Effects of symbiotic population impairment on microbiome composition and longevity of Bactrocera dorsalis.

In order to understand the role of symbionts for their insect hosts, it is customary to treat them with antibiotics or to sterilize eggs (treatments), resulting in aposymbiotic and axenic insects, respectively. Such axenic insects can then be compared with untreated controls. Fruit flies often bear complex communities which are greatly reduced by such treatments. However, the bacterial community is not completely eliminated. Here, we examine the effect of these procedures on the structure of the remaining bacterial communities in Bactrocera dorsalis (Diptera: Tephritidae) and on the insect longevity. The antibiotics (Norfloxacin and Ceftazedime) were administered to 1-day-old adult flies through sugar meal for 7 days, and eggs were surface sterilized and dechorionated to produce axenic lines. The flies were starved of protein before they were offered full diets or diets containing non-essential amino acids only. Antibiotic and egg disinfection treatments resulted in a significant reduction of the vast majority of gut bacterial populations, especially Proteobacteria, Firmicutes and Bacteroidetes. On the other hand, antibiotic allowed the persistence of Actinobacteria, Cyanobacteria and Acidobacteria populations. In untreated control flies, longevity was extended irrespective of diet quality in comparison to treated flies. Conversely, when gut bacteria were largely reduced (aposymbiotic and axenic flies), longevity was reduced in the non-essential amino acids diet treatment versus slightly improved in the presence of a protein diet. We discuss these results in an ecological-life-history perspective.

Pharmacological evidence of Vitex thyrsiflora, Entandrophragma cylindricum, and Anonidium mannii used for the management of inflammation in Cameroon.

Background Inflammation is the most common health problem faced in life relating to a vast number of diseases. The present study evaluated the pharmacological effect of three plants (Vitex thyrsiflora, Entandrophragma cylindricum, and Anonidium mannii) commonly used in the Cameroon pharmacopeia for the management of inflammatory response. Methods The pharmacological effect was characterized by the antioxidant capacity, anti-inflammatory, analgesic, and antipyretic properties of the ethanol extracts of the three plants. Antioxidant capacity was determined using total phenolic content, total flavonoid content, hydrogen peroxide, ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging assays. Anti-inflammatory activity was evaluated in vitro by protein denaturation and hypotonic-induced hemolysis methods and in vivo by carrageenan paw edema method. Analgesic and antipyretic activities were studied in vivo using acetic acid-induced writhing and brewer's yeast-induced hyperpyrexia models. Results All selected extracts showed high phenolic (15.93-64.45 mgCAE/g) and flavonoid (336.03-1053.48 mgCAE/g) contents and high ferric reducing power (288.75-364.91 mgCAE/g). These extracts exhibited good DPPH (IC50 = 0.30-1.65 µg/mL), ABTS (IC50 = 0.52-1.90 µg/mL), and H2O2 (IC50 = 1.40-3.55 µg/mL) radical scavenging activities. All extracts inhibited protein denaturation (6.79-82.27%) and protected the erythrocyte membrane from lysis induced by hypotonic solution (18.90-88.00%). The extracts significantly reduced dose-dependent paw edema (p < 0.05), fever, and abdominal writhing (p < 0.001) especially at 400 mg/kg. Conclusions All extracts exhibited interesting antioxidant properties, as well as significant anti-inflammatory, analgesic, and antipyretic effects.

Toxicological studies of stem bark extract from Schefflera barteri Harms (Araliaceae).

BACKGROUND: The use of herbal medicines as complements or alternatives to orthodox medicines has been on the increase. There has been the erroneous belief that these medicines are free from adverse effects. Schefflera barteri is popularly used in the West region of Cameroon for the treatment of various diseases such as diarrhea, spasm, pneumonia and animals bite. Considering the ethnopharmacological relevance of this plant, this study was designed to investigate the possible toxic effects of the stem bark extract of S. barteri. METHODS: The extract was prepared by maceration of stem bark dry powder in methylene chloride/methanol mixture. Phytochemical analysis was performed by chemical reaction method. Oral acute toxicity study was carried out by administering single geometric increasing doses (2 to 16 g/kg body weight) of plant extract to Swiss albino mice. For sub-acute toxicity study, repeated doses (100, 200, 400 and 800 mg/kg bw) of plant extract were given to Wistar albino rats for 28 consecutive days by oral route. At the end of the treatment period, hematological and biochemical parameters were assessed, as well as histopathological studies. RESULTS: Phytochemical analysis of stem bark extract of S. barteri revealed the presence of anthocyanins, anthraquinons and saponins. Acute toxicity results showed that the LD50 was greater than 16000 mg/kg. Sub-acute treatment significantly (P < 0.05) increased the level of serum transaminase, proteins and HDL cholesterol. On the other hand, the extract significantly (P < 0.05) reduced the level of leucocytes as well as neutrophils, basophils and monocytes in female. No significant variation of serum creatinine, LDL cholesterol, serum triglycerides as well as liver, spleen, testicles and ovaries proteins was noted. Histopathological analysis of organs showed vascular congestion, inflammation of peri-portal and vacuolization of hepatocytes at the level of the liver. Leucocytes infiltration of peri-portal veins were noticed on lungs and liver cells as well as inflammatory peri-bronchial and basal membranes seminar tube merely joined on lungs and testis respectively. CONCLUSION: The results suggest that acute administration of the stem bark extract of S. barteri is associated with signs of toxicity, administration over a long duration provokes hepatotoxicity, testes and lungs toxicities.

Antibacterial and Antioxidant Properties of the Methanolic Extract of the Stem Bark of Pteleopsis hylodendron (Combretaceae).

Pteleopsis hylodendron (Combretaceae) is used in Cameroon and West Africa folk medicine for the treatment of various microbial infections (measles, chickenpox, and sexually transmitted diseases). The antibacterial properties of the methanolic extract and fractions from stem bark of Pteleopsis hylodendron were tested against three Gram-positive bacteria and eight Gram-negative bacteria using Agar-well diffusion and Broth microdilution methods. Antioxidant activities of the crude extract and fractions were investigated by DPPH radical scavenging activity and ß-carotene-linoleic acid assays. The methanolic extract and some fractions exhibited antibacterial activities that varied between the bacterial species (ID = 0.00-25.00 mm; MIC = 781-12500 µg/mL and 0.24-1000 µg/mL). The activity of the crude extract is, however, very weak compared to the reference antibiotics (MIC = 0.125-128 µg/mL). Two fractions (F(E) and F(F)) showed significant activity (MIC = 0.97 µg/mL) while S. aureus ATCC 25922 was almost resistant to all the tested fractions. In addition, the crude extract and some fractions showed good antioxidant potential with inhibition values ranging from 17.53 to 98.79%. These results provide promising baseline information for the potential use of this plant as well as some of the fractions in the treatment of infectious diseases and oxidative stress.