An overview on red algae bioactive compounds and their pharmaceutical applications.

Objectives To review red algae bioactive compounds and their pharmaceutical applications. Content Seaweed sources are becoming attractive to be used in health and therapeutics. Among these red algae is the largest group containing bioactive compounds utilized in cosmetic, pharmaceutical, food industry, manure and various supplements in food formula. Various significant bioactive compounds such as polysaccharides (aginate, agar, and carrageenan), lipids and polyphenols, steroids, glycosides, flavanoids, tannins, saponins, alkaloids, triterpenoids, antheraquinones and cardiac glycosides have been reported in red algae. The red algae have rich nutritional components Different polysaccharides of red algae possess the antiviral potential namely agarans, carrageenan, alginate, fucan, laminaran and naviculan. Sulfated polysaccharides and carraginans of red algae are rich source of soluble fibers which can account for antitumor activities depending upon chemistry of various secondary metabolites and metabolism of cell line. Flavons-3-ols containing catechins from many red algae block the telomerase activity in colon cancer cells. Contraceptive agents were tested from red algae as a source for post-coital. Lectin of red algae showed pro-healing properties and anti-ulcerogenic activities. Carragenates from red algae also conferred a positive influence on diabetes. Red algae depicted a reducing effect on plasma lipids and obesity. Porphyran from red alga can act as anti-hyperlipidemic agent also reduces the apolipoprotein B100 via suppression of lipid synthesis in human liver. Summary The polyphenolic extracts of Laurencia undulate, Melanothamnus afaqhusainii and Solieria robusta extract show anti-inflammatory effects against multiple genera of devastating fungi. Antioxidants such as phlorotannins, ascorbic acids, tocopherols, carotenoids from red algae showed toxicity on some cancer cells without side effects. Red algae Laurencia nipponica was found insecticidal against mosquito larvae. Red algae fibers are very important in laxative and purgative activities. Gracilaria tenuistipitat resisted in agricultural lands polluted with cadmium and copper. Outlook In the recent decades biotechnological applications of red algae has been increased. Polysaccharides derived from red algae are important tool for formulation of drugs delivery system via nanotechnology.

Xanthophyll: Health benefits and therapeutic insights.

Xanthophylls constitute a major part of carotenoids in nature. They are an oxidized version of carotenoid. Xanthophyll has widely drawn scientists' attentions in terms of its functionality, bioavailability and diversity. An assortment of xanthophyll varieties includes lutein, zeaxanthin, ß-cryptoxanthin, capsanthin, astaxanthin, and fucoxanthin. Chemically, lutein and zeaxanthin are dipolar carotenoids with hydroxyl groups at both ends of their molecules that bestow hydrophilic properties to them. Hydrophilic affinity in lutein and zeaxanthin makes better bioavailability in reaction with singlet oxygen in water phase, whereas non-polar carotenoids have shown to have less efficiency in scavenging free radicals. Xanthophylls have been studied for their effects in a wide variety of diseases including neurologic, ophthalmologic, oral, allergic and immune diseases. This review highlights pharmaco-pharmaceutical applications of xanthophylls as well asits drug interactions with beta-carotene. Different types of xanthophylls have been shown to have neuroprotective effects. Fucoxanthin demonstrated potent antiplasmodial activity. Lutein and zeaxanthin prevent the progression of age related macular degeneration. They have also demonstrated promising effects on uveitis, retinitis pigmentosa, scleritis, cataracts, glaucoma, retinal ischemia and choroideremia. Astaxanthin showed to have skin protecting effects against ultraviolet light injury. Astaxanthin have anti-allergic activity against the contact dermatitis especially to treat the patients having adverse reactions induced by steroids. Astaxanthin has been reported to exert beneficial effects in preventing oral lichen planus and early stage cancers. ß-cryptoxanthin has been considered a good candidate for prevention of bone loss via osteoblastic bone formation and inhibiting osteoclastic bone resorption. There is also some concern that higher dose of xanthophylls may be linked to increased risk of skin cancer and gastric adenocarcinoma. However this increased risk was not statistically significant when adjusted for confounding factors. Further researches including clinical studies are needed to better evaluate the efficacy and safety of xanthophylls in prevention and treatment of different diseases.