Neutralisation of lethality, myotoxicity and toxic enzymes of Naja kaouthia venom by Mimosa pudica root extracts

Aqueous and alcoholic extracts of dried roots of Mimosa pudica were tested for their inhibitory activity on lethality, myotoxicity and toxic enzymes of Naja kaouthia venom. The aqueous extract, particularly the normal water extract, displayed a significant inhibitory effect on the lethality, myotoxicity and tested enzyme activities of venom compared with alcoholic extracts. The present finding suggests that aqueous extracts of M. pudica root possess compound(s), which inhibit the activity of cobra venom.     

Inhibition of tumour promotion and cell proliferation by plant polyphenols

The plant polyphenols: 2-hydroxy chalcone, quercetin and tannic acid exhibited varying antiproliferative effects on two mouse cell lines—NIH 3T3 and L929. Whilst 2-hydroxy chalcone and tannic acid (at 250 μM concentration) were able to exert 90% and 56% growth inhibition, respectively, quercetin at the same concentration had no effect on NIH 3T3 cells. However, these test compounds could exert significant growth inhibition on L929 cells at a concentration as low as 50 μM. At the highest concentration tested (250 μM), 2-hydroxy chalcone, quercetin and tannic acid showed 87%, 61% and 78% growth inhibition, respectively. The observed difference in potencies of the test compounds for the two cell lines indicated that their actions are cell line specific. When tested in vivo on mice, the order of potency of the test compounds in inhibiting benzo[a]pyrene-induced mouse skin carcinogenesis was tannic acid > 2-hydroxy chalcone > quercetin. No correlation was observed between the efficacy of the test compounds and lipid peroxidation in vivo.     

Daboia russellii and Naja kaouthia venom neutralization by lupeol acetate isolated from the root extract of Indian sarsaparilla Hemidesmus indicus R.Br

The present study reports the isolation and purification of lupeol acetate from the methanolic root extract of Indian medicinal plant Hemidesmus indicus (L.) R.Br. (family: Asclepiadaceae) which could neutralize venom induced action of Daboia russellii and Naja kaouthia on experimental animals. Lupeol acetate could significantly neutralize lethality, haemorrhage, defibrinogenation, edema, PLA(2) activity induced by Daboia russellii venom. It also neutralized Naja kaouthia venom induced lethality, cardiotoxicity, neurotoxicity and respiratory changes in experimental animals. Lupeol acetate potentiated the protection by snake venom antiserum action against Daboia russellii venom induced lethality in male albino mice. Venom induced changes in lipid peroxidation and super oxide dismutase activity was antagonized by lupeol acetate. Snake venom neutralization by lupeol acetate and its possible mechanism of action has been discussed.     

Inhibition of the inflammatory and coagulant action of Bothrops atrox venom by the plant species Marsypianthes chamaedrys

Aim of the study

This study investigated the efficacy of Marsypianthes chamaedrys Vahl (Lamiaceae) inflorescence and leaf extracts in inhibiting the inflammatory and coagulant actions of Bothrops atrox venom.

Materials and methods

Marsypianthes chamaedrys, which is used in Brazil as a folk medicine to treat snakebites and local inflammatory reactions, was tested in vitro to determine its ability to block indirect phospholipase A₂ and direct coagulant activities and in vivo to determine its ability to inhibit leukocyte migration and cytokine release.

Results

In vitro, Marsypianthes chamaedrys showed antiphospholipase A₂ and anticoagulant activities; the latter activity was also confirmed by prothrombin time (PT) and activated partial thromboplastin time (aPTT) in the absence of venom. Of the extracts used, those obtained from the crushed plant had the greater inhibitory activity in in vitro tests, showing that biological activity is affected by the way extracts are obtained. In vivo, Marsypianthes chamaedrys inhibited leukocyte migration and the release of the proinflammatory cytokines IL-6 and TNF-α without altering the concentration of the anti-inflammatory cytokine IL-10.

Conclusions

As specific antivenoms are not effective in neutralizing the local action of Bothrops venoms, characterization of the anti-inflammatory mechanisms induced by Marsypianthes chamaedrys is of vital importance if the extracts of this plant species are to be used in future as adjuvants in the treatment of snakebites.     

Effect of Annona senegalensis rootbark extracts on Naja nigricotlis nigricotlis venom in rats

Annona senegalensis Pers (family: Annonaceae) is used traditionally in Nigeria to treat victims of snakebite. The potency of the methanol extract of the root bark of the plant was tested against cobra (Naja nigricotlis nigricotlis Wetch) venom in rats. The extract was also tested on brine shrimp (Artemia saline Leach). The activity of the extract against the venom induced mortality, occurrence of toxic signs, activity on liver enzymes as well as its ability to reverse experimentally induced increase in body temperature were evaluated. Results indicated that the extract caused reduction in the induced hyperthermia and directly detoxified the snake venom used by 16-33%. It, however, failed to restore the biochemical functions (sGOT and sGPT) of the liver. The extract exhibited an LC(50) of 232.7 microg/ml in the brine shrimp test.     

植物多酚类成分提取分离研究进展

植物多酚是一种广泛存在于植物体内的多元酚类次生代谢产物,随着多酚类成分在抗氧化、抗菌、抗病毒、抗微生物、调血脂和血糖等多方面活性的发现和阐明,植物多酚成为当前研究的热点之一.多酚类成分由于其结构上的复杂性和不稳定性,目前在提取分离上还存在一定的困难.对中药中多酚类成分的提取分离方法进行总结,旨在为下一步分离纯化多酚类成分提供比较系统的信息依据.     

与辐射防护有关的药用植物活性

辐射防护剂在放射治疗、太空探险甚至核战等辐射环境中的应用日益受到关注,但现今所使用的许多人工合成的辐射防护剂都不太理想,因此,许多研究者将目标转移到了丰富的天然药用植物资源上。为了减少新药筛选过程中的盲目性,作者按照与辐射防护作用有关的生物活性分类整理了一些有潜在利用价值的药用植物,并对它们新近的研究进展进行了综述。     

Neutralization of local and systemic toxicity of Daboia russelii venom by Morus alba plant leaf extract

Antivenom therapy is the current best therapy available for the treatment of fatal snake envenomation. However, the antivenom offers less or no protection against local effects such as extensive edema, hemorrhage, dermo‐, myonecrosis and inflammation at the envenomed region. Viperidae snakes are highly known for their violent local effects and such effects have been commonly treated with plant extracts without any scientific validation in rural India. In this investigation Morus alba plant leaf extract has been studied against the Indian Vipera/Daboia russelii venom induced local and systemic effects. The extract completely abolished the in vitro proteolytic and hyaluronolytic activities of the venom. Edema, hemorrhage and myonecrotic activities were also neutralized efficiently. In addition, the extract partially inhibited the pro‐coagulant activity and completely abolished the degradation of Aα chain of human fibrinogen. Thus, the extract processes potent antisnake venom property, especially against the local and systemic effects of Daboia russelii venom. Copyright © 2009 John Wiley & Sons, Ltd.     

植物多糖增强肿瘤杀伤效应细胞的增殖活性和细胞毒活性

目的：观察红景天、红芪、地黄、枸杞子、沙参和芦荟的多糖成分对T－AK细胞增殖活性和杀瘤活性的增强作用。方法：用抗CD3单抗（CD3McAb）和rIL-2激活诱生T－AK细胞,观察6种植物多糖在诱生、扩增和杀瘤过程中对T－AK细胞增殖活性、IL－2R表达水平以及杀伤Raji细胞和L1210细胞活性的影响。结果：6种植物多糖（1－100μg/mL）单独对T－AK细胞的增殖无明显作用,但在rIL-2和CD3McAb存在下,可不同程度地增强T－AK细胞的增殖能力和杀瘤活性,并增加T－AK细胞IL－2R的表达。结论：红景天、红芪、地黄、枸杞子、沙参和芦荟的多糖成分增强T－AK细胞的增殖和杀伤活性,其作用效应与其促进IL－2R的表达有关。     

植物多酚干预脂质代谢紊乱作用机制研究进展

脂质代谢紊乱是诱发肥胖症、高脂血症和2型糖尿病等慢性代谢疾病的重要危险因素,也是代谢综合症等慢性疾病预防的关键目标。植物多酚以多种方式参与调控机体的胆固醇吸收、甘油三酯合成和分泌以及血浆低密度脂蛋白氧化等生理进程,在维持或改善机体脂质代谢平衡中发挥着重要作用。该文就近年来植物多酚在预防和改善脂质代谢紊乱及其相关的作用机制进行综述。