Avocado seeds employed to treat pains, multi-drug resistant TB

Do not throw away that avocado seed because it may save your life. Until now, avocado fruits and seeds have been shown to be effective in treating hypertension, diabetes, bad cholesterol, rheumatism, asthma, infectious processes as well as diarrhoea and dysentery but new studies have found that extracts of avocado seed also have protective effect on the pancreas, kidneys and liver; and could be used to relieve pain and treat multi drug-resistant tuberculosis (TB). CHUKWUMA MUANYA, Assistant Editor (Head Insight Team, Science and Technology) writes.

Commonly called avocado, Persea americana is a tree that belongs to the laurel family, Lauraceae, and is one of the 150 varieties of avocado pear. This plant is indigenous to Central and South America, but it is now cultivated in the United States of America, Asia, parts of Europe, and Tropical Africa.

A new study published in Malaysian Journal of Medical Sciences concluded: “In summary, the plant extract exerted a dose-dependent protective effect on the pancreas, kidneys and liver, like the reference drug glibenclamide did. Taken together, the results of present study provide a pharmacological basis for the folkloric use of the hot-water extract of P. americana seeds in the management of diabetes mellitus.”

The study is titled “Hypoglycaemic and Tissue-Protective Effects of the Aqueous Extract of Persea Americana Seeds on Alloxan-Induced Albino Rats.”

Researchers have also found that avocado seeds extract could be used as painkiller.

The study titled “Analgesic effect of the aqueous seed extract of Persea Americana Mill (Lauraceae)” was published in Journal of Pharmaceutical and Allied Sciences.

The researchers noted: “Persea americana is one of the medicinal plants used in Nigeria for pain relief. Based on its ethno-medicinal use in pain management, the seed of the plant was extracted with distilled water and screened for analgesic activity. The analgesic screening was done in mice using four models: acetic acid-induced writhing; formalin -induced pain, tail immersion and hot plate methods. The mice were divided into five groups of five each. The first group in all models served as control and received normal saline, the next three groups received either 100, 200 or 400 mg/kg of the extract respectively. The last group was given a reference drug, either pentazocine (10 mg/kg) or aspirin (100 mg/kg). The extract at all doses tested showed a significant reduction of the number of writhes (p < 0.05) compared with the control.

“The extract also showed significant reduction of the paw licking time in the formalin induced pain test. Its effect was about the same in both phases (p<0.05). A significant increase in the mean reaction time of mice in the tail immersion and hot plate tests (p<0.05) was also produced by the extract in comparison with the control. Inhibition of the synthesis of prostaglandins may account for its peripheral analgesic effect, while its action on central receptors may account for its central analgesic activities. In conclusion, the plant has significant non-dose dependent peripheral and central analgesic effects.

Another study published in BMC Complementary and Alternative Medicine found that avocado seeds could be used to treat multi drug resistant-TB.

The study is titled “Antiprotozoal and antimycobacterial activities of Persea americana seeds.”

The Mexican researchers noted: “Persea americana seeds are widely used in traditional Mexican medicine to treat rheumatism, asthma, infectious processes as well as diarrhoea and dysentery caused by intestinal parasites.

“The chloroformic and ethanolic extracts of P. americana seeds were prepared by maceration and their amoebicidal, giardicidal and trichomonicidal activity was evaluated. These extracts were also tested against Mycobacterium tuberculosis H37Rv (causative organism of TB), four mono-resistant and two multidrug resistant strains of M. tuberculosis as well as five non-tuberculosis mycobacterium strains by MABA assay.

“The chloroformic and ethanolic extracts of P. americana seeds showed significant activity against E. histolytica, G. lamblia and T. vaginalis (IC50

“The CHCl3 and EtOH seed extracts from P. americana showed amoebicidal and giardicidal activity. Importantly, the CHCl3 extract inhibited the growth of a Multi Drug Resistant (MDR) M. tuberculosis isolate and three out of four mono-resistant reference strains of M. tuberculosis H37Rv, showing a MIC = 50 μg/ml. This extract was also active against the NTM strains, M. fortuitum, M. avium, M. smegmatis and M. abscessus, with MIC values

According the researchers, avocado seeds (crude or toasted) are employed in traditional Mexican medicine to treat skin rashes, diarrhea, and dysentery caused by helminthes (worms) and amoebas, for the cure of infectious processes caused by fungi and bacteria, as well as for the treatment of asthma, high blood pressure, and rheumatism. The seeds of P. americana used alone or mixed with other species, such as Psidium guajava (guava) Mentha piperita or Ocimum basilicum (basil/nchuanwu in Ibo and effirin in Yoruba), are mainly employed for the treatment of diarrhoea.

The presence of fatty acids (linoleic, oleic, palmitic, stearic, linolenic, capric and myristic acids), polyphenols (catechin, isocatechin, protocyanidin, flavonoids, tannins and proanthocyanidin monomerics), saponins, glucosides (D-perseit, D-α-manoheptit, D-monoheptulose, persiteol), sterols (β-sitosterol, campesterol, stigmasterol, cholesterol), the amino acid carnitine and two glucosides of abscicic acid have been described for P. americana seeds. High concentrations of catechins, procyanidins and hydroxycinnamic acid have recently been determined in 100 per cent ethyl acetate (EtOAc), in 70 per cent acetone and 70 per cent methanol (MeOH) extracts obtained from P. americana peel and seeds, while the pulp extract was rich in hydroxybenzoic acid, hydroxycinnamic acid and procyanidins.

Indeed, the medicinal relevance of the various parts of this tropical plant is enormous. The effects of aqueous seed extracts of Persea americana on the blood pressure, plasma, and tissue lipids of albino rats were investigated by Imafidon and Amaechina, and their results suggested that the use of the aqueous seed extract of this plant in the treatment of hypertension might produce a favourable lipid profile.

Alhassan and colleagues also evaluated the hypoglycaemic (blood glucose lowering) activity of P. americana aqueous seed extracts on alloxan-induced diabetic rats and concluded that the anti-diabetic effects of the extract might be due to certain mineral elements and phytochemicals and that an increase in weight could be due to proper nutrient utilisation that is most likely induced by the avocado seed extract.

However, the work by Okonta et al. suggests that P. americana can lower blood glucose levels in cases of mild hyperglycemia (high blood glucose) but not severe hyperglycemia. Edem et al. studied the effects of aqueous avocado pear seed extracts on normal and alloxan-induced diabetic rats, and their results suggested a restorative (protective) effect of the extract on pancreatic islet (insulin-producing) cells.

The work of Mahadeva et al., concentrated on the mechanism of the anti-diabetic activity of P. americana. The insulin-stimulative and antioxidative effects of Persea americana were evaluated in streptozotocin (STZ)-treated rats. This group found that the activities of pathophysiological enzymes such as serum aspartate transaminase (AST), serum alanine transaminase (ALT), and serum alkaline phosphatase (ALP) were altered in the serum of rats that had been treated with glyclazide, which was used as the standard reference drug, but not control rats. These results revealed the tissue protective nature of Persea americana fruits.

Earlier studies had associated air pollution to rise in chronic disease such as heart attack, strokes, diabetes, hypertension, cancer to mention but a few.

But scientists have found that extracts of the leaves, fruits, seeds and bark of avocado can protect the body from the damages of air pollution.

Indeed, scientists have found higher levels of vitamin E may help protect the lungs from particulates – tiny particles of harmful smog.

These particles come from a variety of sources, including power plants, factories, trucks and cars and the burning of wood. They can travel deep into the lungs and have been associated with increased numbers of hospital admissions for heart attacks and strokes.

A study from King’s College London and Nottingham University, United Kingdom, suggests higher blood levels of vitamin E may minimise the effects of exposure.

The study was published in the American Journal of Respiratory and Critical Care Medicine.

Also, scientists had suggested that extracts of the nutritious avocado fruit might be able to lessen the liver damage caused by the hepatitis viruses.

A study carried out at Shizuoka University in Japan and published in Journal of Agricultural and Food Chemistry suggested the avocado fruit might have potential. Rats were given a chemical, which causes similar liver damage to the hepatitis viruses, and fed 22 different types of fruit to see if they made any difference.

The researchers found five compounds extracted from fruit to have a beneficial effect, and the most potent of these came from the avocado.

The scientists are still not sure whether the same effect could be found in humans, and say further studies are needed. They also have no idea how the avocado extract actually has this effect.

Precisely how much help this would be to stem the damage caused by hepatitis in humans is as yet unclear, as often patients are wholly unaware of their infection until serious damage has taken place.