Plant resources -- Aloe052991 黄力维052983 徐雍羽

Kingdom: Plantae(植物界 )

Division: Magnoliophyta（木兰门）Class: Liliopsida（百合纲）Order: Asparagales（天门冬目）Family: Asphodelaceae（日光兰科）Genus: Aloe

Morphological Feature：

Most Aloes have a rosette of large, thick, fleshy leaves. The leaves are often lance(茅 )-shaped with a sharp apex（顶点） and a spiny（多针刺的） margin. Aloe flowers are tubular（管状的） , frequently Brown, pink or red and are born on densely clustered, simple or branched leafless stems.Many species of Aloe are seemingly stemless, with the rosette growing directly at ground level; other varieties may have a branched or un-branched stem from which the fleshy leaves spring. They vary in disecis from grey to bright green and are sometimes striped（有条纹的） or grasped.

Introduction

Introduction

Aloe vera (Aloe vera Linn, synonym: aloe vera barbadensisMill.) is in family Liliaceae, which is a tropical plant easily grown in hot and dry climates.

• Numerous cosmetics and medicinal products are made from the mucilaginous tissue, called aloe vera gel, located in the center of the aloe vera leaf.

• Aloe vera gel has been used for many indications since the Roman era or even long before.

Aloe Extracts

• Burn wound healing

• Antifungal

• Anti-diabetes

• anti-obesity

• Anti-inflammation

• Burn wound healing is one of major indications of aloe vera gel use in many countries.

• Existing evidence demonstrates that aloe vera used in a variety of dosage forms might be effective in shortening the duration of wound healing in first to second degree burns, and it tended to increase rate of success to healing and rate of epithelialization.

Burn Wound Healing

• These effects might be due to several mechanisms including an increasing collagen synthesis and rate of epithelialization by the effect of acemanan (mannose-6 phosphate) to stimulate fibroblasts, an anti-inflammatory effect, an antimicrobial effect, and a moisturizing effect.

• Aloe vera products are also safe for topical use. There was no withdrawal or serious adverse reaction reported in the included studies.

Antifungal activity of Aloe vera leaves• Aloe vera fresh leaves

hydroalcoholic plant extract was tested against the mycelial growth of Botrytis gladiolorum, Fusarium oxysporum f.sp. gladioli, Heterosporium pruneti and Penicillium gladioli on Czapek-agar medium.

• The minimum fungicidal concentration (MFC) varied between 80 and 100 μl/ml, depending on the fungal species.

Aloe Extracts’ Effect On Diabetic• Extracts of aloe gum effectively increased glucose

tolerance in both normal and diabetic rats.• The hypoglycemic effect of single dose of the bitter

principle was extended over a period of 24 h with maximum hypoglycemia observed at 8 h while chronic administration (exudate twice daily and the bitter principle once a day for 4 days) showed maximum reduction in plasma glucose level at the 5th day.

• Hypoglycemic effect of aloe and its bitter principle is mediated through stimulation of synthesis and/or release of insulin from the beta-cells of Langerhans.

Aloe Extracts’ Effect On Obesity• Because of its reputed anti-diabetic activity, scientists have

decided to investigate its effect on obesity.

• The NS2 extract significantly reduced body weight, fat pads and liver weight, and blood glucose levels compared to the control and HF-NS1.

• Although NS1 significantly lost body weight, paradoxically tissue weights and glucose levels were not significantly different from control rats.

• This data suggests that NS2 extract has both antiobesity and antidiabetic properties.

Extracts

• Aloe Emodin

• APS-1

• Dihydrocoumarin

• Production of large amounts of TNF has been implicated in the liver damage during sepsis, viral hepatitis, alcoholic hepatitis, ischemia-reperfusion liver injury and fulminant hepatic failure, as well as in chemical-induced hepatotoxicity. Accordingly, TNF displayed a direct TNF-R1-dependent toxicity towards hepatocytes, both in vitro and in vivo

• Aloe emodin inhibited both basal and TNF-triggered activation of extracellular signal-regulated kinase (ERK), and a selective blockade of ERK activation mimicked the cytoprotective action of the drug.

Aloe emodin protects L929 cells from TNF-induced death

Aloe Emodin

• Aloe emodin also has the anticancer effect in two human liver cancer cell lines, Hep G2 and Hep 3B.

• It inhibited cell proliferation and induced apoptosis in both examined cell lines, but with different the anti-proliferative mechanisms.

Aloe Emodin

• In Hep G2 cells, aloe-emodin induced p53 expression and was accompanied by induction of p21 expression that was associated with a cell cycle arrest in G1 phase. In addition, aloe-emodin had a marked increase in Fas/APO1 receptor and Bax expression.

• In contrast, with p53-deficient Hep 3B cells, the inhibition of cell proliferation of aloe-emodin was mediated through a p21-dependent manner that did not cause cell cycle arrest or increase the level of Fas/APO1 receptor, but rather promoted aloe-emodin induced apoptosis by enhancing expression of Bax.

Effects of aloe-emodin on the proliferation inhibition of Hep G2 and

Hep 3B cell lines

APS-1• APS-1 is a polysaccharide which is isolated from fresh

leaves of Aloe vera.• It is demonstrated to be free radical scavenging in

superoxide and hydroxyl radical assays, inhibitory to the copper-mediated oxidation of human low density lipoprotein (LDL), and protective against hydrogen peroxide (H2O2)-induced lesion to rat PC12 cell ( pheochromocytoma cell line).

• The result suggested that APS-1 could be of considerable preventive and therapeutic significance to some free radical associated health problems such as coronary heart ailments, Parkinson’s and Alzheimer’s diseases.

Scavenging activity of APS-1 against superoxide radical generated in PMS/NADH system with ascorbic acid as a positive control.

Aloe dihydrocoumarin is an antioxidant and a candidate of immunomodulatory drug on the immune system and can balance physiological reactive oxygen species (ROS) levels which may be useful to maintain homeostasis.

Machanism of Dihydrocoumarin It is beneficial in regulating ROS levels by

directly scavenging ROS and promoting the oxygen production in the respiratory burst of macrophages. The superoxide anion and nitric oxide released from respiratory burst

response of macrophages can kill invading pathogen or cancer cells in immune response.

Machanism of Dihydrocoumarin

HSA(human serum albumin), is the most abundant protein in blood plasma, is the most important drug carrier protein.

It has a strong affinity for a variety of chemical

species. As a consequence, HSA should play an important role in the biological fate of dihydrocoumarin.

REFERENCES• Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical

University, Kaohsiung 807, Taiwan, ROC Department of Pharmacy, Ta-Jen Institute of Technology, Ping-Tung 907, Taiwan. The antiproliferative activity of aloe-emodin is through p53-dependent and p21-dependent apoptotic pathway in human hepatoma cell lines. Life Sciences 71 (2002) 1879–1892.

• Jun H. Wu, Chen Xu, Cheng Y. Shan, Ren X. Tan. Antioxidant properties and PC12 cell protective effects of APS-1, a polysaccharide from Aloe vera var. chinensis. Life Sciences 78 (2006) 622 – 630.

• J.K. Grover *, S. Yadav, V. Vats. Medicinal plants of India with anti-diabetic potential. Journal of Ethnopharmacology 81 (2002) 81-100.

• Oana Rosca-Casian, Marcel Parvu, Laurian Vlase, Mircea Tamas. Antifungal activity of Aloe vera leaves. Fitoterapia 78 (2007) 219–222.

• Ljubica Harhaji, Sanja Mijatovic, Danijela Maksimovic-Ivanic, Dusan Popadic, Aleksandra Isakovic, Biljana Todorovic-Markovic, Vladimir Trajkovic. Aloe emodin inhibits the cytotoxic action of tumor necrosis factor. European Journal of Pharmacology 568 (2007) 248–259.

• N.R.S. Sibuyi, D.R. Katerere, T. Boboyi, A.M. Madiehe. Dietary supplementation with Aloe ferox extracts reverses obesity in rats.

• Xiu-Feng Zhang, Ling Xie, Yang Liu, Jun-Feng Xiang, Lin Li, Ya-Lin Tang *. Molecular interaction and energy transfer between human serum albumin and bioactive component Aloe dihydrocoumarin. Journal of Molecular Structure xxx (2008) xxx–xxx.

• Ratree Maenthaisong, Nathorn Chaiyakunapruk*, Surachet Niruntraporn, Chuenjid Kongkaew. The efficacy of aloe vera used for burn wound healing: A systematic review. Sciencedirect 3 3 ( 2 0 0 7 ) 7 1 3 – 7 1 8