Anti-inflammatory and anti-arthritic effects of methanol extract of the stem bark of Boswellia dalzielii Hutch (Burseraceae) in rats

Escin's Action on Bradykinin Pathway: Advantageous Clinical Properties for an Unknown Mechanism?

Escin, extracted from horse chestnut (Aesculus hippocastanum) has anti-edema and anti-inflammatory effects. It is used to treat several clinical conditions, including venous insufficiency, pain, inflammation, and edema. Considering escin's pharmacodynamic, the inhibition of the bradykinin pathway represents a particular effect, decreasing the local edema and conferring an advantage in comparison to other compounds. In this narrative review, we described the effects of escin considering its effects on bradykinin pathway.

Markhamia lutea leaves aqueous and ethanolic extract with curative anti-inflammatory activity attenuates paclitaxel toxicity in rat's intestine

OBJECTIVES

Markhamia lutea (M. lutea, Bignoniaceae) is mainly found in tropical/neotropical regions of America, Africa and Asia. The plant's leaves, stems or roots are used to treat anaemia, bloody diarrhoea, parasitic and microbial infections. This study evaluates anti-inflammatory properties (in vitro) of Markhamia lutea and their curative effects on paclitaxel-induced intestinal toxicity (in vivo).

METHODS

The anti-inflammatory potential of Markhamia lutea was tested over cytokines (TNF-alpha, IL-6, IL-1β, IL-10), reactive oxygen species (ROS) and enzymes (cyclooxygenase and 5-lipoxygenase). While in vivo, intestinal toxicity was induced for 10 days by oral administration of paclitaxel (3 mg/kg, 0.05 mL). Animals in each group were further treated with aqueous (300 mg/kg) and ethanolic (300 mg/kg) leaves extracts of Markhamia lutea during 7 days and clinical symptoms were recorded, hematological, biochemical and histological analysis were subsequently performed.

RESULTS

In vitro, aqueous (250 μg/mL) and ethanolic (250 μg/mL) extracts of Markhamia lutea inhibited the activities of cyclooxygenase 1 (56.67 % and 69.38 %), cyclooxygenase 2 (50.67 % and 62.81 %) and 5-lipoxygenase (77.33 % and 86.00 %). These extracts inhibited the production of intracellular ROS, extracellular ROS and cell proliferation with maximum IC50 of 30.83 μg/mL, 38.67 μg/mL and 19.05 μg/mL respectively for the aqueous extract, then 25.46 μg/mL, 27.64 μg/mL and 7.34 μg/mL respectively for the ethanolic extract. The extracts also inhibited the production of proinflammatory cytokines (TNFα, IL-1β and IL-6) and stimulated the production of anti-inflammatory cytokines (IL-10). In vivo, after administration of paclitaxel, the aqueous and ethanolic extracts of Markhamia lutea significantly reduced the weight loss, the diarrheal stools and the mass/length intestines ratio of the treated animals compared to the animals of the negative control group. Biochemically, the extracts lead to a significant drop in serum creatinine and alanine aminotransferase levels, followed by a significant increase in alkaline phosphatase. In addition to bringing the haematological parameters back to normal values after disturbance by paclitaxel, the extracts caused tissue regeneration in the treated animals.

CONCLUSIONS

In vitro, aqueous and ethanolic extracts of Markhamia lutea showed anti-inflammatory properties (inhibition of COX1, COX2, 5-LOX activities, inhibition of ROS production and cell proliferation); in vivo, the same extracts showed curative properties against intestinal toxicity caused by paclitaxel.

Antioxidant and anti-inflammatory effects of Boswellia dalzielii and Hibiscus sabdariffa extracts in alloxan-induced diabetic rats

Diabetes mellitus (DM) is one of the leading worldwide public health problems. It is characterized by hyperglycemia which induces oxidative stress and inflammation, both involved in the pathogenesis of diabetes. We previously showed that Boswellia dalzielii (BD) and Hibiscus sabdariffa (HS) extracts reduced hyperglycemia and hyperlipidemia in alloxan-induced diabetic rats. In the present study, we evaluated the antioxidant and anti-inflammatory activities of both plants in alloxan-induced diabetic rats. Two sets of experiments were conducted in male Wistar rats subjected to a single intraperitoneal injection of alloxan monohydrate (150 mg/kg, b. w.). Then, diabetic rats were daily administered with either BD (1st set of experiments) or HS (2nd set of experiments) at 100, 200, and 400 mg/kg orally for 21 consecutive days. Glibenclamide (10 mg/kg) was also administered as a reference drug. At the end of the study, the animals were anesthetized, and blood samples were collected from each animal. Then, oxidative stress and inflammatory biomarkers in the serum were determined. We found that treatment with BD and HS significantly reduced malondialdehyde (MDA) and enhanced the levels of reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). These extracts also significantly decreased the inflammatory markers tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β). From the results obtained, it can therefore be concluded that BD and HS have the potential to being developed as natural sources of antioxidant and anti-inflammatory agents that can be used for the prevention or treatment of DM.

Evaluation of antihyperglycemic activity of aqueous stem bark extract of Boswellia dalzielii in alloxan-induced diabetic Wistar rats

Background

Diabetes mellitus is one of the leading causes of morbidity and mortality globally. Although synthetic hypoglycemic agents are commonly used to manage this disorder, such medications, besides being unable to cure the disease, are expensive and associated with side effects. Conversely, medicinal plants have emerged as effective, safe and affordable alternative treatments. Boswellia dalzielii plant has been reported to possess ethnomedicinal properties for the treatment of various health conditions; however, scientific studies exploring this plant as antihyperglycemic agent are still limited. Thus, this study evaluated the antihyperglycemic activity of aqueous stem bark extract (ASBE) of B. dalzielii in alloxan-induced diabetic Wistar albino rats.

Methods

Phytochemical screening of the ASBE of B. dalzielii was conducted. Twenty male Wistar albino rats weighing 100–150 g divided into 4 groups (A–D) of five rats were used for the study. Group A served as the normal control and received neither ASBE of B. dalzielii nor glibenclamide. The treatment for the other three groups was as follows: Group B, 10 mg/kg of glibenclamide (diabetic control); Group C, 500 mg/kg ASBE of B. dalzielii; and Group D, 1000 mg/kg ASBE of B. dalzielii. Treatments were administered orally every 24 h for a period of 2 weeks. Blood glucose level and body weight were evaluated at weeks 0, 1 and 2. Histomorphological features of the rats’ pancreas in all the groups were compared.

Results

The phytochemical analysis revealed the presence of alkaloids, saponins, tannins, cardiac glycosides, flavonoids, carbohydrates, steroids and triterpenes. The two different doses of the plant extract significantly reduced blood glucose level at weeks 1 and 2 (all p < 0.05), with the 1000 mg/kg dose demonstrating a greater reduction compared with glibenclamide at week 2 (p = 0.014). However, only the 500 mg/kg dose led to restoration, albeit slight, of the pancreatic islet cells.

Conclusion

This study suggests that B. dalzielii plant exhibits a potent antihyperglycemic activity evidenced by reduced blood glucose levels and slight restoration of pancreatic islet cells. This plant could be, therefore, considered in the treatment of diabetes mellitus.

Graphical Abstract

Bioprospecting for Anti-COVID-19 Interventions From African Medicinal Plants: A Review

The emergence of the novel coronavirus (SARS-CoV-2) that emanated from Wuhan in China in 2019 has become a global concern. The current situation warrants ethnomedicinal drug discovery and development for delivery of phytomedicines with potential for the treatment of COVID-19. The aim of this review is to provide a detailed evaluation of available information on plant species used in African traditional medicines with antiviral, anti-inflammatory, immunomodulatory, and COVID-19 symptoms relieving effects. Literature from scientific databases such as Scopus, PubMed, Google scholar, African Journals OnLine (AJOL), Science Direct, and Web of Science were used for this review. A total of 35 of the 38 reviewed plants demonstrated a wide range of antiviral activities. Bryophyllum pinnatum, Aframomum melegueta, Garcinia kola, Sphenocentrum jollyanum, Adansonia digitata, Sutherlandia frutescens, Hibiscus sabdariffa, Moringa oleifera, and Nigella sativa possess a combination of antiviral, immunomodulatory, anti-inflammatory, and COVID-19 symptoms relieving activities. Nine, 13, and 10 of the plants representing 23.7%, 34.2%, and 26.3% of the plants studied had antiviral activity with 3 other activities, antiviral activity with 2 other activities, and antiviral with one pharmacological activity alone, respectively. The plants studied were reported to be relatively safe at the subchronic toxicity level, except for 2. The study provides baseline information on the pharmacological activities, toxicity, and chemical components of 9 African medicinal plants with antiviral, immunomodulatory, anti-inflammatory, and symptoms relieving activities, thereby making the plants candidates for further investigation for effectiveness against COVID-19.

Inflammation and ROS in arthritis: management by Ayurvedic medicinal plants

Chronic joint inflammatory disorders like osteoarthritis and rheumatoid arthritis, which are manifested by joint dysfunction, show an upsurge in inflammation and oxidative stress. Although conventional anti-arthritic drugs are being used to relieve pain from arthritic symptoms, they usually cause severe side effects. Traditionally used Ayurvedic medicinal plants are a promising alternative for the management of arthritic symptoms, as they are safe and effective. Ayurvedic medicinal plants improve arthritic symptoms by reducing joint tenderness, joint pain, swelling, bone and cartilage damage, and increasing knee flexion, walking distance and sports activities. These beneficial effects of Ayurvedic medicinal plants on arthritis are mediated through various cellular mechanisms including inhibition of the inflammatory markers NF-κB, cytokines, adipokines, PGE2, NO, iNOS, COX-2, and MMPs and induction of antioxidant status by decreasing free radicals, lipid peroxidation, and myeloperoxidase, and increasing antioxidant enzymes, Nrf2, and HO-1. Thus, a strategy requires using these Ayurvedic medicinal plants to treat arthritis. This article describes the status of inflammation and oxidative stress in arthritic conditions. We also provide evidence that Ayurvedic medicinal plants and their bioactive components are highly effective in improving arthritic symptoms.

Investigation of ethnomedicinal use of Commiphora leptophloeos (Mart.) J. B. Gillett (Burseraceae) in treatment of diarrhea

ETHNOPHARMACOLOGICAL RELEVANCE

Commiphora leptophloeos (Mart.) J.B. Gillett, popularly known as "imburana", "imburana-de-cheiro" or "imburana-de-espinho", has been used in folk medicine for the treatment of gastrointestinal diseases, such as diarrhea. The indian tribes "Kairir-Shokó and shokó use the bark to treat diarrhea. However, there is no scientific evidence to justify the therapeutic use of this species.

AIM OF THE STUDY

To investigate the ethnomedicinal use of Commiphora leptophloeos, with respect to the antimicrobial, antisecretory, antimotility and antispasmodic activities of the crude ethanolic extract obtained from its leaves (CL-EtOH_L) and the mechanism underlying this action in rodents.

MATERIAL AND METHODS

In the evaluation of antibacterial and antifungal activities was determined the minimum inhibitory concentration (MIC) of the extract, against different strains of bacteria and fungi. All experimental protocols were approved by the Animal Ethics Committee of the Federal University of Paraíba (045/2016). In addition, behavioral screening and acute toxicity assessment of CL-EtOH_L were performed in female mice (n = 6). In the investigation of antidiarrheal activity (n = 6), frequency of defecation and number of liquid stools, were classified during 4 h, and intestinal fluid and transit were measured. In addition, the antispasmodic effect on rat ileum (n = 5) was also investigated.

RESULTS

The ethanolic extract is rich in flavonoids and the main were identified as C-glycosylated flavonoids (isoorientin, orientin, and vitexin). In the evaluation of antimicrobial and antifungal activity, the extract showed moderate efficacy only against the tested strains of Candida krusei ATCC-6258, Candida parapsilosis ATCC-22019 and Candida glabrata ATCC-90030. The extract had no toxic effect until 2000 mg/kg. In castor oil-induced diarrhea, CL-EtOH_L inhibited, in a dose-dependent manner, both total defecation frequency (ED₅₀ = 380.4 ± 145.4 mg/kg) and the number of watery stools (ED₅₀ = 151.2 ± 76.3 mg/kg). The extract showed no effect on fluid accumulation or normal intestinal transit. On the other hand, when the animals were pretreated with castor oil, the extract decreased the distance traveled by the activated charcoal (ED₅₀ = 177.0 ± 50.3 mg/kg). In the investigation of antispasmodic effect, CL-EtOH_L antagonized the contractions induced by KCl 30 mM (IC₅₀ = 208.2 ± 25.9 μg/mL) and CCh 10^-6 M (IC₅₀ = 95. ± 22.0 μg/mL). To verify the participation of muscarinic receptors in this effect, cumulative carbachol curves were performed in the absence and presence of the extract, and a non-competitive pseudo-irreversible antagonism of these receptors was observed.

CONCLUSION

The data indicate that ethanol extract obtained from the leaves of Commiphora leptophloeos has an antidiarrheal effect due to inhibition of the intestinal motility and antispasmodic effect, through the antagonism of muscarinic receptors. In addition, we suggest that flavonoids isolated from CL-EtOH_L may be responsible for antidiarrheal activity of this extract. This explains its ethnomedicinal use in the treatment of diarrhea.

Anti-inflammatory and anti-cancer activities of frankincense: Targets, treatments and toxicities

The oleogum resins of Boswellia species known as frankincense have been used for ages in traditional medicine in India, China and the Arabian world independent of its use for cultural and religious rituals in Europe. During the past two decades, scientific investigations provided mounting evidence for the therapeutic potential of frankincense. We conducted a systematic review on the anti-inflammatory and anti-cancer activities of Boswellia species and their chemical ingredients (e.g. 3-O-acetyl-11-keto-β boswellic acid, α- and β-boswellic acids, 11-keto-β-boswellic acid and other boswellic acids, lupeolic acids, incensole, cembrenes, triterpenediol, tirucallic acids, and olibanumols). Frankincense acts by multiple mechanisms, e.g. by the inhibition of leukotriene synthesis, of cyclooxygenase 1/2 and 5-lipoxygenase, of oxidative stress, and by regulation of immune cells from the innate and acquired immune systems. Furthermore, frankincense modulates signaling transduction responsible for cell cycle arrest and inhibition of proliferation, angiogenesis, invasion and metastasis. Clinical trials showed the efficacy of frankincense and its phytochemicals against osteoarthritis, multiple sclerosis, asthma, psoriasis and erythematous eczema, plaque-induced gingivitis and pain. Frankincense revealed beneficial effects towards brain tumor-related edema, but did not reduce glioma size. Even if there is no treatment effect on brain tumors itself, the management of glioma-associated edema may represent a desirable improvement. The therapeutic potential against other tumor types is still speculative. Experimental toxicology and clinical trials revealed only mild adverse side effects. More randomized clinical trials are required to estimate the full clinical potential of frankincense for cancer therapy.

In Vitro Anti-Inflammatory and In Vivo Antiarthritic Activities of Aqueous and Ethanolic Extracts of Dissotis thollonii Cogn. (Melastomataceae) in Rats

Dissotis thollonii Cogn. (Melastomataceae) is a tropical plant widely used in traditional Cameroonian medicine to relieve and treat many pathologies. It is widespread in the western region where it is used to treat typhoid fever, gastrointestinal disorders, and inflammatory diseases. The purpose of this study is to scientifically demonstrate the anti-inflammatory and antiarthritic properties of the aqueous and ethanolic extracts of the leaves of Dissotis thollonii. The anti-inflammatory properties were evaluated in vitro by inhibition tests for cyclooxygenase, 5-lipoxygenase, protein denaturation, extracellular ROS production, and cell proliferation; while antiarthritic properties were evaluated in vivo in rats using the zymosan A-induced monoarthritis test and the CFA-induced polyarthritis model. This study shows that aqueous and ethanolic extracts at a concentration of 1000 μg/ml inhibit the activity of cyclooxygenase (47.07% and 63.36%) and 5-lipoxygenase (66.79% and 77.7%) and protein denaturation (42.51% and 44.44%). Similarly, both extracts inhibited extracellular ROS production (IC₅₀ = 5.74 μg/ml and 2.96 μg/ml for polymorphonuclear leukocytes, 7.47 μg/ml and 3.28 μg ml for peritoneal macrophages of mouse) and cell proliferation (IC₅₀ = 16.89 μg/ml and 3.29 μg/ml). At a dose of 500 mg/kg, aqueous and ethanolic extracts significantly reduce edema induced by zymosan A (69.30% and 81.80%) and CFA (71.85% and 79.03%). At the same dose, both extracts decreased sensitivity to mechanical hyperalgesia with 69.00% and 70.35% inhibition, respectively. Systemic and histological analyzes show that both extracts maintain the studied parameters very close to normal and greatly restored the normal architecture of the joint in animals. Dissotis thollonii would therefore be a very promising source for the treatment of inflammatory diseases.

Evaluation In Vivo and In Vitro of the Antioxidant, Antinociceptive, and Anti-Inflammatory Activities of Biflavonoids From Ouratea hexasperma and O. ferruginea

Ouratea species are used for the treatment of inflammation-related diseases such as rheumatism and arthritic disorders. The Ouratea genus is a rich source of flavonoids and bioflavonoids and for this reason we evaluated the effects of the biflavonoid fractions from the leaves of O. hexasperma (OHME) and O. ferruginea (OFME) in the in vivo model of complete Freund’s adjuvant (CFA)-induced arthritis and in the in vitro model of oxidative stress and cellular viability. The CFA-induced arthritis model in rats was followed by paw volume, articular incapacitation and Randall-selitto models, as well as quantification of cytokines and serum C-terminal telopeptide of type I collagen levels. OHME and OFME demonstrated antinociceptive and anti-inflammatory activities, as well as improvement in articular incapacity and reduction in levels of interleukin 1β (IL-1β), IL-6, tumor necrosis factor α, and type 1 collagen, and increased cell viability. No adverse effects were observed. The results suggest that OHME and OFME can reduce inflammation and bone resorption besides their antioxidant action.