Determination and estimation of pharmacokinetic profile of caffeine in form of extract of green tea leaves and its analogy with synthetic form

Activated Carbon for Drug Delivery from Composite Biomaterials: The Effect of Grinding on Sirolimus Binding and Release

Activated carbon (AC) could be potentially useful as a drug carrier in fiber polymer scaffolds destined for prolonged drug delivery. To be introduced, AC must be ground into smaller-sized particles to be introduced in scaffolds, as most biocompatible scaffolds consist of fibers with a diameter of less than 1 µm. In this study, the adsorption of sirolimus (SRL) from phosphate-buffered saline (PBS) solution and blood plasma (BP) onto AC of AX-21 type, as well as the release of SRL from AC depending on its fragmentation, were studied. Two-stage grinding of the AC, first with a ball mill, and then with a bead mill, was performed. Grinding with a bead mill was performed either in water or in polyvinylpyrrolidone to prevent aggregation of AC particles. Dynamic light scattering and scanning electron microscopy (SEM) demonstrated that the size of the particles obtained after grinding with a ball mill was 100–10,000 nm, and after grinding with a bead mill, 100–300 nm. Adsorption in PBS was significantly higher than in BP for all fractions, and depended on SRL concentration. The fraction obtained after grinding with a ball mill showed maximal SRL adsorption, both in PBS and BP, and slow SRL release, in comparison with other fractions. The 100–300 nm AC fractions were able to adsorb and completely release SRL into BP, in contrast to other fractions, which strongly bound a significant amount of SRL. The data obtained are to be used for controlled SRL delivery, and thus in the modification of drug delivery in biological media.

Emerging techniques for determining the quality and safety of tea products: A review

Spectroscopic techniques, electrochemical methods, nanozymes, computer vision, and modified chromatographic techniques are the emerging techniques for determining the quality and safety parameters (e.g., physical, chemical, microbiological, and classified parameters, as well as inorganic and organic contaminants) of tea products (such as fresh tea leaves, commercial tea, tea beverage, tea powder, and tea bakery products) effectively. By simplifying the sample preparation, speeding up the detection process, reducing the interference of other substances contained in the sample, and improving the sensitivity and accuracy of the current standard techniques, the abovementioned emerging techniques achieve rapid, cost-effective, and nondestructive or slightly destructive determination of tea products, with some of them providing real-time detection results. Applying these emerging techniques in the whole industry of tea product processing, right from the picking of fresh tea leaves, fermentation of tea leaves, to the sensory evaluation of commercial tea, as well as developing portable devices for real-time and on-site determination of classified and safety parameters (e.g., the geographical origin, grade, and content of contaminants) will not only eliminate the strong dependence on professionals but also help mechanize the production of tea products, which deserves further research. Conducting a review on the application of spectroscopic techniques, electrochemical methods, nanozymes, computer vision, and modifications of chromatographic techniques for quality and safety determination of tea products may serve as guide for other types of foods and beverages, offering potential techniques for their detection and evaluation, which would promote the development of the food industry.

Rosmarinic acid attenuates inflammation in experimentally induced arthritis in Wistar rats, using Freund's complete adjuvant

AIM

The purpose of our investigation is to evaluate the anti-arthritic potential of isolated rosmarinic acid from the rind of Punica granatum.

METHOD

Rosmarinic acid was isolated by bioactivity-guided isolation from butanolic fraction of Punica granatum and acute toxicity of rosmarinic acid was carried out. The experiment was conducted at doses of 25 and 50 mg/kg, in Freund's complete adjuvant (FCA)-induced arthritic rats. Various parameters, that is arthritic score, paw volume, thickness of paw, hematological, antioxidant and inflammatory parameters such as glutathione (GSH), superoxide dismutase (SOD), malonaldehyde (MDA) and tumor necrosis factor-α (TNF-α) were also estimated.

RESULTS

Rosmarinic acid significantly decreased the arthritic score, paw volume, joint diameter, white blood cell count and erythrocyte sedimentation rate. It also significantly increased body weight, hemoglobin and red blood cells. The significantly decreased levels of TNF-α were observed in treated groups as compared to arthritic control rats (P < 0.001). At the same time antioxidant parameters (like GSH and SOD) were increased significantly while levels of MDA were significantly decreased (P < 0.001).

CONCLUSION

The outcome of the present research concludes that rosmarinic acid showed significant anti-arthritic potential in FCA-induced arthritis in Wistar rats. This study represented the therapeutic role of rosmarinic acid from Punica granatum for the management of arthritis/rheumatoid arthritis/osteoarthritis and related inflammatory complications with negligible side effects which was still far from complete mitigation with available conventional medicines.

Interaction among hERG channel blockers is a potential mechanism of death in caffeine overdose

Caffeine overdose death is due to cardiac arrest, but its mechanism has not been explored in detail. In this study, our data showed that caffeine significantly prolonged the heart rate-corrected QT interval (QTc) of rabbits in vivo (P<0.05; n=7). Caffeine was also found to be a hERG channel blocker with an IC₅₀ of 5.04mM (n=5). Although these two findings likely link caffeine overdose death with hERG channel blockade, the amount of caffeine consumption needed to reach the IC₅₀ is very high. Further study demonstrated that addition another hERG blocker could lower the consumption of caffeine significantly, no matter whether two hERG blockers share the same binding sites. Our data does not rule out other possibility, however, it suggests that there is a potential causal relationship between caffeine overdose death with hERG channel and the interaction among these hERG blockers.