Anticancer and Antiviral Activity of Marine Algae

Cancer continues to be a global killer, despite the enormous research has developed during the past few decade. According to recent statistics, cancer accounts 23% of total deaths in the India and is the second most common cause of death after the heart disease. Cancer accounts for nearly 1 of every 4 deaths”. Moreover, according to Lee Jong-Wook, former Director General of the WHO, “by the year 2020, cancer could kill more than 10.3 million people per year unless action is taken in both the field of prevention and treatment”. Cancer is caused by both intrinsic factors (such as inherited mutations, hormones, and immune conditions) and extrinsic factors (such as tobacco, diet, radiation, and infectious organisms;). Increasing incidence of cancer prevalence in India is ever-growing. The management of cancer by surgical intervention and chemotherapy is not always convencing because the vulnerable virulence of the cancer cell transcends into secondary cancer sites. Ever-growing interest in cytotoxic natural compounds has been prior interest among the scientist working in the area of cancer biology. It is evidenced by literature that natural compounds from Indian system of medicine, fruits and vegetables have been shown excellent cytotoxic anticancer property with its unique phytoconstituents. The search of anticancer entities from marine algae from marine resources has another phase of dice to find out the hidden gold under deep sea. There are three important species of algae namely the red, brown and green algae in the ocean ecology. In particular red algae species acanthophora spicifera are viewed as special floral for its nutritive and biological properties. However, the exploitation of acanthophora spicifera in not expanded up to the mark. This is one of the main reason we have chosen this species which is widely distributed in the Gulf of Mannar, Mandapam, for scientific exploration. The work presented in thesis is pure quantitative data from collection of marine algae to proven anticancer role in human cancer cell line as well as antiviral role against human viral pathogens. Earlier literature on this species revels phytoconstituents like sterols, acanthophorin A, acanthophorin B and many flavonoids. In addition antioxidant effect of acanthophora spicifera have been proven. We have demonstrated for the first time that crude alcoholic extracts of Acanthophora spicifera was injected orally shown the anticancer properties by exerting its effect by reducing tumor weight, tumor volume, mean survival day with restoration haematological abnormalities in in vivo cancer model. This preliminary work has prompted us to fractionate crude extract and locate active bioactive fraction. In order to achieve above statements we have used bioactive guided fractionation tool using robust in vitro assays namely cytotoxic assay and free radical scavenging assay. The ethyl acetate fraction from Acanthophora spicifera was identified as bioactive by means of its significant effects in showing selective cytotoxic activity and free radical scavenging activity. It is interesting to observe bidirectional bioactive property of ethyl acetate fraction as pro-oxidant and antioxidant with qualitative phytochemical like phenolic flavanoids and tannins. Further our interest is isolate bioactive cytotoxic constituents from ethyl acetate fraction of Acanthophora spicifera using conventional column chromatography with the mobile phase of chloroform: methanol. We were identified 3 compounds in which 2 compounds are flavonoids and 1 served as tannins. The compounds are namely Quercetin, Isoquercetin and Gallic acid. The quantitative estimation of these compounds is assayed by HPLC and HPTLC. The identified compounds basically possess antioxidant properties. It is known fact that participation of oxidative stress in cancer directly links those antioxidants on cancer prevention. The flow cytometry analysis of isoquercetin HT29 and HepG2 cells at the concentration of 50 μg/ml clearly shown G1/S phase and sub-G1 phase of apoptosis respectively. In order to prove the above experiments in vivo set up, we have used DEN induced hepatocellular carcinoma in rats. Similar to in vitro the isoquercetin 5 and 10 mg/kg body weight treated DEN rats has exhibited anticancer property by following mechanism. a) it influence the liver morphology by restoring the abnormal liver function markers induced by DEN. b) It exerted its antioxidant role by enhancing antioxidant enzymes including non-enzymatic enzymes like glutathione and decrease in oxidative stress markers. c) In influences the liver apoptosis markers and produces beneficial effects on liver morphology. The reason for antiviral screening for isoquercetin form acanthophora spicifera is because most of the viral pathogens irreversible influence the cancer induction and also it has been very strong evidence of literature suggests the antiviral effect of red algae in in vitro set up. CONCLUSION: It is concluded that the red algae species Acanthophora spicifera has been explored in chemical and biological aspects. The poly-phenolic and tannins present in the acanthophora spicifera possesses significant anticancer, antioxidant and antiviral properties in in vitro and in vivo experimental conditions. However there are further studies need to be established in molecular and nuclear level. Due to limitation and time line which restricts us to proceed further. It is also concluded that further exploration of this species in various biological properties beyond antiviral and anticancer is warranted

Exploration of Phyllanthus acidus mediated silver nanoparticles and its activity against infectious bacterial pathogen

Abstract In our present investigation, synthesis of nontoxic, eco friendly and cost effective silver nanoparticles, Phyllanthus acidus (P. acidus) was used as starting material. The influence of phyto-constituents present in aqueous extracts of Phyllanthus acidus was found to be effective in reduction of silver nitrate to free silver nanoparticles (PA-AgNPs). HPTLC finger print analysis reveals the presence of flavonoid, quercetin in aqueous extracts of Phyllanthus acidus. Surface plasmon racemonance exhibited λ max at 462 nm through UV–Vis spectroscopy. Zeta size revealed that the size of nanoparticles were with in the range of 65–250 nm with polydisperse index (PDI) of 0.451. The negative charge of zeta potential value (− 16.4) indicates repulsion among PA-AgNPs with their excellent stability. FESEM-EDAX, XRD and TEM analysis confirmed the presence of nano-crystalline PA-AgNPs with different morphological textures. Further, PA-AgNPs has shown potent antibacterial effect on E. coli cells. The greater antibacterial effect (viable and dead cells) of PA-AgNPs were confirmed by using acridine orange (AO) dye which can able to provide insight of healthy as well as damaged DNA. Live cells emit florescence green and dead cells (treated with PA-AgNPS at 20 and 40 µg/ml) appear as pale orange red colour. Post treatment, investigations of PA-AgNPs on E. coli cells under SEM was found to be effective against cell membrane damages which leads to cell death or cell growth arrest. Hence, from the above findings, we strongly recommend silver nanoparticles from Phyllanthus acidus can be used as a potential source for antimicrobial agent for chronic infections and also against other harmful microorganisms