Microwave-assisted extraction and rapid isolation of ursolic acid from the leaves of Eucalyptus × hybrida Maiden and its quantification using HPLC-diode array technique.

Ursolic acid (UA) is the most important bioactive phytoconstituent of Eucalyptus × hybrida Maiden leaves and exhibits anticancer, antimutagenic, anti-inflammatory, antioxidative, and antiprotozoal activities. In this study, microwave-assisted extraction technique was employed for rapid isolation of UA from the leaves of Eucalyptus × hybrida and simultaneously HPLC-diode array method was developed for the quantification of UA. Effects of several experimental parameters on the extraction efficiencies of UA, such as type and volume of extraction solvents, microwave power and extraction time, were evaluated. The optimal extraction conditions were found to be 20 mL of a mixture of chloroform/methanol, 60:40; liquid-to-material ratio, 4:1; preleaching time, 10 min; microwave power, 600 W; temperature, 50°C; and microwave irradiation time, 5 min. Under the optimum conditions, the yield of UA was found to be 1.95 ± 0.08% in the dry leaves of Eucalyptus × hybrida. The results showed that microwave-assisted extraction is a more rapid extraction method with higher yield and lower solvent consumptions than the conventional method. It is a faster, convenient, and appropriate method and it may be used for rapid isolation and quantification of UA and other important phytoconstituents present in the leaves of Eucalyptus × hybrida.

Antidiabetic Potential of Naturally Occurring Sesquiterpenes: A Review.

Diabetes Mellitus (DM) is an endocrine disease, which is the 3rd leading cause of death in humans; additionally, it is one of the major key concerns over the globe. The high levels of glucose in the blood stream are as well characterized by hyperglycaemia leading to serious damage to the heart, blood vessels, kidney, eyes, and nerves. The best treatment of DM is still not available; many scientists worldwide are trying hard to seek out suitable treatment of DM. Though numerous synthetic drugs are developed for the treatment of diabetes but their utility has been hampered because of several side effects and poor efficacy. Among various approaches for the treatment of DM, herbal medicine, enriched extracts, and naturally derived molecules are most effective. Plant based herbal medicines contain many bioactive phytochemicals, such as terpenoids, alkaloids, flavonoids & phenolics, etc. which are used in the treatment of many diseases. The plant-derived molecules and their suitable structure modification have given many leads or drugs to the world like sesquiterpene; artemisinin and their derivatives artemether & artesunate as an antimalarial drugs. Sesquiterpenes are available in the human diet and are largely taken as components of the many folk medicines and dietary supplements. Sesquiterpenes have a wide range of biological activities, such as anti-cancer, anti-inflammatory, anti-nociceptive, immunomodulatory, antidiabetic and antimicrobial, which make them potential targets for the development of new therapeutics and their usage for medical purposes. Natural products have gained the attention of the world due to their large number of biological activities, high safety and fewer side effect. The review mainly focuses on bioactive sesquiterpenes such as ß-caryophyllene, dysidine, farnesol & eremanthin, etc., a class of terpenoids that may play an important role in the treatment or prevention of this gruesome disorder like diabetes, with their underlying mechanisms for the blood-glucose-lowering property.

Determination and locational variations in the quantity of hydroxyanthraquinones and their glycosides in rhizomes of Rheum emodi using high-performance liquid chromatography.

Locational variations in the quantity of five hydroxyanthraquinone derivatives (emodin glycoside (1), chrysophanol glycoside (2), emodin (3), chrysophanol (4) and physcion (5)) in the rhizomes of Rheum emodi are described. A simple and reliable method was developed for quantitation of compounds (1-5) in the methanolic extract of rhizomes of R. emodi using reverse-phase high-performance liquid chromatography (HPLC) with photo-diode array detector (PDA). The separation was carried out using a Purospher((R))-Star RP-18 e column (4.6mm i.d.x 250 mm, 5 microm) under the following conditions: acetonitrile:methanol (95:5, v/v) (solvent A) and water:acetic acid (99.9:0.1, v/v) (solvent B) as mobile phase with a linear gradient elution at a flow rate of 0.8 mL/min. The detection wavelength was set at 290 nm. Regression equation revealed a linear relationship (r(2)>0.9901) between the mass of hydroxyanthraquinone derivatives injected and the peak areas. The detection limits (S/N=3) ranged from 0.56 to 3.50 ng/mL and the recoveries ranged from 95.7 to 103.5% for five hydroxyanthraquinone derivatives. Compound 2 was found in maximum quantity (up to 2.23%) in the rhizomes from all the three locations (L(1), L(2) and L(3)) while compound 5 was found in the least quantity (up to 0.19%).

Mycobacterium tuberculosis persistence in various adipose depots of infected mice and the effect of anti-tubercular therapy.

The adipocytes are one of the non-professional phagocytes postulated to be a haven for Mycobacterium tuberculosis during persistence in the human host. The adipocyte - M. tuberculosis interaction data available to date are ex vivo. The present study was primarily aimed to investigate M. tuberculosis infection of adipocytes in course of infection of mouse model. Using primary murine adipocytes, the study first confirmed the infection and immunomodulation of natural adipocytes by M. tuberculosis. The bacilli could be isolated form visceral, subcutaneous, peri renal and mesenteric adipose depots of immunocompetent mice infected with M. tuberculosis intravenously. The bacilli could be isolated from adipocytes and the stromal vascular fraction, even though the numbers were significantly higher in the latter. The bacterial burden in the adipose depots was comparable to those in lungs in the early phase of infection. But with time, the burden in the adipose depots was either decreased or kept under control, despite the increasing burden in the lungs. Infected mice treated with standard anti tubercular drugs, despite effective elimination of bacterial loads in the lungs, continued to harbour M. tuberculosis in adipose depots at loads similar to untreated mice in the late infection phase.