Evaluation of anti-allergic and anti-anaphylactic activity of ethanolic extract of Zizyphus jujuba fruits in rodents

The present study reports the anti-allergic activity of ethanolic extract of Zizyphus jujuba Mill., Rhamnaceae, and its possible mode of action. The effect of extract of Z. jujuba at different doses (250, 500 and 1000 mg/kg, orally) was simulated on studied animal models of asthma and allergy: a) milk induced eosinophilia and leukocytosis; b) compound 48/80 induced mast cell degranulation; and, c) active and passive cutaneous anaphylaxis. In addition, extract of Z. jujuba's effect on sensitized guinea pig ileum (ex vivo) and tracheal chain preparations (in vitro) were investigated.Treatment with extract of Z. jujuba at all doses significantly: prevented the milk-induced eosinophilia and compound 48/80 induced degranulation of mesenteric mast cells; decreased passive cutaneous and active anaphylactic reactions. In addition, extract of Z. jujuba inhibited acetylcholine as well as histamine induced tracheal chain contraction, and also antigen induced contraction of sensitized guinea pig ileum (Shultz-Dale inhibition test). Furthermore, it exhibited also free radicals scavenging activity (in vitro). The observed anti-allergic and anti-anaphylactic activity of extract of Z. jujuba may be largely through the stabilization of mast cells by the membrane presence of phytoconstituents (steroidal saponins and flavonoids).

Liposomes as potential carrier system for targeted delivery of polyene antibiotics.

The development of new therapeutic modalities involves the use of drug carrier, such as liposomes, which can modify pharmacokinetic and bio-distribution of drug profile. Polyene antibiotics incorporation into liposomes improves its availability at the site, bio-distribution and therapeutic index mainly through the engulfment of liposomes by circulating monocytes/macrophages and transportation to the site of infection. Polyene antibiotics (AmB, SJA-95, HA-1-92) and other antibiotics (streptomycin, tobramycin, quinolones, anti-tubercular and anti-cancer drugs), liposomal preparations are described with possible advantages from therapeutic efficacy and toxicity point of view. The polyene macrolide antibiotics liposomal preparations proved to be more effective in the treatment of systemic mycosis. The AmB-cyclodextrin derivatives inclusion complex is a major breakthrough in liposomal preparation which can be converted into aqueous phase of liposome. Liposomal drug incorporated preparation has been one of the important areas of research for developing the existing polyene antibiotics into useful chemotherapeutic agents in clinical medicine. In recent past other antibiotics have also been incorporated into liposomes using wide variety of materials, phosphatidylethanolamine derivatives (pegylated liposomes, enzyme sensitive conjugates, fluidosomes of anti-cancer drugs and poly lactic/glycolic acid microspheres for anti-tuberculosis drugs). In addition, attempts were also made to extend the receptor mediated drug targeting and to review some relevant patents.

Anti-diabetic activity of embelin: involvement of cellular inflammatory mediators, oxidative stress and other biomarkers.

Embelin (benzoquinone), an active constituent of methanolic extracts of the fruit of Embelia basal (Myrsinaceae), was studied in high fat diet (HFD)+streptozotocin (STZ) diabetic rats. Treatment of embelin (25 and 50 mg/kg/day, p.o.) for 3 weeks to HFD+STZ diabetic rats elicited insignificant increase in body weight, reduced the elevated plasma glucose, glycosylated haemoglobin and pro-inflammatory mediators (interleukin 6 and tumour necrosis factor α) significantly. Furthermore, embelin treatment at both the doses significantly decreased the elevated malondialdehyde, restored depleted glutathione, antioxidant enzymes, superoxide dismutase and catalase in liver. The increased lipid profiles in HFD+STZ diabetic rats were also reduced by embelin treatment significantly. Embelin treatment to HFD+STZ diabetic rats also improved the altered histoarchitecture of ß-islets of pancreas and hepatocytes. The embelin effect on progression of type 2 diabetes mellitus in rats appears to be through the inhibition of intracellular pro-inflammatory mediators, lowering of lipid profile and amelioration of oxidative stress. Considering the pharmacological activity profile of embelin, it is suggested that embelin be a useful diabetic modulator or adjuvant along with clinically effective anti-diabetic drugs in the treatment of type 2 diabetes mellitus and needs to be clinically evaluated on human subjects.