Bioactive derivatives of curcumin attenuate cataract formation in vitro

The consumption of sea buckthorn (Hippophae rhamnoides L.) effectively alleviates type 2 diabetes symptoms in spontaneous diabetic rats

Sea buckthorn (Hippophae rhamnoides L.) is described by various beneficial effects as it contains several bioactive substances characterized by antioxidant effects. These effects are closely related to the reduction of oxidative stress that is involved in the development of the disease. One such diseases is Diabetes mellitus, the prevalence of which is growing and is associated primarily with diet, lack of exercise and/or genetics. This study intends to examine the effects of sea buckthorn and metformin on body weight, water and feed intake, glycaemia, insulinemia, sorbitol accumulation and cataract development in Zucker diabetic fatty rats, which represent an animal model of type 2 Diabetes mellitus, as well as to characterize the individual content of bioactive substances and the antioxidant activity of sea buckthorn. Particular concentrations were applied (500 and 1000 mg.kg-1 body weight of sea buckthorn, and combinations with 150 mg.kg-1 body weight of metformin) by gastric gavage. The total antioxidant capacity and bioactive compounds were determined by spectrophotometric analysis. The best results of the study showed suppression of hyperglycaemia, water intake, decreased sorbitol levels in the lens of the eyes after sea buckthorn treatment. Determination of bioactive compounds showed significantly higher values in dry berries when compared to fresh berries of sea buckthorn and high total antioxidant capacity. Our results represent an interest in sea buckthorn and its potential use in the treatment of Diabetes mellitus as well as other experimental studies.

Tailored Functionalization of Natural Phenols to Improve Biological Activity

Phenols are widespread in nature, being the major components of several plants and essential oils. Natural phenols' anti-microbial, anti-bacterial, anti-oxidant, pharmacological and nutritional properties are, nowadays, well established. Hence, given their peculiar biological role, numerous studies are currently ongoing to overcome their limitations, as well as to enhance their activity. In this review, the functionalization of selected natural phenols is critically examined, mainly highlighting their improved bioactivity after the proper chemical transformations. In particular, functionalization of the most abundant naturally occurring monophenols, diphenols, lipidic phenols, phenolic acids, polyphenols and curcumin derivatives is explored.

Novel flourescent spiroborate esters: potential therapeutic agents in in vitro cancer models

The current treatment system in cancer therapy, which includes chemotherapy/radiotherapy is expensive and often deleterious to surrounding healthy tissue. Presently, several medicinal plants and their constituents are in use to manage the development and progression of these diseases.They have been found effective, safe, and less expensive. In the present study, we are proposing the utility of a new class of curcumin derivative, Rubrocurcumin, the spiroborate ester of curcumin with boric acid and oxalic acid (1:1:1), which have enhanced biostability for therapeutic applications. In vitro cytocompatibility of this drug complex was analysed using MTT assay, neutral red assay, lactate dehydrogenase assay in 3T3L1 adipocytes. Anti tumour activity of this drug complex on MCF7 and A431 human cancer cell line was studied by morphological analysis using phase contrast microscopy, Hoechst staining and cell cycle analysis by FACS. To explore the chemotherapeutic effect, the cytotoxic effect of this compound was also carried out. Rubrocurcumin is more biostable than natural curcumin in physiological medium. Our results prove that this curcumin derivative drug complex possess more efficacy and anti-cancer activity compared with curcumin. The findings out of this study suggests this novel compound as potential candidate for site targeted drug delivery.

Drug delivery to the lens for the management of cataracts

Cataracts are one of the most prevalent diseases of the lens, affecting its transparency and are the leading cause of reversible blindness in the world. The clarity of the lens is essential for its normal physiological function of refracting light onto the retina. Currently there is no pharmaceutical treatment for prevention or cure of cataracts and surgery to replace the affected lens remains the gold standard in the management of cataracts. Pharmacological treatment for prevention of cataracts is hindered by many physiological barriers that must be overcome by a therapeutic agent to reach the avascular lens. Various therapeutic agents and formulation strategies are currently being investigated to prevent cataract formation as access to surgery is limited. This review provides a summary of recent research in the field of drug delivery to the lens for the management of cataracts including models used to study cataract treatments and discusses the future perspectives in the field.

Curcumin, A Potential Therapeutic Candidate for Anterior Segment Eye Diseases: A Review

Curcumin, the major curcuminoid of the turmeric, has been extensively used in many countries since ancient time for preventing and/or treating a multitude of diseases. This review is to illustrate the researches on the properties of curcumin and its potential therapeutic efficacy in major anterior segment eye diseases. The bio-medical potential of curcumin is restricted because of its low solubility and digestive bioavailability. This review will discuss promising research in improving curcumin bioavailability through structural modification. In vitro and in vivo research made progress in studying the beneficial effects of curcumin on major anterior segment eye diseases, including anti-angiogenesis effect in corneal diseases; anti-inflammation or anti-allergy effects in dry eye disease, conjunctivitis, anterior uveitis; anti-proliferation and pro-apoptosis effects in pterygium; anti-oxidative stress, anti-osmotic stress, anti-lipid peroxidation, pro-apoptosis, regulating calcium homeostasis, sequestrating free radicals, protein modification and degradation effects in cataracts; neuroprotective effects in glaucoma. Curcumin exhibited to be a potent therapeutic candidate for treating those anterior segment eye diseases.

Anticataractogenesis Mechanisms of Curcumin and a Comparison of Its Degradation Products: An in Vitro Study

Curcumin (Cur) exhibits anticataractogenesis activity. This study aimed to compare the activities of Cur with those of its degradation products in a series of in vitro lens protein turbidity assays. The results show that Cur (200 μM) ameliorates selenite-induced crystallin aggregation, and the mean OD value was 0.10 ± 0.02 (p < 0.05), which was significantly different from controls (0.15 ± 0.01) after incubating for 3 days. However, Cur did not significantly inhibit calcium-induced proteolysis after incubating for 3 days. Such results were supported by isothermal titration calorimetry observation that Cur binds with selenite but not with calcium. Presence of Cur and the degradation products examined (ferulic acid, cinnamic acid, vanillin, and vanillic acid) indicates significantly protective activities on lens γ-crystallins after UVC exposure for 3 h. Among the compounds examined, only ferulic acid exhibited a significant inhibitory effect against UVB-induced turbidity with a mean OD of 0.32 ± 0.01 (p < 0.05), which was significantly different from controls (0.49 ± 0.02). The previously reported anticataract effects of Cur may stem not only from Cur but also from its degradation products through various cataractogenesis mechanisms in vitro.

The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions

In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO3(2-) and DCCM/SeO3(2-) complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation.