Amelioration of Experimental Hepatotoxicity in Rats by Portulaca oleracea Linn. from Kashmir Himalaya.

BACKGROUND: Traditionally, Portulaca oleracea Linn. is used for treating abscesses, dysentery and liver diseases. In addition, recent studies have reported its efficacy as an analgesic, as neuroprotective, anti-inflammatory, bronchodilatory, and anticancer agent, besides antioxidant, wound healing and other important pharmacological actions. AIMS AND OBJECTIVES: For curing liver diseases, Chinese use juice from the fresh leaves of Portulaca oleracea Linn. Hence, to prove this claim, an in-vivo hepatoprotective study of extracts from Portulaca oleracea Linn. against carbon tetrachloride hepatotoxic rats was carried out. METHODS: The in-vitro antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and hepatoprotective activity of extracts of Portulaca oleracea Linn. was assessed against the carbon tetrachloride-induced toxicity rat model. RESULTS: The extracts of Portulaca oleracea Linn produced concentration-dependent percentage inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and most significantly, by methanol extract. Among the extracts, methanol extract showed a significant decrease in Serum glutamic oxaloacetic transaminase (SGOT), Serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP) levels and a significant increase in total protein (TP) levels against carbon tetrachloride-induced liver toxicity. CONCLUSION: From the results obtained, it was concluded that methanol extract of Portulaca oleracea Linn. possesses significant DPPH free radical scavenging and hepatoprotective potential.

Potential of carboxymethyl cellulose and γ-irradiation to maintain quality and control disease of peach fruit.

Carboxymethyl cellulose (CMC) coatings alone and in combination with gamma irradiation were tested for maintaining the storage quality and control of post-harvest gray and black mold disease of peach. Matured green peaches were CMC coated at levels 0.5-1.0% (w/v) and gamma irradiated at 1.2 kGy. The treated fruit including control was stored under ambient (temperature 25 ± 2°C, RH 70%) and refrigerated (temperature 3 ± 1°C, RH 80%) conditions. In fruits treated with individual treatments of 1.0% (w/v) CMC; 1.2 kGy irradiation and combination of 1.0% (w/v) CMC and 1.2 kGy irradiation, no decay was recorded up to 6, 8 and 14 days of ambient storage. Irradiation alone at 1.2 kGy prevented the onset of disease incidence up to 4 days compared to 2 days by 1.0% (w/v) CMC coating following 30 days of refrigeration. Combination of CMC at 1.0% (w/v) and 1.2 kGy irradiation prevented disease incidence of peach up to 7 days during post-refrigerated storage at 25 ± 2°C, RH 70% following 30 days of refrigeration. Above combinatory treatment can be of great potential in facilitating the marketing of the fruit, thereby benefiting the growers.

Gamma irradiation induced modification of bean polysaccharides: impact on physicochemical, morphological and antioxidant properties.

In the present study starches from four bean varieties viz. red, yellow, black and white, were gamma irradiated in the dose range of 5-25 kGy to investigate the effect of radiation processing on physicochemical, morphological and antioxidant properties. Studies revealed positive correlation between gamma irradiation and solubility (r=0.91), irradiation and water absorption capacity (r=0.82) and negative correlations between irradiation and swelling power (r=-0.92), irradiation and pasting properties (r=-0.91) and irradiation and thermal properties (r=-0.89). Microscopic observation under scanning electron microscope indicated the development of surface cracking and fractures on the surface of starch granules with increase in dose. X-ray diffractometry revealed no significant change in diffraction patterns between control and irradiated starches, except a decrease in relative crystallinity. Irradiation increased the proportions of both rapidly digestible starch and enzyme resistant starch of bean starches and significantly prevented the retrogradation of bean starches during storage. Results of the DPPH radical scavenging activity and ferric reducing power indicated significant (p≤0.05) increase in antioxidant activity of all irradiated bean starches with increase in dose.

Yeast CAF-1 assembles histone (H3-H4)2 tetramers prior to DNA deposition.

Following acetylation, newly synthesized H3-H4 is directly transferred from the histone chaperone anti-silencing factor 1 (Asf1) to chromatin assembly factor 1 (CAF-1), another histone chaperone that is critical for the deposition of H3-H4 onto replicating DNA. However, it is unknown how CAF-1 binds and delivers H3-H4 to the DNA. Here, we show that CAF-1 binds recombinant H3-H4 with 10- to 20-fold higher affinity than H2A-H2B in vitro, and H3K56Ac increases the binding affinity of CAF-1 toward H3-H4 2-fold. These results provide a quantitative thermodynamic explanation for the specific H3-H4 histone chaperone activity of CAF-1. Surprisingly, H3-H4 exists as a dimer rather than as a canonical tetramer at mid-to-low nanomolar concentrations. A single CAF-1 molecule binds a cross-linked (H3-H4)2 tetramer, or two H3-H4 dimers that contain mutations at the (H3-H4)2 tetramerization interface. These results suggest that CAF-1 binds to two H3-H4 dimers in a manner that promotes formation of a (H3-H4)2 tetramer. Consistent with this idea, we confirm that CAF-1 synchronously binds two H3-H4 dimers derived from two different histone genes in vivo. Together, the data illustrate a clear mechanism for CAF-1-associated H3-H4 chaperone activity in the context of de novo nucleosome (re)assembly following DNA replication.

Carboxymethyl cellulose coating and low-dose gamma irradiation improves storage quality and shelf life of pear (Pyrus communis L., Cv. Bartlett/William).

Carboxymethyl cellulose (CMC) coatings alone and in combination with gamma irradiation were tested for maintaining the storage quality and extending shelf life of pear. Matured green pears were CMC coated at levels 0.25% to 1.0% w/v and gamma irradiated at 1.5 kGy. The treated fruit including control was stored under ambient (temperature 25 ± 2 °C, RH 70%) and refrigerated (temperature 3 ± 1 °C, RH 80%) conditions. Irradiation alone at 1.5 kGy gave 8 and 4 d extension in shelf life of pear following 45 and 60 d of refrigeration, respectively. CMC coating at 1.0% w/v was effective in giving 6 and 2 d extension in shelf life of pear following 45 and 60 d of refrigeration, respectively. All combinatory treatments delayed the decaying of pear during postrefrigerated storage, but combination of 1.0% w/v CMC and 1.5 kGy irradiation proved significantly (P≤0.05) effective in maintaining the storage quality and delaying the decaying of pear. The above combinatory treatment gave an extension of 12 and 6 d in shelf life of pear during postrefrigerated storage at 25 ± 2 °C, RH 70% following 45 and 60 d of refrigeration.