Antisickling Activity and Thermostability of Anthocyanins Extract from a Congolese Plant, Hymenocardia acida Tul. (Hymenocardiaceae)

Phytochemical Characterization and In Vitro Evaluation of the Anti-Sickle Cell Activity of Aqueous and Ethanolic Extracts of Two Medicinal Plants from Niger: Flueggea virosa (Roxb. ex Willd.) Royle and Kigelia africana (Lam.) Benth

Sickle cell anaemia is a hereditary blood disorder that attacks the red blood cells and deforms them, giving them a sickle shape. Sickle cell anaemia is a serious health problem in the West African country of Niger. Moreover, the cost associated with medical care is very high. The main objective of this study is to contribute to the valorisation of Flueggea virosa (Roxb. ex Willd.) Royle (aerial part), Kigelia africana (lam), and Benth (leaves) from Niger were used to treat sickle cell disease using aqueous and ethanolic extracts of phytochemical compounds. To achieve this objective, the evaluation of anti-sickle cell activity was carried out in vitro using the Emmel technique through the normalisation rate. The analyses showed that the aqueous and ethanolic extracts contained various classes of bioactive substances known for their valuable biological activities. The chemical composition rich in bioactive compounds led to very good results in biological assays. Thus, from a dose of 0.05 mg/mL, the ethanolic extracts of the two plants normalised up to 75% of the sickle cells. As the rate of normalisation was shown to be dose-dependent, at a dose of 10 mg/mL, the ethanolic extracts showed the best rates of sickle cell normalisation, with 95% for F. virosa and 93% for K. africana. Phytochemical screening was used to correlate the secondary metabolite and anti-sickle cell activities of the extracts from the two plants. These results may justify the use of these two species in traditional medicine for the treatment of sickle cell disease in Niger. The inclusion of these plants in phytomedicines could provide significant relief to people suffering from sickle cell disease.

Inhibitory and Reversal Effects of Extracts and Fractions of Anogeissus leiocarpa (DC.) Guill. & Perr. on Sodium Metabisulphite– induced Polymerization of Sickle Cell Haemoglobin

Background:

The leaves and stem bark of Anogeissus leiocarpa (DC.) Guill. & Pirr. (Combretaceae) are commonly included in recipes used for the management of sickle cell disease in western part of Nigeria.

Objective:

The present study was carried out to evaluate the potential of methanol extract and various fractions of A. leiocarpa leaves and stem bark to inhibit as well as reverse sodium metabisulphite induced polymerization of sickle cell haemoglobin.

Method:

The modified Emmel test was used to evaluate the inhibitory activity and the reversal effects of the extracts and fractions of both the leaves and the stem bark of A. leiocarpa in vitro.

Results:

Both the leaves and the stem bark extracts of A. leiocarpa were effective at inhibiting as well as reversing sodium metabisulphite induced polymerization of sickle cell haemoglobin, though the activity was higher in the leaves (94.52 ± 0.80% and 95.67 ± 0.67% respectively) when compared with the stem bark (51.79 ± 2.46 % and 50.45 ± 3.18 % respectively). The ethyl acetate fraction of both leaves and stem bark also gave good activities in both test methods with percentage reversal of 82.74 ± 1.82% and 67.63 ± 2.18% respectively.

Conclusions:

: A. leiocarpa extracts and ethyl acetate fractions exhibit good inhibition and reversal of sodium metabisulphite–induced polymerization of sickle cell haemoglobin thus justifying its inclusion in remedies used for the traditional management of sickle cell.

Herbal Drug use in Sickle Cell Disease Management; Trends and Perspectives in Sub-Saharan Africa - A Systematic Review

INTRODUCTION

Nigeria has the largest burden of Sickle Cell Disease (SCD) with estimated 100,000 new born affected annually. SCD is a Hemoglobin (Hb) disorder with the major form resulting from the substitution of a polar glutamate (Glu) by non-polar Valine (Val) in an invariant region of Hbβ chain-subunit. Species of Hb found in the sickle cell trait are HbA and HbS in a 60:40 proportion, in SCD only HbS, in the HbC disease only HbC, and in the SC disease it's HbS and HbC in a 50:50 equal proportion.

OBJECTIVE

This paper reviews herbal medicines usage in sub-Saharan Africa (sSA) to ameliorate the crisis associated with SCD. The model Hb tetramer suggests a higher membrane affinity of HbS and HbC, promoting dehydration of RBCs, with concomitant in vivo crystallization. Some drawbacks using these herbal drugs include; poor bioavailability and the lack of proper pharmacovigilance monitoring procedures arising from weak governance structure combined with under reporting of herbal usage to physicians were discussed. Probable epigenetic loci that could be targeted using phytomedicines for effective SCD management were also discussed.

METHODS

Using search engines, several databases including Google scholar, PubMed, Academic Resource Index were utilized as a source for relevant publications/ literature. The protein coordinates for the Hb tetramer were obtained from the Protein Data Bank (PDB).

CONCLUSION

Manipulation of epigenetics to achieve better SCD management involves careful thinking. Herein, we discuss some epigenetic interactions that could be putatively tweaked with a view of enhancing soluble bioactive small molecular components with the potential to reactivate γ -globin genes, thereby boosting immune response in patient with SCD.

Antisickling activity of butyl stearate isolated from Ocimum basilicum (Lamiaceae)

OBJECTIVE

To perform phytochemical analyses on the leaves of Ocimum basilicum L. (O. basilicum), to elucidate the structure of isolate and then perform the antisickling activity on the crude extract and on the isolate.

METHODS

The Emmel test performed on the acidified methanolic extract of this plant was used to evaluate the antisickling activity. The structure characterization of the active compound was performed using chromatographic techniques for the separation and the spectroscopic ones for structure elucidation (1H-NMR, 13C-NMR, COSY, HMBC).

RESULTS

The chemical screening on the crude extract revealed the presence of polyphenols (flavonoids, anthocyanins, leucoanthocyanins, tannins, quinones) alkaloids, saponins, triterpenoids and steroids. The obtained extract after evaporation yielded 34.50 g (11.5%) out of 300 g of powdered leaves of O. basilicum. The acidified methanolic extract and butyl stearate showed an interesting antisickling activity.

CONCLUSIONS

The acidified methanolic extract and butyl stearate from O. basilicum displayed a good antisickling activity. To the best of our knowledge, this is the first time to report the antisickling activity of this compound in this plant. The synthesized compound presented the same spectroscopic characteristics than the natural one and the antisickling activities of its derivatives are understudying.

Vasorelaxant and antihypertensive effects of methanolic extracts from Hymenocardia acida Tul

ETHNOPHARMACOLOGICAL RELEVANCE

In Congolese traditional medicine, decoctions of Hymenocardia acida root bark (HaRB) and trunk bark (HaTrB) are used for the treatment of conditions assumed to be hypertension. In this work, we propose to study the vasorelaxant effect of HaRB and HaTrB methanolic extracts on isolated rat thoracic aorta, to characterize the group of molecules responsible for the observed vasorelaxant activity, to evaluate the in vitro antioxidant activity of these extracts and to determine the antihypertensive activity of the HaRB extract on spontaneously hypertensive rats (SHR).

MATERIALS AND METHODS

The vasorelaxant effect of the HaRB and HaTrB methanolic extracts was studied on endothelium-intact aortic rings pre-contracted with phenylephrine (PE, 1μM). The mechanism of this vasorelaxant effect was investigated on endothelium-denuded vessels and on endothelium-intact aortic rings in the presence of three inhibitors: l-N(G)-nitroarginine methyl ester (100μM), indomethacin (10μM) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (10μM). To determine the nature of the compounds responsible for the vasorelaxant activity, we carried out a fractionation of the extracts and a thiolysis of the most active fraction followed by a liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) analysis. The extracts antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) colorimetric assay. In vivo anti-hypertensive activity of the HaRB extract was conducted on SHR.

RESULTS

HaRB and HaTrB methanolic extracts produced a concentration-dependent vasorelaxation on intact aortic rings pre-contracted with PE (1μM). The vasorelaxant responses obtained were 95.3±1.5% (5μg/ml) and 100.6±3.0% (1μg/ml), respectively. The effect was markedly attenuated by removal of endothelium or pretreatment of aortic rings with all inhibitors except indomethacin. The LC/ESI-MS analysis of the thiolysis products indicated that the fraction which caused the most important vasorelaxation (97.9±2.5% at 3μg/ml) was a mixture of procyanidins and prodelphinidins, with a predominance of procyanidins. Both extracts and all fractions from HaRB extract showed a DPPH scavenging activity, ranging from 0.4 to 0.8 quercetin-equivalents. The HaRB methanolic extract reduced the systolic blood pressure in SHR (from 214±3mmHg to 194±4mmHg) after a 5-week treatment.

CONCLUSIONS

The methanolic extracts of Hymenocardia acida root and trunk bark have vasorelaxant activity. The vasorelaxant effect observed is endothelium-dependent and seems mainly mediated through the NO-cGMP pathway. The COX pathway is not involved. The vasorelaxant activity appears to be due to polymeric procyanidins and prodelphinidins. These extracts also have an antioxidant effect. The extract of Hymenocardia acida root bark shows a significant but weak antihypertensive activity in SHR.

Traditional herbal management of sickle cell anemia: lessons from Nigeria

Background. Patients in West Africa where sickle cell anemia (SCA) is endemic have for ages been treated with natural products, especially herbs, as, is still the case in rural communities. Objective. In this paper we look closely at some of these herbs to see if there are any lessons to be learnt or clues to be found for optimizing the treatments based on them, as had been done in the case of NIPRISAN, which was developed from herbs in Nigeria based on Yoruba Medicine. Methods. Select publications on SCA, its molecular biology and pathology, and actual and experimental cases of herbal treatment were perused in search of molecular clues that can be linked to chemical constituents of the herbs involved. Results. The study revealed that during the last 2-3 decades, much progress was made in several aspects of SCA pharmacology, especially the approval of hydroxyurea. As for SCA herbalism, this paper revealed that antisickling herbs abound in West Africa and that the most promising may yet be found. Three new antisickling herbs (Entandrophragma utile, Chenopodium ambrosioides, and Petiveria alliacea) were reported in May 2011. At NIPRD, where NIPRISAN was developed, three other recipes are currently awaiting development. Conclusion. The study raised the hope that the search in the Tropics for more effective herbal recipes for managing sickle cell anaemia will be more fruitful with time and effort.