Encapsulation of Triphasia trifolia extracts by pH and thermal dual-sensitive chitosan hydrogels for controlled release.

Recent studies have developed varied delivery systems incorporating natural compounds to improve the limitations of plant extracts for clinical use while enabling their controlled release at treatment sites. For the first time, ethanolic limeberry extract (Triphasia trifolia) has been successfully encapsulated in thermo-sensitive chitosan hydrogels by a facile in situ loading. The extract-incorporated chitosan hydrogels have a pH value of nearly 7.00, gelation temperatures in the range of 37-38 °C, and exhibit an open-cell porous structure, thus allowing them to absorb and retain 756 % of their mass in water. The in vitro extract release from the hydrogels is driven by both temperature and pH, resulting in more than 70 % of the initial extract being released within the first 24 h. Although the release half-life of hydrogels at pH 7.4 is longer, their release capacity is higher than that at pH 6.5. Upon a 2 °C increase in temperature, the time to release 50 % initial extract is sharply reduced by 20-40 %. The release kinetics from the hydrogels mathematically demonstrated that diffusion is a prominent driving force over chitosan relaxation. Consequently, the developed hydrogels encapsulating the limeberry extract show their heat and pH sensitivity in controlled release for treating chronic wounds.

Anti-arthritic activity and phytochemical composition of "Cao Khai" (Aqueous extracts of Coptosapelta flavescens Korth.).

For a long time, ethnic minorities in Ninh Thuan province have combined "Day Khai" (Coptosapelta flavescens Korth) with many other medicinal herbs, creating an esoteric remedy called "Cao Khai"-an aqueous extract from Day Khai. This study tested an aqueous extract from "Day Khai" for total phenolics, total flavonoids, antioxidant, and anti-inflammatory activity in an in vivo mice model. The aqueous extracts of raw materials C. flavescens collected in different regions were found to have phenolics, flavonoids, and antioxidant capacity in vitro according to DPPH, ABTS, RP, TAC, and FRAP methods. This study evaluated the effect of C. flavescens on arthritis of Complete Freund's adjuvant (CFA) induced-mice by observing changes in the degree of edema in the leg joints blood index and histology. The findings indicated that the "Cao Khai" had anti-inflammatory benefits and lowered the inflammatory symptoms in mice equivalent to Mobic medications (p < 0.05) while also limiting cartilage tissue damage after 14 days of usage. As a result, it is clear that "Cao Khai" can be considered a medicinal herb with tremendous potential for usage as an addition to illness therapy that should be protected and cultivated.

New Plant Species Showing Antiprotozoian Activity.

The effects of extracts of ten plant species from Russia and five species from Vietnam on the growth and survival of ciliates Tetrahymena pyriformis were studied. T. pyriformis belongs to the subkingdom Protozoa, which also includes pathogens of protozoan infections. Extraction of dried plants was carried out with acidic and alkaline aqueous solutions, as well as with an aqueous ethanol. Various amounts of extracts were added to the ciliate cells, and the number of cells survived after incubation for 1 and 24 h was recorded. We found that our samples of several plants, including wormwood, harmala, and licorice, similarly to those studied earlier, exhibit antiprotozoal activity, which may indicate that the secondary metabolites are the same in plants from different regions. Using the ciliate T. pyriformis as a model organism, the presence of antiprotozoal activity in extracts of lilac, chondrilla, cinquefoil, hop, and elm was shown for the first time.

Alfa glucosidase inhibitory, anti inflammatory activities and a new furanocoumarin derivative of Ruellia tuberosa.

Rullia tuberosa L. is used for treatment of diabetes mellitus, anti-inflammation, etc. However, its hypoglycaemic and anti inflammatory activities has not been investigated so far. In the present study, the α-glucosidase inhibitory, anti inflammatory activities of the extract of this plant were investigated. Our results showed that the crude extract as well as ethyl acetate and methanol fractions showed α-glucosidase inhibitory activity with IC50 of 15.84, 4.73 and 8.27 µg/ml, respectively. In addition, the hexane and ethyl acetate fractions are capable of inhibiting LPS-induced NO production with IC50 of 17.41 and 23.95 µg/mL, respectively. From the ethyl acetate and methanol fractions, eight compounds, including isobargaptol 5-O-ß-D-glucopyranoside (1), syringaresinol (2), catechin (3), pulmatin (4), stigmast-4-en-3-on (4), verbascoside (5), hydroxymethylfurfural (6), rutin (7), and homoplantaginin (8) were extracted and isolated. Their chemical structures were elucidated by spectroscopic method including MS, 1 D and 2 D- NMR and comparison with the literature values.

Enhanced Solubility of Alkaloids by Complexation with Polycarboxylic Materials for Controlled Release Formulations: Case of Peschiera fuchsiaefolia.

Malaria is a major public health problem with hundreds of thousands of deaths yearly. Extracts of Peschiera fuchsiaefolia (Pf), an Apocynaceae family plant, are used as malaria treatment by several populations. Artemisinin is another effective largely used antimalarial agent but susceptible to generate resistant forms of Plasmodium. To reduce the risk of new resistant strains' appearance, the WHO recommended artemisinin-based combination therapy (ACT) with another bioactive agent, ensuring a long duration of antiplasmodial activity. Pf alkaloids are good candidates for ACT, but their solubility is very low. This research was aimed to improve the solubility of Pf alkaloids by complexation via their amine groups with carboxylate groups of carboxymethylstarch (CMS), an excipient used to formulate oral dosage forms for controlled drug release. It was found that when complexed as CMS-Pf, the solubility of Pf is increased (four to five times in function of dissolution medium). A new specific and faster approach to evaluate the solubility was proposed, measuring the effective saturation concentration of the compound of interest via one of its specific capacities, i.e., absorption capacity at a specific wavelength or antioxidant properties. This approach is more convenient for solubility evaluation of various active agents from complexes or crude extracts, or in heterogeneous samples. Also, the storage stability was markedly improved from 1 week for Pf co-processed with maltodextrin (MD/Pf) to several months for CMS-Pf (in similar controlled temperature and humidity conditions). The co-processing as MD/Pf or complexation as CMS-Pf affected physical properties but not the biological (i.e., antioxidant) activity of Pf.

A new benzofuran derivative from the leaves of Ficus pumila L.

A new benzofuran derivative, pumiloside (1), together with seven known flavonoid glycosides, afzelin (2), astragalin (3), quercitrin (4), isoquercitrin (5), kaempferol 3-O-rutinoside (6), rutin (7) and kaempferol 3-O-sophoroside (8) were isolated from the leaves of Ficus pumila. Their structures were established by spectroscopic data and comparison with the literature values.

New cerebroside and chondrocyte proliferation activity of Caryota mitis L.

Caryota mitis L., a flowering plant, belongs to the family Arecaceae. In Vietnam, its fruits were used to treat joint pain. The present study was designed to investigate the phytochemicals and chondrocyte proliferation activity of C. mitis L. fruits on young human chondrocyte. The results showed that all of extracts (crude extract as well as n-hexane, chloroform, ethyl acetate and methanol fractions) were stimulated the growth of chondrocyte at 0.1 µg/mL; 0.01 µg/mL concentrations, of which the n-hexane and methanol fractions significantly increased the proliferation of chondrocyte by 30.75 and 24.42% at concentrations of 0.01 µg/mL, respectively. Repeated chromatography of the methanol fraction on silica gel, Sephadex LH-20 and ODS columns afforded a new cerebroside and eight known ones. Their structures were elucidated by analysis of spectral data and in comparison with the published reports.

New naphthalene derivative from the leaves of Cassia grandis L.

Cassia grandis is used for the treatment of skin disorders, back pain, aches, etc. in Vietnamese traditional medicine. In this paper, phytochemicals of the leaves were investigated. A new naphthalene derivative (1, cassgranon D) and, seven known compounds rutin (2), afzelin (3), quercitrin (4), epicatechin (5), (-)-epiafzelechin (6), isoquercitrin (7) and aloe emodin (8) were isolated from the ethyl acetate and methanol extracts. Their structures were elucidated by spectral evidences (UV, IR, MS, 1H, 13C, DEPT, HSQC and HMBC NMR), as well as by comparing with published data.

Flavonoids with hepatoprotective activity from the leaves of Cleome viscosa L.

One new flavonol glycoside named visconoside C (1), together with seven known flavonol glycosides, quercetin 3-O-ß-d-glucopyranoside 7-O-α-l-rhamnopyranoside (2), quercetin 7-O-α-l-rhamnopyranoside (3), astragalin (4), kaempferol 3-O-(4-O-acetyl)-α-l-rhamnopyranoside (5), kaempferol 7-O-α-l-rhamnopyranoside (6), kaempferitrin (7) and kaempferol 3-O-ß-d-glucopyranoside 7-O-α-l-rhamnopyranoside (8) were isolated by various chromatography methods from the leaves of Cleome viscosa L. Their structures were elucidated by IR, UV, HR-ESI-MS and NMR (1D & 2D) experiments. The cytotoxicity and hepatoprotective activities using HepG2 human hepatoma cell line of 1 were measured by MTT assay. At the concentration of 25 µM and 50 µM, 1 showed cytotoxic activity against HepG2 cells (cell viability was decreased to 22.2 and 23.0%, respectively, compared with doxorubicin control), while at the concentration of 100 µM, 1 showed hepatoprotective activity against CCl4-induced hepatotoxicity on HepG2 cells (34.3%, compared with quercetin control).

A new flavan from the Drynaria bonii H. Christ rhizomes.

In Vietnam, the medicinal plant Drynaria bonii H. Christ is used for the treatment of osteoporosis, bone fractures, and stimulate the growth of hair, treat tinnitus (Ho 2002; Loi 2004). In this article, experiments were designed to investigate the proliferation activity of ethanol, n-hexane, chloroform, ethyl acetate and methanol extracts from D. bonii rhizomes on MG-63 human osteoblast-like cells. The results showed that methanol and hexane extracts had the ability to proliferate MG-63 cells at the concentration varying from 0.1 to 0.01 µg/mL. In particular, at the concentration of 0.01 µg/mL, hexane and methanol extracts illustrated the highest proliferation ratio with 9.31% and 6.16%, respectively. By column chromatography, a new compound named drynaether A (1) and five known compounds uracil (2), 4'-hydroxy-7-methoxyflavan (3), kaempferol (4), indole-3-carboxylic acid (5) and protocatechuic acid (6) were isolated and identified from the methanol extract.

Drybonioside, a new glucoside from the Drynaria bonii H. Christ rhizomes.

Drynaria bonii H. Christ, a Vietnam traditional medicinal plant, is used for the treatment of osteoporosis, bone fractures, tinnitus, etc. (Ho PH. 2002. Vietnamese plants. Hanoi: Publisher of Young; Loi DT. 2004. Medicinal plants and remedy of Vietnam. Hanoi: Publisher of Medicine). Based on column chromatography, a new glucoside named drybonioside (5) and four known compounds α-tocopherol (1), 24-methylencycloartan-3ß-ol (2), triphyllol (3) and ethyl ß-D-fructopyranoside (4) were isolated and identified from hexane and methanol extracts of D. bonii. The structures of new compound were elucidated on the basis of NMR and MS spectroscopic analysis.

Carboxymethyl starch and lecithin complex as matrix for targeted drug delivery: I. Monolithic mesalamine forms for colon delivery.

For drugs expected to act locally in the colon, and for successful treatment, a delivery device is necessary, in order to limit the systemic absorption which decreases effectiveness and causes important side effects. Various delayed release systems are currently commercialized; most of them based on pH-dependent release which is sensitive to gastrointestinal pH variation. This study proposes a novel excipient for colon delivery. This new preparation consists in the complexation between carboxymethyl starch (CMS) and Lecithin (L). As opposed to existing excipients, the new complex is pH-independent, inexpensive, and easy to manufacture and allows a high drug loading. FTIR, X-ray, and SEM structural analysis all support the hypothesis of the formation of a complex. By minor variation of the excipient content within the tablet, it is possible to modulate the release time and delivery at specific sites of the gastrointestinal tract. This study opens the door to a new pH-independent delivery system for mesalamine targeted administration. Our novel formulation fits well with the posology of mesalamine, used in the treatment of Inflammatory Bowel Disease (IBD), which requires repeated administrations (1g orally four times a day) to maintain a good quality of life.

Gemcitabine plus carboplatin compared with carboplatin in patients with platinum-sensitive recurrent ovarian cancer: an intergroup trial of the AGO-OVAR, the NCIC CTG, and the EORTC GCG.

PURPOSE: Most patients with advanced ovarian cancer develop recurrent disease. For those patients who recur at least 6 months after initial therapy, paclitaxel platinum has shown a modest survival advantage over platinum without paclitaxel; however, many patients develop clinically relevant neurotoxicity, frequently resulting in treatment discontinuation. Thus, an alternative regimen without significant neurotoxicity was evaluated by comparing gemcitabine plus carboplatin with single-agent carboplatin in platinum-sensitive recurrent ovarian cancer patients. METHODS: Patients with platinum-sensitive recurrent ovarian cancer were randomly assigned to receive either gemcitabine plus carboplatin or carboplatin alone, every 21 days. The primary objective was to compare progression-free survival (PFS). RESULTS: Three hundred fifty-six patients (178 gemcitabine plus carboplatin; 178 carboplatin) were randomly assigned. Patients received a median of six cycles in both arms. With a median follow-up of 17 months, median PFS was 8.6 months (95% CI, 7.9 to 9.7 months) for gemcitabine plus carboplatin and 5.8 months (95% CI, 5.2 to 7.1 months) for carboplatin. The hazard ration (HR) for PFS was 0.72 (95% CI, 0.58 to 0.90; P = .0031). Response rate was 47.2% (95% CI, 39.9% to 54.5%) for gemcitabine plus carboplatin and 30.9% (95% CI, 24.1% to 37.7%) for carboplatin (P = .0016). The HR for overall survival was 0.96 (95% CI, 0.75 to1.23; P = .7349). While myelosuppression was significantly more common in the combination, sequelae such as febrile neutropenia or infections were uncommon. No statistically significant differences in quality of life scores between arms were noted. CONCLUSION: Gemcitabine plus carboplatin significantly improves PFS and response rate without worsening quality of life for patients with platinum-sensitive recurrent ovarian cancer.