Hyaluronic acid (HA) is a high molecular weight biopolysacharide, discovered in 1934, by Karl Meyer and his assistant, John Palmer in the vitreous of bovine eyes. Hyaluronic acid is a naturally occurring biopolymer, which has important biological functions in bacteria and higher animals including humans. It is found in most connective tissues and is particularly concentrated in synovial fluid, the vitreous fluid of the eye, umbilical cords and chicken combs. It is naturally synthesized by a class of integral membrane proteins called hyaluronan synthases, and degraded by a family of enzymes called hyaluronidases. This review describes metabolisms, different physiological and pathological functions, basic pharmacological properties, and the clinical use of hyaluronic acid. Keywords: hyaluronic acid; metabolism; toxicityList of abbreviations CD44 = cell surface glycoprotein; CDC37 = intracellular HA-binding protein; Da = dalton; DNA = deoxynucleotid acid; ECM = extracellular matrix; EM = electron microscopy; GHAP = glial hyaluronate-binding protein; GIT = gastrointestinal tract; HA = hyaluronic acid; HARE = hyaluronic acid receptor for endocytosis; HAS1, HAS2, and HAS3 = types of hyaluronan synthases 1, 2 and 3; IHABP = intracellular HA-binding protein; IMP = integral membrane protein; IL-1 = interleukine 1; LM = light microscopy; LYVE-1 = lymphatic vessel endocytic receptor; MRHD = maximum recommended human dose; NS = normal saline; OA = osteoarthrosis; P-32 = protein-32; RHAMM = receptor for hyaluronic acid mediated mobility; RHAMM/IHABP = receptor for hyaluronic acid mediated mobility/intracellular HA-binding protein; TDLo = toxic dose low; TIMP-1 = tissue inhibitor of matrix metalloproteiness 1;TNF-α = tumor necrosis factor alpha; TSG-6 = tumor necrosis factor-α-stimulated gene-6; t 1/2 = half-life; UDP = uridine diphosphate

Carrageenan is a natural carbohydrate (polysaccharide) obtained from edible red seaweeds. The name Carrageenan is derived from the Chondrus crispus species of seaweed known as Carrageen Moss or Irish Moss in England, and Carraigin in Ireland. Carraigin has been used in Ireland since 400 AD as a gelatin and as a home remedy to cure coughs and colds. It grows along the coasts of North America and Europe. Carrageenans are used in a variety of commercial applications as gelling, thickening, and stabilising agents, especially in food products and sauces. Aside from these functions, carrageenans are used in experimental medicine, pharmaceutical formulations, cosmetics, and industrial applications.Keywords: carrageenan; pharmacokinetics; toxicity; biological activity List of abbreviations 3,6-AG = 3,6, anhydro-galactose, 5-HT = 5-hydroxytryptamine, 6-APA = 6-amino penicillanic acid, ADI = acceptable daily intake, AG = amino guanidine, AIDS = acquired immune deficiency syndrome, AT-III = anti-thrombin-III, bw = body weight, COX-2 = cyclooxygenase-2, eNOS = endothelial nitric oxide synthase, FAO = food and agriculture organization, HC-II = heparin co-factor II, HIV = human immunodeficiency virus, HPV = human papilloma virus, HSV = herpes simplex virus, IFAC = international food additives council, iNOS = inducible nitric oxide synthase, JECFA = Joint FAO/WHO Expert Committee on Food Additives, L-NMMA = NG-monomethyl-l-arginine, nNOS = neuronal nitric oxide synthase, NO = nitric oxide, NOS = nitric oxide synthase, NSAIDs = non-steroidal antiinflammatory drugs, PGs = prostaglandins, SSL = sodium stearoyl lactylate, TNF-α = tumour necrosis factor-α

Epigallocatechin gallate is the major component of the polyphenolic fraction of green tea and is responsible for most of the therapeutic benefits of green tea consumption. A number of preclinical in vivo and in vitro experiments as well as clinical trials have shown a wide range of biological and pharmacological properties of polyphenolic compounds such as anti-oxidative, antimicrobial, anti-allergic, anti-diabetic, anti-inflammatory, anti-cancer, chemoprotective, neuroprotective and immunomodulatory effects. Epigallocatechin gallate controls high blood pressure, decreases blood cholesterol and body fat and decreases the risk of osteoporotic fractures. Further research should be performed to monitor the pharmacological and clinical effects of green tea and to more clearly elucidate its mechanisms of action and the potential for its use in medicine.

The present 15 days study was undertaken to evaluate the cardioprotective potential of the prenylated isoflavones osajin and pomiferin isolated from the infructences of Maclura pomifera, Moraceae, against ischemia-reperfusion induced injury in rat hearts as a model of antioxidant-based composite therapy. The study was performed on isolated, modified Langendorff-perfused rat hearts and the ischemia of heart was induced by stopping coronary flow for 30 min followed by 60 min of reperfusion (14 ml min -1 ). The Wistar rats were divided into four groups. The first treatment group received osajin (5 mg/kg/day in 0.5% Avicel); the second treatment group received pomiferin (5 mg/kg/day in 0.5% Avicel); the placebo group received only 0.5 Avicel; the last was an untreated control group. Biochemical indicator of oxidative damage-lipid peroxidation product malondialdehyde, antioxidant enzymes -superoxide dismutase, glutathione peroxidase, total antioxidant activity in serum and myocardium were evaluated. The effect of osajin and pomiferin on cardiac function, left ventricular end-diastolic pressure, left ventricular pressure and peak positive +dP/dt ischemia and reperfusion, also was examined.The results demonstrate that osajin and pomiferin attenuates the myocardial dysfunction provoked by ischemiareperfusion. This was confirmed by an increase in both antioxidant enzyme values and total antioxidant activity. The cardioprotection provided by osajin and pomiferin treatment results from the suppression of oxidative stress and this correlates with improved ventricular function.

The present study aims to investigate the antidiabetic as well as the effect on lipid peroxidation of three different doses (50, 100, and 200 mg/kg) of Cleome droserifolia aerial parts methanolic extract in comparison with glibenclamide in alloxan-induced diabetic rats.Forty-two rats (35 diabetic and 7 normal) were included in this study. Oral administration of 100 and 200 mg/kg of the methanolic extract for 3 weeks significantly (P < 0.05) restored the blood glucose level, plasma malondialdehyde and urine sugar to near the physiological values whereas the effect of 50 mg/kg was not significant.Furthermore, from the HPLC chromatograms, we identified the presence of three flavonoids (quercetin, kaempferol, and isorhamnetin) together with three phenolic acids (sinapinic acid, ferulic acid and 4-coumaric acid) which may explain at least in part some of the antidiabetic and antioxidative properties observed in this study.