Systematic review of Ethiopian medicinal plants used for their anti-inflammatory and wound healing activities

Ethnopharmacological relevance: Plant materials are used worldwide as complementary and alternative therapeutics for the treatment of various illnesses. In Ethiopia, folk medicines are utilized across a wide range of cultures and settings. Ethiopia has numerous plant species of which around 12% are endemic, making it a rich source of medicinal plants that are potentially important for human wellbeing. Aim of the study: The aim of this study was to assess Ethiopian medicinal plants with anti-inflammatory or wound healing activities, in an attempt to compile the information required for further investigation of their potential role in the management of lymphoedema. Methods: A systematic review protocol was developed according to the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) statement. The protocol for this review was registered on PROSPERO with registration number CRD42019127471. This review considers all controlled in vivo and in vitro anti-inflammatory and wound healing studies evaluating the efficacy and safety of Ethiopian medicinal plants. The search strategy included all articles containing descriptors such as Ethiopia, medicinal plants, herbal products, care, management, lymphoedema, lymphedema, swelling, podoconiosis, elephantiasis, wound, wound healing, inflammation, and anti-inflammatory that were published up to June 28, 2019. Outcomes were measured as the percentage of inflammatory and pro-inflammatory cell inhibition, as the percentage of carrageenan-induced oedema (anti-inflammation) inhibition, and the percentage of cell migration and proliferation (wound healing). For quality assessment of individual animal studies, the Risk of Bias tool for animal intervention studies (SYRCLE’s RoB tool) criteria was used. For quality assessment of individual in vitro studies, the OECD guidelines and the WHO Good Laboratory Practice (GLP) handbook were used. Results: A total of 46 articles on anti-inflammatory and 17 articles on wound healing properties were reviewed. For the in vivo studies, Swiss albino mice and Wistar rats were used, and the concentration of plant extracts or fractions administered to the lab animals varied considerably. Acetone extract of Vernonia amygdalina showed the fastest anti-inflammatory activity at lower concentrations in carrageenan-induced paw oedema. Conclusion: Lawsonia inermis, Azadirachta indica, Achyranthes aspera, and Cuminum cyminum are the most studied plant species in terms of anti-inflammatory activity, while Lawsonia inermis and Azadirachta indica are the most studied for wound healing. The most common in vivo techniques used for the anti-inflammatory and the wound healing assays were carrageenan-induced paw oedema, and excision and incision wound models, respectively

In Vivo Anti-inflammatory and Antinociceptive Activities of Extracts of Rosa abyssinica and Salvia nilotica

In vivo Rosa abyssinica Lindley (Rosaceae) and Salvia nilotica Juss. Exjecr (Lamiaceae) using carrageenan-induced paw oedema and formalin test, respectively. It was observed that the 80% methanol extracts of both plants could significantly lower carrageenan-induced paw oedema at doses of 200 mg/kg, p.o. Among the solvent fractions, the acetone, chloroform and methanol fractions of  S. nilotica exhibited anti-inflammatory activity, the strongest being that of the acetone fraction. On the other hand, only the acetone fraction of R. abyssinica was found to be active. The anti-inflammatory activities of the extracts and the fractions were comparable with that of the known anti-inflammatory drug, indomethacin at the tested concentrations. The results of the formalin test revealed that the acetone fractions of R. abyssinica and S. nilotica significantly inhibit formalin-induced nociception in mice particularly during the late phase. The results obtained confirmed that the extracts obtained from both R. abyssinica and S. nilotica possess genuine anti-inflammatory and antinociceptive activities, which support the folkloric use of the herbs to treat inflammatory disorders