Isolation and characterization of anti-inflammatory and analgesic compounds from Uapaca staudtii Pax (Phyllanthaceae) stem bark

From Plant to Chemistry: Sources of Antinociceptive Non-Opioid Active Principles for Medicinal Chemistry and Drug Design

Pain is associated with many health problems and a reduced quality of life and has been a common reason for seeking medical attention. Several therapeutics are available on the market, although side effects, physical dependence, and abuse limit their use. As the process of pain transmission and modulation is regulated by different peripheral and central mechanisms and neurotransmitters, medicinal chemistry continues to study novel ligands and innovative approaches. Among them, natural products are known to be a rich source of lead compounds for drug discovery due to their chemical structural variety and different analgesic mechanisms. Numerous studies suggested that some chemicals from medicinal plants could be alternative options for pain relief and management. Previously, we conducted a literature search aimed at identifying natural products interacting either directly or indirectly with opioid receptors. In this review, instead, we have made an excursus including active ingredients derived from plants whose mechanism of action appears from the literature to be other than the modulation of the opioid system. These substances could, either by themselves or through synthetic and/or semi-synthetic derivatives, be investigated in order to improve their pharmacokinetic characteristics and could represent a valid alternative to the opioid approach to pain therapy. They could also be the basis for the study of new mechanisms of action in the approach to this complex and disabling pathology.

Qianghuo Shengshi decoction exerts anti-inflammatory and analgesic via MAPKs/CREB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese Medicine Qianghuo Shengshi decoction (QSD) is widely used in the treatment of nervous headache, rheumatoid arthritis, sciatica, allergic purpura, and other clinical diseases in China. However, the underlying mechanisms of its anti-inflammatory and analgesic effects has not been elucidated.

AIM OF THE STUDY

The aim of this study was to confirm the anti-inflammatory and analgesic effects and the underlying mechanism of QSD in vivo. In addition, this study was also to isolate and analyze the main active components of QSD by high performance liquid chromatography (HPLC).

MATERIALS AND METHODS

In this study, the acetic acid writhing test, hot plate test and ear swelling test and formalin test were carried out to explore the anti-inflammatory and analgesic effects of QSD. The doses were set to 7.8 g/kg, 15.6 g/kg and 31.2 g/kg body weight. Western blot was utilized to study further possible mechanisms of QSD. Moreover, the HPLC method was used to isolate and identify the components in the extraction of QSD.

RESULTS

Twelve characteristic peaks were recognized in the HPLC spectrum, which all were the known compounds. The QSD exhibited dose-dependent effects in anti-inflammatory and analgesic aspects. Compared with model group, the writhing times of in groups of different doses of QSD (15.6 g/kg and 31.2 g/kg (oral administration = p.o.)) were reduced by 33.0% and 45.8% and indicated the QSD showed significant (p < 0.05) peripheral analgesic effect. QSD ((31.2 g/kg), p.o.) showed significant(p < 0.05) analgesic effect in the hot plate test. Inhibition rates of QSD ((15.6 g/kg and 31.2 g/kg), p.o.) in ear swelling test induced by p-xylene were 27.5% and 54.6% and demonstrated the significant (p < 0.05) anti-inflammatory activity. QSD ((31.2 g/kg), p.o.) significantly (p < 0.05) reduced times of paw licking in formalin test, and its inhibition rates were 34.3% and 28.0% in Phase I and Phase Ⅱ response, respectively. Western blot results showed that QSD inhibited the phosphorylation of mitogen-activated protein kinase (MAPK) protein and cAMP response element-binding protein (CREB).

CONCLUSIONS

These results of this study undoubtedly confirmed that QSD expressed obvious analgesic and anti-inflammatory activities. Anti-inflammatory and analgesic effects of QSD may be achieved by regulating the MAPKs protein and further regulating the expression of CREB. In all, QSD may play an anti-inflammatory and analgesic role through a variety of active ingredients.

Advances in Research on Chemical Constituents and Their Biological Activities of the Genus Actinidia

Kiwi, a fruit from plants of the genus Actinidia, is one of the famous fruits with thousand years of edible history. In the past twenty years, a great deal of research has been done on the chemical constituents of the Actinidia species. A large number of secondary metabolites including triterpenoids, flavonoids, phenols, etc. have been identified from differents parts of Actinidia plants, which exhibited significant in vitro and in vivo pharmacological activities including anticancer, anti-inflammatory, neuroprotective, anti-oxidative, anti-bacterial, and anti-diabetic activities. In order to fully understand the chemical components and biological activities of Actinidia plants, and to improve their further research, development and utilization, this review summarizes the compounds extracted from different parts of Actinidia plants since 1959 to 2020, classifies the types of constituents, reports on the pharmacological activities of relative compounds and medicinal potentials.

Phytochemical profiling of bioactive compounds, anti-inflammatory and analgesic potentials of Habenaria digitata Lindl.: Molecular docking based synergistic effect of the identified compounds

ETHNOPHARMACOLOGICAL RELEVANCE

Members of Orchidaceae family has a long history in herbal and Chinese medicines. Members of this family are most commonly famous in the management of inflammation and analgesia in folk medicine. Habenaria digitata, an unexplored specie of Orchidaceae is found in North areas of Pakistan and is used by the local population for the management of analgesia and inflammation.

AIM OF THE STUDY

Based on the effective outcomes of the natural products as alternative therapies, we have evaluated Habenaria digitata for the management of analgesia and inflammation. The aim of the designed project is to provide a scientific basis of using this plant for the management of analgesia and inflammation.

MATERIALS AND METHODS

The H. digitata crude extract (Hd.Cr) and subfractions, i.e. n-hexane (Hd.Hex), chloroform (Hd.Chf), ethyl acetate (Hd.EtAc), n-butanol (Hd.Bt) and aqueous (Hd.Aq) were used. The GC-MS analysis was used for the identification of phytochemicals. The plants samples were subjected to cyclooxygenase (COX 2) and lipoxygenase (5-LOX) enzymes assays. The hot plate model, acetic acid induced writhing and formalin induced paw licking models were used for in-vivo analgesic studies. The in-vivo anti-inflammatory potential was determined with carrageenan induced paw edema test. Molecular docking studies of the identified compounds were carried out by using Molecular Operating Environment (MOE, 2016.08).

RESULTS

The GC-MS analysis confirmed sixty-five compounds in Hd.Cr. Among the fractions, Hd.Chf and Hd.EtAc displayed highest activities. The observed IC₅₀ values were 21.30 and 32.39 μg/ml against COX 2 while 14.42and 16.40 μg/ml for 5-LOX respectively. The in-vivo inflammatory and analgesic studies were pre-requisited with acute toxicity tests. In carrageenan induced inflammation, Hd.Chf excelled the standard drug aspirin by giving 62.92% inhibition of paw edema at 4^th h. Similarly, at highest concentration (75 mg/kg) of acetic acid induced analgesia, Hd.Chf was more potent than the standard drug. In formalin method, Hd.Chf exhibited 85.81% inhibition at phase-I and 74.15% at Phase-II. In hot plate model, Hd.Chf exhibited average reaction time of 10.90 at 15, 30, 45 and 60 min intervals. Docking studies supported our results and confirm the synergistic effects of phytochemicals.

CONCLUSIONS

Our experimental results concluded that H. digitata contains several bioactive compounds. These bioactive compounds synergistically have therapeutic efficacy for the management of inflammation and analgesia. We have confirmed both of these potentials from the in-vitro and in-vivo experiments. Moreover, it is also obvious that the chloroform and ethyl acetate fractions are rich in these bioactive compounds. Specifically, the Hd.Chf is observed to be more practical in all the tested models of analgesia and inflammation. Computed binding energies of the compounds revealed that all the compounds have synergistic effect to prevent analgesia and inflammation.