Evaluation of the wound healing properties of Acalypha langiana in diabetic rats.

Acalypha langinia is a well-known plant in the traditional medicine. Based on its traditional use, this plant was selected for evaluation of its wound healing potential. Topical application twice a day for 7 days of 0.05%, 0.1%, 0.2%, 0.4% and 0.5% sterile solution of aqueous extract from leaves of A. langinia significantly increased the healing process.

Wound healing properties of Hylocereus undatus on diabetic rats.

Aqueous extracts of leaves, rind, fruit pulp and flowers of Hylocereus undatus were studied for their wound healing properties. Wound healing effects were studied on incision (skin breaking strength), excision (percent wound contraction) and the nature of wound granulation tissues, which were removed on day 7 and the collagen, hexosamine, total proteins and DNA contents were determined, in addition to the rates of wound contraction and the period of epithelialization. In streptozotocin diabetic rats, where healing is delayed, topical applications of H. undatus produced increases in hydroxyproline, tensile strength, total proteins, DNA collagen content and better epithelization thereby facilitating healing. H. undatus had no hypoglycemic activity.

Antioxidant and free radical scavenging activities of 5,7,3'-trihydroxy-3,6,4'-trimethoxyflavone from Brickellia veronicaefolia.

The antioxidant and antiradical activities of 5,7,3'-trihydroxy-3,6,4'-trimethoxyflavone or centaureidin isolated and characterized from Brickellia veronicaefolia were elucidated by heat-induced oxidation in a beta-carotene and linoleic acid system and by the 1,1-diphenyl-2-picrylhydrazyl decoloration test. The centaureidin (32.1%) exhibited antioxidative activity less than that of BHT (95.5%) and alpha-tocopherol (95.9%) on oxidation in a beta-carotene and linoleic acid system. A moderate antiradical effect (47.6%) compared with BHT (96.7%) and alpha-tocopherol (94.6%) in DPPH decoloration test was found.

Triterpenes from Agarista mexicana as potential antidiabetic agents.

Hypoglycaemic activity-guided fractionation together with chemical analysis led to the isolation of 12-ursene and a novel triterpene 23,24 dimethyl-24-ethyl-stigmast-25-ene from the chloroform extract of the dried stem of A. mexicana. Identification was based on spectroscopic methods. The isolated triterpenes were tested for hypoglycaemic activity in normal and alloxman-diabetic CD1 mice 25-30 g at a dose of 50 mg/kg body weight. The blood glucose levels were determined before and 1.5, 3, 4.5 and 24 h after intraperitoneal drug administration. The results showed that the triterpenes produced a significant hypoglycaemic effect in normal as well as in diabetic mice. Comparison was made between the action of the triterpenes and a known hypoglycaemic drug, tolbutamide (50 mg/kg). The 12-ursene was found to be slow and less effective than tolbutamide, and the 23,24 dimethyl-24-ethyl-stigmast-25-ene was shown to be more effective than tolbutamide.

Cell populations during tumorigenesis in Eu-myc transgenic mice.

Transgenic mice bearing a c-myc oncogene under control of the immunoglobulin heavy chain (Igh) enhancer (Eu-myc mice) (1, reviewed in 2) undergo a reproducible series of developmental stages and die from malignancies of the B lymphocyte lineage. To investigate the cellular events underlying tumorigenesis in this model, we quantified B lymphoid subpopulations and turnover at various stages of this process. An early stage was characterized by the presence in the blood of many large proliferating B lineage cells marked by surface antigen phenotype IgM+l-, B220low, CD5-, Mac-1low. During a prolonged intermediate 'remission' phase of different duration in each mouse, B lymphocytes in the periphery were non-proliferative, few, and of conventional phenotype (IgM+, B220+, CD5-, Mac-1-), while subsets of precursor B cells were both numerous and highly proliferative in the bone marrow. In the final stage of tumorigenesis, large proliferating cells similar in phenotype to those of the early period reappeared and increased rapidly in numbers. This B cell tumorigenic progression occurred independently of interactions with T lymphocytes. Evidence of massive cell death in the bone marrow during the intermediate phase, plus molecular characterization of the final tumors, suggested that the end of the peripheral 'remission' period and entry into the terminal stage of tumorigenesis may be due to a clone of cells acquiring the ability to circumvent normal processes of cell death and elimination that usually regulate the egress of B cells from the bone marrow to the periphery.