A review of the traditional use of southern African medicinal plants for the treatment of inflammation and inflammatory pain

Anti-inflammatory effects of the plant family Amaryllidaceae

ETHNOPHARMACOLOGICAL RELEVANCE

Members of the plant family Amaryllidaceae are widely recorded in traditional systems of medicine. Their usage for inflammatory conditions is most prominent, with substantive evidence emerging from several locations around the world.

AIM OF THE STUDY

This survey was undertaken to identify such plant taxa, highlight the countries from which they originate and afford details of the ailments against which they are utilized. The undertaking also sought to establish the in vitro and in vivo activities of Amaryllidaceae plant extracts in inflammation-based assays. Furthermore, it set out to unravel the molecular mechanisms used to explain these effects.

MATERIALS AND METHODS

Over six-hundred articles were identified in searches carried out on SciFinder, Scopus, ScienceDirect, PubMed and Google Scholar. These were condensed to around 170 that formulated the basis of the text. The keyword engaged was 'Amaryllidaceae' in conjunction with 'inflammation' or 'anti-inflammatory', as well as the names of individual genera combined with the latter two.

RESULTS

Fifty-one species from thirty-five countries were identified for their uses against inflammation. Twenty-four of such conditions were discernible, of which their applicability in wound healing and pain management was most conspicuous. The utilization of all plant parts was apparent, preparations of which were used primarily via topical application. Extracts of seventy-three species (from twenty-three genera) were examined in nearly thirty inflammation-based assays where their activities in vitro and in vivo were shown to be significant. They were effective in vivo against pain and swelling as well as wound healing, without detriment towards test subjects. The in vitro studies were carried out mainly in mononuclear cells such as macrophages, leukocytes, lymphocytes and neutrophils against which their cytotoxic effects were seen to be minimal. The modes of operation were shown to involve modulation of both pro-inflammatory (such as NF-κB, TNF-α, IL-6, IFN-γ, COX and NO) and anti-inflammatory (such as IL-10) factors.

CONCLUSIONS

The Amaryllidaceae is showcased as a platform highly conducive towards studies in the inflammation arena. Potent activities in instances were observed via in vitro and in vivo models of study, bolstered by the significant amounts of information emerging from traditional forms of medicine. It is conceivable that the family may yield future anti-inflammatory chemotherapeutics, particularly those related to its alkaloid principles.

An imprecise probability approach-based determination of over-represented southern African plant genera and families used in ethnopharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

The analyses of patterns of over-representation of southern African traditional medicinal plants at the genus and family level provide information about the differences in plant use among southern African countries and disease categories. 'Over-representation' refers to the phenomenon whereby the proportion of plants belonging to a taxonomic group is higher in ethnobotanical pharmacopoeia than in the total flora.

AIM OF THE STUDY

This study aimed to use the Imprecise Dirichlet Model (IDM) to analyse data from ten southern African countries to establish how over-represented medicinal plant families compare with over-represented genera, how over-represented medicinal taxa differ among countries in this region of Africa, and how over-represented taxa differ among six major disease categories.

MATERIALS AND METHODS

Floral data for the total species composition of each country were obtained from online databases. Medicinal plant species lists were generated from published surveys, inventories, and books. IDM calculations were executed using the inverse of the cumulative beta probability density function in Microsoft Excel™. Python programming language source code was used to calculate Pearson correlation (r) values and Jaccard coefficients (J).

RESULTS

Nine of forty-two over-represented medicinal plant families in southern Africa (group 1) do not have over-represented genera. Seven of the forty genera with the highest margins of over-representation belong to under-represented families. Nineteen of the forty-two over-represented families have margins of over-representation smaller than the cumulative margins of their over-represented genera. Groups of countries with similar overall flora (J ≥ 0.333) are Botswana and Namibia (group 2), Malawi, Mozambique, Zambia and Zimbabwe (group 3). The families and genera with the highest margins of over-representation are Loganiaceae and Albizia in group 1, Combretaceae and Vachellia in group 2, Dioscoreaceae and Senna in group 3, and Sapotaceae and Solanum in group 4 (South Africa). The families and genera with the highest margins of over-representation across disease categories are Ebenaceae and Albizia, Canellaceae and Dicoma, Combretaceae and Pterocelastrus, Ebenaceae and Bersama, Francoaceae and Erythrina, and Aristolochiaceae and Strychnos for plants used in the treatment of STIs, febrile and mosquito-vector diseases, microbial infections, pain, skin conditions, and female sexual/reproductive problems, respectively.

CONCLUSIONS

Genus-level calculations are more efficient in generating taxonomic lists that can be used for ethnopharmacological investigations due to the exclusion of under-represented genera. Limiting the size of geographical areas from which medicinal plant lists are sampled and targeting plants used to treat specific types of disease prevents the underestimation of niche over-represented taxa.

Topical Antiedematogenic Activity of the Essential Oil of Psidium brownianum Mart. (OEPB) in Murine Ear Edema Models

Psidium brownianum Mart is reported in the literature by antinociceptive and antioxidant activities, indicating that this species' secondary metabolites might be used to control inflammatory processes. The present study aimed to characterize the topical antiedematogenic activity of the essential oil of Psidium brownianum Mart. (OEPB) in ear edema models by different inflammatory agents. Female Swiss mice (25-35 g) and Wistar albino rats (200-300 g) were used throughout tests (n=6/group) on acute or chronic edema models induced by single and multiple topical applications. The OEPB is administered topically pure or at a concentration of 100 or 200 mg/mL. The antiedematogenic mechanism of OEPB was analyzed by administering capsaicin, arachidonic acid, histamine, and phenol at the best effective dose (200 mg/mL). The results showed a significant reduction of edema-induced single (28.87 %) and multiple (50.13 %) applications of croton oil compared to the negative control group. Regarding potential mechanisms of action, OEPB (200 mg/mL) inhibited the development of edema triggered by capsaicin (29.95 %), arachidonic acid (22.66 %), phenol (23.35 %), and histamine (75.46 %), suggesting an interference with the histaminergic pathway. These results indicate that OEPB presents a topical antiedematogenic effect in acute and chronic murine models, possibly interfering with inflammatory pathways triggered by mediators such as histamine.

Leaf extracts of eight selected southern African medicinal plants modulate pro-inflammatory cytokine secretion in LPS-stimulated RAW 264.7 macrophages

This study investigates the anti-inflammatory properties of extracts prepared from the leaves of eight southern African medicinal plants used traditionally to treat inflammation and pain. The inhibitory effect of aqueous and ethanol extracts on the release of pro-inflammatory cytokines was determined in lipopolysaccharide (LPS) stimulated and unstimulated RAW 264.7 murine macrophage cells. The levels of interleukin (IL)-1β, IL-6, tumour necrosis factor-α (TNF-α), interferon-gamma (IFN-γ), monocyte chemoattractant protein 1 (MCP-1) and macrophage inflammatory protein (MIP)-2 release were determined using cytokine multiplex-bead assays. The ethanol extracts of Melianthus comosus Vahl (commonly known as honey flower), Tetradenia riparia (Hochst.) Codd (misty plume bush) and Warburgia salutaris (G. Bertol.) Chiov. (pepper-bark tree), demonstrated the most significant inhibitory activity, with over 50-fold inhibition of IL-1β, IL-6 and TNF-α levels in LPS-stimulated RAW 264.7 macrophages. The aqueous extract of M. comosus also significantly inhibited the secretion of all the tested cytokines and chemokines. Phytochemical investigation of M. comosus ethanol leaf extract using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) led to the detection of crassolide, deoxylimonoic acid D-ring-lactone, 2-hydroxynonanoic acid and 5-noniloxytryptamine. To the best of our knowledge, the cytokine inhibition properties of most of the medicinal plants screened in this study are reported for the first time. Our results support the use of southern African medicinal plants as anti-inflammatory remedies and provide an insight into the immunomodulatory mechanisms of action.

Morphological diversity and fruit production of wild Salacia kraussii (Celastraceae) on the Northern Coast of KwaZulu-Natal, South Africa

This study aimed to assess morphological diversity within Salacia kraussii, a fruit and medicinal wild plant species, based on morphological features and compared the fruit production among morphological types (morphotype) that naturally occur on the northern coast of KwaZulu-Natal. Following one species plant survey, a description of the qualitative morphological features revealed that S. kraussii individuals mainly differed in their leaf shapes, having elliptic, oblong, or obovate leaves. That led us to the identification of three morphotypes, namely Salacia kraussii 'elliptic', Salacia kraussii 'oblong' and Salacia kraussii 'obovate'. The analysis of variance (one-way ANOVA) of plant quantitative features indicated that plant height, stem diameter, branch number, leaf number and area, and fruit number were significantly different between plants from different sites (p-values < 0.05) and morphotypes (p-values < 0.01). Generally, S. kraussii grows in KwaZulu-Natal as a suffrutex with many stems and exhibits short plant height, small stem diameter, branches, and little foliage per stem. The average fruit number recorded per plant stem was likewise few. Plants growing in Sikhalasenkosi (site1) dominated in average plant height (35.58 cm), leaf number (45), number of branches (4), and number of fruits (5). Plants with elliptic leaves constantly dominated in average plant height (34.45 cm), foliage (36 leaves of 16.29 cm2 each), number of branches (4), and number of fruits (5). A few plants exhibited a strong vegetative vigor and produced more than 20 fruits. There was a highly positive correlation (CC = 0.8) between plant height and leaf number, branch number and leaf number, and branch number and fruit number. However, a negative correlation (CC = -0.1) was recorded between the leaf area and stem diameter. Overall, the study showed wide morphological diversity and fruit production within and between populations of S. kraussii, on the northern coast of KwaZulu-Natal.

Preserving Ethnoveterinary Medicine (EVM) along the Transhumance Routes in Southwestern Angola: Synergies between International Cooperation and Academic Research

This study delves into the ethnoveterinary medicine (EVM) practiced by pastoralists along the transhumance routes in southwestern Angola. Within the framework of three cooperation projects, we conducted 434 interviews, collecting information on 89 taxa used for treating 16 livestock diseases. The most cited species was Ptaeroxylon obliquum (132 citations), followed by Salvadora persica (59) and Elaeodendron transvaalense (49). Contagious bovine pleuropneumonia (CBPP) was the disease most cited (223 citations; 44 species), followed by wounds (95; 20) and Newcastle (86; 14). We found that 30 species and 48 uses have not been previously reported in the ethnoveterinary literature. Jaccard index (mean value = 0.13) showed a greatly diversified knowledge among the ethnic groups: Kuvale and Nyaneka were the most knowledgeable and should be included in the various strategies for disseminating EVM in the area. Most informants recognized that abundance of some species decreased in the last years as a result of human activities and climatic changes. Finally, we discuss challenges in preserving the EVM in the area. Our findings suggest that preservation of the EVM in southwestern Angola is widely impacted by the access to biomedicine. Future studies should investigate the opportunity to integrate traditional medicine into mainstream development projects, which is crucial for decolonizing the veterinary sector in Angola.

Wikstroemia indica (L.) C. A. Mey. Exerts analgesic activity by inhibiting NaV1.7 channel

ETHNOPHARMACOLOGICAL RELEVANCE

Wikstroemia indica (L.) C. A. Mey. is traditionally used for the treatment of gastrointestinal disorders, respiratory illnesses, skin infections, and inflammatory conditions. Despite extensive evidence of its biological potential, including antipyretic, antimicrobial, antifungal, anti-inflammatory, and diuretic properties, there are currently no reports indicating its analgesic effects.

AIM OF THE STUDY

Crude extracts from W. indica stems were examined for anti-nociceptive activity. Additionally, an in-depth investigation was conducted to uncover the molecular basis for the possible analgesic phenomenon.

MATERIALS AND METHODS

W. indica stems were subjected to ethanol extraction. To evaluate the in vivo analgesic activity, both chemical and physical-induced pain models were employed. Additionally, single-cell electrophysiological recordings were performed on human embryonic kidney 293T (HEK293T) cells expressing NaV1.7 channel.

RESULTS

Crude extracts derived from W. indica exhibited significant efficacy in mitigating the pain sensation, as evidenced by their substantial effects in both acetic acid-induced and heat-induced pain models. Further screening unveiled osthenol as a key bioactive compound responsible for mediating the analgesic properties of W. indica. Osthenol directly interacts with the pore domain of NaV1.7 channels, leading to channel inhibition. Importantly, this interaction is independent of any changes in the channel gating modifier domain.

CONCLUSION

Both W. indica and osthenol demonstrate potential as effective anti-nociceptive agents in preclinical studies. Their analgesic effects are likely achieved by inhibiting the NaV1.7 channel, which is crucial in pain initiation, transmission, and modulation. These results elucidate the molecular basis of the W. indica as a pain-relieving medication. Additionally, osthenol holds great potential in advancing the development of anti-nociceptive drugs targeting the NaV1.7 channel.

Biochemical characterization of bioinspired nanosuspensions from Swertia chirayita extract and their therapeutic effects through nanotechnology approach

Swertia chirayita is used as a traditional medicinal plant due to its pharmacological activities, including antioxidant, antidiabetic, antimicrobial, and cytotoxic. This study was aimed to evaluate the therapeutic efficacy of newly synthesized nanosuspensions from Swertia chirayita through nanotechnology for enhanced bioactivities. Biochemical characterization was carried out through spectroscopic analyses of HPLC and FTIR. Results revealed that extract contained higher TPCs (569.6 ± 7.8 mg GAE/100 g)) and TFCs (368.5 ± 9.39 mg CE/100 g) than S. chirayita nanosuspension, TPCs (500.6 ± 7.8 500.6 ± 7.8 mg GAE/100 g) and TFCs (229.5± 3.85 mg CE/100 g). Antioxidant activity was evaluated through DPPH scavenging assay, and nanosuspension exhibited a lower DPPH free radical scavenging potential (06 ±3.61) than extract (28.9± 3.85). Anti-dabetic potential was assessed throughα-amylase inhibition and anti-glycation assays. Extract showed higher (41.4%) antiglycation potential than 35.85% nanosuspension and 19.5% α-amylase inhibitory potential than 5% nanosuspension. Biofilm inhibition activity against E. coli was higher in nanosuspension (69.12%) than extract (62.08%). The extract showed high cytotoxicity potential (51.86%) than nanosuspension (33.63%). These nanosuspensions possessed enhanced bioactivities for therapeutic applications could be explored further for the development of new drugs.

Inhibition of pro-inflammatory cytokines by selected southern African medicinal plants in LPS-stimulated RAW 264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Bark is frequently used in southern African traditional medicine to treat inflammation, yet it remains to be rigorously examined for its immunological and anti-inflammatory activity.

AIM OF THE STUDY

Barks obtained from ten important and popular southern Africa plants were evaluated for their anti-inflammatory and immunomodulatory properties against the secretion of some pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, tumour necrosis factor-α (TNF-α), and interferon-gamma (IFN-γ) as well as chemokines (monocyte chemoattractant protein 1 (MCP-1) and macrophage inflammatory protein (MIP)-2) in murine RAW 264.7 macrophages.

MATERIALS AND METHODS

The inhibitory effects of aqueous and ethanol extracts were determined using cytokine multiplex-bead assays in lipopolysaccharide (LPS)-stimulated and unstimulated RAW 264.7 cells.

RESULTS

Overall, the ethanol extracts were more potent cytokine inhibitors compared to the aqueous extracts. The LPS-stimulated cells treated with the ethanol extracts of Erythrina lysistemon Hutch., Pterocelastrus rostratus Walp. Syzygium cordatum Hochst. ex Krauss and Warburgia salutaris (G. Bertol.) Chiov., demonstrated significant (p < 0.005) inhibition up to 85% of IL-1β, IL-6, and TNF-α secretion compared to the LPS control. Additionally, P. rostratus and S. cordatum aqueous bark extracts substantially decreased the secretion of all the tested cytokines and chemokines. Chemical investigation of the S. cordatum extract resulted in the identification of four ellagic acid derivatives: ellagic acid 4-O-α-rhamnopyranoside (1), ellagic acid 4-O-α-4″-acetylrhamnopyranoside (2), 3-O-methylellagic acid 4'-O-α-3″-O-acetylrhamnopyranoside (3) and 3-O-methylellagic acid 4'-O-α-4″-O-acetylrhamnopyranoside (4), along with mixtures of ellagic acid 4-O-α-2″-acetylrhamnopyranoside (5), ellagic acid 4-O-α-3″-acetylrhamnopyranoside (6) and ellagic acid (7). Their structures were confirmed by mass spectrometry, NMR spectroscopy, and comparison with data from literature.

CONCLUSION

The cytokine inhibition properties of most of the medicinal plants screened herein are reported for the first time. Our results provide insights into the mechanism of action by which the selected southern African medicinal plants regulate inflammation.

Study on medicinal food plants in the Gaoligongshan Biosphere Reserve, the richest biocultural diversity center in China

BACKGROUND

Traditional knowledge associated with medicinal food plants (MFPs) plays a vital role in fighting hidden hunger and safeguarding the health of local people. MFPs resources are abundant in the Gaoligongshan area, a biosphere reserve with the richest biocultural diversity in China. Local people of different linguistic groups also have rich traditional botanical knowledge. However, there are still few comprehensive and systematic studies on MFPs there.

METHODS

Ethnobotanical investigation including market survey, semi-structured interviews, free listing and key informant interviews was conducted in the Gaoligongshan area, Western Yunnan, Southwest China. A total of 13 local farmers' markets were selected and information about medicinal food plants, including food categories, medicinal and edible parts, modes of consumption, medicinal effects, and distribution were collected. The relative occurrence frequency (RFO) and cultural food significance index (CFSI) were calculated to identify the culturally significant MFPs.

RESULTS

A total of 184 species of MFPs, belonging to 83 families, were collected in the Gaoligongshan area, including vegetables (77), medicinal diets (26), fruits (25), spices (18), herbal tea (13), tea substitutes (11), substitutes for staple food (8), nuts (5), oils and fats (4), and dye material (1). The most frequently used families were Fabaceae, Asteraceae and Apiaceae, with 11, 10, and 9 species, respectively. The most frequently used plant parts were the stems, followed by fruits and leaves. Based on the evaluation results of the CFSI and RFO indices, 18 species of MFPs with magnificent local cultural importance have been screened out, such as Houttuynia cordata, Eryngium foetidum, Sechium edule, Centella asiatica and Pseudocydonia sinensis.

CONCLUSION

These findings have guiding significance for conservation of traditional knowledge associated with MFPs and facilitation of scientific utilization of MFPs to meet local people's needs for a healthy life.

Cytotoxic and Phytotoxic Activities of Native Brazilian Forest Gabiroba (Campomanesia xanthocarpa Berg.), Fruits, and Flour against Shrimp (Artemia salina L.) and Lettuce (Lactuca sativa L.)

Gabiroba, a native fruit in Brazil's Atlantic Forest region, has significant nutritional and therapeutic properties. However, due to its seasonality, consumption by the population is limited. Thus, the development of gabiroba byproducts would add significant value to the food and therapeutic industries. Therefore, it is essential to study and support the lack of toxicity of gabiroba fruit extracts. In the present study, physicochemical analyses of fresh fruits (GF) and dehydrated whole gabiroba flour (WGF) and preliminary toxicity analyses of WGF were performed. The toxicity results showed a microcrustacean LC50 of >1000 mg/mL when exposed to WGF extracts at various concentrations (10-1000 μg/mL; p = 0.062) using the Artemia salina method, with no evidence observed of proliferative activity or toxic metabolic compounds in the WGF extract. The phytotoxicity of WGF using Lactuca sativa L. allowed germination and root growth at various concentrations of WGF extract, with the lowest (100 μg/mL) and highest (1000 μg/mL) concentrations exhibiting 98.3% and 100% seed germination, respectively. In conclusion, these results indicate that the WGF preparation preserved the nutritional and antioxidant potential of gabiroba fruits and that WGF is safe for use as a raw material in the food industry and for therapeutic purposes.

Formulation of Entandrophragma utile into an Herbal Emulgel for the Management of Inflammation

Introduction: Globally, the incidence of inflammation and inflammatory disorders has continued to rise at an alarming rate. Entandrophragma utile is a species of flowering plant widely distributed in Africa and has been used for the management of sickle cell disease, rheumatism, ocular inflammation, duodenal and stomach ulcers. This research aims to formulate and evaluate an anti-inflammatory herbal emulgel using an extract from Entandrophragma utile stem bark (EUB). Method: Using a carrageenan-induced paw oedema model, the anti-inflammatory efficacy of EUB the extract was assessed. The formulated Entandrophragma utile emulgels (EUE) were characterized, and their anti-inflammatory activity was demonstrated, by utilizing diclofenac emulgel-treated rats with complete Freund's adjuvant (CFA)-induced arthritis model as the positive control group. Results: The emulgels formulated had characterization results within acceptable ranges; pH (4.25-5.80), viscosity (418.9-112.8 mPas), spreadability (25.00-31.82 gcm/s), extrudability (30.86-51.02 g/cm2), and a swelling index of (30-60%). The emulgel produced a concentration-dependent inflammatory inhibition with a peak effect (117.97%) at the end of the 4th week which was comparable to that of commercial diclofenac (127.19%). The phytochemical analysis led to the identification of saponins, flavonoids, phenols, and tannins as active secondary metabolites. Conclusions: The stem bark extract of E. utile possessed noteworthy (p < 0.05) reduction in inflammation in comparison to diclofenac and its emulgel formulation showed enormous potential for treating inflammation and pain.

Phytochemical Composition and Antioxidant and Anti-Inflammatory Activities of Humboldtia sanjappae Sasidh. & Sujanapal, an Endemic Medicinal Plant to the Western Ghats

Ethnomedicinal plants are important sources of drug candidates, and many of these plants, especially in the Western Ghats, are underexplored. Humboldtia, a genus within the Fabaceae family, thrives in the biodiversity of the Western Ghats, Kerala, India, and holds significant ethnobotanical importance. However, many Humboldtia species remain understudied in terms of their biological efficacy, while some lack scientific validation for their traditional uses. However, Humboldtia sanjappae, an underexplored plant, was investigated for the phytochemical composition of the plant, and its antioxidant, enzyme-inhibitory, anti-inflammatory, and antibacterial activities were assessed. The LC-MS analysis indicated the presence of several bioactive substances, such as Naringenin, Luteolin, and Pomiferin. The results revealed that the ethanol extract of H. sanjappae exhibited significant in vitro DPPH scavenging activity (6.53 ± 1.49 µg/mL). Additionally, it demonstrated noteworthy FRAP (Ferric Reducing Antioxidant Power) activity (8.46 ± 1.38 µg/mL). Moreover, the ethanol extract of H. sanjappae exhibited notable efficacy in inhibiting the activities of α-amylase (47.60 ± 0.19µg/mL) and β-glucosidase (32.09 ± 0.54 µg/mL). The pre-treatment with the extract decreased the LPS-stimulated release of cytokines in the Raw 264.7 macrophages, demonstrating the anti-inflammatory potential. Further, the antibacterial properties were also evident in both Gram-positive and Gram-negative bacteria. The observed high zone of inhibition in the disc diffusion assay and MIC values were also promising. H. sanjappae displays significant anti-inflammatory, antioxidant, antidiabetic, and antibacterial properties, likely attributable to its rich composition of various biological compounds such as Naringenin, Luteolin, Epicatechin, Maritemin, and Pomiferin. Serving as a promising reservoir of these beneficial molecules, the potential of H. sanjappae as a valuable source for bioactive ingredients within the realms of nutraceutical and pharmaceutical industries is underscored, showcasing its potential for diverse applications.

Wild Vitex agnus-castus L.: Phytochemical Characterization, Acute Toxicity, and Bioactive Properties

Wild Vitex agnus-castus (VAC) is a Mediterranean plant that is rich in bioactive metabolites. This study aimed to validate, for the first time, the beneficial use of VAC fruits and fruit decoctions (VFDs) through in vitro and in vivo trials. Forty-one volatile components were detected in VAC fruits, with 1,8-cineole (30.3%) comprising the majority. The antioxidant activity of VFD was measured by using different in vitro methods (EC₅₀ of 0.16 mg/mL by β-carotene bleaching inhibition assay) and by measuring the DNA protection power. Using the disc diffusion assay, the antimicrobial activity of VFD was evaluated, and it exhibited a noticeable anticandidal activity. VFD did not cause any toxicity or mortality in rats treated with doses > 200 mg/kg. Using the acetic acid writhing test, the antinociceptive activity of VFD was measured. Our results showed that VFD at 200 mg/kg exhibited a higher analgesic activity (81.68%) than acetylsalicylic acid used as a positive control (74.35%). Its gastroprotective ability was assessed by HCl/ethanol-induced gastric lesions, which were remarkably inhibited (84.62%) by intraperitoneal administration of VFD. This work helps to validate the popular use of VAC to treat nociceptive, inflammatory, and gastric disorders and encourages researchers to further investigate the identification of pharmacological compounds from this species.

Apigetrin-enriched Pulmeria alba extract prevents assault of STZ on pancreatic β-cells and neuronal oxidative stress with concomitant attenuation of tissue damage and suppression of inflammation in the brain of diabetic rats

In the present study, in vitro, in vivo, and in silico models were used to evaluate the therapeutic potential of Pulmeria alba methanolic (PAm) extract, and we identified the major phytocompound, apigetrin. Our in vitro studies revealed dose-dependent increased glucose uptake and inhibition of α-amylase (50% inhibitory concentration (IC₅₀)= 217.19 µg/mL), antioxidant (DPPH, ferric-reducing activity of plasma (FRAP), and lipid peroxidation (LPO) [IC₅₀ = 103.23, 58.72, and 114.16 µg/mL respectively]), and anti-inflammatory potential (stabilizes human red blood cell (HRBC) membranes, and inhibits proteinase and protein denaturation [IC₅₀ = 143.73, 131.63, and 198.57 µg/mL]) by the PAm extract. In an in vivo model, PAm treatment reversed hyperglycemia and attenuated insulin deficiency in rats with streptozotocin (STZ)-induced diabetes. A post-treatment tissue analysis revealed that PAm attenuated neuronal oxidative stress, neuronal inflammation, and neuro-cognitive deficiencies. This was evidenced by increased levels of antioxidants enzymes (superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH)), and decreased malondialdehyde (MDA), proinflammatory markers (cyclooxygenase 2 (COX2), nuclear factor (NF)-κB and nitric oxide (NOx)), and acetylcholinesterase (AChE) activities in the brain of PAm-treated rats compared to the STZ-induced diabetic controls. However, no treatment-related changes were observed in levels of neurotransmitters, including serotonin and dopamine. Furthermore, STZ-induced dyslipidemia and alterations in serum biochemical markers of hepatorenal dysfunction were also reversed by PAm treatment. Extract characterization identified apigetrin (retention time: 21,227 s, 30.48%, m/z: 433.15) as the major bioactive compound in the PAm extract. Consequently, we provide in silico insights into the potential of apigetrin to target AChE/COX-2/NOX/NF-κB Altogether the present study provides preclinical evidence of the therapeutic potential of the apigetrin-enriched PAm extract for treating oxidative stress and neuro-inflammation associated with diabetes.

The traditional use of Southern African medicinal plants to alleviate fever and their antipyretic activities

ETHNOPHARMACOLOGICAL RELEVANCE

Multiple plant species are used traditionally in southern Africa to treat fever. This review summarises the traditional use, highlights promising plant species and focuses on validation studies to highlight future areas of research.

AIM OF THE STUDY

This study aimed to critically review the use of southern African plants to alleviate fever. Additionally, an examination of research into those plants was undertaken to highlight gaps in the literature with the aim of stimulating further research in this field.

MATERIALS AND METHODS

Ethnobotanical books, reviews and primary research studies were searched to identify plant species traditionally used to treat fever in southern Africa and to summarise the current knowledge and identify areas requiring further research. This study was non-biased and did not have any taxonomic preferences, nor did it favour any southern African healing systems over the others.

RESULTS

The traditional therapeutic uses of 203 southern African plant species to alleviate fever were recorded. Leaves and roots/bulbs/rhizomes were the most commonly used plant part, and they were most commonly prepared as decoctions or infusions and consumed orally. Notably, only twenty-two species (∼11% of the identified species) have been scientifically evaluated for antipyretic properties, with substantially fewer mechanistic studies evident.

CONCLUSIONS

Despite the availability of ethnobotanical records, the antipyretic properties of southern African medicinal plants are poorly reported. Indeed, the efficacy of most plants is yet to be verified and very few mechanistic studies are available.

Attenuation of hyperglycemia-associated dyslipidemic, oxidative, cognitive, and inflammatory crises via modulation of neuronal ChEs/NF-κB/COX-2/NOx, and hepatorenal functional deficits by the Tridax procumbens extract

Tridax procumbens (cotton buttons) is a flowering plant with a medicinal reputation for treating infections, wounds, diabetes, and liver and kidney diseases. The present research was conducted to evaluate the possible protective effects of the T. procumbens methanolic extract (TPME) on an experimentally induced type 2 diabetes rat model. Wistar rats with streptozotocin (STZ)-induced diabetes were randomly allocated into five groups of five animals each, viz., a normal glycemic group (I), diabetic rats receiving distilled water group (II), diabetic rats with 150 (III) and 300 mg/kg of TPME (IV) groups, and diabetic rats with 100 mg/kg metformin group (V). All treatments were administered for 21 consecutive days through oral gavage. Results: Administration of the T. procumbens extract to diabetic rats significantly restored alterations in levels of fasting blood glucose (FBG), body weight loss, serum and pancreatic insulin levels, and pancreatic histology. Furthermore, T. procumbens significantly attenuated the dyslipidemia (increased cholesterol, low-density lipoprotein-cholesterol (LDL-C), triglycerides, and high-density lipoprotein (HDL) in diabetic rats), serum biochemical alterations (alanine transaminase (ALT), aspartate transaminase (AST), alanine phosphatase (ALP), blood urea nitrogen (BUN), creatinine, uric acid, and urea) and full blood count distortion in rats with STZ-induced diabetes. The TPME also improved the antioxidant status as evidenced by increased superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and decreased malondialdehyde (MDA); and decreased levels of cholinesterases (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)), and proinflammatory mediators including nuclear factor (NF)-κB, cyclooxygenase (COX)- 2, and nitrogen oxide (NOx) in the brain of rats with STZ-induced diabetes compared to rats with STZ-induced diabetes that received distilled water. However, TPME treatment failed to attenuate the elevated monoamine oxidases and decreased dopamine levels in the brain of rats with STZ-induced diabetes. Extract characterization by liquid chromatography mass spectrometry (LC-MS) identified isorhamnetin (retention time (RT)= 3.69 min, 8.8%), bixin (RT: 25.06 min, 4.72%), and lupeol (RT: 25.25 min, 2.88%) as the three most abundant bioactive compounds that could be responsible for the bioactivity of the plant. In conclusion, the TPME can be considered a promising alternative therapeutic option for managing diabetic complications owing to its antidiabetic, antihyperlipidemic, antioxidant, and anti-inflammatory effects in rats with STZ-prompted diabetes.

Antimicrobial potential of the Mayan medicine plant Matayba oppositifolia (A. Rich.) Britton against antibiotic-resistant priority pathogens

ETHNOPHARMACOLOGICAL RELEVANCE

The bark of Matayba oppositifolia (A. Rich.) Britton (commonly known as "huaya" or "palo huacax") is commonly utilized in traditional Mayan medicine for treating diarrhea and for canker and other sores.

AIM OF THE STUDY

The aim of this study was to investigate the in-vitro antimicrobial activity of M. oppositifolia bark extracts against drug-susceptible and -resistant ESKAPE-E pathogens. In addition, the phytochemical composition of the best antibacterial extract was analyzed.

MATERIALS AND METHODS

The bark extracts were prepared with different solvents, including water, n-hexane, ethyl acetate and methanol. These were tested against ESKAPE-E (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp., including Escherichia coli) strains using Resazurin Microtiter Assay. In addition, the composition of the most active extract was analyzed by GC-MS.

RESULTS

The aqueous and organic bark extracts showed activity on drug-susceptible and -resistant ESKAPE-E microbes (MIC = 1000-31.25 μg/mL). The n-hexane bark extract was more active against the superbugs carbapenem-resistant K. pneumoniae (MIC = 500-31.25 μg/mL) and A. baumannii (MIC = 250-125 μg/mL). The GC-MS analysis of this extract allowed the identification of 12 phytochemicals as the potential antibacterial compounds. The major compounds identified were palmitic acid (1), friedelan-3-one (2) and 7-dehydrodiosgenin (3).

CONCLUSION

The present study reveals the strong in-vitro antibacterial activity of the n-hexane extract from the bark of M. oppositifolia and demonstrates the potential of natural products as a source of antibacterial compounds or phytomedicines that are specifically effective against drug-resistant ESKAPE-E bugs. Additionally, our investigation contributes to the ethnopharmacological knowledge and reappraisal of Mayan medicinal flora, as well as supports the traditional use of the bark of the medicinal plant M. oppositifolia for the treatment of infectious diseases.

Research Hotspots and Trends on Acupuncture for Anti-Inflammation: A Bibliometric Analysis from 2011 to 2021

Purpose

We here explored the research status, research hotspots, and development trend of acupuncture against inflammation from both quantitative and qualitative aspects through bibliometrics.

Methods

We used CiteSpace and VOSviewer to analyze the literature about acupuncture against inflammation from 2011 to 2021 in the Web of Science Core Collection database by using a visual knowledge map.

Results

In total, 1479 articles were included, and the number of articles published each year exhibited an upward trend. The largest number of articles were published in China (661), followed by the United States (287) and South Korea (164). The most productive institution is Beijing University of Chinese Medicine (72), while the most influential institution is the Capital Medical University (0.28). Evidence-based Complementary and Alternative Medicine (131) is the journal that published most articles on the topic. Lin Yiwen is the most prolific author, and Borovikova L is the most influential co-cited author. The keywords that have burst in the last 2 years are inflammation and activation. The keywords with the highest frequency of use are electroacupuncture (EA), inflammation, and expression.

Conclusion

The number of publications on acupuncture for anti-inflammation research is rapidly increasing. China is a productive country, but the influence of centrality is poor. Research institutions are concentrated in universities, and the whole collaborative network needs to be strengthened. The anti-inflammatory mechanism of acupuncture is the main focus of research in this field. Regulation of immune cell balance by acupuncture may be a hot topic in mechanism research. At present, immune cells, vagus nerve, signal pathway, inflammatory corpuscles, cytokines and neurotransmitters are popular research topics. In the future, the basic research of acupuncture for anti-inflammation transformed into clinical practice may be a trend. EA and bee venom acupuncture may be promising research directions for acupuncture treatment for inflammatory diseases.

Insight into the possible mechanism(s) involved in the antinociceptive and antineuropathic activity of Descurainia sophia L. Webb ex Prantl essential oil

ETHNOPHARMACOLOGICAL RELEVANCE

Descurainia sophia (L.)(Brassicaceae), popularly known as "Khaksheer", is a native species widely distributed in Iran. The seeds and essential oil has been used in local traditional medicine (Persian folk ethnomedicine) to treat fever, inflammation, back pain, and headache.

AIM OF THE STUDY

To investigate in vitro anti-nociceptive and antineuropathic activities of Descurainia sophia seeds essential oil (DSEO) in rats and to determine the possible mechanism(s) involved.

MATERIALS AND METHODS

The antinociceptive activity of DSEO or Linolenic acid (LA) was evaluated using the formalin induced paw licking test followed by determination on the role of NO-cGMP-K+ channel pathway as well as a number of non-opioid receptor systems (vanilloid, dopamine, cannabinoid, serotonin, peroxisome proliferator activated, and adrenergic receptors) in the modulation of DSEO-induced antinociceptive activity. Additionally, the cervical spinal cord contusion (CCS) model was used to study antineuropathic potential of DSEO or LA.

RESULTS

DSEO exerted significant (p < 0.05) antinociceptive activity in formalin test (both phases) and altered mechanical allodynia and hyperalgesia observed in the CCS model. Pretreatment with glibenclamide, Nω-nitro-L-arginine methyl ester, tranilast, methylene blue, SCH23390, SR141716A and SR144528 restored DSEO-induced antinociceptive activity observed in the formalin test. Furthermore, LA also reduced nociceptive responses induced in the formalin and CCS models.

CONCLUSION

DSEO inhibits inflammatory mediated nociceptive response partly via the modulation of NO-cGMP-K+ channels pathway well as the activation of vanilloid, dopamine, and cannabinoid receptors, and exerts antineuropathic activity possibly via the modulation of inflammatory mediated activity. Thus, these findings confirm the Persian ethno-medicine claim on the efficacy of D. Sophia.

Anti-inflammatory effects of Pikad Tri-phol-sa-mut-than remedy, consisting of dried fruits of Aegle marmelos (L.) Corrêa, Coriandrum sativum L., and Morinda citrifolia L

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammation has been known to possess some essential roles in many diseases, especially those with chronic or severe conditions. Pikad Tri-phol-sa-mut-than, a Thai traditional herbal remedy, has long been used to treat gastrointestinal sicknesses, fever, and severe illness caused by the deformities of Tridosha. In particular, this recipe has also been applied for inflammation-related conditions including gout and rheumatoid arthritis. The Pikad Tri-phol-sa-mut-than recipe consists of dried fruits of three herbs including Aegle marmelos (L.) Corrêa, Morinda citrifolia L., and Coriandrum sativum L. Each of these plant components of Pikad Tri-phol-sa-mut-than exhibited anti-inflammatory activities. However, anti-inflammatory effect of Pikad Tri-phol-sa-mut-than remedy has not been reported.

AIM OF THE STUDY

The objective of this study was to elucidate the anti-inflammatory activities of Pikad Tri-phol-sa-mut-than extract (TS) against acute and chronic inflammation in rats.

MATERIALS AND METHODS

To study the effects of TS on acute inflammation, ethyl phenylpropiolate (EPP)-induced ear edema, carrageenan- and arachidonic acid (AA)-induced hind paw edema models were carried out. In addition, cotton pellet-induced granuloma formation was performed to specify the inhibitory effects of TS on chronic inflammation.

RESULTS

The topical application of TS significantly inhibited EPP-induced ear edema in rats. In the carrageenan- and AA-induced paw edema models, the oral administration of TS significantly reduced paw volumes, compared to those of the control groups. In addition, the 7-day oral treatment of TS demonstrated a significant suppressive effect on cotton pellet-induced granuloma formation.

CONCLUSIONS

The current study revealed that TS possesses anti-inflammatory activities against acute and chronic inflammation. Our studies support the use of TS in traditional medicine, and the development of TS as a novel natural product for treating diseases associated with inflammation.

Phytochemical analysis and preclinical toxicological, antioxidant, and anti-inflammatory evaluation of hydroethanol extract from the roots of Harpalyce brasiliana Benth (Leguminosae)

ETHNOPHARMACOLOGICAL RELEVANCE

Harpalyce brasiliana Benth (Leguminosae) is a shrub endemic to Brazil, popularly known as "snake's root." This species is used in folk medicine for the treatment of inflammation and snakebites. However, up to now there is no scientific research to justify its popular use. The study aimed to characterize the phytochemical profile of the hydroethanol extract from the roots of H. brasiliana (Hb), to evaluate its antioxidant and anti-inflammatory potential, as well as to investigate its cytotoxicity and acute toxicity.

MATERIALS AND METHODS

The extract was obtained by maceration method using a solution of ethanol:water (70: 30, v/v). The phytochemical profile was obtained by liquid chromatography coupled to mass spectrometry. The cytotoxicity of extract (31-2000 μg/mL) was evaluated in vitro, by the 3-methyl-[4-5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method using murine macrophage and fibroblast cell lines (RAW 247.6 and 3T3, respectively) and by the hemolytic assay. For the in vivo acute toxicity, the extract (2000 mg/kg) was administered and after 14 days the weight (body and organs) and hematological and biochemical parameters were analyzed. Chemical free radical scavenging effect of the extract (125-2000 μg/mL) was investigated through diphenylpicryl hydrazine reduction, total antioxidant capacity, reducing power, hydroxyl radical scavenging, and iron and copper chelating assays. In vitro anti-inflammatory effect of the extract (125, 500, and 2000 μg/mL) was demonstrated through of nitric oxide (NO) analyzed in lipopolysaccharides stimulated RAW 264.7 cells. In vivo anti-inflammatory activities were evaluated in carrageenan-induced paw edema and zymosan-air-pouch models, with gavage administration (post-treatment) of extract at 100, 200, and 400 mg/kg. For the first animal model, the anti-edematogenic activity and myeloperoxidase (MPO) levels were investigated, while in the zymosan-air-pouch model the leukocyte number, MPO, total protein and pro-inflammatory cytokine (IL-1β, IL-6, and TNF-α) levels were quantified. In addition, the oxidative parameters such as malondialdehyde (MDA) and reduced glutathione (GSH) were determined.

RESULTS

The phytochemical profile revealed the presence of 20 compounds, mainly prenylated and geranylated pterocarpans. The extract demonstrated no cytotoxicity in erythrocytes, macrophages and fibroblasts cells at the tested concentrations, as well as no sign of toxicity and mortality or significant alterations on the hematological and biochemical parameters in the acute toxicity model. The extract was also able to neutralize chemical free radicals, with copper and iron chelating effect. For the NO dosage, the extract evidenced the reduction of expression of NO after the administration of the extract (500 and 2000 μg/mL). The edematogenic model revealed a decrease in paw edema and MPO level, while the zymosan-air-pouch model evidenced a reduction of leukocyte number (especially of polymorphornuclears), MPO production, and total protein and cytokine levels, and demonstrated the antioxidant effect through a decrease in MDA and increase in GSH parameters.

CONCLUSION

This approach demonstrates for the first time that Hb is not cytotoxic, has low acute toxicity, and possesses antioxidant and anti-inflammatory properties in preclinical analyses, corroborating its popular use.

The Fight against Infection and Pain: Devil’s Claw (Harpagophytum procumbens) a Rich Source of Anti-Inflammatory Activity: 2011–2022

Harpagophytum procumbens subsp. procumbens (Burch.) DC. ex Meisn. (Sesame seed Family—Pedaliaceae) is a popular medicinal plant known as Devil’s claw. It is predominantly distributed widely over southern Africa. Its impressive reputation is embedded in its traditional uses as an indigenous herbal plant for the treatment of menstrual problems, bitter tonic, inflammation febrifuge, syphilis or even loss of appetite. A number of bioactive compounds such as terpenoids, iridoid glycosides, glycosides, and acetylated phenolic compounds have been isolated. Harpagoside and harpagide, iridoid glycosides bioactive compounds have been reported in countless phytochemical studies as potential anti-inflammatory agents as well as pain relievers. In-depth studies have associated chronic inflammation with various diseases, such as Alzheimer’s disease, obesity, rheumatoid arthritis, type 2 diabetes, cancer, and cardiovascular and pulmonary diseases. In addition, 60% of chronic disorder fatalities are due to chronic inflammatory diseases worldwide. Inflammation and pain-related disorders have attracted significant attention as leading causes of global health challenges. Articles published from 2011 to the present were obtained and reviewed in-depth to determine valuable data findings as well as knowledge gaps. Various globally recognized scientific search engines/databases including Scopus, PubMed, Google Scholar, Web of Science, and ScienceDirect were utilized to collect information and deliver evidence. Based on the literature results, there was a dramatic decrease in the number of studies conducted on the anti-inflammatory and analgesic activity of Devil’s claw, thereby presenting a potential research gap. It is also evident that currently in vivo clinical studies are needed to validate the prior massive in vitro studies, therefore delivering an ideal anti-inflammatory and analgesic agent in the form of H. procumbens products.

Structural Investigation of the Interaction Mechanism between Chlorogenic Acid and AMPA Receptor via In Silico Approaches

Chlorogenic acid (CGA), an important metabolite in natural plant medicines such as honeysuckle and eucommia, has been shown to have potent antinociceptive effects. Nevertheless, the mechanism by which CGA relieves chronic pain remains unclear. α-amino-3-hydroxy-5-methyl-4-isooxazolpropionic acid receptor (AMPAR) is a major ionotropic glutamate receptor that mediates rapid excitatory synaptic transmission and its glutamate ionotropic receptor AMPA type subunit 1 (GluA1) plays a key role in nociceptive transmission. In this study, we used Western blot, surface plasmon resonance (SPR) assay, and the molecular simulation technologies to investigate the mechanism of interaction between CGA and AMPAR to relieve chronic pain. Our results indicate that the protein expression level of GluA1 showed a dependent decrease as the concentration of CGA increased (0, 50, 100, and 200 μM). The SPR assay demonstrates that CGA can directly bind to GluA1 (K_D = 496 μM). Furthermore, CGA forms a stable binding interaction with GluA1, which is validated by molecular dynamics (MD) simulation. The binding free energy between CGA and GluA1 is -39.803 ± 14.772 kJ/mol, where van der Waals interaction and electrostatic interaction are the major contributors to the GluA1-CGA binding, and the key residues are identified (Val-32, Glu-33, Ala-36, Glu-37, Leu-48), which play a crucial role in the binding interaction. This study first reveals the structural basis of the stable interaction between CGA and GluA1 to form a binding complex for the relief of chronic pain. The research provides the structural basis to understand the treatment of chronic pain and is valuable to the design of novel drug molecules in the future.

The chemical composition of different leaf extracts of Lantana fucata Lindl. influences its cytotoxic potential: A study using the Allium cepa model

ETHNOPHARMACOLOGICAL RELEVANCE

One of the most popular plants used to treat diseases in Brazil is Lantana fucata. Like most herbal medicines, its consumption is based on popular knowledge, which, despite being considered effective, may cause side effects.

AIM OF THE STUDY

Since the scientific data on the pharmacological properties of L. fucata are still incipient, this research aimed to evaluate the cytotoxic and genotoxic potential of different types of extracts (infusion, aqueous and hydroalcoholic), characterizing them chemically.

MATERIALS AND METHODS

The cytotoxicity assay was performed by the A. cepa model. The cytotoxicity parameters studied were number of dividing cells and percentage mitotic index (%MI).

RESULTS

The result of the A. cepa assay showed that there was a decrease in the number of dividing cells and the percentage mitotic index as concentrations increased, for all extracts, indicating cytotoxicity. However, the hydroalcoholic extract was the most cytotoxic. Chromatography analysis allowed the characterization of secondary metabolites in the extracts, which were very similar. However, a greater abundance of flavonoids and triterpenoids was observed in the hydroalcoholic extract, suggesting that these compounds are responsible for its greater toxicity.

CONCLUSIONS

Since the highest doses of extracts showed to have a cytotoxic effect, it is suggested that the ingestion of this species occurs in a moderate way.

Anti-Nociceptive and Anti-Inflammatory Activities of the Ethyl Acetate Extract of Belamcanda chinensis (L.) Redouté in Raw 264.7 Cells in vitro and Mouse Model in vivo

Purpose

Inflammation and accompanying pain is a common global health problem that seriously affects human quality of life worldwide. Here, we aimed to investigate the anti-nociceptive and anti-inflammatory activities of the ethyl acetate extract of B. chinensis (EAEBc) along with the underlying mechanisms of action.

Methods

The in vitro anti-inflammatory activity of EAEBc was explored using an LPS-induced RAW264.7 cell inflammatory model. Nitric oxide (NO) production, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 levels were evaluated. In vivo anti-nociceptive and anti-inflammatory activities of EAEBc were assessed with the aid of classical experimental mouse models. In addition, LPS-induced biomarker contents (TNF-α, IL-1β, IL-6, NO, iNOS, and PGE2) and formalin-induced serum inflammatory factors (NO, PGE2, 5-HT, β-EP, substance P, and NE) were determined in mice.

Results

In vitro, EAEBc significantly reduced LPS-induced NO generation and suppressed the production of TNF-α, IL-1β, and IL-6 in RAW264.7 cells in a concentration-dependent manner. In vivo, EAEBc downregulated serum TNF-α, IL-1β, IL-6, NO, iNOS, and PGE2 contents in mice with LPS-induced inflammation in a dose-dependent manner. EAEBc displayed anti-inflammatory activity in carrageenan-induced paw edema and xylene ear edema tests. Intragastric administration of EAEBc at test doses of 100 and 200 mg/kg led to inhibition of nociception and capillary permeability induced by acetic acid to varying degrees. Similarly, EAEBc exerted analgesic effects in the formalin and hot plate tests. In particular, the administration of EAEBc reversed the changes in the levels of inflammatory indicators NO, PGE2, 5-HT, β-EP, substance P, and NE in a mouse model of formalin-induced pain.

Conclusion

Our findings provide considerable evidence to support the extensive application of B. chinensis in traditional medicine and demonstrate the utility of this plant species as an effective candidate for prevention or treatment of various pain and inflammation-related conditions.

Medicinal Plants for Mitigating Pain and Inflammatory-Related Conditions: An Appraisal of Ethnobotanical Uses and Patterns in South Africa

In South Africa, traditional medicine remains the first point of call for a significant proportion of the population seeking primary healthcare needs. This is particularly important for treating common conditions including pain and inflammation which are often associated with many disease conditions. This review focuses on the analysis of the trend and pattern of plants used for mitigating pain and inflammatory-related conditions in South African folk medicine. An extensive search was conducted using various scientific databases and popular ethnobotanical literature focusing on South African ethnobotany. Based on the systematic analysis, 38 sources were selected to generate the inventory of 495 plants from 99 families that are considered as remedies for pain and inflammatory-related conditions (e.g., headache, toothache, backache, menstrual pain, and rheumatism) among different ethnic groups in South Africa. The majority (55%) of the 38 studies were recorded in three provinces, namely, KwaZulu-Natal, Limpopo, and Western Cape. In terms of the number of mentions, the most popular plants used for pain and inflammatory-related conditions in South Africa were Ricinus communis L. (10), Aloe ferox Mill. (8), Pentanisia prunelloides subsp. latifolia (Hochst.) Verdc. (8), Dodonaea viscosa Jacq var. angustifolia (L.f) Benth. (8), (L.) W.T.Aiton. (7) Ruta graveolens L. (7), and Solanum aculeastrum Dunal. (7). The top five plant families represented were Asteraceae (13%), Fabaceae (8%), Apocynaceae (4.3%), Asparagaceae (4%), and Lamiaceae (4%). An estimated 54% of the recorded plants were woody (trees and shrubs) in nature, while the leaves (27%) and roots (25%) were the most dominant plant parts. The use of plants for alleviating pain and inflammatory-related conditions remains popular in South African folk medicine. The lagging ethnobotanical information from provinces such as North West, Gauteng, and Free State remains a gap that needs to be pursued meticulously in order to have a complete country-wide database.

Research Progression of the Genus Merremia: A Comprehensive Review on the Nutritional Value, Ethnomedicinal Uses, Phytochemistry, Pharmacology, and Toxicity

The genus Merremia Dennst. ex Endl. (Convolvulaceae) is a rich source of structurally diverse phytochemicals with therapeutic relevance. This review presents the first comprehensive, up-to-date information and research progression on the nutritional value, ethnomedicinal uses, phytochemistry, pharmacological activities, and toxicity of the genus Merremia. Using the key search term “Merremia”, relevant documents and information were retrieved from electronic databases. Relevant documents were uploaded in RStudio with installed bibliometric software packages and used for data retrieval, tabulation, and network visualization. Bibliometric analysis revealed that ca. 55% of the studies related to Merremia were published in the last decade, which can be grouped into four thematic areas: (i) drug formulation, (ii) taxonomy, (iii) chemical analysis, and (iv) treatment of diseases. Ethnomedicinal uses, phytochemistry, and biological activities studies showed that species in the genus are promising medicinal plants with various pharmaceutical potentials. However, clinical studies to validate the efficacy of the reported bioactivities and the mechanisms underlying the various activities are lacking and should constitute a future research focus. Additionally, reports on the nutritional and antinutritional constituents of Merremia species revealed that the species meet high nutritional quality criteria for animals and are therefore suitable for inclusion in livestock diets. The few available investigations on toxicity indicated that most Merremia species are safe for human and animal use but not with prolonged chronic administration.