Volume 5, Issue 2, February 2015, Pages 146–157
Document heading
Medicinal plants with hepatoprotective activity in Iranian folk medicine
- Open Access funded by Hainan Medical University
- Under a Creative Commons license
Open Access
ABSTRACT
There
are a number of medicinal combinations in the Iranian traditional
medicine which are commonly used as tonic for liver. In this review, we
have introduced some medicinal plants that are used mainly for the
treatment of liver disorders in Iranian folk medicine, with focus on
their hepatoprotective effects particularly against CC14
agent. In this study, online databases including Web of Science, PubMed,
Scopus, and Science Direct were searched for papers published from
January 1970 to December 2013. Search terms consisted of medicinal
plants, traditional medicine, folk medicine, hepatoprotective, Iran,
liver, therapeutic uses, compounds, antioxidant, CC14, anti-inflammatory, and antihepatotoxic, hepatitis, alone or in combination. Allium hirtifolium Boiss., Apium graveolens L., Cynara scolymus, Berberis vulgaris L., Calendula officinalis, Nigella sativa L., Taraxacum officinale, Tragopogon porrifolius, Prangos ferulacea L., Allium sativum, Marrubium vulgare, Ammi majus L., Citrullus lanatus Thunb, Agrimonia eupatoria L. and Prunus armeniaca
L. are some of the medicinal plants that have been used for the
treatment of liver disorders in Iranian folk medicine. Out of several
leads obtained from plants containing potential hepatoprotective agents,
silymarin, β-sitosterol, betalain, neoandrographolide, phyllanthin,
andrographolide, curcumin, picroside, hypophyllanthin, kutkoside, and
glycyrrhizin have been demonstrated to have potent hepatoprotective
properties. Despite encouraging data on possibility of new discoveries
in the near future, the evidence on treating viral hepatitis or other
chronic liver diseases by herbal medications is not adequate.
KEYWORDS
- Medicinal plants;
- Iran;
- Compounds;
- Liver;
- Therapeutic uses;
- CC14
1. Introduction
Liver
diseases which are still a global health problem may be classified as
acute or chronic hepatitis (inflammatory liver diseases), hepatosis (non
inflammatory diseases) and cirrhosis (degenerative disorder resulting
in liver fibrosis). Unfortunately, treatments of choice for liver
diseases are controversial because conventional or synthetic drugs for
the treatment of these diseases are insufficient and sometimes cause
serious side effects[1].
Since
ancient times, mankind has made use of plants in the treatment of
various ailments because their toxicity factors appear to have lower
side effects[2].
Many of the currently available drugs were derived either directly or
indirectly from medicinal plants. Recent interest in natural therapies
and alternative medicines has made researchers pay attention to
traditional herbal medicine. In the past decade, attention has been
centered on scientific evaluation of traditional drugs with plant origin
for the treatment of various diseases. Due to their effectiveness, with
presumably minimal side effects in terms of treatment as well as
relatively low costs, herbal drugs are widely prescribed, even when
their biologically active constituents are not fully identified[3].
The
utility of natural therapies for liver diseases has a long history.
Despite the fact that most recommendations are not based on documented
evidence, some of these combinations do have active constituents with
confirmed antioxidant, anti-inflammatory, anticarcinogenic,
antifibrotic, or antiviral properties. Although a large number of these
plants and formulations have been investigated, the studies were mostly
unsatisfactory. For instance, the therapeutic values, in most of these
studies, were assessed against a few chemicals-induced subclinical
levels of liver damages in rodents. The reasons that make us arrive at
such a conclusion are lack of standardization of the herbal drugs,
limited number of randomized placebo controlled clinical trials, and
paucity of traditional toxicologic evaluations[4].
Hundreds of plants have been so far examined to be taken for a wide spectrum of liver diseases[5 and 6].
Natural products, including herbal extracts, could significantly
contribute to recovery processes of the intoxicated liver. According to
reliable scientific information obtained from the research on medicinal
plants, plants such as Silybum marianum, Glycyrrhiza glabra, Phyllanthus species (amarus, niruri, emblica), and Picrorhiza kurroa
have been widely and most of the time fruitfully applied for the
treatment of liver disorders, exerting their effects via
antioxidant-related properties[ 7, 8, 9 and 10].
Iranians
have been using herbal medicine for the treatment of some common
diseases; as a result, a large number of studies have been conducted to
suggest new wild medicinal plants in different parts of Iran. Iranian
traditional medicine is mostly relied on the consumption of plant
materials. One of the important and well-documented utilities of plant
products is their use as hepatoprotective agents. There are a number of
medicinal combinations in the Iranian traditional medicine which are
commonly used as tonic for liver. Allium hirtifolium Boiss. (A. hirtifolium), Apium graveolens L. (A. graveolens), Cynara scolymus (C. scolymus), Berberis vulgaris L. (B. vulgaris), Calendula officinalis (C. officinalis), Nigella sativa L. (N. sativa), Taraxacum officinale (T. officinale), Tragopogon porrifolius (T. porrifolius), Prangos ferulacea L. (P. ferulacea), Allium sativum L. (A. sativum), Marrubium vulgare L. (M. vulgare), Ammi majus L. (A. majus), Citrullus lanatus (C. lanatus), Agrimonia eupatoria L. (A. eupatoria) and Prunus armeniaca L. (P. armeniaca) are some of medicinal plants that have been used mainly for the treatment of liver disorders in Iranian folk medicine.
2. Medicinal plants
2.1. A. hirtifolium
A. hirtifolium from Alliaceae family, commonly known as Persian shallot (moosir in Persian) is endemic to Iran[ 11]. Based on available pharmaceutical investigations, antioxidant and hepatoprotective effects of A. hirtifolium have been also demonstrated. In addition, A. hirtifolium extracts had antioxidant properties comparable to or slightly higher than garlic extracts[ 12].
The commonly known phytochemical compounds identified in A. hirtifolium are saponins, sapogenins, sulphur containing compounds (e.g. thiosulfinates) and flavonoids including shallomin, quercetin and kaempferol[ 12].
Alliin, alliinase, allicin, s-allyl-cysteine, diallyl disulphide,
diallyltrisulphide, and methylallyltrisulphide are the most important
biological secondary metabolites of A. hirtifolium[ 13]. Disulphide and trisulfide compounds are among the most important compounds existing in A. hirtifolium[ 14].
Researches have shown that both the corn and the flower of shallot
contain a high density of glycosidic flavonols. Linolenic, linoleic,
palmitic, palmitoleic, stearic, and oleic acids have been identified in A. hirtifolium oil, as well[ 15].
Treating rats with hydroalcoholic extract of A. hirtifolium
could protect liver cells against oxidant effects of alloxan, and
consequently caused a significant reduction in serum concentration of
alkaline phosphatase (ALP), alanine transaminase (ALT), and aspartate
transaminase (AST). Biochemical results have confirmed the usefulness of
A. hirtifolium extract in decreasing the destructive effects
of alloxan on liver tissue, and consequently decreasing the enzymes’
leakage into cytosol, which is possibly achieved by herbal antioxidant
compounds including flavonoids[ 12]. It was also reported that consumption of A. hirtifolium caused a reduction in AST level compared to the group with a hypercholesterolemic diet[ 16]. A research on the effect of hydroalcoholic A. hirtifolium extract on the level of liver enzymes in streptozotocin-induced diabetic rats indicated that hydroalcoholic extract of A. hirtifolium
could significantly decrease serum levels of liver enzymes [AST, ALT,
ALP and (lactate dehydrogenase) LDH] in a dose-dependent manner.
Antioxidant micronutrients in the extract of A. hirtifolium may also restore liver damages. Shallomin and other active constituents of A. hirtifolium did not produce any adverse effect on the organs such as liver and kidney[ 17].
2.2. A. graveolens
A. graveolens,
commonly known as celery, is an edible plant of the Umbelliferae family
that grows mostly in the Mediterranean areas. It has been considered as
a medicinal plant for a long time[ 18 and 19]. Data obtained from literature reveal that A. graveolens has many pharmacological properties such as antifungal, antihypertensive, antihyperlipidemic, diuretic, and anticancer[ 20, 21, 22 and 23].
This plant has also been shown to have some other medicinal features
including hyperlipidemic effects as well as antioxidative and
hepatoprotective activities[ 20].
The
active constituents are isoimperatorin, isoquercitrin, linoleic acid,
coumarins (seselin, osthenol, apigravin, and celerin), furanocoumarins
(including bergapten), flavonoids (apigenin, apiin), phenolic compounds,
choline, and unidentified alkaloids[21]. A. graveolens
is full of betacarotene, folic acid, vitamin C, sodium, magnesium,
silica, potassium, chlorophyll, and fiber. The essential oil contains
deltalimonene and various sesquiterpene[ 21 and 22].
Seeds of A. graveolens
are used in Iranian medicine for liver ailments and disorders, have
effects on liver, and exhibit hepatoprotective activities. Examining the
antihepatotoxic effect of A. graveolens seeds’ methanolic extracts on rats’ liver showed a significant hepatoprotective activity[ 21]. The roots open obstruction of the liver and spleen, and help in dropsy and jaundice treatment[ 23]. Due to apigenin-related anti-inflammatory and antioxidant properties, A. graveolens
seeds could counteract the pro-oxidant effect of 2-acetylaminofluorine
through scavenging superoxide radicals, consequently declining hepatic
glutathione-S-transferase (GST) and decreasing release of γ-glutamyl
transpeptidase in serum; as a result, A. graveolens could be assumed as a potent plant against experimentally induced hepatocarcinogenesis in rats[ 24]. In addition, different extracts of the plant were examined for their hepatoprotective activity against CC14-induced
hepatotoxicity in albino rats. The methanolic extracts, comparable to
silymarin as a conventional drug, exhibited a higher hepatoprotective
activity[ 25]. Another study indicated that the extracts of A. graveolens root significantly decreased CC14-induced acute hepatic injury, increasing the activities of AST and ALT and preventing CC14-induced acute liver injury[ 26].
Crude ethanol extract of the whole plant was indicative of
anti-inflammatory effects in rats. Furthermore, topical
anti-inflammatory effects of A. graveolens leaves’ extract have been demonstrated by Mencherini et al[ 27]. Significant anti-inflammatory effect of the aqueous and hexane extracts of A. graveolens
was shown at all doses (100-500 mg/kg body weight). Both extracts
presented remarkable anti-inflammatory effect, which confirmed the
traditional use of A. graveolens in inflammation-associated diseases[ 28].
