Morinda lucida (Rubiaceae), Ocimum gratissimum (Lamiaceae), Carica papaya (Caricaceae) and Phyllanthus amarus (Euphorbiaceae) extracts are among the folkloric remedies that have been con?rmed scientifically to possess clinical values against protozoal and bacterial infections in Nigeria.
Morinda lucida belongs to the plant family Rubiaceae. It is commonly called Brimstone tree. It is Oruwo or Eerewo in Yoruba, Eeze-ogu or Njisi in Igbo.
Commonly called scent leaf, Ocimum gratissimum belongs to the plant family Lamiaceae. It is known as Efinrin ajase in Yoruba, Ebavbokho in Bini, Aai doya ta gida in Hausa, Nchuanwu in Igbo.
Phyllanthus amarus belongs to the plant family Euphorbiaceae. To the Efik it is called oyomokeso amanke edem; geeron-tsuntsaayee (birds millet) in Hausa; Ibo (Asaba) buchioro, Ibo (Umuahia) ngwu; iyeke in Urhobo; and ehin olobe or eyin olobe in Yoruba.
Nigerian researchers have successfully used extracts of Morinda lucida and Carica papaya to stop Helicobacter pylori and indeed stomach ulcer.
A study published in the African Journal of Clinical and Experimental Microbiology observed that ethanolic poor antibacterial activity of the extracts of C. papaya and M. lucida prevented the growth of 80 per cent of Helicobacter pylori strains tested in vitro.
The study is titled: “The Effect of Some Nigerian Local Herbs On Helicobacter pylori.”
The researchers from the Nigerian Institute of Medical Research, Yaba and Lagos State University, Ojo, tested four Nigerian medicinal plants commonly used in the treatment of bacterial infections. They were tested for antimicrobial activity against 20 local strains of Helicobacter pylori recovered from patients with gastro-duodenal ulcers and gastritis.
In vitro agar diffusion assay revealed anti-Helicobacter pylori activity of ethanolic extracts of Carica papaya and Morinda lucida to 80 per cent (16/20) of the isolates tested. While the ethanolic extracts of 0ccimum gratissimum and Phyllanthus amarus inhibited the colonial growth of 35 per cent (7/20) of these strains. The zones of inhibition ranged from 5 to 20 mm in diameter.
Contrastingly, the aqueous extracts of these plants appeared to lack anti-Helicobacter pylori activity except in Morinda Iucida and 0ccimum gratissimum, where inhibition of a total of three isolates was observed. The present results suggest the presence of anti-HeIicobacter pylori principles in ethanolic extracts of Carica papaya and Morinda Iucida and support their future use in the treatment of ulcers and gastritis in Nigeria.
The researchers wrote: “The lack of inhibition observed in water wells con?rmed the viability of all the isolates tested. While the inhibitory effect of 40 per cent ethanol attested to the appropriateness of the reconstitution procedure, the water extracts of these plants implies that water has inadequate power to extract anti-Helicobacter pylori principles from these plants.
“Based on our ?ndings, there is no doubt that these plants hold tremendous clinical promise especially in rural communities, which provide the greater number of patients and severe cases of gastro-duodenal ulcer. The present study is still in its infancy and therefore invite more research studies to elucidate the active anti-Helicobacter pylori substances in these plants, investigate synergy associated with extract combination leading to ultimate suggestion of whether these plants can be combined with orthodox drugs to meet the criteria of gastric acid suppression, H. pylori eradication and stomach protection in the treatment of ulcers and gastritis.”
“In conclusion, the present study has revealed, the tremendous potentials inherent in ethanolic preparations of C. papaya and M. lucida if adopted for future treatment of ulcers and gastritis in Nigeria.”
Another study published in Journal of Medicine and Food also noted that unripe fruit of pawpaw might be beneficial in ulcer cases.
The researchers from the Department of Pharmacology & Toxicology, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, Enugu State, evaluated the anti-ulcer potentials of aqueous (AE) and methanol (ME) extracts of whole unripe Carica papaya fruit using ethanol- and indomethacin-induced gastric ulcer models in rats. The effect of the extracts on small intestinal propulsion was also investigated.
The extracts significantly reduced the ulcer index in both experimental models compared to the control group. ME showed a better protection against indomethacin-induced ulcers, whereas AE was more effective against ethanol-induced gastric ulcers. The extracts also significantly inhibited intestinal motility, with ME showing greater activity.
Oral administration of AE and ME up to 5,000 mg/kg did not produce lethality or signs of acute toxicity in mice after 24 hours. The extracts of unripe C. papaya contain terpenoids, alkaloids, flavonoids, carbohydrates, glycosides, saponins, and steroids. The cytoprotective and antimotility properties of the extracts may account for the anti-ulcer property of the unripe fruit.
Another study published in the American Journal of Chinese Medicine found protective effects of Carica papaya Linn on the exogenous gastric ulcer in rats.
The researchers wrote: “The effects of Carica papaya Linn on exogenous ulcer and histamine-induced acid secretion were studied in rats. The latex of the unripe fruit of C. papaya was effective in protecting the exogenous ulcer. It significantly lessened the acid secretion induced by intravenous infusion of histamine in chronic gastric fistulated rats. Crystalline papain was also effective in protecting the exogenous ulcer and in decreasing the histamine-induced acid secretion in rats. The conclusion is that papain is the active principle in C. papaya that exerts the ulcer-protective effect.”
A study published in Journal of Natural Products concluded: “Morinda lucida is no doubt a potential medicinal plant considering its pharmacological activities and ethno-medical use though it has some significant toxic effects which can be reduced by administering appropriate amount of the extracts for a specific period, preferably short.
“Malaria is a common disease in Africa. The anti - malarial activity of this plant may be compared with that of Artemisia annua in that it has effect on both early and established malaria infections. M. lucida in combination with other potential anti-malarial plants may therefore be a possible source for discovery of new chemotherapeutic agents in the treatment of P. falciparum and other related parasites causing malaria.”
Researchers have also shown that okra, renowned for its slimy flesh, might help prevent stomach ulcers. Extracts of okra, also known as ladies’ fingers, have been shown to gum up the surface of Helicobacter pylori, preventing it from clinging to the stomach wall.
The researchers found that it is not the thick slimy extract of okra that does the trick. Instead, they found a crude extract rich in sugar-coated proteins and complex sugars to be most effective.
According to the study published in Journal of Agricultural and Food Chemistry, this extract worked better than more purified preparations in lab tests.
In conclusion, the present study has revealed, the tremendous potentials inherent in ethanolic preparations of C. papaya and M. lucida if adopted for future treatment of ulcers and gastritis in Nigeria.