Antimicrobial plants

The vast majority of antibiotics used in modern medicine are or have been produced by microorganisms, yeasts or fungi, which belong to the vegetable kingdom. Higher plants mainly produce antimicrobials as a defense mechanism against infections or these substances are constituents of cellular metabolism.

Differentiation of antimicrobial activity in antiseptic, antibacterial, bactericidal, bacteriostatic, antifungal, fungicide, antiviral, virus, will not be done in this entry, just the mention of plants that have shown such activity. I left out of this first communication a large quantity of plants with lesser use in the Latin world.

As expected, besides a long list of plants with antimicrobial activity, a number of chemical compounds responsible for this activity are involved as well. Alkaloids, coumarins, simple phenols, flavones, quinones and tannins are the most common.

ACACIA (Acacia farnesiana, nilotica)

Leaves and fruits

Antibacterial properties of some species of acacia are due to its tannin content in concordance with the extracts concentration.

GARLIC (Allium sativum)

The bulb is used.

Its antibacterial activity has been attributed to a sulfur amino acid, the aliin, with antimicrobial and antioxidant properties. There are a lot of medicinal products prepared from garlic bulbs (bulbs generally dried or aged). In powder, tinctures and so on.

Bardana (Arctium lappa)

This plant is a bit obsolete though its antimycotic properties deserves further studies, at least for nails fungus. I use to prepare an alcoholic extract of fresh roots from 2 years old plants harvested after the plant produce seeds.

LARGE INDIAN CRESS (Tropaeolum majus)

Leaves and flowers are used.

It has antibiotic properties due to their isotianate (sulfur and glucotropoline) content with proven effectiveness against several common bacteria. It is used at external and internal route (in respiratory and urinary systems).

CUMIN (Cuminum ciminum)

Aerial parts.

Cumin essential oil has a strong antifungal activity against several fungi of medical importance.

EUCALYPTUS (Eucalyptus globulus and other sp).

Mature leaves from older branches.

The essential oils are very active due to their eucalyptol content , which gives the characteristic aroma and is used as of the respiratory tract and urinary tract antiseptic. It has proven effective against certain fungi. Its external use is highly recommended as an antiseptic, however internal use must be undertaken with caution.

JACARANDA (Jacaranda mimosaefolia)

Fruits

Glutamic acid, and fixed oils that provide antimicrobial properties both in internal and external use. Its use in foodstuffs preservation is considered.

LICHENS (Cetraria islandica and others)

Many of them owe their antifungal and bacteriotatic properties to their usnic and vulpinic acids content.

MARCELA or MACELA (Achyroclyne satureoides)

The flowers are used.

Hydroalcoholic extract has a proven antiviral activity. Plant is little known worldwide but widely used in the Amazon area and at the south of South America.

YARROW (Achillea millefolium)

Aerial parts are used.

The alcoholic extract has a significant antiviral activity. It is also used locally to cure wounds. Its healing properties have been well known since ancient times.

WALNUT (Juglans regia)

Bark

Bark extracts have shown antimicrobial activity. Scientific publications do not mention active ingredients, but activity against staphylococci, Candida, colibacilar, pseudomonas and other microorganisms.

OREGANO (Origanum vulgare)

Aerial parts

Aqueous and alcoholic extracts and essential oils have powerful antimicrobial activity. Bacteria, fungi and viruses are effectively controlled.

The usual manufacture of aqueous extracts (obtained by decoction) and the alcoholic extracts (obtained by maceration in absolute alcohol or alcohol 96 °), permits a home made elaboration.

GRAPEFRUIT (Citrus paradise)

Extracts of this plant is touted as highly effective against a large number of microorganisms. So far I have found no publications that prove it.

I have seen only one study in which, after damaging the shell of the fruit, an antifungal compound is produced, but is not present in the healthy fruits.

PINE (Pinus silvestris)

The active ingredients are extracted mainly from the needles, leaves and young branches.

The essential oil with several compounds of antiseptic activity is used externally and in the airways (the turpentine is partially responsible for this activity). Has been recommended for urinary tract infections, although there are plants with greater effect and greater safety. The pinosilvina has antifungal activity.

THYME (Thymus vulgaris)

Leaves and flowers.

The essencial oils, the aqueous and alcoholic extracts, containing phenol, thymol and carvacrol, have a powerful antiseptic and antimicrobial activity. Its antiviral activity is widely known, as its antifungal activity, although this requires very frequent applications, probably more than 6 times a day.

When boiling their aerial parts a characteristic aroma of phenols and derivatives, very similar to cloroxilenol (in these regions Espadol).

This antiviral activity with its astringent effect, the presence of tannins, make it a required component of herpes simple medications.

CAT'S CLAW (Uncaria tormentosa)

Roots or rhizome.

Alcoholic or hydroalcoholic extracts are potent antivirals, whereas the aqueous extracts are used as immune enhancers. This is a plant that has proven effective in enhancing the immune system for treatment of different ailments.

Free radicals control

Oxidative chemical reactions are produced by free radicals or agents "prooxidants, during normal cellular metabolic processes. The oxidation involves an exchange of ions with energy release and new radicals and oxidized substances formation.
There is a significant number of free radicals but the most important are the hydroxyl group, the superoxide anion and the hydrogen peroxide.

The body has its own system of control free radicals, through specialized enzymes, the most important, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, together with other substances such as albumin, uric acid and ceruloplastina.

This system, for various reasons, begins to fail and free radicals accumulate, causing major damage at various levels. Block the cell membranes, damage the mitochondria and vital cells, alter the DNA and tissues.

The production of free radicals in the organism is associated primarily with cell respiration and is more evident with aging, inflammation and immune reactions. Abnormal factors that can further enhance their appearance, some dietary deficiencies (eg. Vitamins), intoxications (alcohol, snuff, heavy metals, drugs).

Some of the most common pathological manifestations involving free radicals are, damage to DNA and cancer appearance, heart disease, arthritis and other autoimmune diseases, premature aging, diabetes, brain damage, damage ophthalmic, skin problems.

A help to normal antioxidants control is given by organic foods with antioxidant properties (and possibly supplements), some vitamins (C, E and A, retinol and carotenoids), minerals such as selenium, zinc, magnesium, sulfur, flavonoids and anthocyanins of plants, coenzyme Q and lipoic acid.

The existence of these phenomena is widely established, what still remains to be clarified is the possibility of altering its metabolic dominance through dietary treatments or medications, to reduce its prevalence and consequent damage.

The fact that a recent investigation has not shown any effect of antioxidant vitamins on life expectancy, should serve to trigger the execution of a series of studies demonstrating the importance of antioxidants in achieving better health and welfare of human beings, beyond the years to live.

Antioxidants

Quite new research communications reveal that Vitamins E and C, despite of having known antioxidant properties, did not help on human cardiovascular disease and that other (not stated in the abstract) antioxidants did not stop senility mechanisms, at least in nematodes (worms).

Previous works had demonstrated that rats fed with antioxidants lived more than the controls. These works bring to a first page a quite old argument about antioxidants properties, involving plant antioxidant extracts as well.

As an enthusiastic supporter of antioxidants, that (I believe) allow me now to be writting you full of strengh and hope, I must to get in this argument. In the next posts I will make the attempt to clarify this complex subject.

Addictive substances and medicinal plants

I will only mention in this post addictive behaviours to chemical substances and not those involving customs. Addictions are cases of obsession and compulsion to use substances that produce apparent pleasure and tranquility. Their continued use promote brain changes as tolerance, physical dependence, uncontrollable desire, and if their comsumption is stopped, characteristic symptoms of withdrawal come out. 

The most common addictive substances are alcohol, nicotine, benzodiazepines, opioids and stimulants. The body becomes addicted to the neurological changes that substances produce. Characteristic behaviorial changes are also present. 

Apparently the diverse addictions have similar physiological mechanisms. They act over substances involved in communication between different parts of the brain that released in specific brain sites produce pleasure, or wellness, or over other that are involved in  biological cycles regulation. These substances are neurotransmitters (dopamine, serotonin, GABA) and hormones (melatonin). 

Addictive substances alter hormones and neurotrasmitters production levels and physiological thresholds sensitivity of receptors to these compounds and cause damage to some tissues exposed (eg. Lung tissue or liver cells). 

Both genetics and environment have a direct influence. Researchers have discovered genes directly involved in the mentioned processes  and when there are gene deviations or alterations, the possibility of being addicted is higher. Exposure to environmental factors determines the possibility of addiction, stress and exposure to drugs at an early age and access to substance abuse risk factors are preponderant. 

There are several plants that have been used successfully  in reducing consumption of chemicals and reducing withdrawal symptoms. I will mention the most known and that have been scientifically tested. 

Korean Angelica (Angelica gigas), apparently the essential oil of this plant has successfully modulate the release of dopamine in certain areas of the brain. 

St. John's wort (Hypericum perforatum) modulates several neurochemical pathways. This explains its activity in depression, abstinence from alcohol and not smoking. The hyperacine and hyperforine appear to be the most active compounds. Depression and alcoholism have some neurochemical similarities, such as low activity of serotonin in the brain. 

St. John's wort extract compared with other antidepressants, and there are differences. Has been shown that hypericine stimulates dopamine extracellular levels, also norepinephrine and serotonin as well as glutamate levels, aminoacid responsible for the reactions to panic and stress brain site. It has been evaluated for quitting smoke because of the link between smoking and depression. Primary successes have been achieved. 

Iboga (Tabernanthe iboga) a shrub of equatorial Africa, is used to treat addiction to stimulants. It contains an alkaloid, iboganina, which has shown positive effects on the consumption of nicotine, alcohol, morphine and cocaine in animal trials . Apparently iboganina and some of its derivatives are promising agents for  addiction treatment. 

Kava (Piper methysticum) binds to brain sites associated with addiction and compulsive desire to alcohol, smoking, cocaine and heroin. It has been reported a decline in the desire of those substances consumption. Kavapironas supplementation decreased the effects of abstinence. 

Kudzu (Pueraria lobata) has succeeded in reducing alcohol consumption and the symptoms outcoming. The most important active ingredients are  isoflavones puerarin, daizina and daidzeina. This plant also has anxiolytic effects in several ways and act accordingly. In China its use is widespread both alone and with other natural medicines. 

Lobelia (Lobelia inflata) and other plants like marshmallow (Althaea officinalis) comprise the so-called herbal cigarettes. Lobeline physiologically tends to replace the nicotine, so the body reduces the dependence feeling. 

Nescafe (Mucuna pruriens) has significant levels of levodopa (L-dopa), the dopamine precursor, making it possible to increase levels of neurotrasmitters associated with abstinence. 

Passionflower (Passiflora incarnata) contains a chemical fraction, the benzoflavona that appears to be responsible for most  plant medicinal activity. It has achieved success in reversing tolerance and dependence to psychotropic drugs such as morphine, nicotine and alcohol in animals. 

Medicinal plants chemicals

Medicinal plants chemicals are substances present in plants for specific activities in plants life. Respond to millions years of evolution, different plant species interacting with the environment.

Many compounds are necessary for protection against climate and pollutants agressions (sun, cold, heat, etc.) against predators (herbivores, insects), parasites (worms, insect larvae) or infections (bacteria, fungi, virus). Other compounds are involved in plant reproduction and growth, such as hormones or growth factors, or are used to attract birds and insects to carry out pollen and seeds, thus ensuring reproduction and dispersal of these species. Some compounds are also involved in plants structure to keep them upright and for humidity maintenance. Other compounds are intermediate metabolites of normal chemical reactions.

The main concept is that herbal substances with medicinal activity are vital components of the normal plants physiology and were discovered along many years by human communities that lived in close relationship with nature. Without the aim to classify the active ingredients, it can be said that medicinal actions are fulfilled by chemical reactions, mechanical and physical effects or as nutritional supplementation.

Chemical groups such as alkaloids, saponins, essential fatty acids and glycosides are the most important, with a special remark on subgroups as flavonoids, polyphenols and bitter substances. Fiber, both soluble and insoluble, acts in a mechanical way. The vitamins, minerals and water are nutrients.

Major chemical reactions are: antioxidant activity, performed by a large amount of chemicals (polyphenols, carotenoids), hormonal activity (isoflavones), enzyme regulation (indoles, terpenes), interference with gene replication (saponins), antiparasitic and antimicrobial activity (terpenes) and anti-inflammatory activity.

In another entry I will give examples of activities to make the subject a little more understandable and enjoyable.

Cholesterol metabolism

Ultra simplified explanation of the regulation of cholesterol in the organism. 

The objective is quite straightforward, the process aims to keep cholesterol levels at figures commensurate with the body requirements.

Therefore, as provided by the diet (external cholesterol ) is what is consumed daily and, depending on the food type, mobilizes a very complex mechanism that regulates the formation of cholesterol from the body (synthesis) and the removal of cholesterol excess, if any. 

Cholesterol that is consumed passes from the intestine to the liver, transported as lipid or fat particles, through special vessels and is released from the liver into the blood, where is carried by special proteins that form the complexes known as lipoproteins (LDL and VLDL) . Another complex, the HDL leads cholesterol  back to the liver for disposal. 

Organic synthesis (less than half of total cholesterol) is carried out in cells of the liver, intestine and to a lesser extent in cells of other organs, based on what is known as the energy cycle. Within these cells, at specialized sites in the cytoplasm. Part of the cholesterol produced turns to blood and the rest is stored in the cytoplasm, free or in capsules. 

Excess cholesterol is eliminated from the body through just an unique path, the bile, either as free cholesterol or converted into biliar acids. 

The amount of cholesterol in blood is regulated, as noted earlier, by several parallel mechanisms involved, blood level receptors or detectors, endocrine glands, hormones, special genes, enzymes and small intracellular organs. 

The outer surface of the cell membrane, in contact with bloodstream, has special extensions (like tiny wires) that "measure" continuously blood cholesterol level. These sensors give notice to the involved endocrine glands, pancreas and adrenal, which, depending on the situation, release hormones to increase or decrease cholesterol production in the cells (synthesis). To emphasize that, owing to its importance, one of the hormones involved is insulin. 

These hormones control the exposure of specific genes and the reading of genetic information (transcription) that stimulate (if necessary) enzymes production, which act as accelerators for the 

cholesterol production and its precursors or promoting HDL to remove cholesterol from the bloodstream. 

The reading of genetic information and the production of these enzymes, is carried out in small organs of the cytoplasm and the nucleus almost permanently, something very difficult to imagine, as a factory with an enormous amount of workers that do not stop at any time. They have periods of greater and lesser activity, but the alert and the mechanisms are always active. 

A similar but somewhat simpler mechanism, occurs in the liver for bile formation and cholesterol incorporation. 

I ask the scientists' indulgence and the readers' understanding due to that to write this post on the metabolism of cholesterol, I have had to shorten explanations so its accuracy and clarity are not the best.

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