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Scientists explore detoxification effects of medicinal plants

By Chukwuma Muanya
14 October 2021   |   4:14 am
Researchers have demonstrated the detoxification capacity and protective effects of medicinal plants. They highlighted the detoxification ability of the medicinal plants...


Researchers have demonstrated the detoxification capacity and protective effects of medicinal plants. They highlighted the detoxification ability of the medicinal plants, especially hepato (liver) and nephron (kidney) protective effects.

The study titled “Detoxification capacity and protective effects of medicinal plants (part 2): plant based review” was published in IOSR Journal of Pharmacy.

The researchers, led by Prof. Ali Esmail Al-Snafi, were from the Department of Pharmacology, College of Medicine, Thiqar University, Iraq.

Modern research has shown that a wide range of plants can neutralise or detoxify toxins and protect the body from the toxic effects of drugs and chemicals. These plants included: Agrimonia eupatoria (Agrimony), Alhagi maurorum (Camel thorn plant), Allium sativum (garlic), Alpinia galangal, Anchusa strigosa, Arctium lappa, Artemisia campestris, Asparagus officinalis, Astragalus hamosus, Bauhinia variegata, Benincasa hispida, Brassica nigra, Brassica rapa, Bryonia dioica, Bryophyllum calycinum, Caesalpinia crista, Calendula officinalis, Calotropis procera, Canna indica, Capparis spinosa, Capsella bursa-pastoris, Capsicum frutescens, Carthmus tinctorius, Carum carvi, Cassia occidentalis (stinging weed), Casuarina equisetifolia, Celosia cristata and Chenopodium album.

Agrimonia eupatoria (Agrimony)
According to a study published in the journal Evidence Based Complementary and Alternative Medicine and titled “Antioxidant, Anti-Inflammatory, and Analgesic Activities of Agrimonia eupatoria Infusion”, Agrimonia eupatoria, Rosaceae, commonly known as agrimony, is an erect, perennial herb, up to 100 centimetres high, mostly unbranched, with a cylindrical stem. The pinnate leaves are serrated and covered with soft hairs. Flowers are hermaphrodite with five yellow petals, arranged on slender, terminal spikes. The fruit is surrounded by several rows of soft, hook-shaped bristles.

The aerial parts of agrimony are used to prepare infusions, decoctions, or tinctures (hydroalcoholic extracts) in traditional medicine, due to their antioxidant, anti-inflammatory, astringent, and diuretic properties. Aromatic acids, triterpenes, and tannins have been cited.

Flavonoids belong to an extensive group of polyphenols, and several biological activities, such as anti-inflammatory, antiulcer, anticancer, antiviral, antibacterial, antispasmodic, neuro-protective, anti-atherosclerotic, and antithrombotic, have been attributed to these compounds. Oxidative stress and antioxidant defense have been associated with inflammatory, carcinogenic, and coronary diseases. The recognised antioxidant potential of flavonoids could therefore be responsible for their beneficial actions. Moreover, anti-inflammatory properties, which are sometimes correlated with antioxidant activities, have also been verified for these compounds.

Folk medicine from different countries also reports the strong anti-inflammatory potential of A. eupatoria preparations, which was correlated with the reduction of TNF-α, IL-1β, and IL-6 production in mouse cell cultures. Additionally, it was also previously reported that agrimony ameliorated the chronic ethanol-induced liver injury and that protection was likely due to the suppression of oxidative stress and Toll-like receptor- (TLR-) mediated inflammatory signaling.

The researchers concluded: “Antioxidant, anti-inflammatory, and peripheral analgesic activities were observed for both the Agrimonia eupatoria infusion and/or its polyphenol-enriched fraction at nontoxic doses for the liver and the kidneys. The polyphenol-enriched fraction, essentially constituted by procyanidins and flavonoids, namely, quercetin, kaempferol, apigenin, and luteolin derivatives, was very active for all assays performed, leading to the conclusion that polyphenols have a very important role in these properties of Agrimonia eupatoria.

“The results of the present work corroborate the traditional use of the Agrimonia eupatoria infusion as antioxidant and anti-inflammatory and suggests that its polyphenols contribute to this activity, which may be helpful in developing novel and beneficial antioxidants, anti-inflammatory, and/or peripheral analgesic agents. In addition, isoquercetin, tiliroside, and kaempferol O-acetyl-hexosyl-O-rhamnoside should be considered as lead molecules for designing new pharmacophores, to be applied to the treatment of oxidation- and inflammation-related pathologies.”

Alhagi maurorum (Camel thorn)
According to a study published in Tropical Journal of Pharmaceutical Research and titled “Phytochemical Screening and Hepatoprotective Effect of Alhagi maurorum (Leguminosae) Against Paracetamol-Induced Hepatotoxicity in Rabbits”, Alhagi maurorum extract possesses significant hepato-protective effect against paracetamol-induced hepatotoxicity and this may be due to the presence of flavonoids and tannins.

Allium sativum (garlic)
A study published in Journal of Traditional and Complementary Medicine has demonstrated the antioxidation and detoxification capabilities of garlic on the human liver.

Garlic the bulb of Allium sativum (Liliaceae) is used in the diet as a vegetable or spice, but also has a long history of medicinal use. Garlic has benefits as an antibiotic, anti-atherosclerotic, and has anti-proliferative properties for treating cancer. The principle strong odor and active ingredient of fresh garlic is believed to be allicin (diallyl thiosulphinate) and its degradation products. Intact allicin does not exist in the garlic bulb, but its precursor allicin (S-allyl-L-cysteine sulphoxide) is likely stored in the cytoplasm. When garlic is cut and/or homogenised, the active enzyme system alliinase, most of which is stored in the vacuole, converts alliin to allicin. The biological activity of allicin is attributed to antioxidant activity or thiol disulfide exchange. In addition, a previous study indicated that allicin rapidly reacts with free thiol groups and enters biological membranes.

One of the more abundant non-protein thiols is glutathione (GSH) in mammalian systems. It is the major intracellular thiol protein, and its levels are organ-dependent, varying between 2–10 mM. In the GSH redox system, GSH is a substrate for glutathione peroxidase (GPx). GPx plays an important role in protecting cell proteins and cell membranes from oxidative stress. In addition, glutathione reductase (GRd) is a flavoprotein that regenerates GSH and provides reducing power for various thio-coupled transferases and peroxidases.

It has been shown that GSH and its related enzyme system play an important role in hepatic antioxidation and drug metabolism. Previous studies have shown that allicin can decrease free radical scavenging to lower lipid peroxidation. Allicin can reverse ethanol-induced hepatocytoxicity by enhancing hepatic glutathione (GSH) and GSH-related enzyme system expression.

In a short-term study, allicin selectively expresses the glutathione S-transferase (GST) gene in the murine gastrointestinal tract and liver.

In addition, allicin shows remarkable anti-viral, anti-fungal, and anti-bacterial activity. Allicin significantly inhibits human platelet aggregation and lowers atherosclerosis risk from hyperlipidemia and hypertension in rats fed with a high cholesterol diet. Recently, anti-cancer research showed that allicin decreases GSH levels to inhibit proliferation of the human breast cancer cell line MCF-7. Zhang et al. showed that allicin induces gastric cancer cell apoptosis by decreasing the mitochondrial membrane potential (δΨm) and activating caspase-3, -8, and -9. Allicin also induces apoptosis by regulating caspase-independent or -dependent apoptotic signaling pathway in various cancer cells and autophagic cell death in human liver cancer cell line. However, data regarding the optimum concentration of allicin and its effects on antioxidation and detoxification capabilities in normal hepatocytes are limited.

Cicer arietinum (Chickpea)
Chickpea (Cicer arietinum) is the third most imperative cool-season grain legume crop after the common bean (Phaseolus vulgaris) and field pea (Pisum sativum). Chickpea seeds are a principal and inexpensive source of highly digestible nutrients such as proteins, carbohydrates, vitamins, fibers, minerals, and essential amino acids especially for people in developing countries. It plays a crucial role in ensuring good nutrition and provides food security as its flour contains a higher protein, ash, mineral, and fat content than wheat flour. Besides being an excellent source of fundamental nutrients, chickpea seeds contain a diverse range of certain bioactive compounds that show high antioxidant capacity, anti-diabetic, and anti- inflammatory properties etc., in this way it helps to improve health by decreasing the incidence of diseases. Chickpea comprises a broad variety of polyphenols such as flavone glycosides, flavonols, polymeric pro anthocyanidins, and oligomers. These polyphenols are adept at intercepting singlet oxygen, decreasing oxygen concentration, and deterring first chain instigation by quenching primary radicals.

The hepatoprotective activity of petroleum ether, methanol and aqueous extracts of aerial parts (except fruits) of Cicer arietinum was studied against Carbon tetrachloride (CCl4) induced hepatotoxicity in rats. The plant extracts were administered to the experimental rats (200 and 400 mg/kg/day po for 20 days). The Hepatoprotective activity of these extracts was evaluated by liver function biochemical parameters (serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, serum alkaline phosphatase, total bilirubin, lipid peroxidation, superoxide dismutase, catalase, reduced glutathione) and histopathological studies of liver. Pre-treatment of the rats with petroleum ether, methanol and aqueous extract prior to CCl4 administration caused a significant reduction in the values of SGOT, SGPT, SALP, LPO, total bilirubin and significant increase in SOD, CAT, GSH, almost comparable to the Silymarin. The hepatoprotective activity was confirmed by histopathological examination of the liver tissue of control and treated animals. Histology of liver sections of the animals treated with the extracts showed the presence of normal hepatic cords, absence of necrosis and fatty infiltration.

Cichorium intybus (Chicory)
Common chicory is a somewhat woody, perennial herbaceous plant of the daisy family Asteraceae, usually with bright blue flowers, rarely white or pink.

According to a study published in African Journal of Biotechnology titled “Perspectives and utilisation technologies of chicory (Cichorium intybus): A review”, the plant has a nutritional quality comparable to lucerne as it contains similar proportions of protein, lipid, minerals and other nutrients. Based on its chemical and biological activities, this research work evaluated and overviewed recent advances in utilization technologies and studies of chicory. It focuses on the biochemical compositions and physiological bioactivities of extractives from chicory and clearly states the promising potential utility technologies of the plant: Curative effect as a forage or vegetable with good digestibility, use of chicory in confectionery products and beverages, potential use in discovering new effective medicine and the development of new salubrious functional foods, additives and other profitable green bio-products.

The natural root and root callus extracts of Cichorium intybus were studied for their anti-hepatotoxic effects in Wistar strain of Albino rats against carbon tetrachloride induced hepatic damage. The increased levels of serum enzymes (aspartate transaminase, alanine transaminase) and bilirubin observed in rats treated with carbon tetrachloride were very much reduced in the animals treated with natural root and root callous extracts and carbon tetrachloride. The decreased levels of albumin and proteins observed in rats after treatment with carbon tetrachloride were found to increase in rats treated with natural root and root callus extracts and carbon tetrachloride. These biochemical observations were confirmed by histopathological examination of liver sections.

Citrullus colocynthis (bitter gourd)
Citrullus colocynthis belongs to family Cucurbitaceae. It is commonly called English colocynth, bitter gourd, and wild gourd. In Nigeria, it is called handal and hanzal in Arabic; kwartowa and kwattowa the pulp in Hausa; and egwusi and elili in Igbo.

According to the Useful Plants of West Tropical Africa, the whole of the plant is very bitter, but especially the fruit due to the presence of a bitter glycosidal principle, colocynthin. In the past the purgative action has been ascribed to this, but another intensely bitter weakly basic amorphous alkaloid has been detected and this is drastically purgative. Another less powerful alkaloid has also been found and also other substances. Colocynth of commerce is official in most pharmacopoeias as a purgative and has been used for dropsical and other conditions, and sometimes as a vermifuge. It is the dried pulp of the peeled fruit freed of seeds. The powder is irritating to mucous membranes, strongly hydragogue, cathartic and is usually administered mixed with other drugs on account of its griping action. In the British Army of World War I, ‘No. 9’, given for so many complaints on medical inspection parades, was based on this substance. In small dosage it is violent. In larger doses it is lethal.

Its use as a drug was first recorded in Rome during the reign of Emperor Claudius, A.D. 41–54, whereupon, in a craze of hypochondria by the well-to-do Roman citizen, it attained much popularity — even for political murder, and perhaps of Claudius himself. Bulk to line the stomach wall is evidently able to reduce its action, and it is possible that the dish of pottage which was inedible to the multitude in the Bible, II Kings 4: 38–41 because, perhaps unwittingly, of the presence of colocynth fruit was miraculously made edible by Elisha who added meal to it. In Mauritania the baked fruit is rubbed on camels affected by itch, and an unripe fruit cooked in hot sand is used to treat blennorrhagia (gonorrhoea) in man: the cooked fruit is bored centrally and the glans of the penis is inserted and kept there for an hour in which time a cure is said to be effected.

Its fruit, which is lemon sized, yellowish, green mottled, spongy, and extremely bitter, is a powerful hepatic stimulant and hydragogue cathartic. It is used as a strong laxative. The dried pulp of Citrullus colocynthis has been used for constipation, edema, bacterial infections, cancer and diabetes. From the traditional knowledge it is very clear that the fruits of Citrullus colocynthis have the hepatoprotective activity.

A study published in Journal of Plant Sciences demonstrated the in-vivo hepatoprotective effect of the ethanolic extracts of Citrullus colocynthis against paracetamol-induced hepatotoxicity in albino rats.

The researchers concluded: “From our results we may infer that the mode of action of 90 per cent ethanolic extract of Citrullus colocynthis (200 mg/kg bw) in affording the in-vivo hepatoprotective activity against paracetamol may be due to the cell membrane stabilisation, hepatic cell regeneration and normalising the serum parameters.”