Anti-HIV activities of organic and aqueous extracts of Sutherlandia frutescens and Lobostemon trigonus. J Ethnopharmacol

Port Elizabeth Museum, Port Elizabeth, Eastern Cape, South Africa
Journal of Ethnopharmacology (Impact Factor: 3). 02/2005; 96(1-2):113-9. DOI: 10.1016/j.jep.2004.08.038
Source: PubMed


A screening process was applied to extracts made from Sutherlandia frutescens (L.) R. Br (Fabaceae) and Lobostemon trigonus (Boraginaceae) as identified by the Botany Department, University of Port Elizabeth to detect if any of the extracts inhibited the human immunodeficiency virus (HIV). For purposes of dereplication, sulphated polysaccharides were removed and bovine serum albumin (BSA) was included in the assays to adsorb non-specific tannins potentially present. In the reverse transcriptase (RT) assay, an aqueous extract of the Lobostemon leaves inhibited HIV-1 RT with an IC50 value of 49 microg/ml, while in the protease assay no inhibition was seen. In the alpha- and beta-glucosidase assays, no significant inhibition was seen with the inclusion of BSA, indicating tannin-based inhibitory effects on these two enzymes. The beta-glucuronidase inhibitory activity, however, was retained in the presence of BSA. The study shows that Sutherlandia extracts contain inhibitory compounds active against HIV target enzymes, while aqueous Lobostemon leaf extracts contain a potent HIV-1 RT inhibitor, thus showing a potential mechanistic action of these plants in aiding HIV-positive patients.

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    • "Three subspecies and several regional forms showing genetic and chemical variation have been recognised. S. frutescens (cancer bush), also known as Lessertia frurescens, is extensively used in South Africa in the traditional medicine system to treat various ailments such as cancer, diabetes, stress, fever, colds and wounds (Chadwick et al., 2007; Chinkwo, 2005; Faleschini et al., 2013; Fasinu et al., 2013; Fernandes et al., 2004; Harnett et al., 2005; Kundu et al., 2005). Decoctions and infusions of this plant are traditionally used to treat gastrointestinal ailments, such as stomach aches and intestinal ailments. "
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    ABSTRACT: Sutherlandia frutescens (Fabaceae) commonly known as cancer-bush, is a well-known traditional phytomedicine in South Africa used to treat a range of ailments. There is limited information available on the phytochemistry and chemical variation within and between the S. frutescens and Sutherlandia microphylla species complex. This paper aims to elucidate the chemical variation of phytoconstituents (other than the non-protein amino acids) between the two species S. frutescens and S. microphylla and also between the wild and cultivated varieties of S. frutescens. An UPLC–MS analysis in tandem with chemometric analysis has been performed to assess the metabolite content of aerial plant parts obtained from different populations. Principal component analysis (PCA) was performed to observe groupings and trends in the data matrix. An orthogonal partial least square discriminant analysis (OPLS-DA) was performed which resulted in clear groups between the two taxa. Several flavonoid and triterpenoid glycoside derivatives contribute to the quantitative chemotypic variation within and between the species as observed. The identification of these compounds using advanced chromatographic techniques (UPLC–MS) and chemometric analysis leads to a better understanding of the phytochemical variation of Sutherlandia which can aid in quality control of raw material, phytomedicines and commercial herbal products.
    Full-text · Article · Oct 2014 · Biochemical Systematics and Ecology
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    • "Sutherlandia frutescens, syn. Lessertia frutescens, is a wellknown , multi-purpose medicinal plant in Southern Africa taken to treat symptoms associated with AIDS (Harnett et al., 2005; Mills et al., 2005a, 2005b), and to combat cancer (Tai et al., 2004; Chinkwo, 2005; Kundu et al., 2005), infections (Katerere and Eloff, 2005), inflammation (Fernandes et al., 2004; Ojewale, 2004) and stress (Prevoo et al., 2004). It is a small, attractive, perennial woody shrub of up to 1 m in height. "
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    ABSTRACT: Ethnopharmacological relevance: Sutherlandia frutescens (syn. Lessertia frutescens) is an indigenous plant in Southern Africa and has been extensively studied from the ethnobotanical point of view. Amongst the various traditional uses, several illnesses involving the immune system have been reported. Due to some of the therapeutic effects observed, in relation to the traditional uses reported by the "khoi san" and "nama" people on cancer related illnesses, the plant has been given the local name kankerbos (cancerbush). Recently the plant has also been used amongst HIV/AIDS patients to stimulate the immune system. Materials and methods: Leaves of Sutherlandia frutescens were extracted sequentially with ethanol, 50% ethanol/water, and water at 50 and 100°C. The polysaccharides were extracted with water and fractionated by ion exchange chromatography and gel filtration to obtain enriched polysaccharide fractions. The bioactivities of the fractions were tested in the complement assay. Some of the fractions were treated with the enzyme pectinase, and the fragments thus produced were separated by gel filtration and their activities tested. Monosaccharide compositions and linkage analyses were determined for the relevant fractions. Results: The leaves of Sutherlandia frutescens contain polysaccharides of the pectin type. Fractions from both the water extracts of 50 and 100°C were bioactive. Fractions chosen for further studies showed that the fragment with the highest M(W) after the pectinase treatment had a substantially higher biological effect than the parent molecules. Based on a comparison of the different fractions it was concluded that galactose-rich regions were important for the bioactivity, these being of the AGII and AGI type, with the latter probably being more important than the former. Fragments rich in xylose also gave higher activity than those without it. Conclusions: Our theory that the polysaccharides present in the leaves of Sutherlandia frutescens could be of importance as immunomodulating agents was confirmed. It was also shown that certain types of polysaccharides had a higher effect in the complement system than others. Thus both the water extracts obtained at 50 and 100°C contain interesting biologically active polysaccharides.
    Full-text · Article · Jan 2014 · Journal of ethnopharmacology
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    • "It has been investigated for many of the anecdotal claims. Many of such studies have suggested its potential for beneficial effects in HIV/AIDS (Harnett et al., 2005), cancer (Stander et al., 2007, 2009; Skerman et al., 2011), diabetes (Chadwick et al., 2007; Mackenzie et al., 2009, 2012), inflammation (Ojewole, 2004), microbial infection (Katerere and Eloff, 2005), stress (Prevoo et al., 2004), and convulsion (Ojewole, 2008). Commercial twice-daily Sutherlandia capsules containing 300 mg of powdered dried leaves are also available in the herbal medicines shops in South Africa (Van Wyk and Albrecht, 2008). "
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    ABSTRACT: Sutherlandia frutescens (ST) is a popular medicinal herb widely consumed in Africa by people living with HIV/AIDS. Concomitant use with antiretroviral drugs has generated concerns of herb-drug interaction. This study investigated the inhibitory effects of the crude extracts of ST on the major cytochrome P450 isozymes employing pooled human liver microsomes. Its effect on the metabolic clearance of midazolam using cryopreserved hepatocytes was also monitored. The potential of ST to inhibit human ATP-binding cassette (ABC) transporters (P-gp and BCRP) and the human organic anion transporting polypeptide (OATP1B1 and OATP1B3) activity was assessed using cell lines overexpressing the transporter proteins. ST showed inhibitory potency for CYP1A2 (IC(50) = 41.0 μg/mL), CYP2A6 (IC(50) = 160 μg/mL), CYP2B6 (IC(50) = 20.0 μg/mL), CYP2C8 (IC(50) = 22.4 μg/mL), CYP2C9 (IC(50) = 23.0 μg/mL), CYP2C19 (IC(50) = 35.9 μg/mL) and CYP3A4/5 (IC(50,) = 17.5 μg/mL [with midazolam1'-hydroxylation]; IC(50) = 28.3 μg/mL [with testosterone 6β-hydroxylation]). Time-dependent (irreversible) inhibition by ST was observed for CYP3A4/5 (KI = 296 μg/mL, kinact = 0.063 min(-1)) under the conditions of this study. ST also delays the production of midazolam metabolites in the hepatocytes, decreasing its clearance by 40%. Further, ST inhibited P-gp (IC(50) = 324.8 μg/mL); OATP1B1 (IC(50) = 10.4 μg/mL, and of OATP1B3 (IC(50) = 6.6 μg/mL). The result indicates the potential for HDI between ST and the substrates of the affected enzymes, if sufficient in vivo concentration of ST is attained.
    Full-text · Article · Dec 2012 · Drug metabolism and disposition: the biological fate of chemicals
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