Experimental evaluation of wound healing activity of Croton macrostachyus in rat

Croton macrostachyus Leaf Extract-Mediated Green Synthesis of ZnO Nanoparticles and ZnO/CuO Nanocomposites for the Enhanced Photodegradation of Methylene Blue Dye with the COMSOL Simulation Model

The photodegradation of organic pollutants using metal oxide-based catalysts has drawn great attention as an effective method for wastewater treatment. In this study, zinc oxide nanoparticles (ZnO NPs) and zinc oxide/copper oxide nanocomposites (ZnO/CuO NCs) were fabricated using the leaf extract of Croton macrostachyus as a nontoxic, natural reducing and stabilizing agent. The synthesized samples were characterized by employing X-ray diffraction, microscopic, spectroscopic, and electrochemical methods. The results confirmed the successful synthesis of ZnO NPs and ZnO/CuO NCs with well-defined crystalline structures and morphologies. The prepared samples were tested for the photodegradation of methylene blue (MB) dye under visible light irradiation. Compared to ZnO NPs, ZnO/CuO NCs showed greatly improved photocatalytic performances, particularly with the sample prepared with the 20 mol % Cu precursor (97.02%). The enhancement could be related to the formed p-n heterojunction, which can suppress the recombination of charge carriers and extend the photoresponsive range. A theoretical study of the photocatalytic activity of ZnO/CuO NCs against MB dye degradation was also conducted by using COMSOL Multiphysics software. The results of the simulation are in reasonable agreement with those of the experiment. This study contributes to the development of sustainable and effective photocatalytic materials that are suitable for application in environmental remediation, particularly in the treatment of wastewater.

Wound Healing and Antioxidant Properties of 80% Methanol Leaf Extract of Verbascum sinaiticum (Scrophulariaceae): An Ethiopian Medicinal Plant

Wounds account for severe morbidity, socioeconomic distress, and mortality around the globe. For several years, various herbal products are used to expedite and augment the innate wound healing process. In Ethiopian folkloric medicine, Verbascum sinaiticum L. (V. sinaiticum) is commonly applied as a wound-healing agent. The present study investigated the potential wound healing and antioxidant properties of hydroalcoholic leaf extract of V. sinaiticum. The 80% methanol extract, formulated as 5% (w/w) and 10% (w/w) ointments, was evaluated in excision and incision wound models using nitrofurazone and simple ointment as positive and negative controls, respectively. Parameters such as wound contraction, period of epithelialization, and tensile strength were determined. Moreover, its in vitro antioxidant property was evaluated using a DPPH assay. In the excision model, both doses (5% and 10% w/w) of the extract showed a significant ( $p<0.001$ ) wound healing efficacy compared to the negative control as evidenced by enhanced wound contraction rate and shorter epithelialization time records. In the incision model, the lower dose (5% w/w) ointment formulation of the extract exhibited the maximum increment in tensile strength (85.6%) that was significant ( $p<0.001$ ) compared to negative and untreated controls. Animals treated with 5% w/w ointment, furthermore, showed a significantly ( $p<0.05$ ) higher percentage of tensile strength than nitrofurazone treated ones. Moreover, the hydroalcoholic extract of the plant showed a noticeable free radical scavenging property. The result of the present study upholds the folkloric use of V. sinaiticum in the treatment of wounds.

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, an anti-inflammatory that were published until 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 were 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 ones 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.

Evaluation of Wound Healing Activity of Methanolic Crude Extract and Solvent Fractions of the Leaves of Vernonia auriculifera Hiern (Asteraceae) in Mice

Background

Medicinal plants play an important role in treating various diseases. Vernonia auriculifera Hiern is one of the medicinal plants used traditionally for the management of wounds. However, there were no scientific reports documented so far on the wound healing activities to substantiate the claim. Thus, the present study provides a scientific evaluation for the wound healing potential of the crude extract as well as solvent fractions of the leaves of Vernonia auriculifera Hiern.

Methods

Extraction was carried out by maceration using 80% methanol and part of the crude extract fractionated with chloroform, ethyl acetate, and aqueous solvents. Simple ointment bases were prepared using hard paraffin, cetostearyl alcohol, white soft paraffin and wool fat according to British Pharmacopoeia. Then, two types of ointment formulations were prepared from the extract, ie, 5% w/w and 10% w/w. Mice and rats were employed for wound healing study and dermal toxicity test, respectively. Wound healing effects were evaluated by percent of wound contraction, period of epithelialization, tensile strength, and histological analysis as parameters in excision, incision, and burn wound models. Finally, the data were expressed as mean ± SEM, and the results were analyzed using one-way ANOVA followed by post hoc Tukey-test.

Results

In the excision wound model, the 10% w/w crude extract ointment showed significant wound contraction (P < 0.001) from day 4 to day 18 as compared to the negative control. Both the 5% w/w (P < 0.001) and 10% w/w (P < 0.05) crude extract ointments have showed statistically significant difference in epithelialization period as compared to the negative control. Groups treated with the ethyl acetate and aqueous fractions ointments in incision wound model showed a statistically significant (P < 0.001) increase in tensile. The 10% w/w and 5% w/w ointments of the crude extract showed a significant (P < 0.001) increase in breaking strength compared to simple ointment and the untreated control groups. In burn wound model, significant reduction in epithelialization period was observed in 5% w/w (P < 0.05) and 10% w/w (P < 0.001), and the percentage of wound contraction was significantly increased in most of post wounding days by 10% w/w (P < 0.001) and 5% w/w (P < 0.05) crude extract ointments and compared to the negative control.

Conclusion

The crude, aqueous, and ethyl acetate fraction of Vernonia auriculifera leaves possess wound healing activities. This finding justifies the use of the leaves of this plant for wound healing as claimed in the traditional medicine literature.

In Vivo Evaluation of Wound Healing and Anti-Inflammatory Activity of 80% Methanol Crude Flower Extract of Hagenia abyssinica (Bruce) J.F. Gmel in Mice

BACKGROUND

Hagenia abyssinica (Bruce) J.F. Gmel (Rosaceae) is distributed in the highlands of Ethiopia. The flowers of Hagenia abyssinica (Bruce) J.F. Gmel are used traditionally to treat wound. However, there was no scientific report on wound healing activity of Hagenia abyssinica (Bruce) J.F. Gmel. Thus, this study was initiated to investigate the wound healing and anti-inflammatory activities of 80% methanol crude extract of flowers of Hagenia abyssinica in mice.

OBJECTIVE

The objective of this study was to evaluate the wound healing and anti-inflammatory activity of 80% methanol crude flower extract of Hagenia abyssinica in mice.

METHODS

Air-dried flowers of Hagenia abyssinica were grounded and macerated three times successively by 80% methanol. The dried extract was fractionated with chloroform, ethyl acetate, and water. Phytochemical screening tests were performed according to established procedures. The crude extract and solvent fractions were formulated as ointments. Wound healing activity of the crude extract was evaluated using excision and incision wound models, and the wound healing activities of solvent fractions were evaluated by using the excision wound model. The anti-inflammatory activity of the 80% methanol extract of Hagenia abyssinica was evaluated using carrageenan-induced hind paw edema model in mice.

RESULT

The 2000 mg/kg test dose of the 10% (w/w) crude extract ointment was safe in rats. Both the 5% (w/w) and 10% (w/w) crude extract ointment-treated groups showed significant wound contraction starting from the day 4th. Both 5% (w/w) and 10% (w/w) crude extract ointments showed significant (P < 0.001) increment of tensile strength compared to the negative control. The 10% (w/w) aqueous and ethyl acetate fraction ointment revealed high (P < 0.001) percentage of wound contraction. The 100 mg/kg, 200 mg/kg, and 400 mg/kg oral administration of the crude extract had significant inhibition of the paw edema in mice of carrageenan-induced inflammation.

CONCLUSION

The results of this study evidenced that both 5% w/w and 10% w/w 80% methanol extract ointment of the flowers of Hagenia abyssinica have wound healing and anti-inflammatory effects.

Analgesic and Anti-Inflammatory Effects of 80% Methanol Extract of Leonotis ocymifolia (Burm.f.) Iwarsson Leaves in Rodent Models

BACKGROUND

Pain and inflammation are the major health problems commonly treated with traditional remedies mainly using medicinal plants. Leonotis ocymifolia is one of such medicinal plants used in folkloric medicine of Ethiopia. However, the plant has not been scientifically evaluated. The aim of this study was to evaluate analgesic and anti-inflammatory effects of the 80% methanol leaves extract of Leonotis ocymifolia using rodent models.

METHOD

The central and peripheral analgesic effect of the extract at 100, 200, and 400 mg/kg dose levels was evaluated using hot plate and acetic acid induced writhing rodent models, whereas carrageenan induced paw edema and cotton pellet granuloma methods were used to screen anti-inflammatory effect of the extract at the same dose levels. Acute toxicity test was also done. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test and p < 0.05 was considered significant.

RESULTS

The extract did not produce mortality up to 2000 mg/kg. All tested doses of the extract showed significant analgesic effect with maximum latency response of 62.8% and inhibition of acetic acid induced writhing. Maximum anti-inflammatory effect was recorded at 6 h after induction, with 75.88% reduction in carrageenan induced paw edema. Moreover, all tested doses of extract significantly inhibited the formation of inflammatory exudates and granuloma formation (p < 0.001).

CONCLUSION

The study indicated that the extract was safe in mice and it has both analgesic and anti-inflammatory effect in rodent models.