Velvet beans, mango seed potential cure for snake venom

Written by Sade OguntolaThursday, 15 November 2012

Mango tree and fruit with Velvet beans

Snake bite remains a public health problem in many countries even though it is difficult to be precise about the actual number of cases. It is estimated that the true incidents of snake bites could exceed 5 million per year and causing about 125,000 deaths each year, predominantly within poor communities living in rural areas of countries in Southeast Asia and Africa. 

Snake venom antidotes are expensive; it’s often a long way to the nearest doctor and it can be difficult to store the medicine properly in the warm climate. As a result, many local people rely on natural resources for treating potentially fatal bites. In addition to its high cost and other limited effectiveness, there is a need to develop novel therapeutics to maximise the utility of the snakebite therapies that are available.

The traditional medicine to treat snakebite victims still plays an important role in the primary health care worldwide, especially in rural areas and poor communities in the third world countries where the practice is common.

Because natural products of higher plants may give a new source of medication, there are many research groups that are now engaged in medicinal plants research not only for the discovery of new drugs, but possibly for discovering compounds with novel mechanisms of action that can stimulate new fields of research.

Research to develop treatment for local snake bite is therefore a clinical priority and has focused on the application of natural or synthetic compounds. One traditional medicine for snake bite treatment that scientists had evaluated is an extract of Mucuna pruriens seed.

Plants used as remedy for snakebite abound in many communities. However, many of the reported studies lack detailed scientific investigation, which is needed in the development of medicinal agents from plants.

Mucuna pruriens (velvet bean) has been used by native Nigerians as a prophylactic for snakebite. In certain regions of Nigeria, the beans have been prescribed by traditional practitioners as an oral prophylactic for snakebites. 

In a new study, researchers found that velvet bean extracts protect against the lethal and venom-induced harmful effects to the Javan spitting cobra venoms on the heart.

According to the study, the protective action of velvet bean extract against the effect of cobra venom was only on the heart, but does not involve the blood vessel.

The study entails the researchers investigating the effect of extracts of velvet beans on the responses of isolated heart atria and aortic rings from rats. Dried velvet seed meal was soaked in distilled water for 24 h at 4°C with stirring. The extract was centrifuged and the supernatant is termed M. pruriens seed extract (MPE). 

The researchers wrote: “Rats pretreated with the MPE were protected against the cardiovascular depressant effects of N. sputatrix (Javan spitting cobra) venoms, including depression in blood pressure and heart rate.”

The 2012 study was entitled “Effect of Mucuna pruriens seed extract pretreatment on the responses of spontaneously beating rat atria and aortic ring to Naja sputatrix (Javan spitting cobra) Venom. It was published Evidence Based Complement Alternative Medicine.

Previously, preliminary studies have shown that velvet bean seed extract antibodies raised from rabbits were able to neutralise the toxic effects of several Asiatic cobra venoms in mice. In addition, laboratory studies showed that velvet bean seed extract protects from the toxic effect of Calloselasma rhodostoma (Malayan pit viper) and N. sputatrix venoms on the heart and respiratory system.

What is more, a potential herb that scientists are assessing its effectiveness in developing new antisnake venom was Hibiscus aethiopicus. The plant, commonly called Dwarf yellow hibiscus, has long been used as a medicinal plant by traditional healers, 

In a study, researchers found that ethanolic extracts of Hibiscus aethiopicus stops bleeding from viper snake bite. Using extracts of Hibiscus aethiopicus and venom of viper snake at a concentration between 500 and 1000 mg/kg caused no signs of haemorrhage after 32 hours. However, after 24 hours, all tested guinea pigs showed less inhibition (<60%) compared to that obtained after 32 hours.

They wrote: “Results of the evaluation assays of antisnake venom activity showed that H. aethiopicus induced noticeable and significant neutralisation capacity against venom of viper snake.”

Aside the researcher suggesting that having the extract before snake bite can act as a prophylactic agent, they wrote “The extract of the H. aethiopicus showed high neutralising potency against such effect within six hours of venom injection.”

Still findings proved that a potential snake bite remedy lies in mango seed kernel. A study evaluating the ethanolic extract from seed kernels of Thai mango (Mangifera indica), found that it’s as a potent snake bite treatment for Malayan pit viper and Thai cobra venoms in laboratory conditions.

The ethanolic extract from fresh mango seed kernels was obtained by chopping and blending the seed kernels before it was extracted with hot ethanol, centrifuged and the ethanol evaporated off under reduced pressure. 

The 2009 study, documented in the journal, Molecules, submitted that from its finding, “extracts from mango seed kernels may be applied in the field, complementing antivenom therapy in the neutralisation of venom-induced local effects.”

Though medicinal plants remain largely unnoticed and neglected, protective activity of African locust bean tree in treating snake bites was also buttressed by experts. The African locust bean tree, P. biglobosa, is a perennial tree legume used as a source of food, medicinal agents, timber and is of high commercial value. In West Africa, a decoction of the leaves, bark and roots is used in treating leprosy, eye sores, toothache, fever and hypertension as well as wound and ulcer and in treating snake bite.

Previously, a report studying the ability of Anacardium occidentale (cashew nut tree) bark extract to neutralise enzymatic, as well as pharmacological effects induced by viper’s venom, which are both responsible for local effects of the bite such as swelling at the point of bite.

The inability of the blood to clot damages vital organs of the body, making the bark extract a useful alternative in the conventional snake bite treatment.

Link:

http://tribune.com.ng/index.php/natural-health/50930-velvet-beans-mango-seed-potential-cure-for-snake-venom