Development, Characterization, and Evaluation of Novel Broad-Spectrum Antimicrobial Topical Formulations from Cymbopogon martini (Roxb.) W. Watson Essential Oil.

BACKGROUND: Skin infections were the most frequently encountered of all infections and the 4th leading cause of nonfatal disease burden. Topical drugs have been used for the management of skin infections. The growing concern of drug resistance to the topical agents has warned the need for continuous development of novel drug. Essential oils are the best candidate for new drug with different mode of action and target as they are rich in chemical constituents. OBJECTIVE: To evaluate and develop safe and effective topical antimicrobial formulations from essential oil of Cymbopogon martini. Method. Essential oil was extracted using hydrodistillation aerial part C. martini and topical formulations were prepared in five different semisolid bases. In vitro antimicrobial investigations were performed on essential oil and topical formulations. Skin sensitizations of the formulations were evaluated using guinea pig maximization. RESULTS: The essential oil of C. martini has shown broad-spectrum antimicrobial potency against all tested organisms with MIC value ranging from 0.65 to 10 µg/ml. Absolute inhibitions of growth of fungi were observed against Trichophyton mentagrophytes and Trichophyton rubrum at concentrations above 1% of oil and against Microsporum canis and Trichophyton verrucosum at a concentration of 4% oil. Among topical formulations, the highest antimicrobial activity was recorded in hydrophilic ointment followed by macrogol blend ointment. The antimicrobial activity of oil was higher in fungal pathogen compared to bacteria. Gram positive bacteria were more sensitive than gram negative bacteria. Hydrophilic and macrogol blend ointment containing 5% oil did not produce any skin sensitization on guinea pigs. CONCLUSION: In conclusion, topical formulations of C. martini essential oil can be alternative topical agents with safe broad-spectrum activity for the treatment of skin disorder. Further studies should focus on shelf life study and clinical study of the product.

Evaluation of anthelmintic potential of the Ethiopian medicinal plant Embelia schimperi Vatke in vivo and in vitro against some intestinal parasites.

BACKGROUND: Embelia schimperi has been used for the treatment of intestinal parasites especially tapeworm infestations for centuries in Ethiopia. However, there is lack of scientific based evidences regarding the efficacy, safety and phytochemical analysis of this plant despite its frequent use as an anthelmintic. This study has therefore evaluated the efficacy and acute toxicity of E. schimperi thereby generating relevant preclinical information. METHODS: The anthelmintic activities of the crude hydroalcoholic extract of E. schimperi and the isolated compound, embelin, were conducted using in vivo and in vitro models against the dwarf tapeworm, Hymenolepis nana, and the hookworm, Necator americanus, respectively. LD50 of the crude hydroalcoholic extract was determined using Swiss albino mice following the OECD guidelines. Chemical characterization of the isolated embelin was conducted using UV-spectroscopy, HPLC and NMR. RESULTS: In the acute toxicity study no prominent signs of toxicity and mortality were recorded among the experimental animals at the highest administered dose. Hence the LD50 of the plant was found to be higher than 5000 mg/kg. In vivo cestocidal activity of the crude hydroalcoholic extract of E. schimperi showed 100% parasite clearance at 1000 mg/kg, while the diammonium salt of embelin showed 85.3% parasite clearance at 750 mg/kg. The in vitro anthelminthic activity study revealed that the LC50 value of the crude extract and albendazole were 228.7 and 51.33 µg/mL, respectively. CONCLUSION: The results clearly indicated that the hydroalcoholic extract of E. schimperi and the diammonium salt of the isolated compound embelin had anthelmintic activity against hookworm larva in vitro and H. nana in vivo. Hence the findings of this study showed Embelia schimperi appears to possess some anthelmintic activity that may support the usage of these plants by local traditional healers to treat helminthic infestations.

Insecticidal Activity of Some Traditionally Used Ethiopian Medicinal Plants against Sheep Ked Melophagus ovinus.

Twelve medicinal plants and a commercially used drug Ivermectin were examined for insecticidal activity against Melophagus ovinus sheep ked at different time intervals using in vitro adult immersion test. The findings show that at 3.13 µL/mL, 6.25 µL/mL and 12.5 µL/mL concentration of Cymbopogon citratus, Foeniculum vulgare and Eucalyptus globulus essential oils respectively, recorded 100% mortalities against M. ovinus within 3 hour of exposure. Significantly higher insecticidal activity of essential oils was recorded (P = 0.00) when compared to 10 µ g/mL Ivermectin after 3-hour exposure of M. ovinus at a concentration of ≥1.57 µ L/mL, ≥3 µ L/mL, and ≥12.7 µ L/mL essential oils of C. citratus, F. vulgare, and E. globulus, respectively. Among essential oils, C. citratus has showed superior potency at a three-hour exposure of the parasite (P = 0.00) at a concentration of ≥0.78 µ L/mL. Strong antiparasitic activity was recorded by aqueous extract of Calpurnia aurea (80% mortality) at a concentration of 200 mg/mL within 24 h among aqueous extracts of 9 medicinal plants. The results indicated all the four medicinal plants, particularly those tested essential oils, can be considered as potential candidates for biocontrol of M. ovinus sheep ked.

Investigation on the antibacterial properties of garlic (Allium sativum) on pneumonia causing bacteria.

The antibacterial activity of the crude aqueous extract of garlic was investigated against some pneumonia causing bacteria by an agar dilution technique. The results revealed that Streptococcus pneumoniae standard test organism was completely inhibited by 7.8 mg/ml of media and the clinical isolate of Klebsiella pneumoniae was completely inhibited by 24.38 mg/ml of media, indicating that Streptococcus pneumoniae is the most sensitive and Klebsiella pneumoniae the least. Garlic could be used as an effective antibacterial agent for these pathogenic microorganisms.