ACTIVITIES OF AQUEOUS EXTRACTS OF MALLOTUS OPPOSITIFOLIUM ON SHIGELLA DYSENTERIAE A1-INDUCED DIARRHOEA IN RATS

Anti‐shigellosis activity of the aqueous extract of garlic, clove and fenugreek

Shigellosis causes severe diarrhea and, in some cases, death in children. In this study, we investigated the in vitro and in vivo anti‐shigellosis efficacy of some aqueous herbal extracts or their chosen mixtures, including fenugreek seed, black seed, clove, garlic, and ginger. The antibacterial potential was assessed by well diffusion and microdilution assays. The extracts' minimum inhibitory concentrations ranged from 0.39 to 12.5 mg/ml. The water extract of garlic and combinations of garlic with either fenugreek or clove extracts had the highest antibacterial efficacy, hence these extracts were chosen for the in vivo investigation. Rats were given a Shigella dysenteriae inoculum and then administrated two doses (100 and 200 mg/kg bw) of the selected herbal extracts or the antibiotic ciprofloxacin (20 mg/kg bw) to treat Shigellosis in vivo. The results showed that garlic and clove extract mixtures (G6, 200 mg/kg bw), garlic and fenugreek mixtures (G7 and G8, 100 and 200 mg/kg bw), and ciprofloxacin group (G9, 20 mg/kg bw) had the best anti‐Shigellosis efficacy. G7 (garlic and fenugreek mixtures (100 mg/kg bw) outperformed almost all other groups evaluated. This group had lower defecation frequency, lower stool‐Shigella loudness, restored body weight, recovered hematological, and liver and kidney functions, besides exhibited no anatomical alterations in the colon tissue that were comparable to the uninfected group. As a result, in the treatment of Shigella, this extract combination may be suggested as a viable therapeutic alternative to antibiotics.

Identifying the mechanism of eriosematin E from Eriosema chinense Vogel. for its antidiarrhoeal potential against Shigella flexneri-induced diarrhoea using in vitro, in vivo and in silico models

The main objective of the present investigation was to mechanistically evaluate the potency of the root extract (EEC), its bioactive chloroform fraction (CEC) and eriosematin E (ECM) isolated from Eriosema chinense against Shigella flexneri-induced sub-chronic model of infectious diarrhoea using in vitro, in vivo, and in silico methods. The in vitro antibacterial activity against pathogenic strain of S. flexneri demonstrated maximum effect of ECM followed by CEC and EEC in inhibiting growth of bacteria. Further, for in vivo evaluation, was carried out by inducing diarrhoea to the rats by administering oral suspension of S. flexneri to the animals, which was followed by treatment for a period of 6 days. EEC at 200, CEC at 100 and ECM at 10 mg/kg, p.o. showed promising effect, where EEC and ECM were found to be more effective showing maximum % protection on 6th day. Results also demonstrated a significant restoration of altered antioxidants, pro-inflammatory cytokines (IL-1β and TNF-α) expression, electrolyte balance, Na⁺/K⁺-ATPase activity and was also supported by histopathological examinations. Molecular docking study revealed that, eriosematin E inactivated the protease activity of SepA, a protein secreted by Shigella, which is responsible for disruption of epithelial barrier integrity. Thus, the overall observation confirmed the role of eriosematin E from E. chinense in treatment of Shigella flexneri-induced infectious diarrhoea.

The antidiarrhoeal evaluation of Psidium guajava L. against enteropathogenic Escherichia coli induced infectious diarrhoea

ETHNOPHARMACOLOGICAL RELEVANCE

The plant Psidium guajava L. (Myrtaceae), commonly used as an edible fruit is traditionally used worldwide in treatment of various gastrointestinal problems including diarrhoea. The leaves of the plant have also been evaluated for antidiarrhoeal activity in various chemical induced diarrhoea models.

OBJECTIVE

The main objective of the present study was to evaluate the potency of P. guajava leaves and its major biomarker quercetin against enteropathogenic Escherichia coli (EPEC) induced infectious diarrhoea using preclinical and computational model.

MATERIAL AND METHODS

P. guajava alcoholic leaf extract (PGE) was initially standardized using HPLC taking quercetin as a biomarker and was then subjected to antidiarrhoeal evaluation on rats in an EPEC induced diarrhoea rat model. The study included assessment of various behavioral parameters, initially for 6 h and then for up to 24 h of induction which was followed by estimation of stool water content, density of EPEC in stools and blood parameters evaluation. The colonic and small intestinal tissues of the treated animals were subjected to various biochemical estimations, in vivo antioxidant evaluation, estimation of ion concentration, Na⁺/K⁺-ATPase activity, assessment of pro-inflammatory cytokines and histopathological studies. Further, the major biomarker off PGE, quercetin was subjected to molecular docking studies with Na⁺/K⁺-ATPase and EPEC.

RESULTS

The results demonstrated a significant antidiarrhoeal activity of quercetin (50 mg/kg), PGE at 200 and 400 mg/kg, p.o., where quercetin and PFGE at 200 mg/kg, p.o. were found to be more prominent, as confirmed through higher % protection, water content of stools and density of EPEC in stools. PGE and its biomarker quercetin also significantly recovered the WBC, Hb, platelets loss and also revealed a significant restoration of altered antioxidants level, pro-inflammatory cytokines (IL-1β and TNF-α) expression and had positive influence on Na⁺/K⁺-ATPase activity. The docking studies of quercetin with Na⁺/K⁺-ATPase showed favourable interactions and residues Glu 327, Ser 775, Asn 776, Glu 779 and Asp 804 of Na⁺/K⁺-ATPase were adequately similar to quercetin for donating ligands for binding, while quercetin was also found to terminate the linkage between mammalian cells and EPEC thus, preventing further infection from EPEC.

CONCLUSION

Inhibition in intestinal secretion, reduced nitric oxide production and inflammatory expression along with reactivation of Na⁺/K-ATPase activity could be attributed to the observed antidiarrhoeal potential of PGE against infectious diarrhoea, where quercetin was confirmed to be the main contributing factor.

Quercetin a major biomarker of Psidium guajava L. inhibits SepA protease activity of Shigella flexneri in treatment of infectious diarrhoea

The leaves of the plant Psidium guajava L. (Myrtaceae) has been traditionally used in treatment of various gastrointestinal disorders including diarrhoea and have also been reported for its potent antidiarrhoeal activity on various chemical induced diarrhoea models. The objective of our present study was to evaluate the potency of the leaf extract of the plant Psidium guajava (PGE) along with its major biomarker quercetin against Shigella flexneri-induced sub chronic model of infectious diarrhoea. PGE at 100, 200 and 400 mg/kg, p.o. and quercetin at 50 mg/kg, p.o. were administered to Shigella flexneri-induced diarrhoeal rats for five days and various behavioural parameters were evaluated on 1st, 3rd and 5th day of treatment. This was followed by assessment of stool water content, density of Shigella flexneri in stools and blood parameters examination. After treatment, colon and small intestine of rats was dissected and subjected to biochemical estimations, cytokine profiling, antioxidant evaluations, ion concentration determination, Na⁺/K⁺-ATPase activity and histopathology. Molecular docking studies on crystal structure of Secreted Extracellular Protein A (SepA) from Shigella flexneri with biomarker quercetin was also performed. PGE at 200 mg/kg followed by quercetin depicted maximum antidiarrhoeal potential, which was confirmed through diarrhoea score and % protection, while PGE at 400 mg/kg showed similar effect to PGE 200 mg/kg thus, the later may have ceiling effect. PGE and quercetin also significantly reduced the density of Shigella flexneri in stools, water content of stools and restored the alterations observed in blood parameters, antioxidant status and pro-inflammatory cytokines (IL-6 and TNF-α) expression. These parameters contributed in normalization of electrolyte balance, reactivation of Na⁺/K⁺-ATPase activity and repairing of epithelial tissue damage, confirmed through histopathology. Docking simulation studies revealed the role of quercetin in inactivating the protease activity of SepA, a protein secreted by Shigella, which disrupts epithelial barrier integrity during infection and also manages its signal production. Thus, the overall results confirmed the role of quercetin as a major biomarker for the observed antidiarrhoeal potential of P. guajava against Shigella flexneri induced infectious diarrhoea.

The potency of eriosematin E from Eriosema chinense Vogel. against enteropathogenic Escherichia coli induced diarrhoea using preclinical and molecular docking studies

The main objective of the present study was to evaluate the potential of eriosematin E (ECM) isolated from the roots of Eriosema chinense against enteropathogenic Escherichia coli (EPEC) induced diarrhoea. ECM isolated from the bioactive chloroform fraction of E. chinense was subjected to antidiarrhoeal evaluation on rats against diarrhoea, induced by the oral suspension of EPEC. The study included evaluation of behavioral parameters for 6 h and up to 24 h of induction, followed by estimation of water content, the density of EPEC in stools and evaluation of various blood parameters. Further, the colonic and small intestinal tissues were subjected to biochemical estimations, antioxidant evaluation, determination of ion concentration, Na⁺/K⁺ -ATPase activity, pro-inflammatory cytokines assessment and histopathology. Finally, the impact of ECM on Na⁺/K⁺-ATPase was studied through molecular docking studies. Significant antidiarrhoeal potential of ECM was demonstrated at 5 and 10 mg/kg, p.o., however, ECM at 10 mg/kg, p.o. was found to be more effective, as confirmed through higher % protection, density of EPEC in stools and water content of stools. ECM also significantly increased the level of WBC, Hb, platelets and revealed restoration of altered antioxidants, pro-inflammatory cytokines (IL-1β and TNF-α) status and also reactivated the suppressed Na⁺/K⁺-ATPase activity, which was also confirmed through docking studies showing H-bonding of hydroxyl group of ECM with amino acids Asp 190, Asn 167 and Glu 169 thus, maintaining proper electrolyte balance and also prevented epithelial tissue damage. The overall effect of ECM may be attributed to the decline in the elevated level of cytokines, inhibition in nitric oxide production and reactivation of Na⁺/K⁺-ATPase activity resulting in reduced intestinal secretion.

African Herbal Remedies with Antioxidant Activity: A Potential Resource Base for Wound Treatment

The use of traditional herbal remedies as alternative medicine plays an important role in Africa since it forms part of primary health care for treatment of various medical conditions, including wounds. Although physiological levels of free radicals are essential to the healing process, they are known to partly contribute to wound chronicity when in excess. Consequently, antioxidant therapy has been shown to facilitate healing of such wounds. Also, a growing body of evidence suggests that, at least, part of the therapeutic value of herbals may be explained by their antioxidant activity. This paper reviews African herbal remedies with antioxidant activity with the aim of indicating potential resources for wound treatment. Firstly, herbals with identified antioxidant compounds and, secondly, herbals with proven antioxidant activity, but where the compound(s) responsible for the activity has not yet been identified, are listed. In the latter case it has been attempted to ascribe the activity to a compound known to be present in the plant family and/or species, where related activity has previously been documented for another genus of the species. Also, the tests employed to assess antioxidant activity and the potential caveats thereof during assessment are briefly commented on.

Effects of Oxalis barrelieri L. (Oxalidaceae) aqueous extract on diarrhea induced by Shigella dysenteriae type 1 in rats

AIM

Oxalis barrelieri is a medicinal plant commonly used in Cameroon, for the treatment of many diarrheal diseases. The antibacterial properties of O barrelieri aqueous extract (WOb) against Shigella dysenteriae type 1 were investigated in vitro and in vivo.

METHODS

Antibacterial activity was evaluated in vitro by disc diffusion method and by macrodilution method. S dysenteriae type 1 at a dose of 1.2 × 109 CFU was administrated orally to rats to induce shigellosis. For 6 consecutive days, diarrheic rats were treated with O barrelieri aqueous extract (50 and 100 mg/kg BW) or norfloxacin (20 mg/kg BW). The diarrheal stool weight and S dysenteriae type 1 density were assessed during the treatment period, and death rate recorded. Nitric oxide production in blood and in colonic homogenate and blood parameters were assessed, and the histological section of the colon was performed in the survivors.

RESULTS

The minimal inhibitory concentration and minimal bactericidal concentration of WOb were, respectively, 6 mg/mL and 25 mg/mL. The mean minimal bactericidal concentration/minimal inhibitory concentration ratio for WOb against S dysenteriae type 1 was high (˃4); WOb could be classified as a bacteriostatic drug. WOb significantly (P < .01) reduced bacterial density and diarrheal stool weight. WOb decreased nitric oxide production (P < .01) in the large intestine and protected the mucosa of the colon from bacterial destruction.

CONCLUSION

The results suggest that O barrelieri aqueous extract possesses bacteriostatic and antidiarrheal activities and reduces damages caused to intestinal mucosa barrier by pathogenic mechanisms of Shigella. This extract could be used as an alternative therapeutic for infectious diarrhea.

Activity of medicinal plants from Ghana against the parasitic gut protist Blastocystis

ETHNOPHARMACOLOGICAL RELEVANCE

The plants tested in this study were examples of plants historically used to treat or alleviate several types of stomach disorders manifested by e.g. stomachache, diarrhoea or dysentery. These plants have been consumed typically as a decoction, sometimes mixed with other flavourings. The aim of this study was to evaluate the anti-Blastocystis activity of 24 plant parts from 21 medicinal plants from Ghana.

MATERIALS AND METHODS

The medicinal plants were collected in the Greater Accra region of Ghana. Every plant part was tested in three different extracts; an ethanolic, a warm, and a cold water extract, at a final concentration of 1 mg/mL for the initial screening, and in a range from 0.0156 to 1mg/mL for determination of inhibitory concentrations. The obligate anaerobic parasitic gut protist Blastocystis (subtype 4) was used as a 48 h old subcultivated isolate in the final concentration of 10(6) cells/mL. Plant extracts inoculated with Blastocystis were incubated at 37 °C for 24 h and 48 h. Both MIC minimum inhibitory concentration (MIC90) assays and minimal lethal concentration (MLC) assays were performed after 24 h and 48 h. The half maximal inhibitory concentration (IC50) was derived after 24 h and 48 h. Antimicrobial activity was tested against two Gram-positive and two Gram-negative bacteria for all 24 plant parts at a final concentration of 1mg/mL.

RESULTS

Screening of the 24 different plant parts showed significant anti-Blastocystis activity of six of the ethanolic extracts: Mallotus oppositifolius, IC50, 24 h 27.8 µg/mL; Vemonia colorata, IC50, 24 h 117.9 µg/mL; Zanthoxylum zanthoxyloides, cortex IC50, 24 h 255.6 µg/mL; Clausena anisata, IC50, 24 h 314.0 µg/mL; Z. zanthoxyloides, radix IC50, 24 h 335.7 µg/mL and Eythrina senegalensis, IC50, 24 h 527.6 µg/mL. The reference anti-protozoal agent metronidazole (MTZ) had an IC50, 24 h of 7.6 µg/mL. Only C. anisata showed antimicrobial activity at a concentration of 800 µg/mL.

CONCLUSION

Six ethanolic plant extracts showed significant anti-parasitic activity against Blastocystis. M. oppositifolius showed nearly as good activity as the reference anti-protozoal drug MTZ. Historically, the active plants found in this study have been used against dysentery, diarrhoea or other stomach disorders. Nowadays they are not used specifically for dysentery, but they are being used as medicinal plants against various stomach disorders.

Historical versus contemporary medicinal plant uses in Ghana

ETHNOPHARMACOLOGICAL RELEVANCE

Three extraordinary, historical documents stemming from observations made in 1697, 1803 and 1817 quote medicinal plant uses among the Fante, Ga and Ashanti people of present-day Ghana, and can be linked to original botanical specimens in European herbaria. This provides a unique opportunity to gain insight to the historical materia medica of Ghana and compare this to contemporary medicinal plant uses. By critical literary and taxonomic review, the present study (re-)establishes the earliest known history of many important Ghanaian medicinal plants, and assesses the scale of change and loss of medicinal plant knowledge in Ghana over time. The study provides the foundation to reconstruct lost or discontinued Ghanaian plant uses in local or ethnopharmacological contexts.

MATERIALS AND METHODS

Historical botanical specimens were located in the herbaria of University of Copenhagen Herbarium (C) and British Museum of Natural History (BM). The classification and synonymy of the specimens were updated for the study, and the historical vernacular names and medicinal uses of the plants compared with 20th/21st century literature. The plants of the historical Ga materia medica were (re-)collected to aid in semi-structured interviews. The interviews aimed to document the contemporary uses and names of the plants among the Ga, and to determine to what extent the historical medicinal uses and names are extant.

RESULTS AND DISCUSSION

The study identified 100 species in historical medicinal use in Ghana, which could be linked to 134 unique uses and 105 vernacular names in Twi (Ashanti/Fante) and Ga. Most of the plants are common in Ghana. At least 52% of the historical vernacular names appear to still be in use today. Of the specific historical uses, 41 (31%) were traced among contemporary medicinal plant uses in Ghana and represent some of the most important Ghanaian medicinal plant species. However, 93 (69%) of the historical uses could not be traced and appears to be discontinued or forgotten. Among the Ga, two medicinal plants species have become rare or locally extinct, and thus the vast majority of the loss of knowledge appears to be due to cultural extinction.

CONCLUSIONS

The scientifically strong voucher material allowed for identification of a high number of historical medicinal plants and their roots in traditional Ghanaian medicine systems 2-300 years ago. The materia medica of the Fante, Ga and Ashanti of Ghana has changed considerably over time. The "forgotten" historical uses warrant further studies to determine the pharmacological activity of these plants. This could provide the foundation for reconstruction of historical medicinal plant uses in evidence-based modern contexts.

Antityphoid and radical scavenging properties of the methanol extracts and compounds from the aerial part of Paullinia pinnata

Paullinia pinnata Linn (Sapindaceae) is a medicinal plant, locally used in the West Region of Cameroon for the treatment of typhoid fever. This work was designed to evaluate the antityphoid and antioxidant activities of the extracts and compounds of P. pinnata.

The methanol extracts of the leaves and stems were tested for antityphoid and antioxidant activities. Compounds were isolated, and their structures elucidated by analysis of spectroscopic data in conjuction with literature data and tested for the same activities. The leaf extract was also tested in vivo for its antityphoid potential in a Salmonella typhimurium-induced typhoid fever model in Wistar rats.

Seven known compounds: methylinositol (1), β-sitosterol (2), friedelin (3), 3β-(β-D-Glucopyranosyloxy)stigmast-5-ene (4), (3β)-3-O-(2′-Acetamido-2′-deoxy-β-D-glucopyranosyl) oleanolic acid (5), (3β,16α-hydroxy)-3-O-(2′-Acetamido-2′-deoxy-β-D-glucopyranosyl) echinocystic acid (6) and (3β,)-3-O-[β-D-glucopyranosyl-(1″-3′)-2′-acetamido-2′-deoxy-β-D-galactopyranosyl]oleanolic acid (7) were isolated. Compounds 5 and 1 showed the highest antibacterial (MIC = 0.781-1.562 μg/ml) and DPPH radical scavenging (RSa50 = 19.27 ± 4.43 μg/ml) activities respectively. The maximum extract dose (446.00 mg/kg bw) had comparable activity with ciprofloxacin (7.14 mg/kg bw) and oxytetracycline (5 mg/kg bw). The extract induced significant dose-dependent increase of WBCs and lymphocytes.

These results support the ethnomedicinal use of P. pinnata and its isolated Compounds could be useful in the standardization of antityphoid phytomedicine from it.

Protective role of lactobacilli in Shigella dysenteriae 1–induced diarrhea in rats

OBJECTIVE

Studies on lactic acid bacteria exemplify their use against various enteropathogens in vitro. Nevertheless, in vivo effects of Lactobacillus during Shigella infection have not been evaluated. The present study evaluated the effect of Lactobacillus rhamnosus and Lactobacillus acidophilus on neutrophil infiltration and lipid peroxidation during Shigella dysenteriae 1-induced diarrhea in rats.

METHODS

The rats were divided into eight groups (n = 6 in each group). Induced rats received single oral dose of S. dysenteriae (12 x 10(8) colony-forming units [cfu]/mL). Treated rats received L. rhamnosus (1 x 10(7) cfu/mL) or L. acidophilus (1 x 10(7) cfu/mL) orally for 4 d, alone or in combination, followed by Shigella administration. At the end of the experimental period, animals were sacrificed and the assay of the activity of alkaline phosphatase, myeloperoxidase, and antioxidants and the estimation of lipid peroxides were performed. Activity staining of superoxide dismutase and catalase was done in addition to gelatin zymography for matrix metalloproteinase (MMP; MMP-2 and MMP-9) activity. A portion of the intestinal tissue was fixed in 10% formalin for histologic studies.

RESULTS

Administration of S. dysenteriae 1 alone resulted in increased levels of myeloperoxidase, lipid peroxidation, alkaline phosphatase, and the expression of MMP-2 and MMP-9 with concomitant decrease in the antioxidant levels. Pretreatment with the combination of L. rhamnosus (1 x 10(7) cfu/mL) and L. acidophilus (1 x 10(7) cfu/mL) significantly attenuated these changes when compared with the diseased group. Histologic observations were in correlation with biochemical parameters.

CONCLUSION

Lactobacillus rhamnosus plus L. acidophilus offered better protection when compared with individual treatment with these strains during Shigella infection.