Evaluation of natural gum-based cryogels for soft tissue engineering.

In this study, three natural biomaterials, Locust bean gum (LBG), Xanthan gum (XG), and Mastic gum (MG), were combined to form cryogel scaffolds. Thermal and chemical characterizations revealed the successful blend formation from LBG-XG (LX) and LBG-XG-MG (LXM) polymers. All blends resulted in macro-porous scaffolds with interconnected pore structures under the size of 400 µm. The swollen cryogels had similar mechanical properties compared with other polysaccharide-based cryogels. The mean tensile and compressive modulus values of the wet cryogels were in the range of 3.5-11.6 kPa and 82-398 kPa, respectively. The sustained release of the small molecule Kartogenin from varying concentrations and ratios of cryogels was in between 32 and 66% through 21 days of incubation. Physical, mechanical, and chemical properties make LX and LXM polysaccharide-based cryogels promising candidates for cartilage and other soft tissue engineering, and drug delivery applications.

Acacia mearnsii gum: A residue as an alternative gum Arabic for food stabilizer.

Acacia mearnsii gum is not commercially exploited, being characterized as residue from A. mearnsii cultivation. This work investigated the A. mearnsii gum polysaccharide composition, its cytotoxicity and the technological effect as a stabilizer in ice cream. A. mearnsii gum showed a similar chemical structure to commercial gum Arabic and did not decrease the viability and proliferation of fibroblast cells (Balb/3T3) and hepatocarcinoma (HepG2). Rheological tests showed that the ice cream stabilized by the A. mearnsii gum had a more structured system (more interactions between the mixture components) and the same melting characteristics as the ice cream samples made with commercial gum Arabic. The results showed that A. mearnsii gum, which is actually an agro-industrial residue from tannin production for industry, is a potential stabilizing gum for the food industry, contributing to the economic development of the exploitation chain of A. mearnsii products and by-products.

In vitro evaluation of reactive nature of E- and Z-guggulsterones and their metabolites in human liver microsomes using UHPLC-Orbitrap mass spectrometer.

Guggulipid is known to be useful for hypercholesterolemia, arthritis, acne, and obesity. These activities are attributed to its two principal isomeric active constituents, viz., E- and Z-guggulsterones. There are several side effects reported for guggulipid, which include widespread erythematous papules in a morbilliform pattern and macules localized to the arms; swelling and erythema of the face with burning sensation; pruritis; and bullous lesions on the lower legs with associated headaches, myalgia and itching. We hypothesized that one probable reason for these toxic reactions could be the formation of electrophilic reactive metabolites (RMs) of guggulsterones and their subsequent reaction with cellular proteins. Unfortunately, no report exists in the literature highlighting detection of RMs of guggulsterone isomers. Accordingly, the present study was undertaken to investigate the potential of E- and Z-guggulsterones to form RMs in human liver microsomes (HLM) using glutathione (GSH) and N-acetylcysteine (NAC) as trapping agents. The generated samples were analysed using ultra-high performance liquid chromatography (UHPLC) coupled to an Orbitrap mass spectrometer. The analysis of incubations with trapping agents highlighted that hydroxylated metabolites of guggulsterone isomers showed adduction with GSH and NAC. Even direct adducts of guggulsterone isomers were observed with both the trapping agents. The in silico toxicity potential of E- and Z-guggulsterones and their RMs was predicted using ADMET Predictor™ software and comparison was made against reported toxicities of guggulipid.

Toxicity studies of a gum guggul extract formulation administered by gavage to Sprague Dawley (Hsd:Sprague Dawley SD) rats and B6C3F1/N mice.

Gum guggul extracts (GGEs) are botanical preparations derived from the oleoresin of the Commiphora mukul tree. The preparations are traditionally used in Ayurvedic medicine to treat hyperlipidemia, obesity, diabetes, atherosclerosis, and inflammatory conditions such as arthritis. In the United States, GGEs are marketed as dietary supplements. GGE toxicity was evaluated due to widespread human exposure through increasing dietary supplement use, demonstrated metabolic and hormone-altering effects, and a lack of available information to adequately assess safe use in humans. Male and female Sprague Dawley (Hsd:Sprague Dawley SD) rats and B6C3F1/N mice were administered a GGE formulation in corn oil by gavage for 28 days or 3 months. Oral gavage was chosen as the route of exposure for these studies because human exposure primarily occurs by ingestion of encapsulated GGE supplements. (Abstract Abridged).

Synthesis and evaluation of hydrophobically modified fenugreek gum for potential hepatic drug delivery.

The objective of this study was to hydrophobically modify fenugreek gum (FG) and to further evaluate the potential application of the obtained derivative in liver-targeted drug delivery system. Stearic acid (C18) was conjugated with FG (FG-C18) by a simple esterification reaction. The obtained FG-C18 was then characterized on its chemical structure by Fourier transform infrared spectroscopy and 1H-nuclear magnetic resonance. The self-assembled nanomicelles (NMs) of FG-C18 in water were prepared by an ultrasonication method. The average diameter and zeta potential of FG-C18 NMs were 196.70 ± 6.12 nm and -31.79 ± 1.58 mV, respectively. FG-C18 NMs appeared as spherical particles under transmission electron microscopy and possessed a critical micellar concentration of 0.042 mg/ml by pyrene fluorescence probe method. A low toxicity of FG-C18 was revealed on both HepG2 and MCF-7 cells at 0.1-100 mg/ml. Haemolysis of FG-C18 was less than 5%. Cellular uptake of coumarin-6 into HepG2 cells was enhanced by treating with C6-loaded FG-C18 NMs compared to free coumarin-6. These results suggest that FG-C18 have a potential application for a liver targeted drug delivery.

Phenolics composition, antioxidant properties and toxicological assessment of Prosopis alba exudate gum.

The objective of this work was to deepen on the study of functional properties of the phytochemicals present in Prosopis alba exudate gum (G), as well as to rule out possible adverse effects of some of its components. Commonly employed purification methods were compared. Filtration prevents further loss of potentially bioactive compounds. The filtrated gum showed a higher concentration of phenolics, flavonoids and tannins than arabic gum, which was correlated with better in vitro antioxidant properties. Particularly, tannins, commonly considered as toxic compounds in exudate gums, were found in lower concentration than in others gums obtained from genus Prosopis and Acacia. The toxicological evaluation performed on rats did not show symptoms of intoxication associated with the administration of the gum. These results provide useful evidence to support the potential use of G as a safe functional food additive with the added benefit of taking advantage of a non-exploited natural resource.

Safety Assessment of Galactomannans as Used in Cosmetics.

The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of 16 galactomannans as used in cosmetics. These ingredients are legume polysaccharides that function mostly as hair/skin-conditioning agents and viscosity-increasing agents in cosmetic products. Their substantial molecular sizes suggest that skin penetration of these ingredients would be unlikely. The Panel concluded that these galactomannans are safe in the present practices of use and concentration described in this safety assessment.

A comprehensive evaluation of the toxicology of the "Deli" cast sheet process used in experimental cigarettes.

CONTEXT: Manufacture of cigarettes results in tobacco by-products, some of which can be processed and added back to cigarettes. Such additions (known as reconstituted tobacco or reconstituted leaf) have been shown to reduce tar yields. A new process (termed "Deli" cast sheet) is a potential refinement of the reconstitution process. OBJECTIVE: Compare toxicity of smoke from experimental cigarettes made with reconstituted leaf with that from cigarettes made with Deli cast sheet. MATERIALS AND METHODS: Analytical chemistry, Salmonella mutagenicity and cytotoxicity assays were used to evaluate the composition biological activity of mainstream smoke from experimental cigarettes made with Deli cast sheet or with reconstituted leaf. The effect of different amounts of guar and propylene glycol in Deli cast sheet was also evaluated. RESULTS: Small increases in the amount of nitrogen oxides were found as a result of inclusion of the Deli cast sheet when compared with reconstituted leaf; no differences in cytotoxicity or mutagenicity were found. CONCLUSION: The Deli process neither significantly modified chemical composition of smoke nor affected its biological activity, as measured by the mutagenicity and cytotoxicity assays used here.

Guggulipid of Commiphora mukul, with antiallodynic and antihyperalgesic activities in both sciatic nerve and spinal nerve ligation models of neuropathic pain.

CONTEXT: Guggulipid is a neutral fraction of ethyl acetate extract of gum resin of the tree Commiphora mukul Engl. (Burseraceae) and used in Ayurvedic medicine for treatment of neurological disorders. OBJECTIVES: The present study was undertaken to assess the antiallodynic and antihyperalgesic activities of guggulipid in rats. MATERIALS AND METHODS: The screening study included the CCI and L5-L6 SNL models of neuropathic pain. Guggulipid (100 and 50 mg/kg) or saline was administered intraperitoneally in a blinded, randomized manner from postoperative day (POD) 7 to 13. Paw withdrawal duration (PWD) to spontaneous pain, chemical allodynia and mechanical hyperalgesia and paw withdrawal latency (PWL) to mechanical allodynia and thermal hyperalgesia were tested before surgery, before and after guggulipid or saline administration (from POD7 to 13) and after the withdrawal of treatment (from POD14 to 20). RESULTS: The activity profiles of the different doses of guggulipid were found to vary with time. In CCI rats, guggulipid (100 and 50 mg/kg) significantly (p < 0.05) reduced the spontaneous pain, mechanical allodynia and mechanical and thermal hyperalgesia responses and the LD50 of guggulipid was 1600 mg/kg. In SNL rats, both doses of guggulipid were found to be ineffective in reversing the spontaneous pain but showing antiallodynic and antihyperalgesic activity. DISCUSSION AND CONCLUSION: The results demonstrated that guggulipid produce antinociception in the peripheral nerve injury (CCI and SNL) models of neuropathic pain. The underlying mechanisms are expected to be modulating microglial activation occurring due to peripheral nerve injury.

Acute hepatitis caused by a natural lipid-lowering product: when "alternative" medicine is no "alternative" at all.

BACKGROUND/AIMS: The general public's growing mistrust of the pharmaceutical industry and its perception of the lack of adverse effects of "natural" therapy have lead to the increasing use of "alternative drugs" for hypercholesterolemia. METHODS: A sixty-three year old woman presented with severe hypertransaminasemia that had developed progressively over a few weeks. For six months she had been taking Equisterol, an over-the-counter lipid-lowering product containing guggulsterol and red yeast rice extract. The product had been prescribed for hypercholesterolemia because the patient had developed hepatotoxicity while on lovastatin. RESULTS: Liver biopsy revealed severe lobular necroinflammatory changes with an eosinophilic infiltrate. The episode was regarded as an adverse drug reaction after exclusion of other possible causes of acute liver disease and the prompt normalization of liver function tests after Equisterol had been discontinued. Red yeast rice extract's cholesterol-lowering properties are largely due to fungal metabolites known as monacolins, one of which--monacolin K--is identical to lovastatin. CONCLUSIONS: The choice of an alternative medicine approach in this case subjected the patient to "re-challenge" with the official medicine agent that had previously caused mild hepatotoxicity. Physicians should keep in mind that "alternative" medicine is not always the safest alternative and sometimes it is not even "alternative."