1. Introduction
Known and used for centuries, medicinal plants remain potential sources for finding new remedies useful in treating or ameliorating various diseases including diabetes and inflammatory diseases.
Diabetes is a metabolic disorder that generates severe dysfunctions such as neuropathy, vasculopathy, dyslipidemia, retinopathy, and cardiovascular disease [
1]. The incidence of this condition is constantly increasing, from 400 million people in 2016 it is estimated that it will reach 642 million people with type II diabetes in 2040 [
2]. Antidiabetic drugs such as acarbose, miglitol, and voglibose reduce the degradation and absorption of sugars by inhibiting the digestive enzymes - α-amylase and α-glucosidase, involved in these processes. However, these drugs also have side effects and that is why alternatives are sought from natural sources [
3].
The drugs used to treat inflammation and pain are nonsteroidal drugs that generally have numerous side effects such as ulcers and hemorrhages [
4,
5]. Their long-term use even leads to cardiovascular, metabolic, endocrine and ophthalmological damage [
5].
Medicinal plants have been used in folk medicine to treat many inflammatory diseases and remain important sources of new anti-inflammatory and antioxidant agents [
6,
7]. Inhibition of enzymes involved in the inflammatory process such as lipoxygenase and hyaluronidase is the basis for finding new treatments for allergies and inflammatory diseases [
8,
9]. Oxidative stress generated by reactive oxygen species (ROS) has been associated with pathological inflammatory processes and DNA distortions followed by carcinogenesis and tumors [
10].
Lipoxygenase (LOX) is involved in inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, psoriasis, allergic rhinitis, atherosclerosis, and certain types of cancer. During LOX activity, peroxy radicals are formed in the reaction medium that can function as sources of free radicals. Thus, antioxidants that have free radical scavenging activity can also act as LOX inhibitors [
11].
Hyaluronidase acts on hyaluronic acid which is an important part of the extracellular matrix and is involved in many physiological processes such as embryogenesis, wound healing, and cell migration [
7,
12]. Studies have led to the discovery in plants of hyaluronidase inhibitors (tannins, cucumbers, flavonoids) that can be used as anti-inflammatory and anti-allergic agents, as antitumor agents, in the treatment of bacterial infections and adjuvant in the treatment of arthritis [
13,
14].
Membrane technologies - micro- and ultrafiltration - are cheap and effective alternatives to traditional technologies for concentrating biologically active compounds. These processes feature low operating and maintenance costs, easy operation at moderate temperatures and pressure, high permittivity, and selective separations. [
15,
16]. These technologies can be successfully used for the purification and concentration of plant extracts while maintaining their functional and nutritional properties [
17,
18].
Artemisia vulgaris and Artemisia absinthium are two plants of the Asteraceae family (Compositae) used in traditional medicine due to their numerous therapeutic properties.
Artemisia vulgaris (known as mugwort) is a shrub of temperate zones in Europe, Asia, North Africa, and North America [
19]. The plant has been used in folk medicine for the treatment of gastrointestinal and gynecological diseases, alleviation of hypertension and disorders of the nervous system [
20,
21] as well as for culinary purposes. Studies have revealed various pharmacological properties of
A. vulgaris, such as anti-inflammatory, antioxidant, antitumor, and immunomodulatory activities [
22,
23].
Artemisia absinthium L. - also known as wormwood - has been known for centuries and used in folk medicine for gastrointestinal and urinary disorders, fever, and helminthiases [
24,
25].
A. absinthium has been shown to be effective as an antiparasitic and a digestive [
25], as well as for reducing symptoms of leukemia, sclerosis, diabetes, malaria, and even some types of cancer in recent years [
26].
Trigonella foenum-graecum (also known as fenugreek) is an annual herb from the Fabaceae family known for its medicinal and culinary properties since ancient times. Fenugreek is grown and used as a spice in many countries from Asia, Europe, and Africa and is considered to have a high nutraceutical value [
27]. In folk medicine, this plant is used especially for immunity stimulation and for digestive and reproductive disorders [
28]. Seed powder lowers blood sugar, and improves symptoms in patients with type 2 diabetes [
29]. The seeds and leaves of this herb are rich in flavonoids, alkaloids, and saponins which confer medicinal properties [
30]. While fenugreek seeds of fenugreek have been widely investigated for the treatment of inflammation, cancer, and diabetes, little is known about their leaves.
The present paper analyzed the antidiabetic and anti-inflammatory activity of the plants: Artemisia vulgaris, A. absinthium, and Trigonella foenum-graecum by testing the ability to inhibit α-amylase, α-glucosidase activity, respectively, hyaluronidase (HYA) and lipoxygenase (LOX) activity.
4. Conclusions
The phytochemical screening, the antidiabetic and anti-inflammatory potential of Artemisia vulgaris, Artemisia absinthium, and Trigonella foenum-graecum concentrated hydroalcoholic extracts by inhibiting α-amylase and α-glucosidase, respectively lipoxygenase and hyaluronidase were analyzed.
The T. foenum-graecum extracts showed a higher genistin content and Artemisia species showed a higher polyphenols and flavones content. The T. foenum-graecum extracts showed high antioxidant activity by all methods of analysis.
The T. foenum-graecum extracts showed a high inhibitory activity on all enzymes studied (α-amylase, α-glucosidase, hyaluronidase, and lipoxygenase). The Artemisia absinthium concentrated extract showed high inhibitory activity on LOX, while Artemisia vulgaris concentrated extract has a significant inhibitory effect on HYA. Thus, these herbs can be potential sources of phytocompounds useful in the management of type 2 diabetes and inflammatory diseases.
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