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Studi scientifici sull'Aloe Arborescens



Effetti dell'aloe sulla leucemia negli uomini

Induction of apoptosis in human leukaemic cell lines K562, HL60 and U937 by diethylhexylphthalate isolated from Aloe vera Linne.

Lee KH, Hong HS, Lee CH, Kim CH. Animal Resource Research Center, Konkuk University, Seoul, Korea.

We investigated the effect of diethylhexylphthalate (DEHP) from Aloe vera Linne on the apoptosis of human leukaemic cell lines K562, HL60 and U937 to examine its pharmacological activity. At a level of 10 microg mL(-1) DEHP a significant anti-leukaemic effect was observed for all three cell lines, as measured by clonogenic assay. After treatment with 10 microg mL(-1) DEHP for 4 h, agarose gel electrophoresis and flow cytometric analysis confirmed the occurrence of apoptosis. These results indicate that DEHP isolated from Aloe vera Linne has a potent antileukaemic effect, and thus represents a new type of pharmacological activity with respect to human leukaemic cells. PMID: 11007077

Anti-leukaemic and anti-mutagenic effects of di(2-ethylhexyl)phthalate isolated from Aloe vera Linne.

Lee KH, Kim JH, Lim DS, Kim CH. Animal Resource Research Center, Konkuk University, Seoul, Korea.

Extracts of Aloe vera Linne have been found to exhibit cytotoxicity against human tumour cell lines. This study examines the anti-tumour effects of di(2-ethylhexyl)phthalate (DEHP) isolated from Aloe vera Linne, in human and animal cell lines. Its anti-mutagenic effects were examined using Salmonella typhimurium TA98 and TA100 strains. Growth inhibition was specifically exerted by DEHP against three leukaemic cell lines at concentrations below 100 microg mL(-1). At 100 microg mL(-1) DEHP, K562, HL60 and U937 leukaemic cell lines showed growth inhibition of 95, 97 and 95%, respectively. DEHP exhibited an inhibitory activity of 74, 83 and 81%, respectively, in K562, HL60 and U937 cell lines at a concentration of 10 microg mL(-1). At a concentration of 1 microg mL(-1), DEHP exerted an inhibitory activity of 50, 51 and 52%, respectively, in K562, HL60 and U937. In a normal cell line, MDBK, DEHP exerted 30% growth inhibition at a concentration of 100 microg mL(-1), and showed no inhibitory activity at concentrations below 50 microg mL(-1). It was found that DEHP exerted anti-mutagenic activity in the Salmonella mutation assay. The number of mutant colonies of Salmonella typhimurium strain TA98 upon exposure to AF-2 (0.2 microg/plate) decreased in a concentration-dependent manner in the presence of different DEHP concentrations (decreasing to 90.4, 83.9, 75.4, 69.6 and 46.9%, respectively, for DEHP concentrations of 100, 50, 10, 5 and 1 microg/plate). In the case of Salmonella typhimurium strain TA100, DEHP reduced AF-2-induced mutagenicity at 1, 5, 10, 50 and 100 microg/plate to 57.4, 77.5, 80.0, 89.0 and 91.5%, respectively. The isolated compound from Aloe vera Linne, DEHP, was considered to be the active principle responsible for anti-leukaemic and anti-mutagenic effects in-vitro. PMID: 10864149

Tumori neuroectodermici

Aloe-emodin is a new type of anticancer agent with selective activity against neuroectodermal tumors.

Pecere T, Gazzola MV, Mucignat C, Parolin C, Vecchia FD, Cavaggioni A, Basso G, Diaspro A, Salvato B, Carli M, Palu G. Department of Histology, Microbiology, and Medical Biotechnologies, Medical School, University of Padova, Italy.

Here we report that aloe-emodin (AE), a hydroxyanthraquinone present in Aloe vera leaves, has a specific in vitro and in vivo antineuroectodermal tumor activity. The growth of human neuroectodermal tumors is inhibited in mice with severe combined immunodeficiency without any appreciable toxic effects on the animals. The compound does not inhibit the proliferation of normal fibroblasts nor that of hemopoietic progenitor cells. The cytotoxicity mechanism consists of the induction of apoptosis, whereas the selectivity against neuroectodermal tumor cells is founded on a specific energy-dependent pathway of drug incorporation. Taking into account its unique cytotoxicity profile and mode of action, AE might represent a conceptually new lead antitumor drug. PMID: 10850417

Studio degli effetti dell'aloe contro tumori della pelle.

Adverse and beneficial effects of plant extracts on skin and skin disorders.

Mantle D, Gok MA, Lennard TW. Department of Surgery, Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU.

Plants are of relevance to dermatology for both their adverse and beneficial effects on skin and skin disorders respectively. Virtually all cultures worldwide have relied historically, or continue to rely on medicinal plants for primary health care. Approximately one-third of all traditional medicines are for treatment of wounds or skin disorders, compared to only 1-3% of modern drugs. The use of such medicinal plant extracts for the treatment of skin disorders arguably has been based largely on historical/anecdotal evidence, since there has been relatively little data available in the scientific literature, particularly with regard to the efficacy of plant extracts in controlled clinical trials. In this article therefore, adverse and beneficial aspects of medicinal plants relating to skin and skin disorders have been reviewed, based on recently available information from the peer-reviewed scientific literature. Beneficial aspects of medicinal plants on skin include: healing of wounds and burn injuries (especially Aloe vera); antifungal, antiviral, antibacterial and acaricidal activity against skin infections such as acne, herpes and scabies (especially tea tree (Melaleuca alternifolia) oil); activity against inflammatory/immune disorders affecting skin (e.g. psoriasis); and anti-tumour promoting activity against skin cancer (identified using chemically-induced two-stage carcinogenesis in mice). Adverse effects of plants on skin reviewed include: irritant contact dermatitis caused mechanically (spines, irritant hairs) or by irritant chemicals in plant sap (especially members of the Ranunculaceae, Euphorbiaceae and Compositae plant families); phytophotodermatitis resulting from skin contamination by plants containing furocoumarins, and subsequent exposure to UV light (notably members of the Umbelliferae and Rutaceae plant families); and immediate (type I) or delayed hypersensitivity contact reactions mediated by the immune system in individuals sensitized to plants or plant products (e.g. peanut allergy, poison ivy (Toxicodendron) poisoning). PMID: 11482001

Effetti dell'aloe contro i tumori cerebrali

Acemannan purified from Aloe vera induces phenotypic and functional maturation of immature dendritic cells.

Lee JK, Lee MK, Yun YP, Kim Y, Kim JS, Kim YS, Kim K, Han SS, Lee CK. College of Pharmacy, Chungbuk National University, Cheongju 361-763, South Korea.

Acemannan, a major carbohydrate fraction of Aloe vera gel, has been known to have antiviral and antitumoral activities in vivo through activation of immune responses. The present study was set out to define the immunomodulatory activity of acemannan on dendritic cells (DCs), which are the most important accessory cells for the initiation of primary immune responses. Immature DCs were generated from mouse bone marrow (BM) cells by culturing in a medium supplemented with GM-CSF and IL-4, and then stimulated with acemannan, sulfated acemannan, and LPS, respectively. The resultant DCs were examined for phenotypic and functional properties. Phenotypic analysis for the expression of class II MHC molecules and major co-stimulatory molecules such as B7-1, B7-2, CD40 and CD54 confirmed that acemannan could induce maturation of immature DCs. Functional maturation of immature DCs was supported by increased allogeneic mixed lymphocyte reaction (MLR) and IL-12 production. The differentiation-inducing activity of acemannan was almost completely abolished by chemical sulfation. Based on these results, we propose that the adjuvant activity of acemannan is at least in part due to its capacity to promote differentiation of immature DCs. PMID: 11460308

Sarcomi

Decreased mortality of Norman murine sarcoma in mice treated with the immunomodulator, Acemannan.

Peng SY, Norman J, Curtin G, Corrier D, McDaniel HR, Busbee D. Department of Anatomy, College of Veterinary Medicine, Texas A & M University, College Station 77843.

An extract from the parenchyma of Aloe barbadensis Miller shown to contain long chain polydispersed beta (1,4)-linked mannan polymers with random O-acetyl groups (acemannan, Carrisyn) was found to initiate the phagocyte production of monokines that supported antibody dependent cellular cytotoxicity and stimulated blastogenesis in thymocytes. Acemannan, in both enriched and highly purified forms, was administered intraperitoneally to female CFW mice into which murine sarcoma cells had been subcutaneously implanted. The rapidly growing, highly malignant and invasive sarcoma grew in 100% of implanted control animals, resulting in mortality in 20 to 46 days, dependent on the number of cells implanted. Approximately 40% of animals treated with acemannan at the time of tumor cell implantation (1.5 x 10(6) cells) survived. Tumors in acemannan-treated animals exhibited vascular congestion, edema, polymorphonuclear leukocyte infiltration, and central necrosing foci with hemorrhage and peripheral fibrosis. The data indicate that in vivo treatment of peritoneal macrophages stimulates the macrophage production of monokines, including interleukin-1 and tumor necrosis factor. The data further indicate that sarcomas in animals treated i.p. with acemannan at the time of tumor cell implantation were infiltrated by immune system cells, became necrotic, and regressed. The combined data suggest that acemannan-stimulated synthesis of monokines resulted in the initiation of immune attack, necrosis, and regression of implanted sarcomas in mice. PMID: 1910624

Tumori dei polmoni

The therapeutic potential of Aloe Vera in tumor-bearing rats.

Corsi MM, Bertelli AA, Gaja G, Fulgenzi A, Ferrero ME. Institute of General Pathology, Medical Faculty, University of Milan, Italy.

Aloe Vera has been claimed to contain several important therapeutic properties, including anticancer effects. The effect of Aloe Vera administration was studied on a pleural tumor in rat. Growth of Yoshida AH-130 ascite hepatoma cells injected (2 x 10(5) in 0.1 ml) into pleura of male inbred Fisher rats was evaluated at different times (7th and 14th days). Data show that the use of Aloe Vera proved a therapeutic method, and that the present experimental model could be useful in the study of other therapeutics treatments in vivo.
PMID: 10093794



Cancro Chemioterapia