso de Chlorella vulgaris); II (polvo de extracto metanólico de Chlorella vulgaris); III (polvo de extracto acuoso de Spirulina platensis); IV (polvo de extracto metanólico de Spirulina platensis), y V (grupo control). La dosis usada fue de 25 g/día/rata. Después de seis días, se evaluaron todos los parámetros y cambios macroscópicos en los órganos. Resultados: Se encontraron alcaloides y flavonoides en los extractos metanólicos de Chlorella vulgaris y Spirulina platensis (Arthrospira). Se detectaron glucósidos cardiacos y esteroides en los extractos de Spirulina platensis. Los extractos de Chlorella vulgaris inhibieron el crecimiento de Bacillus cereus. Las ratas alimentadas con los polvos de Chlorella vulgaris y Spirulina platensis incrementaron el conteo de leucocitos y los valores de hemoglobina comparados con el grupo control (p<0,001). Las transaminasas (SGOT y SGPT) se encontraron en valores normales, pero con diferencias significativas entre los grupos (p<0,001). Conclusiones: Estos polvos son ricos en componentes fitoquímicos activos, pero solo los extractos de Chorella vulgaris mostraron efecto antibacteriano. No se encontraron signos de toxicidad aguda en ningún parámetro.

Antioxidant enzyme activity and malondialdehyde levels can be modulated by Piper betle, tocotrienol rich fraction and Chlorella vulgaris in aging C57BL/6 mice

OBJECTIVE: The aim of this study was to determine the erythrocyte antioxidant enzyme activity and the superoxide dismutase, catalase, glutathione peroxidase, and plasma malondialdehyde levels in aging mice and to evaluate how these measures are modulated by potential antioxidants, including the tocotrienol-rich fraction, Piper betle, and Chlorella vulgaris. METHOD: One hundred and twenty male C57BL/6 inbred mice were divided into three age groups: young (6 months old), middle-aged (12 months old), and old (18 months old). Each age group consisted of two control groups (distilled water and olive oil) and three treatment groups: Piper betle (50 mg/kg body weight), tocotrienol-rich fraction (30 mg/kg), and Chlorella vulgaris (50 mg/kg). The duration of treatment for all three age groups was two months. Blood was withdrawn from the orbital sinus to determine the antioxidant enzyme activity and the malondialdehyde level. RESULTS: Piper betle increased the activities of catalase, glutathione peroxidase, and superoxide dismutase in the young, middle, and old age groups, respectively, when compared to control. The tocotrienol-rich fraction decreased the superoxide dismutase activity in the middle and the old age groups but had no effect on catalase or glutathione peroxidase activity for all age groups. Chlorella vulgaris had no effect on superoxide dismutase activity for all age groups but increased glutathione peroxidase and decreased catalase activity in the middle and the young age groups, respectively. Chlorella vulgaris reduced lipid peroxidation (malondialdehyde levels) in all age groups, but no significant changes were observed with the tocotrienol-rich fraction and the Piper betle treatments. CONCLUSION: We found equivocal age-related changes in erythrocyte antioxidant enzyme activity when mice were treated with Piper betle, the tocotrienol-rich fraction, and Chlorella vulgaris. However, Piper betle treatment showed increased antioxidant enzymes activity during aging.

Hot water extract of Chlorella vulgaris induced DNA damage and apoptosis

OBJECTIVES: The aim of this study was to determine the antiproliferative and apoptotic effects of hot water extracts of Chlorella vulgaris on hepatoma cell line HepG2. INTRODUCTION: The search for food and spices that can induce apoptosis in cancer cells has been a major study interest in the last decade. Chlorella vulgaris, a unicellular green algae, has been reported to have antioxidant and anti-cancer properties. However, its chemopreventive effects in inhibiting the growth of cancer cells have not been studied in great detail. METHODS: HepG2 liver cancer cells and WRL68 normal liver cells were treated with various concentrations (0-4 mg/ml) of hot water extract of C. vulgaris after 24 hours incubation. Apoptosis rate was evaluated by TUNEL assay while DNA damage was assessed by Comet assay. Apoptosis proteins were evaluated by Western blot analysis. RESULTS: Chlorella vulgaris decreased the number of viable HepG2 cells in a dose dependent manner (p < 0.05), with an IC50 of 1.6 mg/ml. DNA damage as measured by Comet assay was increased in HepG2 cells at all concentrations of Chlorella vulgaris tested. Evaluation of apoptosis by TUNEL assay showed that Chlorella vulgaris induced a higher apoptotic rate (70 percent) in HepG2 cells compared to normal liver cells, WRL68 (15 percent). Western blot analysis showed increased expression of pro-apoptotic proteins P53, Bax and caspase-3 in the HepG2 cells compared to normal liver cells WRL68, and decreased expression of the anti-apoptotic protein Bcl-2. CONCLUSIONS: Chlorella vulgaris may have anti-cancer effects by inducing apoptosis signaling cascades via an increased expression of P53, Bax and caspase-3 proteins and through a reduction of Bcl-2 protein, which subsequently lead to increased DNA damage and apoptosis.